A maximum theoretical density measuring instrument based on pore integrated module and a testing method thereof

Abstract

The present invention provides a maximum theoretical density measuring instrument and a testing method based on a pore integrated module, and belongs to the technical field of theoretical density measurement. The measuring instrument comprises a sample measurement module, a volume calibration module, a gas-liquid guide integrated module, a liquid level pressure sensing module and a water storage module. The sample measurement module and the volume calibration module are respectively installed on the upper left and right sides of the gas-liquid guide integrated module, the water storage module is installed below the gas-liquid guide integrated module, and the liquid level pressure sensing module is embedded in the lower part of the gas-liquid guide integrated module, wherein two liquid level pressure sensors are respectively arranged vertically coaxially with the sample measurement module and the volume calibration module. The measuring instrument first fully extracts the gas in the sample gap and the internal pores through a miniature oil-free vacuum pump, and then extracts water from the water storage module to the sample measurement module through the liquid level calibration module, and measures the volume of water displaced by the sample. The measuring instrument reduces the error and can automatically complete functions such as air extraction, liquid filling, calibration and measurement.

Description

Technical Field

[0001] The invention relates to the technical field of theoretical density determination, in particular to a maximum theoretical density determination instrument based on a pore integrated module and a testing method. Background Art

[0002] The maximum theoretical density refers to the density of a material under an ideal condition of zero void ratio, and is a necessary physical index for calculating the void ratio of porous materials and composite materials containing voids. The accuracy of the maximum theoretical density determination has an important influence on the performance determination of porous materials and composite materials containing voids and the accuracy of the void ratio index calculation, especially for measuring the durability of asphalt pavement.

[0003] According to the national standard JT / T 834-2012, the maximum theoretical relative density meter for asphalt mixtures currently available on the market first immerses the sample in water, then evacuates the negative pressure container so that the gaps and internal pores of the sample are filled with water, then measures the mass of the water displaced by the sample, and finally calculates the ratio of the dry mass of the sample to the mass of the water displaced by the sample to obtain the ratio of the maximum theoretical density of the asphalt mixture to the water density.

[0004] This method has problems such as large size, low integration, cumbersome operation and long time consumption, which leads to large errors in the final measurement results and low instrument accuracy. The specific manifestations are as follows:

[0005] (1) Large false volume

[0006] After the sample is submerged in water, the bubbles in the sample gaps float up. At this time, they are affected by the atmospheric pressure above the water surface, the surface tension of water at the edge of the gaps, the vapor pressure formed by the diffusion of water molecules after vacuuming, and the pressure generated by the water level. After the negative pressure oscillation operation, the bubbles in most pores cannot be completely discharged due to excessive resistance. In this case, the sample volume measured by the instrument includes the actual volume of the sample and the false volume formed by the unexpelled gas, which leads to a larger measured volume of the mixture and a smaller maximum theoretical relative density.

[0007] (2) Low integration

[0008] During the maximum theoretical relative density test, the negative pressure container needs to be connected to the vacuum pump pipeline first, and then vacuumed and shaken repeatedly, and then the negative pressure container is transferred to a constant temperature water tank to measure the mass of the water discharged by the sample; the vacuum pump and the constant temperature water tank work independently and have low integration, resulting in multiple sample transfers during the entire process, which increases the random error of the measurement results.

[0009] (3) Complicated operation

[0010] In the process of measuring the mass of water displaced by the sample, it is necessary to first completely immerse the sample and the negative pressure container under vacuum in a constant temperature water tank, weigh the overall mass of the sample and the negative pressure container in water, then take them out, pour out the sample, weigh the mass of the negative pressure container in water alone, subtract the two to get the mass of the sample in water, and finally subtract the mass of the sample in water from the mass of the sample after drying to get the mass of the water displaced by the sample.

[0011] (4) It takes too long

[0012] During the vacuuming process, the vacuum degree of the negative pressure container needs to be maintained at 97.3kPa, and it needs to oscillate several times every two minutes. In order to achieve a better exhaust effect, the entire vacuuming process takes up to 20 minutes. When measuring the mass of boiling water displaced by the sample, in order to make the sample temperature reach 25°C, it needs to be immersed in a constant temperature water tank for about 10 minutes. In summary, the entire measurement process takes a long time.

[0013] Therefore, the key to solving the above problems is how to achieve simple and effective exhaustion of the gas in the sample gap and internal pores. The present invention designs a maximum theoretical density measuring instrument and testing method based on a pore integrated module, which can well solve the above problems. Summary of the invention

[0014] The invention provides a maximum theoretical density measuring instrument and a testing method based on a pore integrated module to solve the problems of large volume, low integration, complicated operation and long time consumption of the current maximum theoretical relative density instrument for asphalt mixture.

[0015] The measuring instrument includes a sample measurement module, a volume calibration module, a gas-liquid guide integrated module, a liquid level pressure sensing module and a water storage module. The sample measurement module and the volume calibration module are respectively installed on the upper left and right sides of the gas-liquid guide integrated module, the water storage module is installed below the gas-liquid guide integrated module, and the liquid level pressure sensing module is embedded in the lower part of the gas-liquid guide integrated module, wherein two liquid level pressure sensors are respectively arranged vertically coaxially with the sample measurement module and the volume calibration module.

[0016] Wherein, the sample measurement module includes a sample chamber cover, a sample chamber cover O-ring, a sample cup and a sample chamber filter;

[0017] The sample chamber cover is in the shape of a hollow cylinder, with an opening at the lower end, a closed upper end, and a cavity in the middle. A left limit block of the sample chamber cover and a right limit block of the sample chamber cover are symmetrically arranged on the outer side of the lower end of the sample chamber cover. An O-ring sealing groove of the sample chamber cover is provided on the lower end surface of the sample chamber cover, and an O-ring of the sample chamber cover is embedded in the O-ring sealing groove of the sample chamber cover.

[0018] The sample cup is in the shape of a hollow cylinder, with an opening at the top, a cavity in the middle, and a closed bottom. A protruding cylinder is provided downward in the center of the bottom surface, and an external thread for connecting the sample cup is provided on the outside of the cylinder. A central hole is provided through the center of the cylinder, and the lower end opening of the central hole is the liquid inlet and outlet of the sample cup. A sample cavity filter is installed at the liquid inlet and outlet of the sample cup, and a sample cup scale line is engraved on the outside of the upper part of the sample cup;

[0019] The volume calibration module includes a water measuring chamber cover, a water measuring chamber cover O-ring and a water measuring cup; the water measuring chamber cover is in the shape of a hollow cylinder, with an opening at the lower end, a closed upper end, and a cavity in the middle. A left limit block and a right limit block of the water measuring chamber cover are symmetrically arranged on the outer side of the lower end of the water measuring chamber cover. A water measuring chamber cover O-ring sealing groove is opened on the lower end surface of the water measuring chamber cover, and the water measuring chamber cover O-ring is embedded in the water measuring chamber cover O-ring sealing groove;

[0020] The measuring cup is in the shape of a hollow cylinder, with an open top, a cavity in the middle, and a closed bottom. A protruding cylinder is provided in the center of the lower end surface, and an external thread for connecting the measuring cup is provided on the outer side of the cylinder. A central hole is provided through the center of the cylinder, and the lower end opening of the central hole is the liquid inlet and outlet of the measuring cup. The outer side of the upper part of the measuring cup is engraved with measuring cup scale lines;

[0021] The water storage module includes a water reservoir, a water reservoir filter and a water reservoir temperature sensor. The water reservoir is hollow in design and stores water inside. The water reservoir temperature sensor is immersed below the water surface in the water reservoir.

[0022] The liquid level pressure sensor module includes a sample chamber liquid level pressure sensor, a sample chamber liquid level pressure sensor flange, a water measuring chamber liquid level pressure sensor and a water measuring chamber liquid level pressure sensor flange;

[0023] The O-ring of the sample chamber liquid level pressure sensor is fixed in the middle groove of the sample chamber liquid level pressure sensor;

[0024] A sample cavity liquid level pressure sensor flange center hole is opened in the center of the sample cavity liquid level pressure sensor flange, the periphery of the sample cavity liquid level pressure sensor flange center hole protrudes upward to form a sample cavity liquid level pressure sensor flange boss, and four sample cavity liquid level pressure sensor flange through holes are symmetrically opened on the periphery of the sample cavity liquid level pressure sensor flange boss;

[0025] The O-ring of the water measuring chamber liquid level pressure sensor is fixed in the middle groove of the water measuring chamber liquid level pressure sensor;

[0026] A water cavity liquid level pressure sensor flange center hole is opened at the center of the water cavity liquid level pressure sensor flange, the periphery of the water cavity liquid level pressure sensor flange center hole protrudes upward to form a water cavity liquid level pressure sensor flange boss, and four water cavity liquid level pressure sensor flange through holes are symmetrically opened at the periphery of the water cavity liquid level pressure sensor flange boss;

[0027] The gas-liquid guide integrated module includes a gas-liquid guide integrated module body, a sample chamber air inlet valve, a sample chamber air extraction valve, a water measuring chamber air inlet valve, a water measuring chamber air extraction valve, a sample chamber water supply and drainage valve, a water measuring chamber water supply and drainage valve, a water measuring chamber filter, a water reservoir control valve, a micro oil-free vacuum pump and a micro oil-free vacuum pump connection sheet metal;

[0028] The upper surface of the gas-liquid guide integrated module body is symmetrically provided with grooves for installing the sample measurement module and the volume calibration module. The left groove on the upper surface of the gas-liquid guide integrated module body is symmetrically provided with two notches radially outwardly from the groove, corresponding to the entrance and exit of the left limit block of the sample chamber cover and the entrance and exit of the right limit block of the sample chamber cover respectively;

[0029] Below the entrance and exit of the left limit block of the sample chamber cover and the entrance and exit of the right limit block of the sample chamber cover, an annular sample chamber cover limit groove is opened radially outward along the left groove, the annular lower plane of the sample chamber cover limit groove is the sample chamber cover placement platform, a sample chamber air path opening is opened on the sample chamber cover placement platform, a sample chamber air path common channel is opened vertically downward at the sample chamber air path opening, a sample cup placement platform lower than the sample chamber cover placement platform is opened radially inward along the groove on the sample chamber cover placement platform, a sample cup connecting groove is opened in the center of the sample cup placement platform, a sample chamber liquid level pressure measurement channel is opened downward through the sample cup connecting groove, the connection between the sample cup connecting groove and the sample chamber liquid level pressure measurement channel is the sample chamber liquid path opening, the lower port of the sample chamber liquid level pressure measurement channel is the sample chamber liquid level pressure measurement channel opening, and a sample chamber liquid level pressure sensor placement groove is opened radially outward below the sample chamber liquid level pressure measurement channel opening;

[0030] The groove on the right side of the upper surface of the main body of the gas-liquid guide integrated module is symmetrically opened along the radial outward direction of the groove, and two notches are respectively corresponding to the left and right limit block entrances and exits of the water measuring chamber cover, and an annular water measuring chamber cover limit groove is opened radially outward along the right groove below the left and right limit block entrances and exits of the water measuring chamber cover, and the annular lower plane of the water measuring chamber cover limit groove is a water measuring chamber cover placement platform, and a water measuring chamber air passage is opened on the water measuring chamber cover placement platform, and a water measuring chamber air passage is opened vertically downward at the water measuring chamber air passage A common channel, a water measuring cup placement platform is opened radially inwardly along the groove on the water measuring chamber cover placement platform and is lower than the water measuring chamber cover placement platform, a water measuring cup connection groove is opened in the center of the water measuring cup placement platform, a water measuring chamber liquid level pressure measurement channel is opened downwardly through the water measuring cup connection groove, a water measuring chamber liquid junction is formed at the connection point between the water measuring cup connection groove and the water measuring chamber liquid level pressure measurement channel, a lower end of the water measuring chamber liquid level pressure measurement channel is a water measuring chamber liquid level pressure measurement channel opening, and a water measuring chamber liquid level pressure sensor placement groove is opened radially outwardly below the water measuring chamber liquid level pressure measurement channel opening;

[0031] A common air inlet entrance and a micro oil-free vacuum pump placement groove are provided at the front of the right side surface of the gas-liquid guide integrated module body, a common air inlet entrance is provided horizontally to the left of a common air inlet entrance, a common air extraction channel outlet and a micro oil-free vacuum pump exhaust channel entrance are provided on the left side surface of the micro oil-free vacuum pump placement groove, a common air extraction channel is provided horizontally to the left of the common air extraction channel outlet, a micro oil-free vacuum pump exhaust channel is provided horizontally to the left through the micro oil-free vacuum pump exhaust channel entrance, and a micro oil-free vacuum pump exhaust channel outlet is formed on the left side surface of the gas-liquid integrated guide module body;

[0032] A sample cavity air inlet valve fixing threaded hole, a sample cavity air inlet valve air release channel entrance and a sample cavity air inlet valve air inlet channel exit are provided on the left side of the front surface of the main body of the gas-liquid guide integrated module; a sample cavity air inlet valve air release channel is provided horizontally and rearwardly at the sample cavity air inlet valve air release channel entrance; a sample cavity air inlet valve air inlet channel is provided horizontally and rearwardly at the sample cavity air inlet valve air inlet channel exit; and the sample cavity air inlet valve air inlet channel is communicated with the common air inlet channel;

[0033] A sample cavity air extraction valve fixed threaded hole, a sample cavity air extraction valve air extraction channel outlet and a sample cavity air extraction valve air extraction channel inlet are correspondingly provided below the sample cavity air inlet valve fixed threaded hole, the sample cavity air inlet valve air exhaust channel inlet and the sample cavity air inlet valve air inlet channel outlet; a sample cavity air extraction valve air extraction channel is provided horizontally backward at the sample cavity air extraction valve air exhaust channel outlet; the sample cavity air inlet valve air exhaust channel and the sample cavity air extraction valve air extraction channel are both connected to the sample cavity gas path common channel; a sample cavity air extraction valve air exhaust channel is provided horizontally backward at the sample cavity air extraction valve air exhaust channel inlet; and the sample cavity air extraction valve air exhaust channel is connected to the common air exhaust channel;

[0034] The right side of the front surface of the main body of the gas-liquid guide integrated module is provided with a water-measuring chamber air inlet valve fixing threaded hole, a water-measuring chamber air inlet valve air inlet channel outlet and a water-measuring chamber air inlet valve air release channel inlet, the water-measuring chamber air inlet valve air inlet channel outlet is horizontally opened backwards, the water-measuring chamber air inlet valve air inlet channel is connected with the public air inlet channel, and the water-measuring chamber air inlet valve air release channel inlet is horizontally opened backwards;

[0035] A water measuring chamber air extraction valve fixed threaded hole, a water measuring chamber air extraction valve exhaust channel inlet and a water measuring chamber air extraction valve exhaust channel outlet are correspondingly provided below the water measuring chamber air inlet valve fixed threaded hole, the water measuring chamber air inlet valve air inlet channel outlet and the water measuring chamber air inlet valve exhaust channel inlet, a water measuring chamber air extraction valve exhaust channel is provided horizontally backwards from the water measuring chamber air extraction valve exhaust channel inlet, the water measuring chamber air extraction valve exhaust channel is connected with the common exhaust channel, a water measuring chamber air extraction valve exhaust channel is provided horizontally backwards from the water measuring chamber air extraction valve exhaust channel outlet, the water measuring chamber air extraction valve exhaust channel is both connected with the water measuring chamber air path common channel;

[0036] The bottom of the sample cavity air intake valve is provided with a sample cavity air intake valve inlet, a sample cavity air intake valve outlet and a sample cavity air intake valve through hole, and the sample cavity air intake valve inlet and the sample cavity air intake valve outlet are provided with a sample cavity air intake valve sealing pad;

[0037] The bottom of the sample cavity air extraction valve is provided with a sample cavity air extraction valve inlet, a sample cavity air extraction valve outlet and a sample cavity air extraction valve through hole, and the sample cavity air extraction valve inlet and the sample cavity air extraction valve outlet are provided with a sample cavity air extraction valve sealing pad;

[0038] A water measuring chamber air intake valve inlet, a water measuring chamber air intake valve outlet and a water measuring chamber air intake valve through hole are provided at the bottom of the water measuring chamber air intake valve, and a water measuring chamber air intake valve sealing gasket is provided on the water measuring chamber air intake valve inlet and the water measuring chamber air intake valve outlet;

[0039] The bottom of the water-measuring cavity air-extraction valve is provided with a water-measuring cavity air-extraction valve inlet, a water-measuring cavity air-extraction valve outlet and a water-measuring cavity air-extraction valve through hole, and a water-measuring cavity air-extraction valve sealing gasket is provided on the water-measuring cavity air-extraction valve inlet and the water-measuring cavity air-extraction valve outlet;

[0040] The top of the left pagoda head of the micro oil-free vacuum pump is the micro oil-free vacuum pump suction port, and the top of the right pagoda head is the micro oil-free vacuum pump exhaust port. The micro oil-free vacuum pump suction port is equipped with a micro oil-free vacuum pump suction port O-ring;

[0041] The micro oil-free vacuum pump is connected to the sheet metal. There are large through holes for the micro oil-free vacuum pump to connect to the sheet metal at the four corners of the edge, and four small through holes for the micro oil-free vacuum pump to connect to the sheet metal are symmetrically opened on both sides of the center;

[0042] The rear part of the right side surface of the main body of the gas-liquid guide integrated module is provided with a water reservoir control valve fixing threaded hole, a common liquid path channel opening and a water reservoir control valve connecting channel opening, the common liquid path channel opening is provided with a common liquid path channel horizontally to the left, and the water reservoir control valve connecting channel opening is provided with a water reservoir control valve connecting channel horizontally to the left;

[0043] A water reservoir connection groove is opened at the right rear of the lower surface of the main body of the gas-liquid guide integrated module, a water reservoir communication channel opening is opened above the water reservoir connection groove, a water reservoir communication channel is opened upward from the water reservoir communication channel opening, and the water reservoir communication channel is connected with the water reservoir control valve communication channel;

[0044] The left side of the rear surface of the main body of the gas-liquid guide integrated module is provided with a sample cavity water supply and drainage valve fixing threaded hole, a sample cavity communication channel opening and a sample cavity water supply and drainage valve communication channel opening, a sample cavity communication channel is opened forward of the sample cavity communication channel opening, the sample cavity communication channel is connected with the sample cavity liquid level pressure measurement channel, a sample cavity water supply and drainage valve communication channel is opened forward of the sample cavity water supply and drainage valve communication channel opening, and the sample cavity water supply and drainage valve communication channel is connected with the public liquid path channel;

[0045] The right side of the rear surface of the main body of the gas-liquid guide integrated module is provided with a water measuring chamber water supply and drainage valve fixing threaded hole, a water measuring chamber connecting channel opening and a water measuring chamber filter placement groove, a water measuring chamber connecting channel is opened forward of the water measuring chamber connecting channel opening, the water measuring chamber connecting channel is connected with the water measuring chamber liquid level pressure measurement channel, a water measuring chamber water supply and drainage valve connecting channel opening is opened in front of the water measuring chamber filter placement groove, a water measuring chamber water supply and drainage valve connecting channel is opened forward of the water measuring chamber water supply and drainage valve connecting channel opening, and the water measuring chamber water supply and drainage valve connecting channel is connected with the public liquid path channel;

[0046] A micro oil-free vacuum pump connection sheet metal fixing threaded hole is opened on the right front of the lower surface of the gas-liquid guide integrated module body, a sample cavity liquid level pressure sensor flange fixing threaded hole is opened on the left side of the lower surface of the gas-liquid guide integrated module body, and a water-measuring cavity liquid level pressure sensor flange fixing threaded hole is opened on the right side of the lower surface of the gas-liquid guide integrated module body;

[0047] The sample cavity water supply and drainage valve through holes are provided at four corners of the lower surface of the sample cavity water supply and drainage valve, the sample cavity water supply and drainage valve outlet and the sample cavity water supply and drainage valve inlet are provided at the middle of the lower surface of the sample cavity water supply and drainage valve, the sample cavity water supply and drainage valve inlet outer ring is provided with a sample cavity water supply and drainage valve inlet O-ring sealing groove, the sample cavity water supply and drainage valve outlet and the sample cavity water supply and drainage valve inlet O-ring sealing groove are provided with a sample cavity water supply and drainage valve outlet O-ring sealing groove, the sample cavity water supply and drainage valve inlet O-ring and the sample cavity water supply and drainage valve outlet O-ring are respectively placed in the sample cavity water supply and drainage valve inlet O-ring sealing groove and the sample cavity water supply and drainage valve outlet O-ring sealing groove;

[0048] The four corners of the lower surface of the water-measuring cavity water-supply and drainage valve are provided with water-measuring cavity water-supply and drainage valve through holes, the middle part of the lower surface of the water-measuring cavity water-supply and drainage valve is provided with a water-measuring cavity water-supply and drainage valve outlet and a water-measuring cavity water-supply and drainage valve inlet, the outer ring of the water-measuring cavity water-supply and drainage valve inlet is provided with a water-measuring cavity water-supply and drainage valve inlet O-ring sealing groove, the water-measuring cavity water-supply and drainage valve inlet O-ring sealing groove is provided with a water-measuring cavity water-supply and drainage valve outlet O-ring sealing groove, the water-measuring cavity water-supply and drainage valve inlet O-ring and the water-measuring cavity water-supply and drainage valve outlet O-ring are respectively placed in the water-measuring cavity water-supply and drainage valve inlet O-ring sealing groove and the water-measuring cavity water-supply and drainage valve outlet O-ring sealing groove;

[0049] The water reservoir control valve through holes are provided at the four corners of the lower surface of the water reservoir control valve, the water reservoir control valve outlet and the water reservoir control valve inlet are provided at the middle of the lower surface of the water reservoir control valve, the outer ring of the water reservoir control valve inlet is provided with a water reservoir control valve inlet O-ring sealing groove, the water reservoir control valve outlet and the outer ring of the water reservoir control valve inlet O-ring sealing groove are provided with a water reservoir control valve outlet O-ring sealing groove, the water reservoir control valve inlet O-ring and the water reservoir control valve outlet O-ring are respectively placed in the water reservoir control valve inlet O-ring sealing groove and the water reservoir control valve outlet O-ring sealing groove;

[0050] The cavity between the liquid inlet and outlet of the sample cup, the gas path of the sample cavity and the cavity cover of the sample cavity is the sample cavity;

[0051] The cavity between the liquid inlet and outlet of the water measuring cup, the air passage of the water measuring cavity and the water measuring cavity cover is the water measuring cavity.

[0052] As mentioned above, the sample chamber filter is placed in the sample cup connection groove, and the sample cup is connected and tightened from above through the sample cup connection external thread and the sample cup connection groove internal thread until the sample cup contacts the sample cup placement platform;

[0053] The measuring cup is connected and fastened from above through the measuring cup connecting external thread and the measuring cup connecting groove internal thread until the measuring cup contacts the measuring cup placement platform;

[0054] The water reservoir filter screen is placed in the water reservoir connecting groove, and the water reservoir connecting groove and the external joint are sealed by threaded connection and then pressed and fixed. The water reservoir temperature sensor is placed below the liquid level in the water reservoir.

[0055] The sample cavity liquid level pressure sensor is embedded and installed in the sample cavity liquid level pressure sensor placement groove, the upper end of the sample cavity liquid level pressure sensor flange boss presses the rear end of the sample cavity liquid level pressure sensor, the sample cavity liquid level pressure sensor and the sample cavity liquid level pressure measurement channel opening are fixedly sealed through the sample cavity liquid level pressure sensor O-ring, the side of the sample cavity liquid level pressure sensor flange boss cooperates with the sample cavity liquid level pressure sensor placement groove, the fastening screw is screwed into the sample cavity liquid level pressure sensor flange fixing threaded hole through the sample cavity liquid level pressure sensor flange through the sample cavity liquid level pressure sensor flange through hole, and the sample cavity liquid level pressure sensor flange is fixed on the lower surface of the gas-liquid guide integrated module body;

[0056] The water measuring chamber liquid level pressure sensor is embedded and installed in the water measuring chamber liquid level pressure sensor placement groove. The upper end of the water measuring chamber liquid level pressure sensor flange boss presses the rear end of the water measuring chamber liquid level pressure sensor. The water measuring chamber liquid level pressure sensor and the water measuring chamber liquid level pressure measurement channel opening are fixed and sealed through the water measuring chamber liquid level pressure sensor O-ring. The side surface of the water measuring chamber liquid level pressure sensor flange boss cooperates with the water measuring chamber liquid level pressure sensor placement groove. The fastening screw is screwed into the water measuring chamber liquid level pressure sensor flange fixing threaded hole through the water measuring chamber liquid level pressure sensor flange through the water measuring chamber liquid level pressure sensor flange through hole, and the water measuring chamber liquid level pressure sensor flange is fixed on the lower surface of the gas-liquid guide integrated module body.

[0057] The air suction port of the micro oil-free vacuum pump passes through the O-ring of the air suction port of the micro oil-free vacuum pump and is aligned with the outlet of the common air suction channel, and the exhaust port of the micro oil-free vacuum pump is aligned with the inlet of the exhaust channel of the micro oil-free vacuum pump;

[0058] The fastening screw is screwed into the threaded hole at the corresponding position at the bottom of the micro oil-free vacuum pump through the small through hole of the micro oil-free vacuum pump connecting sheet metal, and the fastening screw is screwed into the micro oil-free vacuum pump connecting sheet metal fixing threaded hole on the lower surface of the gas-liquid guide integrated module body through the large through hole of the micro oil-free vacuum pump connecting sheet metal. After the fastening screw is tightened, the micro oil-free vacuum pump is fixedly connected to the gas-liquid guide integrated module body, and the micro oil-free vacuum pump exhaust port is sealed with the public exhaust channel outlet.

[0059] The inlet of the sample cavity air inlet valve is aligned with the outlet of the sample cavity air inlet valve inlet channel, the outlet of the sample cavity air inlet valve is aligned with the inlet of the sample cavity air inlet valve exhaust channel, the fastening screw is screwed into the fixed threaded hole of the sample cavity air inlet valve through the through hole of the sample cavity air inlet valve, after the fastening screw is tightened, the sample cavity air inlet valve forms a fixed seal with the main body of the gas-liquid guide integrated module through the sealing gasket of the sample cavity air inlet valve;

[0060] The inlet of the sample cavity air extraction valve is aligned with the outlet of the sample cavity air extraction valve air extraction channel, the outlet of the sample cavity air extraction valve is aligned with the inlet of the sample cavity air extraction valve air release channel, the fastening screw is screwed into the fixed threaded hole of the sample cavity air extraction valve through the through hole of the sample cavity air extraction valve, after the fastening screw is tightened, the sample cavity air extraction valve forms a fixed seal with the main body of the gas-liquid guide integrated module through the sealing gasket of the sample cavity air extraction valve;

[0061] The inlet of the water measuring chamber air intake valve is aligned with the outlet of the air intake channel of the water measuring chamber air intake valve, and the outlet of the water measuring chamber air intake valve is aligned with the inlet of the air release channel of the water measuring chamber air intake valve. The fastening screw is screwed into the fixed threaded hole of the water measuring chamber air intake valve through the through hole of the water measuring chamber air intake valve. After the fastening screw is tightened, the water measuring chamber air intake valve forms a fixed seal with the main body of the gas-liquid guide integrated module through the water measuring chamber air intake valve sealing gasket;

[0062] The inlet of the water measuring chamber air pumping valve is aligned with the outlet of the water measuring chamber air pumping valve air pumping channel, and the outlet of the water measuring chamber air pumping valve is aligned with the inlet of the water measuring chamber air pumping valve air release channel. The fastening screw is screwed into the fixed threaded hole of the water measuring chamber air pumping valve through the through hole of the water measuring chamber air pumping valve. After the fastening screw is tightened, the water measuring chamber air pumping valve forms a fixed seal with the main body of the gas-liquid guide integrated module through the water measuring chamber air pumping valve sealing gasket.

[0063] The inlet of the sample chamber water supply and drainage valve is aligned with the opening of the sample chamber communication channel, the outlet of the sample chamber water supply and drainage valve is aligned with the opening of the sample chamber water supply and drainage valve communication channel, the fastening screw is screwed into the fixed threaded hole of the sample chamber water supply and drainage valve through the through hole of the sample chamber water supply and drainage valve, and after the fastening screw is tightened, the sample chamber water supply and drainage valve and the main body of the gas-liquid guide integrated module form a fixed seal;

[0064] The water measuring chamber filter is placed in the water measuring chamber filter placement groove, the water measuring chamber water supply and drainage valve inlet is aligned with the water measuring chamber communication channel opening, the water measuring chamber water supply and drainage valve outlet is aligned with the water measuring chamber water supply and drainage valve communication channel opening, the fastening screw is screwed into the water measuring chamber water supply and drainage valve fixing threaded hole through the water measuring chamber water supply and drainage valve through hole, after the fastening screw is tightened, the water measuring chamber water supply and drainage valve and the gas-liquid guide integrated module body form a fixed seal;

[0065] The inlet of the water reservoir control valve is aligned with the opening of the common liquid channel, the outlet of the water reservoir control valve is aligned with the opening of the water reservoir control valve connecting channel, the fastening screw is screwed into the fixed threaded hole of the water reservoir control valve through the through hole of the water reservoir control valve, and after the fastening screw is tightened, the water reservoir control valve and the main body of the gas-liquid guide integrated module form a fixed seal.

[0066] The sample chamber air inlet valve, sample chamber air extraction valve, water measuring chamber air inlet valve, water measuring chamber air extraction valve, sample chamber water supply and drainage valve, water measuring chamber water supply and drainage valve and water reservoir control valve are all seat-mounted solenoid valves, which are sealed with the smooth surface through sealing gaskets.

[0067] The material of the sample chamber cover, sample cup, water measuring chamber cover, water measuring cup and the main body of the gas-liquid guide integrated module is 0.14W·m -1 ·K -1 ~0.2W·m -1 ·K -1 The thickness of the sample chamber cover and the water measuring chamber cover shall not be less than 20mm.

[0068] The sample cups are divided into six specifications according to the different sample quantities to be tested, as shown in Table 1.

[0069] Table 1 Sample cup specifications and classification

[0070]

[0071] The testing method of the measuring instrument comprises the following steps:

[0072] S1: Sensor calibration: weigh the sample mass m s , according to the sample mass m s Select the sample cup of corresponding specifications;

[0073] Place the left limit block of the sample chamber cover and the right limit block of the sample chamber cover through the left limit block entrance and the right limit block entrance of the sample chamber cover respectively, and place them on the sample chamber cover placement platform. Rotate the sample chamber cover clockwise to screw the left limit block of the sample chamber cover and the right limit block of the sample chamber cover into the limit groove of the sample chamber cover. The limit groove of the sample chamber cover presses the O-ring of the sample chamber cover between the O-ring sealing groove of the sample chamber cover and the sample chamber cover placement platform to form a seal.

[0074] Pass the left limit block and the right limit block of the water measuring chamber cover through the left limit block entrance and the right limit block entrance of the water measuring chamber cover respectively, place them on the water measuring chamber cover placement platform, rotate the water measuring chamber cover clockwise, screw the left limit block and the right limit block of the water measuring chamber cover into the limit groove of the water measuring chamber cover, and the limit groove of the water measuring chamber cover presses the O-ring of the water measuring chamber cover between the O-ring sealing groove of the water measuring chamber cover and the water measuring chamber cover placement platform to form a seal;

[0075] Open the sample chamber exhaust valve and the water measuring chamber exhaust valve, close the sample chamber water supply and drainage valve, the water measuring chamber water supply and drainage valve, the water reservoir control valve, the sample chamber air intake valve and the water measuring chamber air intake valve, turn on the micro oil-free vacuum pump, and evacuate the sample chamber and the water measuring chamber;

[0076] After 60 seconds, turn off the micro oil-free vacuum pump, the sample chamber air extraction valve and the water measuring chamber air extraction valve, open the sample chamber water supply and drainage valve, the water measuring chamber water supply and drainage valve and the water reservoir control valve, and draw water out of the water reservoir. The water flows through the external hose, the water reservoir connecting channel, the water reservoir connecting channel, the water reservoir control valve connecting channel, the water reservoir control valve connecting channel, the water reservoir control valve outlet, the water reservoir control valve inlet, the public liquid channel outlet and the public liquid channel, and then is divided into two streams. One stream flows through the sample chamber water supply and drainage valve connecting channel, the sample chamber water supply and drainage valve connecting channel, and the water reservoir control valve connecting channel. The sample chamber liquid level pressure sensor is in contact with the sample chamber liquid level pressure sensor. The value of the sample chamber liquid level pressure sensor rises. When water fills the sample chamber liquid level pressure measurement channel and enters the sample cup from the sample cup liquid inlet and outlet, the rising slope of the sample chamber liquid level pressure sensor value curve decreases, and an inflection point is formed between the sample chamber liquid level pressure sensor value curve and the previous rising curve. This point is taken as the sample chamber liquid level pressure initial point P. s0 At the same time, another stream of water flows through the water measuring chamber water supply and drainage valve connecting channel, the water measuring chamber water supply and drainage valve connecting channel port, the water measuring chamber water supply and drainage valve outlet, the water measuring chamber water supply and drainage valve inlet, the water measuring chamber connecting channel port and the water measuring chamber connecting channel in turn, enters the water measuring chamber liquid level pressure measurement channel, reaches the water measuring chamber liquid level pressure measurement channel port, contacts the water measuring chamber liquid level pressure sensor, and the value of the water measuring chamber liquid level pressure sensor rises. When the water fills the water measuring chamber liquid level pressure measurement channel and enters the water measuring cup from the liquid inlet and outlet of the water measuring cup, the rising slope of the water measuring chamber liquid level pressure sensor value curve decreases, forming an inflection point with the previous rising curve;

[0077] When the numerical curves of the sample chamber liquid level pressure sensor and the water measuring chamber liquid level pressure sensor both rise significantly and form an inflection point, close the sample chamber water supply and drainage valve, the water measuring chamber water supply and drainage valve, and the water reservoir control valve, open the sample chamber air intake valve and the water measuring chamber air intake valve, and remove the sample chamber cover and the water measuring chamber cover;

[0078] Inject a known mass m into the sample cup cs1 of water, and record the pressure P measured by the sample chamber liquid level pressure sensor cs1 Repeat the above steps 10 times, and the amount of water injected each time does not exceed one tenth of the total volume of the sample cup. Finally, P cs1 , P cs2 , P cs3 ,……,P cs10 , and the corresponding m cs1 、m cs2 、m cs3 ,……,m cs10 , calibrate the measuring cup 202 in the same way, and obtain P cr1 , P cr2 , P cr3 ,……,P cr10 , and the corresponding m cr1 、m cr2 、m cr3 ,……,m cr10 , the relationship curve between the mass of water added to the sample cup and the value of the sample chamber liquid level pressure sensor and the relationship curve between the mass of water added to the measuring cup and the value of the water chamber liquid level pressure sensor are obtained by least squares fitting;

[0079] Open the sample chamber water supply and drainage valve, the water measuring chamber water supply and drainage valve, and the water reservoir control valve, so that the water in the sample cup passes through the sample cup liquid inlet and outlet, the sample chamber liquid level pressure measurement channel, the sample chamber connecting channel, the sample chamber connecting channel port, the sample chamber water supply and drainage valve inlet, the sample chamber water supply and drainage valve outlet, the sample chamber water supply and drainage valve connecting channel port, and the sample chamber water supply and drainage valve connecting channel to enter the common liquid path channel, and the water in the measuring water cup passes through the measuring water cup liquid inlet and outlet, the water measuring chamber liquid level pressure measurement channel, the water measuring chamber connecting channel, the water measuring chamber connecting channel port, the water measuring chamber water supply and drainage valve inlet, the water measuring chamber water supply and drainage valve outlet, the water measuring chamber water supply and drainage valve connecting channel port, and the water measuring chamber water supply and drainage valve connecting channel to enter the common liquid path channel, and the water discharged from the sample cup and the measuring water cup converges and flows into the water reservoir through the common liquid path channel port, the water reservoir control valve inlet, the water reservoir control valve outlet, the water reservoir control valve connecting channel port, the water reservoir control valve connecting channel, the water reservoir connecting channel, and the water reservoir connecting channel port;

[0080] S2: Preparation before measurement: record the sample mass m s , pour the sample into the sample cup, and rotate and tighten the sample chamber cover and the water chamber cover;

[0081] Record the temperature t measured by the water storage tank temperature sensor, and obtain the density ρ of water at the corresponding temperature t. The known formula is:

[0082] m=ρS s h (1)

[0083] P=ρgh (2)

[0084] in:

[0085] m is the mass of water in the sample cup, S s is the bottom area of ​​the sample cup, h is the height of the water in the sample cup, P is the pressure of the water in the sample cup, and g is the gravitational acceleration. According to formula (1) and formula (2), the relationship curve between the liquid level height of the sample cup and the value of the liquid level pressure sensor in the sample chamber is obtained, and its slope is k s ;

[0086] Similarly, the relationship curve between the liquid level height of the measuring cup and the value of the liquid level pressure sensor in the measuring chamber is obtained, and its slope is k r ;

[0087] S3: Vacuum the two chambers: Open the sample chamber air extraction valve and the water measuring chamber air extraction valve, close the sample chamber air intake valve, the water measuring chamber air intake valve, the sample chamber water supply and drainage valve, the water measuring chamber water supply and drainage valve and the water reservoir control valve, and read the sample chamber liquid level pressure sensor value P bs And the water level pressure sensor value P br , start the micro oil-free vacuum pump;

[0088] The gas in the sample cavity passes through the sample cavity gas path port and sequentially enters the sample cavity gas path common channel, the sample cavity gas extraction valve gas extraction channel, the sample cavity gas extraction valve gas extraction channel outlet, the sample cavity gas extraction valve inlet, the sample cavity gas extraction valve outlet, the sample cavity gas extraction valve exhaust channel inlet and the sample cavity gas extraction valve exhaust channel in the gas-liquid guide integrated module body;

[0089] The gas in the water measuring cavity passes through the water measuring cavity gas path opening and sequentially enters the water measuring cavity gas path common channel, the water measuring cavity air pumping valve air pumping channel, the water measuring cavity air pumping valve air pumping channel outlet, the water measuring cavity air pumping valve inlet, the water measuring cavity air pumping valve outlet, the water measuring cavity air pumping valve air release channel inlet and the water measuring cavity air pumping valve air release channel in the gas-liquid guiding integrated module body;

[0090] The two air flows enter the common exhaust channel, and are discharged in sequence through the common exhaust channel outlet, the micro oil-free vacuum pump exhaust port, the micro oil-free vacuum pump exhaust port, the micro oil-free vacuum pump exhaust channel inlet, the micro oil-free vacuum pump exhaust channel, and the micro oil-free vacuum pump exhaust channel outlet;

[0091] When the sample chamber liquid level pressure sensor value is less than P bs –101000Pa and the water level pressure sensor value of the water chamber is less than P br When the pressure is –101000Pa, the sample chamber and the water measuring chamber reach a vacuum state, and the micro oil-free vacuum pump, the sample chamber exhaust valve, and the water measuring chamber exhaust valve are closed;

[0092] S4: Liquid inlet to the water measuring cup: Open the water reservoir control valve and the water measuring chamber water supply and drainage valve, so that the water in the water reservoir passes through the water reservoir connecting channel, the water reservoir control valve connecting channel, the water reservoir control valve connecting channel port, the water reservoir control valve outlet, enters the water reservoir control valve, the water reservoir control valve inlet, the common liquid path channel port, the common liquid path channel, the water measuring chamber water supply and drainage valve connecting channel, the water measuring chamber water supply and drainage valve connecting channel port, the water measuring chamber water supply and drainage valve outlet, enters the water measuring chamber water supply and drainage valve, the water measuring chamber water supply and drainage valve inlet, the water measuring chamber connecting channel port, the water measuring chamber connecting channel, the water measuring chamber liquid level pressure measurement channel, the water measuring chamber liquid path port and the water measuring cup liquid inlet and outlet, and enters the water measuring cup;

[0093] When the water level pressure sensor of the water measuring chamber measures that the water level in the water measuring cup reaches the scale line of the water measuring cup, the water reservoir control valve and the water supply and drainage valve of the water measuring chamber are closed;

[0094] S5: water measuring chamber air intake: open the water measuring chamber air intake valve, so that the atmosphere enters the water measuring chamber through the common air intake channel entrance, the common air intake channel, the water measuring chamber air intake valve air intake channel, the water measuring chamber air intake valve entrance, the water measuring chamber air intake valve, the water measuring chamber air intake valve outlet, the water measuring chamber air intake valve vent channel entrance, the water measuring chamber air intake valve vent channel, the water measuring chamber air path common channel and the water measuring chamber air path port;

[0095] S6: liquid entering the sample cup: when the water measuring chamber liquid level pressure sensor measures that the pressure above the liquid surface of the water measuring cup reaches atmospheric pressure, the water measuring chamber water supply and drainage valve and the sample chamber water supply and drainage valve are opened, and the water in the water measuring cup passes through the water measuring chamber liquid level pressure measurement channel, the water measuring chamber connecting channel, the water measuring chamber connecting channel port, the water measuring chamber water supply and drainage valve inlet, the water measuring chamber water supply and drainage valve outlet, the water measuring chamber water supply and drainage valve connecting channel port, the water measuring chamber water supply and drainage valve connecting channel, the common liquid path channel, the sample chamber water supply and drainage valve connecting channel, the sample chamber water supply and drainage valve connecting channel port, the sample chamber water supply and drainage valve outlet, the sample chamber water supply and drainage valve inlet, the sample chamber connecting channel port, the sample chamber connecting channel, the sample chamber liquid level pressure measurement channel, the sample chamber liquid path port and the sample cup liquid inlet and outlet in sequence;

[0096] When the liquid level reaches the sample chamber liquid inlet and outlet, the sample chamber liquid level pressure sensor value reaches P s0 When the water level pressure sensor value P is recorded r0 ;

[0097] When the sample chamber liquid level pressure sensor measures that the water level in the sample cup reaches the sample cup scale line, close the sample chamber water supply and drainage valve and the water measuring chamber water supply and drainage valve, and record the sample chamber liquid level pressure sensor value P at this time. s1 And the water level pressure sensor value P r1 ;

[0098] S7: Sample cavity air intake: Open the sample cavity air intake valve to allow the atmosphere to enter the sample cavity through the common air intake channel entrance, the common air intake channel, the sample cavity air intake valve air intake channel, the sample cavity air intake valve entrance, the sample cavity air intake valve, the sample cavity air intake valve outlet, the sample cavity air intake valve exhaust channel entrance, the sample cavity air intake valve exhaust channel, the sample cavity air path common channel and the sample cavity air path port in sequence;

[0099] S8: Two-chamber water return: Open the sample chamber water supply and drainage valve, the water measuring chamber water supply and drainage valve and the water reservoir control valve to return the water in the sample cup and the water measuring cup to the water reservoir through the original route;

[0100] S9: Calculate the density value: Change value of the sample chamber liquid level pressure sensor:

[0101] ΔP s =P s1 –P s0

[0102] The slope k of the curve between the liquid level height of the sample cup and the value of the liquid level pressure sensor in the sample chamber is s , and the liquid level change in the sample cup is:

[0103] Δh s =k s ×ΔP s

[0104] Change value of the water level pressure sensor in the water measuring chamber:

[0105] ΔP r =P r1 –P r0

[0106] The slope k of the curve between the liquid level height of the measuring cup and the value of the liquid level pressure sensor in the measuring chamber is r , and the change in the liquid level of the measuring cup is:

[0107] Δh r =k r ×ΔP r

[0108] The bottom area S of the sample cup s and the bottom area S of the measuring cup r Calculate the sample volume V s for:

[0109] V s =|Δh s |×S s –|Δh r |×S r

[0110] The maximum theoretical density of the sample ρ s for:

[0111] ρ s =m s / V s .

[0112] The beneficial effects of the above technical solution of the present invention are as follows:

[0113] In the above scheme, the relationship between the mass of water in the sample measurement module and the volume calibration module and the measured value of the liquid level pressure sensor module is used to eliminate the influence of temperature on the liquid level pressure. The value measured by the water reservoir temperature sensor in the water storage module accurately corresponds to the density of water at that temperature, thereby realizing the determination of the maximum theoretical density of samples at different temperatures. The gas-liquid guide integrated module extracts the gas in the sample measurement module and the volume calibration module, which can not only exclude the gas in the sample gap to the greatest extent, but also create negative pressure on the sample measurement module and the volume calibration module, thereby realizing the dual functions of exhaust and pumping water. BRIEF DESCRIPTION OF THE DRAWINGS

[0114] Figure 1 It is an exploded view from the upper right front view of the maximum theoretical density measuring instrument based on the pore integrated module of the present invention;

[0115] Figure 2 It is an exploded view from the lower right front side of the maximum theoretical density measuring instrument based on the pore integrated module of the present invention;

[0116] Figure 3 It is a perspective view of the main body of the gas-liquid guide integrated module of the maximum theoretical density measuring instrument based on the pore integrated module of the present invention from the upper right front view;

[0117] Figure 4 It is a perspective view of the gas path part of the gas-liquid guide integrated module main body of the maximum theoretical density measuring instrument based on the pore integrated module of the present invention;

[0118] Figure 5 It is a perspective view of the gas-liquid guide integrated module main body from the upper left rear view angle of the maximum theoretical density measuring instrument based on the pore integrated module of the present invention;

[0119] Figure 6 It is a perspective view of the main body liquid path portion of the gas-liquid guide integrated module of the maximum theoretical density measuring instrument based on the pore integrated module of the present invention;

[0120] Figure 7 It is an exploded view of a seat-mounted solenoid valve of a maximum theoretical density measuring instrument based on a pore integrated module of the present invention;

[0121] Figure 8 It is a schematic diagram of a sample chamber cover of a maximum theoretical density measuring instrument based on a pore integrated module of the present invention;

[0122] Fig. 9It is a schematic diagram of a water measuring chamber cover of a maximum theoretical density measuring instrument based on a pore integrated module of the present invention;

[0123] Fig.10 It is a curve showing the change of the value of the sample cavity liquid level pressure sensor over time in the test of the maximum theoretical density measuring instrument based on the pore integrated module of the present invention;

[0124] Fig.11 It is a curve showing the change of the value of the liquid level pressure sensor of the water cavity in the test of the maximum theoretical density measuring instrument based on the pore integrated module of the present invention over time;

[0125] Fig.12 It is a relationship curve between the mass of water added to the sample cup and the value of the sample cavity liquid level pressure sensor in the test of the maximum theoretical density measuring instrument based on the pore integrated module of the present invention;

[0126] Fig.13 It is a curve showing the relationship between the mass of water added to the measuring cup and the value of the liquid level pressure sensor in the water measuring chamber in the test of the maximum theoretical density measuring instrument based on the pore integrated module of the present invention;

[0127] Fig.14 It is a relationship curve between the liquid level height of the sample cup and the value of the liquid level pressure sensor of the sample cavity in the test of the maximum theoretical density measuring instrument based on the pore integrated module of the present invention;

[0128] Fig.15 The present invention is a curve showing the relationship between the liquid level height of the measuring cup and the value of the liquid level pressure sensor of the measuring chamber in the test of the maximum theoretical density measuring instrument based on the pore integrated module.

[0129] Wherein: 100-sample chamber cover, 101-sample chamber cover right stopper, 102-sample cup, 103-sample cup connecting external thread, 104-sample chamber cover O-ring, 105-sample chamber filter, 106-sample chamber cover O-ring sealing groove, 107-sample cup liquid inlet and outlet, 108-sample chamber cover left stopper, 109-sample chamber, 110-sample cup scale line;

[0130] 200-water measuring chamber cover, 201-right limit block of water measuring chamber cover, 202-water measuring cup, 203-connecting external thread of water measuring cup, 204-O-ring of water measuring chamber cover, 205-sealing groove of O-ring of water measuring chamber cover, 206-liquid inlet and outlet of water measuring cup, 207-left limit block of water measuring chamber cover, 208-water measuring chamber, 209-scale line of water measuring cup;

[0131] 300-water reservoir, 301-water reservoir filter, 302-water reservoir temperature sensor;

[0132] 400-sample chamber liquid level pressure sensor O-ring, 401-sample chamber liquid level pressure sensor, 402-sample chamber liquid level pressure sensor flange boss, 403-sample chamber liquid level pressure sensor flange, 404-water measuring chamber liquid level pressure sensor O-ring, 405-water measuring chamber liquid level pressure sensor, 406-water measuring chamber liquid level pressure sensor flange boss, 407-water measuring chamber liquid level pressure sensor flange, 408-water measuring chamber liquid level pressure sensor flange center hole, 409-water measuring chamber liquid level pressure sensor flange through hole, 410-sample chamber liquid level pressure sensor flange center hole, 411-sample chamber liquid level pressure sensor flange through hole;

[0133] 500-gas-liquid guide integrated module body, 501-sample chamber air inlet valve fixing threaded hole, 502-sample chamber air inlet valve, 503-sample chamber air extraction valve, 504-sample chamber air extraction valve fixing threaded hole, 505-water measuring chamber air inlet valve, 506-water measuring chamber air extraction valve, 507-water measuring chamber air inlet valve fixing threaded hole, 508-water measuring chamber air extraction valve fixing threaded hole, 509-water reservoir control valve, 510-micro oil-free vacuum pump air extraction port O-ring, 511-micro oil-free vacuum pump air extraction port, 512-micro oil-free vacuum pump, 513-micro oil-free vacuum pump connecting sheet metal, 514-public air inlet channel entrance, 515-water reservoir control valve fixing threaded hole, 516-public air extraction channel outlet, 517-micro oil-free vacuum Pump exhaust channel inlet, 518-micro oil-free vacuum pump connection sheet metal fixing threaded hole, 519-water measuring chamber liquid level pressure sensor flange fixing threaded hole, 520-micro oil-free vacuum pump connection sheet metal large through hole, 521-micro oil-free vacuum pump connection sheet metal small through hole, 522-water measuring chamber water supply and drainage valve, 523-water measuring chamber filter, 524-water measuring chamber water supply and drainage valve fixing threaded hole, 525-sample chamber water supply and drainage valve fixing threaded hole, 526-sample chamber liquid level pressure sensor flange fixing threaded hole, 527-sample chamber water supply and drainage valve, 528-sample chamber air outlet, 529-micro oil-free vacuum pump exhaust channel outlet, 530-sample chamber air inlet valve exhaust channel inlet, 531-sample chamber air inlet valve air inlet channel outlet, 532-sample The outlet of the air extraction channel of the cavity suction valve, 533-the inlet of the air release channel of the sample cavity suction valve, 534-the outlet of the air intake channel of the water measuring cavity intake valve, 535-the inlet of the air release channel of the water measuring cavity intake valve, 536-the inlet of the air release channel of the water measuring cavity suction valve, 537-the outlet of the air extraction channel of the water measuring cavity suction valve, 538-the public air intake channel, 539-the placement slot of the micro oil-free vacuum pump, 540-the air path of the water measuring cavity, 541-the public channel of the air path of the sample cavity, 542-the exhaust channel of the micro oil-free vacuum pump, 543-the air release channel of the sample cavity intake valve, 544-the air intake channel of the sample cavity intake valve, 545-the air extraction channel of the sample cavity suction valve, 546-the air release channel of the sample cavity suction valve, 547-the public air extraction channel, 548-the air intake hole of the water measuring cavity intake valve channel, 549-water measuring chamber air inlet valve vent channel, 550-water measuring chamber air channel common channel, 551-water measuring chamber air extraction valve vent channel, 552-water measuring chamber air extraction valve vent channel, 553-water measuring chamber connecting channel port, 554-water measuring chamber filter placement slot, 555-common liquid channel port, 556-water reservoir control valve connecting channel port, 557-water reservoir connecting channel port, 558-water measuring chamber liquid channel port, 559-water measuring chamber chamber cover left limit block entrance and exit, 560-sample chamber chamber cover limit slot, 561-sample chamber chamber cover right limit block entrance and exit, 562-sample chamber liquid channel port, 563-sample chamber chamber cover left limit block entrance and exit, 564-sample chamber water supply and drainage valve connecting channel port, 565-sample chamber liquid level pressure measurement channel port,566-sample chamber liquid level pressure sensor placement slot, 567-water measuring chamber chamber cover right limit block entrance and exit, 568-water measuring chamber chamber cover limit slot, 569-water measuring chamber connecting channel, 570-public liquid path channel, 571-water reservoir control valve connecting channel, 572-water reservoir connecting channel, 573-water reservoir connecting slot, 574-water measuring chamber water supply and drainage valve connecting channel opening, 575-water measuring chamber water supply and drainage valve connecting channel, 576-water measuring chamber liquid level pressure measurement channel, 577-water measuring chamber liquid level pressure measurement channel opening, 578-water measuring chamber liquid level pressure sensor placement slot, 579-sample chamber connecting channel opening, 580-sample chamber water supply and drainage valve connecting channel, 581-sample chamber water supply and drainage valve connecting channel, 582-sample chamber water supply and drainage valve connecting channel, 583-sample chamber water supply and drainage valve connecting channel, 584-sample chamber water supply and drainage valve connecting channel, 585-sample chamber water supply and drainage valve connecting channel, 586-water measuring chamber liquid level pressure measurement channel, 587-water measuring chamber liquid level pressure measurement channel opening, 588-water measuring chamber liquid level pressure sensor placement slot, 589-sample chamber connecting channel opening, 590-sample chamber water supply and drainage valve connecting channel, 591-sample chamber water supply and drainage valve connecting channel, 592-sample chamber water supply and drainage valve connecting channel, 593-sample chamber water supply and drainage valve connecting channel, 594-sample chamber water supply and drainage valve connecting channel, 595-sample chamber water supply and drainage valve connecting channel, 596-sample chamber water supply and drainage valve connecting channel, 597-sample chamber water supply and drainage valve connecting channel, 598-sample chamber water supply and drainage valve connecting channel, 599-sample chamber water supply and drainage valve connecting channel, 590-sample chamber water supply and drainage valve connecting channel, 591-sample chamber water supply and drainage valve connecting channel, 1-sample chamber connecting channel, 582-sample chamber liquid level pressure measurement channel, 583-water measuring cup connecting groove, 584-water measuring cup placing platform, 585-water measuring chamber cover placing platform, 586-sample cup connecting groove, 587-sample cup placing platform, 588-sample chamber cover placing platform, 589-water reservoir control valve through hole, 590-water reservoir control valve outlet, 591-water reservoir control valve inlet O-ring sealing groove, 592-water reservoir control valve inlet, 593-water reservoir control valve outlet O-ring sealing groove, 594-water reservoir control valve inlet O-ring, 595-water reservoir control valve outlet O-ring, 596-water measuring chamber water supply and drainage valve through hole, 597-water measuring chamber water supply and drainage valve outlet, 598-water measuring chamber water supply and drainage valve inlet O-ring sealing groove, 599-water measuring chamber water supply and drainage valve inlet, 600-water measuring chamber water supply and drainage valve outlet O-ring sealing groove, 601-water measuring chamber water supply and drainage valve inlet O-ring, 602-water measuring chamber water supply and drainage valve outlet O-ring, 603-sample chamber water supply and drainage valve through hole, 604-sample chamber water supply and drainage valve outlet, 605-sample chamber water supply and drainage valve inlet O-ring sealing groove, 606-sample chamber water supply and drainage valve inlet, 607-sample chamber water supply and drainage valve outlet O-ring sealing groove, 608-sample chamber water supply and drainage valve inlet O-ring, 609-sample chamber water supply and drainage valve outlet O-ring, 61 0-inlet of sample chamber air intake valve, 611-outlet of sample chamber air intake valve, 612-through hole of sample chamber air intake valve, 613-sealing pad of sample chamber air intake valve, 614-inlet of sample chamber air extraction valve, 615-outlet of sample chamber air extraction valve, 616-through hole of sample chamber air extraction valve, 617-sealing pad of sample chamber air extraction valve, 618-inlet of water measuring chamber air intake valve, 619-outlet of water measuring chamber air intake valve, 620-through hole of water measuring chamber air intake valve, 621-sealing pad of water measuring chamber air intake valve, 622-inlet of water measuring chamber air extraction valve, 623-outlet of water measuring chamber air extraction valve, 624-through hole of water measuring chamber air extraction valve, 625-sealing pad of water measuring chamber air extraction valve, 626-exhaust port of micro oil-free vacuum pump. DETAILED DESCRIPTION

[0134] In order to make the technical problems, technical solutions and advantages to be solved by the present invention more clear, a detailed description will be given below with reference to the accompanying drawings and specific embodiments.

[0135] The invention provides a maximum theoretical density measuring instrument and a testing method based on a pore integrated module.

[0136] like Figure 1 and Figure 2 As shown, the measuring instrument includes a sample measurement module, a volume calibration module, a gas-liquid guide integrated module, a liquid level pressure sensing module and a water storage module. The sample measurement module and the volume calibration module are respectively installed on the upper left and right sides of the gas-liquid guide integrated module, the water storage module is installed below the gas-liquid guide integrated module, and the liquid level pressure sensing module is embedded in the lower part of the gas-liquid guide integrated module, wherein two liquid level pressure sensors are respectively arranged vertically coaxially with the sample measurement module and the volume calibration module.

[0137] The sample measurement module includes a sample chamber cover 100, a sample chamber cover O-ring 104, a sample cup 102 and a sample chamber filter 105;

[0138] like Figure 8 As shown, the sample chamber cover 100 is in the shape of a hollow cylinder, with an open lower end, a closed upper end, and a cavity in the middle. A sample chamber cover left limit block 108 and a sample chamber cover right limit block 101 are symmetrically arranged on the outer side of the lower end of the sample chamber cover 100. A sample chamber cover O-ring sealing groove 106 is opened on the lower end surface of the sample chamber cover 100, and a sample chamber cover O-ring 104 is embedded in the sample chamber cover O-ring sealing groove 106;

[0139] The sample cup 102 is in the shape of a hollow cylinder, with an open upper end, a cavity in the middle, and a closed lower end. A protruding cylinder is provided in the center of the lower end surface, and a sample cup connecting external thread 103 is provided on the outer side of the cylinder. A central hole is opened through the center of the cylinder, and the lower end opening of the central hole is a sample cup liquid inlet and outlet 107. A sample cavity filter 105 is installed at the sample cup liquid inlet and outlet 107. The sample cup scale line 110 is engraved on the outer side of the upper part of the sample cup 102.

[0140] The volume calibration module includes a water measuring chamber cover 200, a water measuring chamber cover O-ring 204 and a water measuring cup 202; Fig. 9 As shown, the water measuring chamber cover 200 is in the shape of a hollow cylinder, with an open lower end, a closed upper end, and a cavity in the middle. A left limit block 207 and a right limit block 201 of the water measuring chamber cover are symmetrically arranged on the outer side of the lower end of the water measuring chamber cover 200. A water measuring chamber cover O-ring sealing groove 205 is opened on the lower end surface of the water measuring chamber cover 200, and a water measuring chamber cover O-ring 204 is embedded in the water measuring chamber cover O-ring sealing groove 205.

[0141] The measuring cup 202 is in the shape of a hollow cylinder, with an open top, a cavity in the middle, and a closed bottom. A protruding cylinder is provided in the center of the lower end surface, and an external thread 203 for connecting the measuring cup is provided on the outer side of the cylinder. A central hole is provided through the center of the cylinder, and the lower end opening of the central hole is a liquid inlet and outlet 206 of the measuring cup. The outer side of the upper part of the measuring cup 202 is engraved with a measuring cup scale line 209;

[0142] The water storage module includes a water reservoir 300, a water reservoir filter 301 and a water reservoir temperature sensor 302. The water reservoir 300 is hollow and stores water inside. The water reservoir temperature sensor 302 is immersed below the water surface in the water reservoir 300.

[0143] The liquid level pressure sensor module includes a sample chamber liquid level pressure sensor 401, a sample chamber liquid level pressure sensor flange 403, a water measuring chamber liquid level pressure sensor 405 and a water measuring chamber liquid level pressure sensor flange 407;

[0144] The sample chamber liquid level pressure sensor O-ring 400 is fixed in the middle groove of the sample chamber liquid level pressure sensor 401;

[0145] A sample cavity liquid level pressure sensor flange center hole 410 is opened in the center of the sample cavity liquid level pressure sensor flange, and the periphery of the sample cavity liquid level pressure sensor flange center hole 410 protrudes upward to form a sample cavity liquid level pressure sensor flange boss 402, and four sample cavity liquid level pressure sensor flange through holes 411 are symmetrically opened on the periphery of the sample cavity liquid level pressure sensor flange boss 402;

[0146] The water measuring chamber liquid level pressure sensor O-ring 404 is fixed in the middle groove of the water measuring chamber liquid level pressure sensor 405;

[0147] A water cavity liquid level pressure sensor flange center hole 408 is opened in the center of the water cavity liquid level pressure sensor flange, and the periphery of the water cavity liquid level pressure sensor flange center hole 408 protrudes upward to form a water cavity liquid level pressure sensor flange boss 406, and four water cavity liquid level pressure sensor flange through holes 409 are symmetrically opened on the periphery of the water cavity liquid level pressure sensor flange boss 406;

[0148] like Figure 3 , Figure 4 , Figure 5 and Figure 6 As shown, the gas-liquid guide integrated module includes a gas-liquid guide integrated module body 500, a sample chamber air inlet valve 502, a sample chamber air extraction valve 503, a water measuring chamber air inlet valve 505, a water measuring chamber air extraction valve 506, a sample chamber water supply and drainage valve 527, a water measuring chamber water supply and drainage valve 522, a water measuring chamber filter 523, a water reservoir control valve 509, a micro oil-free vacuum pump 512 and a micro oil-free vacuum pump connecting sheet metal 513;

[0149] The upper surface of the gas-liquid guide integrated module body 500 is symmetrically provided with grooves for installing the sample measurement module and the volume calibration module. The left groove on the upper surface of the gas-liquid guide integrated module body 500 is symmetrically provided with two notches along the radial direction outward of the groove, which correspond to the left limit block entrance 563 of the sample chamber cover and the right limit block entrance 561 of the sample chamber cover respectively.

[0150] Below the left limiting block entrance and exit 563 of the sample chamber cover and the right limiting block entrance and exit 561 of the sample chamber cover, an annular sample chamber cover limiting groove 560 is opened radially outward along the left groove, and the annular lower plane of the sample chamber cover limiting groove 560 is a sample chamber cover placement platform 588, and a sample chamber gas path opening 528 is opened on the sample chamber cover placement platform 588, and a sample chamber gas path common channel 541 is opened vertically downward at the sample chamber gas path opening 528, and the sample chamber cover placement platform 588 is opened radially inward along the groove below the sample chamber cover placement platform 588. A sample cup placement platform 587 is provided, a sample cup connection groove 586 is provided in the center of the sample cup placement platform 587, a sample cavity liquid level pressure measurement channel 582 is provided downwardly through the sample cup connection groove 586, a sample cavity liquid junction 562 is provided at the connection between the sample cup connection groove 586 and the sample cavity liquid level pressure measurement channel 582, a lower end of the sample cavity liquid level pressure measurement channel 582 is a sample cavity liquid level pressure measurement channel opening 565, and a sample cavity liquid level pressure sensor placement groove 566 is provided radially outwardly below the sample cavity liquid level pressure measurement channel opening 565;

[0151] The right groove on the upper surface of the gas-liquid guide integrated module body 500 is symmetrically opened along the radial direction outward of the groove to the left and right, corresponding to the left limit block entrance 559 and the right limit block entrance 567 of the water measuring chamber cover, respectively. Below the left limit block entrance 559 and the right limit block entrance 567 of the water measuring chamber cover, an annular water measuring chamber cover limiting groove 568 is opened radially outward along the right groove. The annular lower plane of the water measuring chamber cover limiting groove 568 is a water measuring chamber cover placement platform 585. A water measuring chamber gas path opening 540 is opened on the water measuring chamber cover placement platform 585. The water measuring chamber gas path opening 540 is vertically downwardly opened with a water measuring chamber gas path common channel 55 0, a water measuring cup placement platform 584 is opened radially inwardly along the groove and is lower than the water measuring cup placement platform 585, a water measuring cup connection groove 583 is opened in the center of the water measuring cup placement platform 584, and a water measuring chamber liquid level pressure measurement channel 576 is opened downwardly through the water measuring cup connection groove 583, and the connection between the water measuring cup connection groove 583 and the water measuring chamber liquid level pressure measurement channel 576 is a water measuring chamber liquid intersection 558, and the lower end of the water measuring chamber liquid level pressure measurement channel 576 is a water measuring chamber liquid level pressure measurement channel opening 577, and a water measuring chamber liquid level pressure sensor placement groove 578 is opened radially outwardly below the water measuring chamber liquid level pressure measurement channel opening 577;

[0152] A common air inlet 514 and a micro oil-free vacuum pump placement groove 539 are provided at the front of the right side surface of the gas-liquid guide integrated module body 500. A common air inlet 538 is provided horizontally to the left of the common air inlet 514. A common exhaust duct outlet 516 and a micro oil-free vacuum pump exhaust duct inlet 517 are provided on the left side surface of the micro oil-free vacuum pump placement groove 539. A common exhaust duct 547 is provided horizontally to the left of the common exhaust duct outlet 516. A micro oil-free vacuum pump exhaust duct 542 is provided horizontally to the left through the micro oil-free vacuum pump exhaust duct inlet 517. A micro oil-free vacuum pump exhaust duct outlet 529 is formed on the left side surface of the gas-liquid integrated guide module body 500.

[0153] The left side of the front surface of the gas-liquid guide integrated module body 500 is provided with a sample cavity air inlet valve fixing threaded hole 501, a sample cavity air inlet valve air release channel inlet 530 and a sample cavity air inlet valve air inlet channel outlet 531, the sample cavity air inlet valve air release channel inlet 530 is provided with a sample cavity air inlet valve air release channel 543 horizontally backward, the sample cavity air inlet valve air inlet channel outlet 531 is provided with a sample cavity air inlet valve air inlet channel 544 horizontally backward, and the sample cavity air inlet valve air inlet channel 544 is connected with the common air inlet channel 538;

[0154] A sample cavity air extraction valve fixing threaded hole 504, a sample cavity air extraction valve air extraction channel outlet 532 and a sample cavity air extraction valve air extraction channel inlet 533 are correspondingly provided below the sample cavity air intake valve fixing threaded hole 501, the sample cavity air intake valve air release channel inlet 530 and the sample cavity air intake valve air intake channel outlet 531. A sample cavity air extraction valve air extraction channel 545 is provided horizontally backwards from the sample cavity air extraction valve air extraction channel outlet 532. The sample cavity air intake valve air release channel 543 and the sample cavity air extraction valve air extraction channel 545 are both connected to the sample cavity gas path common channel 541. A sample cavity air extraction valve air release channel 546 is provided horizontally backwards from the sample cavity air extraction valve air release channel inlet 533. The sample cavity air extraction valve air release channel 546 is connected to the common air extraction channel 547.

[0155] The right side of the front surface of the gas-liquid guide integrated module body 500 is provided with a water-measuring chamber air inlet valve fixing threaded hole 507, a water-measuring chamber air inlet valve air inlet channel outlet 534 and a water-measuring chamber air inlet valve air release channel inlet 535. The water-measuring chamber air inlet valve air inlet channel outlet 534 is provided with a water-measuring chamber air inlet valve air inlet channel 548 horizontally backward. The water-measuring chamber air inlet valve air inlet channel 548 is connected with the common air inlet channel 538. The water-measuring chamber air inlet valve air release channel inlet 535 is provided with a water-measuring chamber air inlet valve air release channel 549 horizontally backward.

[0156] Below the water measuring chamber air inlet valve fixing threaded hole 507, the water measuring chamber air inlet valve air inlet channel outlet 534 and the water measuring chamber air inlet valve air release channel inlet 535, correspondingly, a water measuring chamber air extraction valve fixing threaded hole 508, a water measuring chamber air extraction valve air release channel inlet 536 and a water measuring chamber air extraction valve air extraction channel outlet 537 are opened. The water measuring chamber air extraction valve air release channel inlet 536 is horizontally opened backwards with a water measuring chamber air extraction valve air release channel 551. The water measuring chamber air extraction valve air release channel 551 is connected to the common air extraction channel 547. The water measuring chamber air extraction valve air extraction channel outlet 537 is horizontally opened backwards with a water measuring chamber air extraction valve air extraction channel 552. The water measuring chamber air inlet valve air release channel 549 and the water measuring chamber air extraction valve air extraction channel 552 are both connected to the water measuring chamber air path common channel 550.

[0157] like Figure 7 As shown, a sample cavity air inlet valve inlet 610, a sample cavity air inlet valve outlet 611 and a sample cavity air inlet valve through hole 612 are formed at the bottom of the sample cavity air inlet valve 502, and a sample cavity air inlet valve sealing gasket 613 is provided on the sample cavity air inlet valve inlet 610 and the sample cavity air inlet valve outlet 611;

[0158] The bottom of the sample cavity air extraction valve 503 is provided with a sample cavity air extraction valve inlet 614, a sample cavity air extraction valve outlet 615 and a sample cavity air extraction valve through hole 616, and a sample cavity air extraction valve sealing gasket 617 is provided on the sample cavity air extraction valve inlet 614 and the sample cavity air extraction valve outlet 615;

[0159] The bottom of the water measuring chamber air inlet valve 505 is provided with a water measuring chamber air inlet valve inlet 618, a water measuring chamber air inlet valve outlet 619 and a water measuring chamber air inlet valve through hole 620, and a water measuring chamber air inlet valve sealing gasket 621 is provided on the water measuring chamber air inlet valve inlet 618 and the water measuring chamber air inlet valve outlet 619;

[0160] The bottom of the water measuring cavity air pumping valve 506 is provided with a water measuring cavity air pumping valve inlet 622, a water measuring cavity air pumping valve outlet 623 and a water measuring cavity air pumping valve through hole 624, and a water measuring cavity air pumping valve sealing gasket 625 is provided on the water measuring cavity air pumping valve inlet 622 and the water measuring cavity air pumping valve outlet 623;

[0161] like Figure 1 As shown, the top of the left pagoda head of the micro oil-free vacuum pump 512 is the micro oil-free vacuum pump suction port 511, and the top of the right pagoda head is the micro oil-free vacuum pump exhaust port 626. The micro oil-free vacuum pump suction port 511 is equipped with a micro oil-free vacuum pump suction port O-ring 510;

[0162] The micro oil-free vacuum pump connection sheet metal 513 has four large through holes 520 for connecting the micro oil-free vacuum pump at the four corners of the edge, and four small through holes 521 for connecting the micro oil-free vacuum pump at the two sides of the center symmetrically;

[0163] The rear part of the right side surface of the gas-liquid guide integrated module body 500 is provided with a water reservoir control valve fixing threaded hole 515, a common liquid path channel opening 555 and a water reservoir control valve communication channel opening 556. The common liquid path channel opening 555 is provided with a common liquid path channel 570 horizontally to the left, and the water reservoir control valve communication channel opening 556 is provided with a water reservoir control valve communication channel 571 horizontally to the left.

[0164] A water reservoir connection groove 573 is formed at the right rear of the lower surface of the gas-liquid guide integrated module body 500, a water reservoir communication channel opening 557 is formed above the water reservoir connection groove 573, a water reservoir communication channel 572 is formed upward from the water reservoir communication channel opening 557, and the water reservoir communication channel 572 is connected to the water reservoir control valve communication channel 571;

[0165] The left side of the rear surface of the gas-liquid guide integrated module body 500 is provided with a sample chamber water supply and drainage valve fixing threaded hole 525, a sample chamber communication channel opening 579 and a sample chamber water supply and drainage valve communication channel opening 564. The sample chamber communication channel opening 579 is provided with a sample chamber communication channel 581 forwardly, and the sample chamber communication channel 581 is connected to a sample chamber liquid level pressure measurement channel 582. The sample chamber water supply and drainage valve communication channel opening 564 is provided with a sample chamber water supply and drainage valve communication channel 580 forwardly, and the sample chamber water supply and drainage valve communication channel 580 is connected to a common liquid path channel 570.

[0166] The right side of the rear surface of the gas-liquid guide integrated module body 500 is provided with a water measuring chamber water supply and drainage valve fixing threaded hole 524, a water measuring chamber communication channel opening 553 and a water measuring chamber filter placement groove 554. The water measuring chamber communication channel opening 553 is provided with a water measuring chamber communication channel 569 forwardly, and the water measuring chamber communication channel 569 is connected with a water measuring chamber liquid level pressure measurement channel 576. The water measuring chamber filter placement groove 554 is provided with a water measuring chamber water supply and drainage valve communication channel opening 574 in front of the water measuring chamber water supply and drainage valve communication channel opening 574, and a water measuring chamber water supply and drainage valve communication channel 575 is provided in front of the water measuring chamber water supply and drainage valve communication channel opening 574, and the water measuring chamber water supply and drainage valve communication channel 575 is connected with the common liquid path channel 570.

[0167] A micro oil-free vacuum pump connection sheet metal fixing threaded hole 518 is opened on the right front of the lower surface of the gas-liquid guide integrated module body 500, a sample chamber liquid level pressure sensor flange fixing threaded hole 526 is opened on the left side of the lower surface of the gas-liquid guide integrated module body 500, and a water chamber liquid level pressure sensor flange fixing threaded hole 519 is opened on the right side of the lower surface of the gas-liquid guide integrated module body 500;

[0168] like Figure 7As shown, sample cavity water supply and drainage valve through holes 603 are opened at four corners of the lower surface of the sample cavity water supply and drainage valve 527, a sample cavity water supply and drainage valve outlet 604 and a sample cavity water supply and drainage valve inlet 606 are opened in the middle of the lower surface of the sample cavity water supply and drainage valve 527, a sample cavity water supply and drainage valve inlet O-ring sealing groove 605 is arranged on the outer ring of the sample cavity water supply and drainage valve inlet 606, a sample cavity water supply and drainage valve outlet O-ring sealing groove 607 is arranged on the outer ring of the sample cavity water supply and drainage valve outlet 604 and the sample cavity water supply and drainage valve inlet O-ring sealing groove 605, a sample cavity water supply and drainage valve outlet O-ring sealing groove 608 and a sample cavity water supply and drainage valve outlet O-ring 609 are respectively placed in the sample cavity water supply and drainage valve inlet O-ring sealing groove 605 and the sample cavity water supply and drainage valve outlet O-ring sealing groove 607;

[0169] The four corners of the lower surface of the water-measuring chamber water-supply-drain valve 522 are provided with water-measuring chamber water-supply-drain valve through holes 596, the middle part of the lower surface of the water-measuring chamber water-supply-drain valve 522 is provided with a water-measuring chamber water-supply-drain valve outlet 597 and a water-measuring chamber water-supply-drain valve inlet 599, the outer ring of the water-measuring chamber water-supply-drain valve inlet 599 is provided with a water-measuring chamber water-supply-drain valve inlet O-ring sealing groove 598, the outer rings of the water-measuring chamber water-supply-drain valve outlet 597 and the water-measuring chamber water-supply-drain valve inlet O-ring sealing groove 598 are provided with a water-measuring chamber water-supply-drain valve outlet O-ring sealing groove 600, the water-measuring chamber water-supply-drain valve inlet O-ring 601 and the water-measuring chamber water-supply-drain valve outlet O-ring 602 are respectively placed in the water-measuring chamber water-supply-drain valve inlet O-ring sealing groove 598 and the water-measuring chamber water-supply-drain valve outlet O-ring sealing groove 600;

[0170] The four corners of the lower surface of the water reservoir control valve 509 are provided with water reservoir control valve through holes 589, the middle part of the lower surface of the water reservoir control valve 509 is provided with a water reservoir control valve outlet 590 and a water reservoir control valve inlet 592, the outer ring of the water reservoir control valve inlet 592 is provided with a water reservoir control valve inlet O-ring sealing groove 591, the outer rings of the water reservoir control valve outlet 590 and the water reservoir control valve inlet O-ring sealing groove 591 are provided with a water reservoir control valve outlet O-ring sealing groove 593, the water reservoir control valve inlet O-ring 594 and the water reservoir control valve outlet O-ring 595 are respectively placed in the water reservoir control valve inlet O-ring sealing groove 591 and the water reservoir control valve outlet O-ring sealing groove 593;

[0171] The cavity between the sample cup liquid inlet and outlet 107, the sample cavity gas passage 528 and the sample cavity cover 100 is the sample cavity 109;

[0172] The cavity between the water measuring cup liquid inlet and outlet 206 , the water measuring chamber air passage 540 and the water measuring chamber cover 200 is the water measuring chamber 208 .

[0173] The sample cavity filter 105 is placed in the sample cup connection groove 586, and the sample cup 102 is connected and fastened with the internal thread of the sample cup connection groove 586 from above through the sample cup connection external thread 103 until the sample cup 102 contacts the sample cup placement platform 587;

[0174] The measuring cup 202 is connected and fastened with the measuring cup connecting groove 583 internal thread from above through the measuring cup connecting external thread 203 until the measuring cup 202 contacts the measuring cup placing platform 584;

[0175] The water reservoir filter screen 301 is placed in the water reservoir connecting groove 573 , and the water reservoir connecting groove 573 and the external joint are sealed by threaded connection and then pressed and fixed. The water reservoir temperature sensor 302 is placed below the liquid level in the water reservoir 300 .

[0176] The sample cavity liquid level pressure sensor 401 is embedded and installed in the sample cavity liquid level pressure sensor placement groove 566, the upper end of the sample cavity liquid level pressure sensor flange boss 402 presses the rear end of the sample cavity liquid level pressure sensor 401, and the sample cavity liquid level pressure sensor 401 is fixedly sealed with the sample cavity liquid level pressure measurement channel opening 565 through the sample cavity liquid level pressure sensor O-ring 400, the side of the sample cavity liquid level pressure sensor flange boss 402 cooperates with the sample cavity liquid level pressure sensor placement groove 566, and the fastening screw is screwed into the sample cavity liquid level pressure sensor flange fixing threaded hole 526 through the sample cavity liquid level pressure sensor flange through hole 411, and the sample cavity liquid level pressure sensor flange 403 is fixed on the lower surface of the gas-liquid guide integrated module body 500;

[0177] The water measuring chamber liquid level pressure sensor 405 is embedded and installed in the water measuring chamber liquid level pressure sensor placement groove 578, the upper end of the water measuring chamber liquid level pressure sensor flange boss 406 presses the rear end of the water measuring chamber liquid level pressure sensor 405, and the water measuring chamber liquid level pressure sensor 405 is fixedly sealed to the water measuring chamber liquid level pressure measurement channel opening 577 through the water measuring chamber liquid level pressure sensor O-ring 404, the side of the water measuring chamber liquid level pressure sensor flange boss 406 cooperates with the water measuring chamber liquid level pressure sensor placement groove 578, and the fastening screw is screwed into the water measuring chamber liquid level pressure sensor flange fixing threaded hole 519 through the water measuring chamber liquid level pressure sensor flange through hole 409 to fix the water measuring chamber liquid level pressure sensor flange 407 on the lower surface of the gas-liquid guide integrated module body 500.

[0178] The micro oil-free vacuum pump suction port 511 passes through the micro oil-free vacuum pump suction port O-ring 510 and is aligned with the common suction channel outlet 516, and the micro oil-free vacuum pump exhaust port 626 is aligned with the micro oil-free vacuum pump exhaust channel inlet 517;

[0179] The fastening screw is screwed into the threaded hole at the corresponding position at the bottom of the micro oil-free vacuum pump 512 through the small through hole 521 of the micro oil-free vacuum pump connecting sheet metal, and the fastening screw is screwed into the micro oil-free vacuum pump connecting sheet metal fixing threaded hole 518 on the lower surface of the gas-liquid guide integrated module body 500 through the large through hole 520 of the micro oil-free vacuum pump connecting sheet metal. After the fastening screw is tightened, the micro oil-free vacuum pump 512 is fixedly connected to the gas-liquid guide integrated module body 500, and the micro oil-free vacuum pump exhaust port 511 is sealed with the common exhaust channel outlet 516.

[0180] The sample cavity air inlet valve inlet 610 is aligned with the sample cavity air inlet valve air inlet channel outlet 531, the sample cavity air inlet valve outlet 611 is aligned with the sample cavity air inlet valve air release channel inlet 530, the fastening screw is screwed into the sample cavity air inlet valve fixed threaded hole 501 through the sample cavity air inlet valve through hole 612, after the fastening screw is tightened, the sample cavity air inlet valve 502 forms a fixed seal with the gas-liquid guide integrated module body 500 through the sample cavity air inlet valve sealing gasket 613;

[0181] The sample chamber exhaust valve inlet 614 is aligned with the sample chamber exhaust valve exhaust channel outlet 532, the sample chamber exhaust valve outlet 615 is aligned with the sample chamber exhaust valve exhaust channel inlet 533, the fastening screw is screwed into the sample chamber exhaust valve fixed threaded hole 504 through the sample chamber exhaust valve through hole 616, after the fastening screw is tightened, the sample chamber exhaust valve 503 forms a fixed seal with the gas-liquid guide integrated module body 500 through the sample chamber exhaust valve sealing gasket 617;

[0182] The water measuring chamber air inlet valve inlet 618 is aligned with the water measuring chamber air inlet valve air inlet channel outlet 534, the water measuring chamber air inlet valve outlet 619 is aligned with the water measuring chamber air inlet valve air release channel inlet 535, the fastening screw is screwed into the water measuring chamber air inlet valve fixing threaded hole 507 through the water measuring chamber air inlet valve through hole 620, after the fastening screw is tightened, the water measuring chamber air inlet valve 505 forms a fixed seal with the gas-liquid guide integrated module body 500 through the water measuring chamber air inlet valve sealing gasket 621;

[0183] The inlet 622 of the water measuring chamber air pumping valve is aligned with the outlet 537 of the water measuring chamber air pumping valve exhaust channel, and the outlet 623 of the water measuring chamber air pumping valve is aligned with the inlet 536 of the water measuring chamber air pumping valve exhaust channel. The fastening screw is screwed into the water measuring chamber air pumping valve fixing threaded hole 508 through the water measuring chamber air pumping valve through hole 624. After the fastening screw is tightened, the water measuring chamber air pumping valve 506 forms a fixed seal with the gas-liquid guide integrated module body 500 through the water measuring chamber air pumping valve sealing gasket 625.

[0184] The sample chamber water supply and drainage valve inlet 606 is aligned with the sample chamber communication channel port 579, the sample chamber water supply and drainage valve outlet 604 is aligned with the sample chamber water supply and drainage valve communication channel port 564, the fastening screw is screwed into the sample chamber water supply and drainage valve fixing threaded hole 525 through the sample chamber water supply and drainage valve through hole 603, and after the fastening screw is tightened, the sample chamber water supply and drainage valve 527 forms a fixed seal with the gas-liquid guide integrated module body 500;

[0185] The water measuring chamber filter 523 is placed in the water measuring chamber filter placement groove 554, the water measuring chamber water supply and drainage valve inlet 599 is aligned with the water measuring chamber communication channel port 553, the water measuring chamber water supply and drainage valve outlet 597 is aligned with the water measuring chamber water supply and drainage valve communication channel port 574, the fastening screw is screwed into the water measuring chamber water supply and drainage valve fixing threaded hole 524 through the water measuring chamber water supply and drainage valve through hole 596, and after the fastening screw is tightened, the water measuring chamber water supply and drainage valve 522 forms a fixed seal with the gas-liquid guide integrated module body 500;

[0186] The inlet 592 of the water reservoir control valve is aligned with the common liquid channel opening 555, the outlet 590 of the water reservoir control valve is aligned with the connecting channel opening 556 of the water reservoir control valve, and the fastening screw is screwed into the fixed threaded hole 515 of the water reservoir control valve through the through hole 589 of the water reservoir control valve. After the fastening screw is tightened, the water reservoir control valve 509 forms a fixed seal with the main body 500 of the gas-liquid guide integrated module.

[0187] The sample chamber air inlet valve 502, the sample chamber air exhaust valve 503, the water measuring chamber air inlet valve 505, the water measuring chamber air exhaust valve 506, the sample chamber water supply and drainage valve 527, the water measuring chamber water supply and drainage valve 522 and the water reservoir control valve 509 are all seat-mounted solenoid valves, which are sealed to the smooth surface by sealing gaskets.

[0188] The material of the sample chamber cover 100, the sample cup 102, the water measuring chamber cover 200, the water measuring cup 202 and the gas-liquid guide integrated module body 500 is 0.14 W·m -1 ·K -1 ~0.2W·m -1 ·K -1 The organic glass, wherein the sample chamber cover 100 and the water measuring chamber cover 200 are not less than 20 mm thick.

[0189] The sample cup 102 is divided into six types of containers according to different amounts of samples to be tested, as shown in Table 1.

[0190] Table 1 Sample cup 102 specification classification table

[0191]

[0192] The testing method of the measuring instrument comprises the following steps:

[0193] S1: Sensor calibration: weigh the sample mass ms , according to the sample mass m s Select a sample cup 102 of corresponding specifications;

[0194] Place the sample chamber cover left limit block 108 and the sample chamber cover right limit block 101 through the sample chamber cover left limit block inlet 563 and the sample chamber cover right limit block inlet 561, respectively, and place them on the sample chamber cover placement platform 588. Rotate the sample chamber cover 100 clockwise to screw the sample chamber cover left limit block 108 and the sample chamber cover right limit block 101 into the sample chamber cover limit groove 560. The sample chamber cover limit groove 560 presses the sample chamber cover O-ring 104 between the sample chamber cover O-ring sealing groove 106 and the sample chamber cover placement platform 588 to form a seal.

[0195] Pass the left limit block 207 and the right limit block 201 of the water measuring chamber cover through the left limit block inlet 559 and the right limit block inlet 567 of the water measuring chamber cover respectively, and place them on the water measuring chamber cover placement platform 585. Rotate the water measuring chamber cover 200 clockwise to screw the left limit block 207 and the right limit block 201 of the water measuring chamber cover into the limit groove 568 of the water measuring chamber cover. The limit groove 568 of the water measuring chamber cover presses the O-ring 204 of the water measuring chamber cover between the O-ring sealing groove 205 of the water measuring chamber cover and the water measuring chamber cover placement platform 585 to form a seal.

[0196] Open the sample chamber exhaust valve 503 and the water measuring chamber exhaust valve 506, close the sample chamber water supply and drainage valve 527, the water measuring chamber water supply and drainage valve 522, the water reservoir control valve 509, the sample chamber air intake valve 502 and the water measuring chamber air intake valve 505, start the micro oil-free vacuum pump 512, and evacuate the sample chamber 109 and the water measuring chamber 208;

[0197] After 60 seconds, the micro oil-free vacuum pump 512, the sample chamber air extraction valve 503 and the water measuring chamber air extraction valve 506 are closed, and the sample chamber water supply and drainage valve 527, the water measuring chamber water supply and drainage valve 522 and the water reservoir control valve 509 are opened to extract water from the water reservoir 300. The water flows through the external hose, the water reservoir connecting channel port 557, the water reservoir connecting channel 572, the water reservoir control valve connecting channel 571, the water reservoir control valve connecting channel port 556, the water reservoir control valve outlet 590, the water reservoir control valve inlet 592, the common liquid channel port 555 and the common liquid channel 570 in sequence, and then is divided into two streams. One stream flows through the sample chamber water supply and drainage valve connecting channel 580, the sample chamber water supply and drainage valve inlet 592, the common liquid channel port 555 and the common liquid channel 570 in sequence. The water valve communication channel port 564, the sample chamber water supply and drainage valve outlet 604, the sample chamber water supply and drainage valve inlet 606, the sample chamber communication channel port 579 and the sample chamber communication channel 581 enter the sample chamber liquid level pressure measurement channel 582, reach the sample chamber liquid level pressure measurement channel port 565, and contact the sample chamber liquid level pressure sensor 401. The value of the sample chamber liquid level pressure sensor 401 rises. When water fills the sample chamber liquid level pressure measurement channel 582 and enters the sample cup 102 from the sample cup liquid inlet and outlet 107, the rising slope of the sample chamber liquid level pressure sensor 401 value curve decreases, and a turning point is formed between the sample chamber liquid level pressure and the previous rising curve. This point is taken as the sample chamber liquid level pressure initial point P s0 At the same time, another stream of water flows through the water measuring chamber water supply and drainage valve connecting channel 575, the water measuring chamber water supply and drainage valve connecting channel port 574, the water measuring chamber water supply and drainage valve outlet 597, the water measuring chamber water supply and drainage valve inlet 599, the water measuring chamber connecting channel port 553 and the water measuring chamber connecting channel 569 in sequence, enters the water measuring chamber liquid level pressure measuring channel 576, reaches the water measuring chamber liquid level pressure measuring channel port 577, contacts the water measuring chamber liquid level pressure sensor 405, and the value of the water measuring chamber liquid level pressure sensor 405 rises. When the water fills the water measuring chamber liquid level pressure measuring channel 576 and enters the water measuring cup 202 from the water measuring cup liquid inlet and outlet 206, the rising slope of the value curve of the water measuring chamber liquid level pressure sensor 405 decreases, forming a turning point with the previous rising curve.

[0198] When the value curves of the sample chamber liquid level pressure sensor 401 and the water measuring chamber liquid level pressure sensor 405 both rise significantly and form an inflection point, close the sample chamber water supply and drainage valve 527, the water measuring chamber water supply and drainage valve 522, and the water reservoir control valve 509, open the sample chamber air intake valve 502 and the water measuring chamber air intake valve 505, and remove the sample chamber cover 100 and the water measuring chamber cover 200;

[0199] Inject a known mass m into the sample cup 102 cs1 water, and record the pressure P measured by the sample chamber liquid level pressure sensor 401 cs1 Repeat the above steps 10 times in total, and the amount of water injected each time does not exceed one tenth of the total volume of the sample cup 102. Finally, P cs1 , Pcs2 , P cs3 ,……,P cs10 , and the corresponding m cs1 、m cs2 、m cs3 ,……,m cs10 , calibrate the measuring cup 202 in the same way, and obtain P cr1 , P cr2 , P cr3 ,……,P cr10 , and the corresponding m cr1 、m cr2 、m cr3 ,……,m cr10 , using the least square method to fit the relationship curve between the mass of water added to the sample cup 102 and the value of the sample chamber liquid level pressure sensor 401 and the relationship curve between the mass of water added to the measuring cup 202 and the value of the measuring chamber liquid level pressure sensor 405;

[0200] Open the sample chamber water supply and drainage valve 527, the water measuring chamber water supply and drainage valve 522, and the water reservoir control valve 509, so that the water in the sample cup 102 passes through the sample cup liquid inlet and outlet 107, the sample chamber liquid level pressure measurement channel 582, the sample chamber connecting channel 581, the sample chamber connecting channel port 579, the sample chamber water supply and drainage valve inlet 606, the sample chamber water supply and drainage valve outlet 604, the sample chamber water supply and drainage valve connecting channel port 564, and the sample chamber water supply and drainage valve connecting channel 580 to enter the common liquid path channel 570, and the water in the measuring water cup 202 passes through the measuring water cup liquid inlet and outlet 206, the water measuring chamber liquid level pressure measurement channel 576, the water measuring chamber The water discharged from the sample cup 102 and the measuring cup 202 converges and flows into the water reservoir 300 through the common liquid channel opening 555, the water reservoir control valve inlet 592, the water reservoir control valve outlet 590, the water reservoir control valve communication channel opening 556, the water reservoir control valve communication channel 571, the water reservoir communication channel 572, and the water reservoir communication channel opening 557;

[0201] S2: Preparation before measurement: record the sample mass m s , pour the sample into the sample cup 102, and rotate and fasten the sample chamber cover 100 and the water chamber cover 200;

[0202] Record the temperature t measured by the water storage temperature sensor 302, and obtain the density ρ of water at the corresponding temperature t. The formula is known:

[0203] m=ρS s h (1)

[0204] P=ρgh (2)

[0205] in:

[0206] m is the mass of water in the sample cup 102, S s is the bottom area of ​​the sample cup 102, h is the height of the water in the sample cup 102, P is the pressure of the water in the sample cup 102, and g is the gravitational acceleration. According to formula (1) and formula (2), the relationship curve between the liquid level height of the sample cup 102 and the value of the sample chamber liquid level pressure sensor 401 is obtained, and its slope is k s ;

[0207] Similarly, the relationship curve between the liquid level height of the measuring cup 202 and the value of the liquid level pressure sensor 405 in the measuring chamber is obtained, and its slope is k r ;

[0208] S3: Vacuuming the two chambers: Open the sample chamber air extraction valve 503 and the water measuring chamber air extraction valve 506, close the sample chamber air intake valve 502, the water measuring chamber air intake valve 505, the sample chamber water supply and drainage valve 527, the water measuring chamber water supply and drainage valve 522 and the water reservoir control valve 509, and read the value P of the sample chamber liquid level pressure sensor 401 bs And the water chamber level pressure sensor 405 value P br , start the micro oil-free vacuum pump 512;

[0209] The gas in the sample cavity 109 passes through the sample cavity gas path opening 528 and sequentially enters the sample cavity gas path common channel 541, the sample cavity gas extraction valve gas extraction channel 545, the sample cavity gas extraction valve gas extraction channel outlet 532, the sample cavity gas extraction valve inlet 614, the sample cavity gas extraction valve outlet 615, the sample cavity gas extraction valve exhaust channel inlet 533 and the sample cavity gas extraction valve exhaust channel 546 in the gas-liquid guide integrated module body 500;

[0210] The gas in the water measuring chamber 208 passes through the water measuring chamber gas passage opening 540, and sequentially enters the water measuring chamber gas passage common channel 550, the water measuring chamber air extraction valve air extraction channel 552, the water measuring chamber air extraction valve air extraction channel outlet 537, the water measuring chamber air extraction valve inlet 622, the water measuring chamber air extraction valve outlet 623, the water measuring chamber air extraction valve air release channel inlet 536 and the water measuring chamber air extraction valve air release channel 551 in the gas-liquid guiding integrated module body 500;

[0211] The two air flows enter the common exhaust channel 547, and are discharged in sequence through the common exhaust channel outlet 516, the micro oil-free vacuum pump exhaust port 511, the micro oil-free vacuum pump exhaust port 626, the micro oil-free vacuum pump exhaust channel inlet 517, the micro oil-free vacuum pump exhaust channel 542, and the micro oil-free vacuum pump exhaust channel outlet 529;

[0212] When the value of the sample chamber liquid level pressure sensor 401 is less than Pbs –101000Pa and the value of the water level pressure sensor 405 in the water measuring chamber is less than P br When the pressure is –101000Pa, the sample chamber 109 and the water measuring chamber 208 reach a vacuum state, and the micro oil-free vacuum pump 512, the sample chamber exhaust valve 503 and the water measuring chamber exhaust valve 506 are closed;

[0213] S4: Liquid filling into the measuring cup: Open the water reservoir control valve 509 and the water measuring chamber water supply and drainage valve 522, so that the water in the water reservoir 300 passes through the water reservoir communication channel 572, the water reservoir control valve communication channel 571, the water reservoir control valve communication channel port 556, the water reservoir control valve outlet 590, the water reservoir control valve 509, the water reservoir control valve inlet 592, the common liquid inlet 590, and the water in the water reservoir 300. The passage opening 555, the common liquid passage 570, the water measuring chamber water supply and drainage valve communication passage 575, the water measuring chamber water supply and drainage valve communication passage opening 574, the water measuring chamber water supply and drainage valve outlet 597, the water measuring chamber water supply and drainage valve 522, the water measuring chamber water supply and drainage valve inlet 599, the water measuring chamber communication passage opening 553, the water measuring chamber communication passage 569, the water measuring chamber liquid level pressure measurement passage 576, the water measuring chamber liquid passage opening 558 and the water measuring cup liquid inlet and outlet 206 enter the water measuring cup 202;

[0214] When the water level pressure sensor 405 of the water measuring chamber measures that the water level in the water measuring cup 202 reaches the water measuring cup scale line 209, the water reservoir control valve 509 and the water measuring chamber water supply and drainage valve 522 are closed;

[0215] S5: water measuring chamber air intake: open the water measuring chamber air intake valve 505, so that the atmosphere passes through the common air intake channel inlet 514, in turn, through the common air intake channel 538, the water measuring chamber air intake valve air intake channel 548, the water measuring chamber air intake valve inlet 618, the water measuring chamber air intake valve 505, the water measuring chamber air intake valve outlet 619, the water measuring chamber air intake valve exhaust channel inlet 535, the water measuring chamber air intake valve exhaust channel 549, the water measuring chamber air path common channel 550 and the water measuring chamber air path port 540 to enter the water measuring chamber 208;

[0216] S6: Liquid entering the sample cup: When the water measuring chamber liquid level pressure sensor 405 measures that the liquid surface above the water measuring cup 202 reaches atmospheric pressure, the water measuring chamber water supply and drainage valve 522 and the sample chamber water supply and drainage valve 527 are opened, and the water in the water measuring cup 202 passes through the water measuring chamber liquid level pressure measurement channel 576, the water measuring chamber connecting channel 569, the water measuring chamber connecting channel port 553, the water measuring chamber water supply and drainage valve inlet 599, the water measuring chamber water supply and drainage valve outlet 597, the water measuring chamber water supply and drainage valve outlet 598, the water measuring chamber water supply and drainage valve outlet 59 ... The water valve communication channel opening 574, the water measuring chamber water supply and drainage valve communication channel 575, the common liquid path channel 570, the sample chamber water supply and drainage valve communication channel 580, the sample chamber water supply and drainage valve communication channel opening 564, the sample chamber water supply and drainage valve outlet 604, the sample chamber water supply and drainage valve inlet 606, the sample chamber communication channel opening 579, the sample chamber communication channel 581, the sample chamber liquid level pressure measurement channel 582, the sample chamber liquid path opening 562 and the sample cup liquid inlet and outlet 107 enter the sample cup 102;

[0217] When the liquid level reaches the sample chamber liquid inlet and outlet 107, the value of the sample chamber liquid level pressure sensor 401 reaches P s0 When the water level pressure sensor 405 of the water chamber is recorded, the value P r0 ;

[0218] When the sample chamber liquid level pressure sensor 401 measures that the water level in the sample cup 102 reaches the sample cup scale line 110, the sample chamber water supply and drainage valve 527 and the water measuring chamber water supply and drainage valve 522 are closed, and the value P of the sample chamber liquid level pressure sensor 401 is recorded. s1 And the water chamber level pressure sensor 405 value P r1 ;

[0219] S7: Sample cavity air intake: Open the sample cavity air intake valve 502, and allow the atmosphere to enter the sample cavity 109 in sequence through the common air intake channel entrance 514, the common air intake channel 538, the sample cavity air intake valve air intake channel 544, the sample cavity air intake valve entrance 610, the sample cavity air intake valve 502, the sample cavity air intake valve outlet 611, the sample cavity air intake valve exhaust channel entrance 530, the sample cavity air intake valve exhaust channel 544, the sample cavity air path common channel 541 and the sample cavity air path port 528;

[0220] S8: Returning water from the two chambers: Open the sample chamber water supply and drainage valve 527, the water measuring chamber water supply and drainage valve 522 and the water reservoir control valve 509, so that the water in the sample cup 102 and the water measuring cup 202 returns to the water reservoir 300 along the original route;

[0221] S9: Calculate the density value: Change value of the sample chamber liquid level pressure sensor 401:

[0222] ΔP s =P s1 –P s0

[0223] The slope k of the relationship curve between the liquid level height of the sample cup 102 and the value of the liquid level pressure sensor 401 in the sample chamber is s , the liquid level change value in the sample cup 102 is obtained as follows:

[0224] Δh s =k s ×ΔP s

[0225] Change value of water level pressure sensor 405 in water measuring chamber:

[0226] ΔP r =P r1 –P r0

[0227] The slope k of the relationship curve between the liquid level height of the measuring cup 202 and the value of the liquid level pressure sensor 405 in the measuring chamber is r , and the change value of the liquid level in the measuring cup 202 is obtained as follows:

[0228] Δh r =k r ×ΔP r

[0229] The bottom area S of the sample cup 102 s and the bottom area S of the measuring cup 202 r Calculate the sample volume V s for:

[0230] V s =|Δh s |×S s –|Δh r |×S r

[0231] The maximum theoretical density of the sample ρ s for:

[0232] ρ s =m s / V s .

[0233] This will be described below with reference to specific embodiments.

[0234] The embodiment of the present invention determines the maximum theoretical density of the asphalt mixture.

[0235] Weighing the asphalt mixture after aging and drying s =4000g, select sample cup with specification 1, S s =200cm 2, install the sample cup, sample chamber cover, water measuring cup and water measuring chamber cover, open the sample chamber air exhaust valve and the water measuring chamber air exhaust valve, close the sample chamber water supply and drainage valve, the water measuring chamber water supply and drainage valve, the water reservoir control valve, the sample chamber air intake valve and the water measuring chamber air intake valve, turn on the micro oil-free vacuum pump, after 60s, close the micro oil-free vacuum pump, the sample chamber air exhaust valve and the water measuring chamber air exhaust valve, open the sample chamber water supply and drainage valve, the water measuring chamber water supply and drainage valve and the water reservoir control valve.

[0236] The water fills the sample chamber liquid level pressure measurement channel and enters the sample cup. The curve of the sample chamber liquid level pressure sensor value changing with time is obtained, as shown in Fig.10 As shown; water fills the water measuring chamber liquid level pressure measurement channel, and after entering the water measuring cup, the water measuring chamber liquid level pressure sensor value change curve over time is obtained, as shown Fig.11 shown.

[0237] Record the initial value P of the sample cup liquid level pressure s0 =897Pa, close the sample chamber water supply and drainage valve, water measuring chamber water supply and drainage valve, and water reservoir control valve, open the sample chamber air inlet valve and water measuring chamber air inlet valve, and remove the sample chamber cover and water measuring chamber cover.

[0238] Add water to the sample cup and measuring cup for calibration. The data is shown in Table 2.

[0239] Table 2 Example calibration data table

[0240]

[0241] The relationship curve between the mass of water added to the sample cup and the value of the sample chamber liquid level pressure sensor is obtained by least squares fitting ( Fig.12 ) and the relationship curve between the mass of water added to the measuring cup and the value of the liquid level pressure sensor in the measuring chamber ( Fig.13 ).

[0242] After the calibration is completed, open the sample chamber water supply and drainage valve, the water measuring chamber water supply and drainage valve and the water reservoir control valve, and the water flows back to the water reservoir.

[0243] Input m s = 4000g, pour the sample into the sample cup, tighten the sample chamber cover and the water chamber cover. The water reservoir temperature sensor value t = 25 ° C, the water density ρ = 0.99705 (g·cm -3 ), and obtain the relationship curve between the sample cup liquid level height and the sample chamber liquid level pressure sensor value ( Fig.14 ), k s =0.0102(cm·Pa -1 ), the relationship curve between the liquid level height of the measuring cup and the value of the liquid level pressure sensor of the measuring chamber ( Fig.15 ), k r =0.0102(cm·Pa -1).

[0244] Open the sample chamber air extraction valve and the water measuring chamber air extraction valve, close the sample chamber air intake valve, the sample chamber water supply and drainage valve, the water measuring chamber air intake valve, the water measuring chamber water supply and drainage valve and the water reservoir control valve, and read the sample chamber liquid level pressure sensor value P bs =101896Pa, water level pressure sensor value P br =101903Pa, start the micro oil-free vacuum pump.

[0245] When the value of the sample chamber liquid level pressure sensor reaches 896Pa and the value of the water measuring chamber liquid level pressure sensor reaches 903Pa, close the micro oil-free vacuum pump, the sample chamber exhaust valve and the water measuring chamber exhaust valve.

[0246] Open the water reservoir control valve and the water supply and drainage valve of the water measuring chamber. When the value of the water measuring chamber liquid level pressure sensor reaches 2473Pa, close the water reservoir control valve and the water supply and drainage valve of the water measuring chamber.

[0247] Open the water measuring chamber air inlet valve. When the value of the water measuring chamber liquid level pressure sensor reaches 103473Pa, open the sample chamber water supply and drainage valve and the water measuring chamber water supply and drainage valve.

[0248] When the value of the sample chamber liquid level pressure sensor reaches 897Pa, record the value of the water chamber liquid level pressure sensor P r0 =103470Pa.

[0249] When the value of the sample chamber liquid level pressure sensor reaches 2465Pa, close the sample chamber water supply and drainage valve and the water measuring chamber water supply and drainage valve, and record the sample chamber liquid level pressure sensor value P s1 =2465Pa and the water level pressure sensor value P r1 =104147Pa;

[0250] Open the sample chamber air inlet valve, sample chamber water supply and drainage valve, water measuring chamber water supply and drainage valve and water reservoir control valve, and the water returns to the water reservoir along the original route. The test is completed.

[0251] Calculate the density value: Sample chamber liquid level pressure sensor change value:

[0252] ΔP s =P s1 –P s0 =2465–897=1568 (Pa)

[0253] The slope k of the comparison curve between the liquid level height in the sample chamber and the liquid level pressure in the sample chamber is s =0.0102(cm·Pa -1 ), and the change value of the sample chamber liquid level is obtained as:

[0254] Δh s =ks ×ΔP s =0.0102×1568=16.0(cm)

[0255] Change value of the water level pressure sensor in the water measuring chamber:

[0256] ΔP r =P r1 –P r0 =104147–103470=677 (Pa)

[0257] The slope k of the comparison curve between the liquid level height in the water measuring chamber and the liquid level pressure in the water measuring chamber is r =0.0102(cm·Pa -1 ), and the change value of the liquid level in the water measuring chamber is obtained as follows:

[0258] Δh r =k r ×ΔP r =0.0102×677≈6.90(cm)

[0259] Sample cup bottom area S s =200cm 2 , measure the bottom area of ​​the water cup S r =200cm 2 ,

[0260] The sample volume was measured to be:

[0261] V s =|Δh s |×S s –|Δh r |×S r =16.0×200–6.90×200=1820(cm 3 )

[0262] The maximum theoretical density of a 4000g asphalt mixture sample is:

[0263] ρ s =m s / V s =4000 / 1820=2.198(g·cm -3 ).

[0264] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A maximum theoretical density measuring instrument based on a pore integrated module, characterized in that: It includes a sample measurement module, a volume calibration module, a gas-liquid guide integrated module, a liquid level pressure sensing module and a water storage module, wherein the sample measurement module and the volume calibration module are respectively installed on the upper left and right sides of the gas-liquid guide integrated module, the water storage module is installed below the gas-liquid guide integrated module, and the liquid level pressure sensing module is embedded in the lower part of the gas-liquid guide integrated module, wherein two liquid level pressure sensors are respectively arranged vertically coaxially with the sample measurement module and the volume calibration module; The sample measurement module includes a sample chamber cover, a sample chamber cover O-ring, a sample cup and a sample chamber filter; The volume calibration module includes a water measuring chamber cover, a water measuring chamber cover O-ring and a water measuring cup; The water storage module includes a water storage tank, a water storage tank filter and a water storage tank temperature sensor; The liquid level pressure sensor module includes a sample chamber liquid level pressure sensor, a sample chamber liquid level pressure sensor flange, a water measuring chamber liquid level pressure sensor and a water measuring chamber liquid level pressure sensor flange; The gas-liquid guide integrated module includes a gas-liquid guide integrated module body, a sample chamber air inlet valve, a sample chamber air extraction valve, a water measuring chamber air inlet valve, a water measuring chamber air extraction valve, a sample chamber water supply and drainage valve, a water measuring chamber water supply and drainage valve, a water measuring chamber filter, a water reservoir control valve, a micro oil-free vacuum pump and a micro oil-free vacuum pump connection sheet metal; The cavity between the liquid inlet and outlet of the sample cup, the gas path of the sample cavity and the cavity cover of the sample cavity is the sample cavity; The cavity between the liquid inlet and outlet of the water measuring cup, the air passage of the water measuring cavity and the water measuring cavity cover is the water measuring cavity.

2. The maximum theoretical density measuring instrument based on the pore integrated module according to claim 1, characterized in that: The sample chamber cover is in the shape of a hollow cylinder, with an open lower end, a closed upper end, and a cavity in the middle. A left limit block and a right limit block of the sample chamber cover are symmetrically arranged on the outer side of the lower end of the sample chamber cover. An O-ring sealing groove of the sample chamber cover is provided on the lower end surface of the sample chamber cover, and an O-ring of the sample chamber cover is embedded in the O-ring sealing groove of the sample chamber cover. The sample cup is in the shape of a hollow cylinder, with an opening at the top, a cavity in the middle, and a closed bottom. A protruding cylinder is provided downward in the center of the bottom surface, and an external thread for connecting the sample cup is provided on the outside of the cylinder. A central hole is provided through the center of the cylinder, and the lower end opening of the central hole is the liquid inlet and outlet of the sample cup. A sample cavity filter is installed at the liquid inlet and outlet of the sample cup, and a sample cup scale line is engraved on the outside of the upper part of the sample cup; The water measuring chamber cover is in the shape of a hollow cylinder, with an opening at the lower end, a closed upper end, and a cavity in the middle. A left limit block and a right limit block of the water measuring chamber cover are symmetrically arranged on the outer side of the lower end of the water measuring chamber cover. An O-ring sealing groove for the water measuring chamber cover is provided on the lower end surface of the water measuring chamber cover, and an O-ring of the water measuring chamber cover is embedded in the O-ring sealing groove of the water measuring chamber cover. The measuring cup is in the shape of a hollow cylinder, with an open top, a cavity in the middle, and a closed bottom. A protruding cylinder is provided in the center of the lower end surface, and an external thread for connecting the measuring cup is provided on the outer side of the cylinder. A central hole is provided through the center of the cylinder, and the lower end opening of the central hole is the liquid inlet and outlet of the measuring cup. The outer side of the upper part of the measuring cup is engraved with measuring cup scale lines; The water reservoir is hollow in design, with water stored inside, and the water reservoir temperature sensor is immersed below the water surface in the water reservoir; The O-ring of the sample chamber liquid level pressure sensor is fixed in the middle groove of the sample chamber liquid level pressure sensor; A sample cavity liquid level pressure sensor flange center hole is opened in the center of the sample cavity liquid level pressure sensor flange, the periphery of the sample cavity liquid level pressure sensor flange center hole protrudes upward to form a sample cavity liquid level pressure sensor flange boss, and four sample cavity liquid level pressure sensor flange through holes are symmetrically opened on the periphery of the sample cavity liquid level pressure sensor flange boss; The O-ring of the water measuring chamber liquid level pressure sensor is fixed in the middle groove of the water measuring chamber liquid level pressure sensor; A water cavity liquid level pressure sensor flange center hole is opened at the center of the water cavity liquid level pressure sensor flange, the periphery of the water cavity liquid level pressure sensor flange center hole protrudes upward to form a water cavity liquid level pressure sensor flange boss, and four water cavity liquid level pressure sensor flange through holes are symmetrically opened at the periphery of the water cavity liquid level pressure sensor flange boss; The upper surface of the gas-liquid guide integrated module body is symmetrically provided with grooves for installing the sample measurement module and the volume calibration module. The left groove on the upper surface of the gas-liquid guide integrated module body is symmetrically provided with two notches radially outwardly from the groove, corresponding to the entrance and exit of the left limit block of the sample chamber cover and the entrance and exit of the right limit block of the sample chamber cover respectively; Below the entrance and exit of the left limit block of the sample chamber cover and the entrance and exit of the right limit block of the sample chamber cover, an annular sample chamber cover limit groove is opened radially outward along the left groove, the annular lower plane of the sample chamber cover limit groove is the sample chamber cover placement platform, a sample chamber air path opening is opened on the sample chamber cover placement platform, a sample chamber air path common channel is opened vertically downward at the sample chamber air path opening, a sample cup placement platform lower than the sample chamber cover placement platform is opened radially inward along the groove on the sample chamber cover placement platform, a sample cup connecting groove is opened in the center of the sample cup placement platform, a sample chamber liquid level pressure measurement channel is opened downward through the sample cup connecting groove, the connection between the sample cup connecting groove and the sample chamber liquid level pressure measurement channel is the sample chamber liquid path opening, the lower port of the sample chamber liquid level pressure measurement channel is the sample chamber liquid level pressure measurement channel opening, and a sample chamber liquid level pressure sensor placement groove is opened radially outward below the sample chamber liquid level pressure measurement channel opening; The groove on the right side of the upper surface of the main body of the gas-liquid guide integrated module is symmetrically opened along the radial outward direction of the groove, and two notches are respectively corresponding to the left and right limit block entrances and exits of the water measuring chamber cover, and an annular water measuring chamber cover limit groove is opened radially outward along the right groove below the left and right limit block entrances and exits of the water measuring chamber cover, and the annular lower plane of the water measuring chamber cover limit groove is a water measuring chamber cover placement platform, and a water measuring chamber air passage is opened on the water measuring chamber cover placement platform, and a water measuring chamber air passage is opened vertically downward at the water measuring chamber air passage A common channel, a water measuring cup placement platform is opened radially inwardly along the groove on the water measuring chamber cover placement platform and is lower than the water measuring chamber cover placement platform, a water measuring cup connection groove is opened in the center of the water measuring cup placement platform, a water measuring chamber liquid level pressure measurement channel is opened downwardly through the water measuring cup connection groove, a water measuring chamber liquid junction is formed at the connection point between the water measuring cup connection groove and the water measuring chamber liquid level pressure measurement channel, a lower end of the water measuring chamber liquid level pressure measurement channel is a water measuring chamber liquid level pressure measurement channel opening, and a water measuring chamber liquid level pressure sensor placement groove is opened radially outwardly below the water measuring chamber liquid level pressure measurement channel opening; A common air inlet entrance and a micro oil-free vacuum pump placement groove are provided at the front of the right side surface of the gas-liquid guide integrated module body, a common air inlet entrance is provided horizontally to the left of a common air inlet entrance, a common air extraction channel outlet and a micro oil-free vacuum pump exhaust channel entrance are provided on the left side surface of the micro oil-free vacuum pump placement groove, a common air extraction channel is provided horizontally to the left of the common air extraction channel outlet, a micro oil-free vacuum pump exhaust channel is provided horizontally to the left through the micro oil-free vacuum pump exhaust channel entrance, and a micro oil-free vacuum pump exhaust channel outlet is formed on the left side surface of the gas-liquid integrated guide module body; A sample cavity air inlet valve fixing threaded hole, a sample cavity air inlet valve air release channel entrance and a sample cavity air inlet valve air inlet channel exit are provided on the left side of the front surface of the main body of the gas-liquid guide integrated module; a sample cavity air inlet valve air release channel is provided horizontally and rearwardly at the sample cavity air inlet valve air release channel entrance; a sample cavity air inlet valve air inlet channel is provided horizontally and rearwardly at the sample cavity air inlet valve air inlet channel exit; and the sample cavity air inlet valve air inlet channel is communicated with the common air inlet channel; A sample cavity air extraction valve fixed threaded hole, a sample cavity air extraction valve air extraction channel outlet and a sample cavity air extraction valve air extraction channel inlet are correspondingly provided below the sample cavity air inlet valve fixed threaded hole, the sample cavity air inlet valve air exhaust channel inlet and the sample cavity air inlet valve air inlet channel outlet; a sample cavity air extraction valve air extraction channel is provided horizontally backward at the sample cavity air extraction valve air exhaust channel outlet; the sample cavity air inlet valve air exhaust channel and the sample cavity air extraction valve air extraction channel are both connected to the sample cavity gas path common channel; a sample cavity air extraction valve air exhaust channel is provided horizontally backward at the sample cavity air extraction valve air exhaust channel inlet; and the sample cavity air extraction valve air exhaust channel is connected to the common air exhaust channel; The right side of the front surface of the main body of the gas-liquid guide integrated module is provided with a water-measuring chamber air inlet valve fixing threaded hole, a water-measuring chamber air inlet valve air inlet channel outlet and a water-measuring chamber air inlet valve air release channel inlet, the water-measuring chamber air inlet valve air inlet channel outlet is horizontally opened backwards, the water-measuring chamber air inlet valve air inlet channel is connected with the public air inlet channel, and the water-measuring chamber air inlet valve air release channel inlet is horizontally opened backwards; A water measuring chamber air extraction valve fixed threaded hole, a water measuring chamber air extraction valve exhaust channel inlet and a water measuring chamber air extraction valve exhaust channel outlet are correspondingly provided below the water measuring chamber air inlet valve fixed threaded hole, the water measuring chamber air inlet valve air inlet channel outlet and the water measuring chamber air inlet valve exhaust channel inlet, a water measuring chamber air extraction valve exhaust channel is provided horizontally backwards from the water measuring chamber air extraction valve exhaust channel inlet, the water measuring chamber air extraction valve exhaust channel is connected with the common exhaust channel, a water measuring chamber air extraction valve exhaust channel is provided horizontally backwards from the water measuring chamber air extraction valve exhaust channel outlet, the water measuring chamber air extraction valve exhaust channel is both connected with the water measuring chamber air path common channel; The bottom of the sample cavity air intake valve is provided with a sample cavity air intake valve inlet, a sample cavity air intake valve outlet and a sample cavity air intake valve through hole, and the sample cavity air intake valve inlet and the sample cavity air intake valve outlet are provided with a sample cavity air intake valve sealing pad; The bottom of the sample cavity air extraction valve is provided with a sample cavity air extraction valve inlet, a sample cavity air extraction valve outlet and a sample cavity air extraction valve through hole, and the sample cavity air extraction valve inlet and the sample cavity air extraction valve outlet are provided with a sample cavity air extraction valve sealing pad; A water measuring chamber air intake valve inlet, a water measuring chamber air intake valve outlet and a water measuring chamber air intake valve through hole are provided at the bottom of the water measuring chamber air intake valve, and a water measuring chamber air intake valve sealing gasket is provided on the water measuring chamber air intake valve inlet and the water measuring chamber air intake valve outlet; The bottom of the water-measuring cavity air-extraction valve is provided with a water-measuring cavity air-extraction valve inlet, a water-measuring cavity air-extraction valve outlet and a water-measuring cavity air-extraction valve through hole, and a water-measuring cavity air-extraction valve sealing gasket is provided on the water-measuring cavity air-extraction valve inlet and the water-measuring cavity air-extraction valve outlet; The top of the left pagoda head of the micro oil-free vacuum pump is the micro oil-free vacuum pump suction port, and the top of the right pagoda head is the micro oil-free vacuum pump exhaust port. The micro oil-free vacuum pump suction port is equipped with a micro oil-free vacuum pump suction port O-ring; The micro oil-free vacuum pump is connected to the sheet metal. There are large through holes for the micro oil-free vacuum pump to connect to the sheet metal at the four corners of the edge, and four small through holes for the micro oil-free vacuum pump to connect to the sheet metal are symmetrically opened on both sides of the center; The rear part of the right side surface of the main body of the gas-liquid guide integrated module is provided with a water reservoir control valve fixing threaded hole, a common liquid path channel opening and a water reservoir control valve connecting channel opening, the common liquid path channel opening is provided with a common liquid path channel horizontally to the left, and the water reservoir control valve connecting channel opening is provided with a water reservoir control valve connecting channel horizontally to the left; A water reservoir connection groove is opened at the right rear of the lower surface of the main body of the gas-liquid guide integrated module, a water reservoir communication channel opening is opened above the water reservoir connection groove, a water reservoir communication channel is opened upward from the water reservoir communication channel opening, and the water reservoir communication channel is connected with the water reservoir control valve communication channel; The left side of the rear surface of the main body of the gas-liquid guide integrated module is provided with a sample cavity water supply and drainage valve fixing threaded hole, a sample cavity communication channel opening and a sample cavity water supply and drainage valve communication channel opening, a sample cavity communication channel is opened forward of the sample cavity communication channel opening, the sample cavity communication channel is connected with the sample cavity liquid level pressure measurement channel, a sample cavity water supply and drainage valve communication channel is opened forward of the sample cavity water supply and drainage valve communication channel opening, and the sample cavity water supply and drainage valve communication channel is connected with the public liquid path channel; The right side of the rear surface of the main body of the gas-liquid guide integrated module is provided with a water measuring chamber water supply and drainage valve fixing threaded hole, a water measuring chamber connecting channel opening and a water measuring chamber filter placement groove, a water measuring chamber connecting channel is opened forward of the water measuring chamber connecting channel opening, the water measuring chamber connecting channel is connected with the water measuring chamber liquid level pressure measurement channel, a water measuring chamber water supply and drainage valve connecting channel opening is opened in front of the water measuring chamber filter placement groove, a water measuring chamber water supply and drainage valve connecting channel is opened forward of the water measuring chamber water supply and drainage valve connecting channel opening, and the water measuring chamber water supply and drainage valve connecting channel is connected with the public liquid path channel; A micro oil-free vacuum pump connection sheet metal fixing threaded hole is opened on the right front of the lower surface of the gas-liquid guide integrated module body, a sample cavity liquid level pressure sensor flange fixing threaded hole is opened on the left side of the lower surface of the gas-liquid guide integrated module body, and a water-measuring cavity liquid level pressure sensor flange fixing threaded hole is opened on the right side of the lower surface of the gas-liquid guide integrated module body; The sample cavity water supply and drainage valve through holes are provided at four corners of the lower surface of the sample cavity water supply and drainage valve, the sample cavity water supply and drainage valve outlet and the sample cavity water supply and drainage valve inlet are provided at the middle of the lower surface of the sample cavity water supply and drainage valve, the sample cavity water supply and drainage valve inlet outer ring is provided with a sample cavity water supply and drainage valve inlet O-ring sealing groove, the sample cavity water supply and drainage valve outlet and the sample cavity water supply and drainage valve inlet O-ring sealing groove are provided with a sample cavity water supply and drainage valve outlet O-ring sealing groove, the sample cavity water supply and drainage valve inlet O-ring and the sample cavity water supply and drainage valve outlet O-ring are respectively placed in the sample cavity water supply and drainage valve inlet O-ring sealing groove and the sample cavity water supply and drainage valve outlet O-ring sealing groove; The four corners of the lower surface of the water-measuring cavity water-supply and drainage valve are provided with water-measuring cavity water-supply and drainage valve through holes, the middle part of the lower surface of the water-measuring cavity water-supply and drainage valve is provided with a water-measuring cavity water-supply and drainage valve outlet and a water-measuring cavity water-supply and drainage valve inlet, the outer ring of the water-measuring cavity water-supply and drainage valve inlet is provided with a water-measuring cavity water-supply and drainage valve inlet O-ring sealing groove, the water-measuring cavity water-supply and drainage valve inlet O-ring sealing groove is provided with a water-measuring cavity water-supply and drainage valve outlet O-ring sealing groove, the water-measuring cavity water-supply and drainage valve inlet O-ring and the water-measuring cavity water-supply and drainage valve outlet O-ring are respectively placed in the water-measuring cavity water-supply and drainage valve inlet O-ring sealing groove and the water-measuring cavity water-supply and drainage valve outlet O-ring sealing groove; Water reservoir control valve through holes are opened at the four corners of the lower surface of the water reservoir control valve, a water reservoir control valve outlet and a water reservoir control valve inlet are opened in the middle of the lower surface of the water reservoir control valve, the outer ring of the water reservoir control valve inlet is provided with a water reservoir control valve inlet O-ring sealing groove, the water reservoir control valve outlet and the outer ring of the water reservoir control valve inlet O-ring sealing groove are provided with a water reservoir control valve outlet O-ring sealing groove, the water reservoir control valve inlet O-ring and the water reservoir control valve outlet O-ring are respectively placed in the water reservoir control valve inlet O-ring sealing groove and the water reservoir control valve outlet O-ring sealing groove.

3. The maximum theoretical density measuring instrument based on the pore integrated module according to claim 2, characterized in that: The sample cavity filter is placed in the sample cup connection groove, and the sample cup is connected and fastened with the sample cup connection groove internal thread from above through the sample cup connection external thread until the sample cup contacts the sample cup placement platform; The measuring cup is connected and fastened from above through the measuring cup connecting external thread and the measuring cup connecting groove internal thread until the measuring cup contacts the measuring cup placement platform; The water reservoir filter screen is placed in the water reservoir connecting groove, and the water reservoir connecting groove and the external joint are sealed by threaded connection and then pressed and fixed. The water reservoir temperature sensor is placed below the liquid level in the water reservoir.

4. The maximum theoretical density measuring instrument based on the pore integrated module according to claim 2, characterized in that: The sample cavity liquid level pressure sensor is embedded and installed in the sample cavity liquid level pressure sensor placement groove, the upper end of the sample cavity liquid level pressure sensor flange boss presses the rear end of the sample cavity liquid level pressure sensor, the sample cavity liquid level pressure sensor and the sample cavity liquid level pressure measurement channel opening are fixedly sealed through the sample cavity liquid level pressure sensor O-ring, the side of the sample cavity liquid level pressure sensor flange boss cooperates with the sample cavity liquid level pressure sensor placement groove, the fastening screw is screwed into the sample cavity liquid level pressure sensor flange fixing threaded hole through the sample cavity liquid level pressure sensor flange through the sample cavity liquid level pressure sensor flange through hole, and the sample cavity liquid level pressure sensor flange is fixed on the lower surface of the gas-liquid guide integrated module body; The water measuring chamber liquid level pressure sensor is embedded and installed in the water measuring chamber liquid level pressure sensor placement groove. The upper end of the water measuring chamber liquid level pressure sensor flange boss presses the rear end of the water measuring chamber liquid level pressure sensor. The water measuring chamber liquid level pressure sensor and the water measuring chamber liquid level pressure measurement channel opening are fixed and sealed through the water measuring chamber liquid level pressure sensor O-ring. The side surface of the water measuring chamber liquid level pressure sensor flange boss cooperates with the water measuring chamber liquid level pressure sensor placement groove. The fastening screw is screwed into the water measuring chamber liquid level pressure sensor flange fixing threaded hole through the water measuring chamber liquid level pressure sensor flange through the water measuring chamber liquid level pressure sensor flange through hole, and the water measuring chamber liquid level pressure sensor flange is fixed on the lower surface of the gas-liquid guide integrated module body.

5. The maximum theoretical density measuring instrument based on the pore integrated module according to claim 2, characterized in that: The micro oil-free vacuum pump suction port passes through the micro oil-free vacuum pump suction port O-ring and is aligned with the common suction channel outlet, and the micro oil-free vacuum pump exhaust port is aligned with the micro oil-free vacuum pump exhaust channel inlet; The fastening screw is screwed into the threaded hole at the corresponding position at the bottom of the micro oil-free vacuum pump through the small through hole of the micro oil-free vacuum pump connecting sheet metal, and the fastening screw is screwed into the micro oil-free vacuum pump connecting sheet metal fixing threaded hole on the lower surface of the gas-liquid guide integrated module body through the large through hole of the micro oil-free vacuum pump connecting sheet metal. After the fastening screw is tightened, the micro oil-free vacuum pump is fixedly connected to the gas-liquid guide integrated module body, and the micro oil-free vacuum pump exhaust port is sealed with the public exhaust channel outlet.

6. The maximum theoretical density measuring instrument based on the pore integrated module according to claim 2, characterized in that: The inlet of the sample cavity air inlet valve is aligned with the outlet of the sample cavity air inlet valve inlet channel, the outlet of the sample cavity air inlet valve is aligned with the inlet of the sample cavity air inlet valve exhaust channel, the fastening screw is screwed into the fixed threaded hole of the sample cavity air inlet valve through the through hole of the sample cavity air inlet valve, after the fastening screw is tightened, the sample cavity air inlet valve forms a fixed seal with the main body of the gas-liquid guide integrated module through the sealing gasket of the sample cavity air inlet valve; The inlet of the sample cavity air extraction valve is aligned with the outlet of the sample cavity air extraction valve air extraction channel, the outlet of the sample cavity air extraction valve is aligned with the inlet of the sample cavity air extraction valve air release channel, the fastening screw is screwed into the fixed threaded hole of the sample cavity air extraction valve through the through hole of the sample cavity air extraction valve, after the fastening screw is tightened, the sample cavity air extraction valve forms a fixed seal with the main body of the gas-liquid guide integrated module through the sealing gasket of the sample cavity air extraction valve; The inlet of the water measuring chamber air intake valve is aligned with the outlet of the air intake channel of the water measuring chamber air intake valve, and the outlet of the water measuring chamber air intake valve is aligned with the inlet of the air release channel of the water measuring chamber air intake valve. The fastening screw is screwed into the fixed threaded hole of the water measuring chamber air intake valve through the through hole of the water measuring chamber air intake valve. After the fastening screw is tightened, the water measuring chamber air intake valve forms a fixed seal with the main body of the gas-liquid guide integrated module through the water measuring chamber air intake valve sealing gasket; The inlet of the water measuring chamber air pumping valve is aligned with the outlet of the water measuring chamber air pumping valve air pumping channel, and the outlet of the water measuring chamber air pumping valve is aligned with the inlet of the water measuring chamber air pumping valve air release channel. The fastening screw is screwed into the fixed threaded hole of the water measuring chamber air pumping valve through the through hole of the water measuring chamber air pumping valve. After the fastening screw is tightened, the water measuring chamber air pumping valve forms a fixed seal with the main body of the gas-liquid guide integrated module through the water measuring chamber air pumping valve sealing gasket.

7. The maximum theoretical density measuring instrument based on the pore integrated module according to claim 2, characterized in that: The inlet of the sample chamber water supply and drainage valve is aligned with the opening of the sample chamber communication channel, the outlet of the sample chamber water supply and drainage valve is aligned with the opening of the sample chamber water supply and drainage valve communication channel, the fastening screw is screwed into the fixed threaded hole of the sample chamber water supply and drainage valve through the through hole of the sample chamber water supply and drainage valve, and after the fastening screw is tightened, the sample chamber water supply and drainage valve and the main body of the gas-liquid guide integrated module form a fixed seal; The water measuring chamber filter is placed in the water measuring chamber filter placement groove, the water measuring chamber water supply and drainage valve inlet is aligned with the water measuring chamber communication channel opening, the water measuring chamber water supply and drainage valve outlet is aligned with the water measuring chamber water supply and drainage valve communication channel opening, the fastening screw is screwed into the water measuring chamber water supply and drainage valve fixing threaded hole through the water measuring chamber water supply and drainage valve through hole, after the fastening screw is tightened, the water measuring chamber water supply and drainage valve and the gas-liquid guide integrated module body form a fixed seal; The inlet of the water reservoir control valve is aligned with the opening of the common liquid channel, the outlet of the water reservoir control valve is aligned with the opening of the water reservoir control valve connecting channel, the fastening screw is screwed into the fixed threaded hole of the water reservoir control valve through the through hole of the water reservoir control valve, and after the fastening screw is tightened, the water reservoir control valve and the main body of the gas-liquid guide integrated module form a fixed seal.

8. The maximum theoretical density measuring instrument based on the pore integrated module according to claim 2, characterized in that: The sample chamber air inlet valve, sample chamber air exhaust valve, water measuring chamber air inlet valve, water measuring chamber air exhaust valve, sample chamber water supply and drainage valve, water measuring chamber water supply and drainage valve and water reservoir control valve are all seat-mounted solenoid valves, which are sealed with the smooth surface through sealing gaskets.

9. The maximum theoretical density measuring instrument based on the pore integrated module according to claim 2, characterized in that: The material of the sample chamber cover, sample cup, water measuring chamber cover, water measuring cup and the main body of the gas-liquid guide integrated module is 0.14W·m -1 ·K -1 ~0.2W·m -1 ·K -1 The thickness of the sample chamber cover and the water measuring chamber cover shall not be less than 20mm.

10. The testing method of the maximum theoretical density measuring instrument based on the pore integrated module according to claim 2, characterized in that: The steps include: S1: Sensor calibration: weigh the sample mass m s , according to the sample mass m s Select the sample cup of corresponding specifications; Place the left limit block of the sample chamber cover and the right limit block of the sample chamber cover through the left limit block entrance and the right limit block entrance of the sample chamber cover respectively, and place them on the sample chamber cover placement platform. Rotate the sample chamber cover clockwise to screw the left limit block of the sample chamber cover and the right limit block of the sample chamber cover into the limit groove of the sample chamber cover. The limit groove of the sample chamber cover presses the O-ring of the sample chamber cover between the O-ring sealing groove of the sample chamber cover and the sample chamber cover placement platform to form a seal. Pass the left limit block and the right limit block of the water measuring chamber cover through the left limit block entrance and the right limit block entrance of the water measuring chamber cover respectively, place them on the water measuring chamber cover placement platform, rotate the water measuring chamber cover clockwise, screw the left limit block and the right limit block of the water measuring chamber cover into the limit groove of the water measuring chamber cover, and the limit groove of the water measuring chamber cover presses the O-ring of the water measuring chamber cover between the O-ring sealing groove of the water measuring chamber cover and the water measuring chamber cover placement platform to form a seal; Open the sample chamber exhaust valve and the water measuring chamber exhaust valve, close the sample chamber water supply and drainage valve, the water measuring chamber water supply and drainage valve, the water reservoir control valve, the sample chamber air intake valve and the water measuring chamber air intake valve, turn on the micro oil-free vacuum pump, and evacuate the sample chamber and the water measuring chamber; After 60 seconds, turn off the micro oil-free vacuum pump, the sample chamber air extraction valve and the water measuring chamber air extraction valve, open the sample chamber water supply and drainage valve, the water measuring chamber water supply and drainage valve and the water reservoir control valve, and draw water out of the water reservoir. The water flows through the external hose, the water reservoir connecting channel, the water reservoir connecting channel, the water reservoir control valve connecting channel, the water reservoir control valve connecting channel, the water reservoir control valve outlet, the water reservoir control valve inlet, the public liquid channel outlet and the public liquid channel, and then is divided into two streams. One stream flows through the sample chamber water supply and drainage valve connecting channel, the sample chamber water supply and drainage valve connecting channel, and the water reservoir control valve connecting channel. The sample chamber liquid level pressure sensor is in contact with the sample chamber liquid level pressure sensor. The value of the sample chamber liquid level pressure sensor rises. When water fills the sample chamber liquid level pressure measurement channel and enters the sample cup from the sample cup liquid inlet and outlet, the rising slope of the sample chamber liquid level pressure sensor value curve decreases, and an inflection point is formed between the sample chamber liquid level pressure sensor value curve and the previous rising curve. This point is taken as the sample chamber liquid level pressure initial point P. s0 At the same time, another stream of water flows through the water measuring chamber water supply and drainage valve connecting channel, the water measuring chamber water supply and drainage valve connecting channel port, the water measuring chamber water supply and drainage valve outlet, the water measuring chamber water supply and drainage valve inlet, the water measuring chamber connecting channel port and the water measuring chamber connecting channel in turn, enters the water measuring chamber liquid level pressure measurement channel, reaches the water measuring chamber liquid level pressure measurement channel port, contacts the water measuring chamber liquid level pressure sensor, and the value of the water measuring chamber liquid level pressure sensor rises. When the water fills the water measuring chamber liquid level pressure measurement channel and enters the water measuring cup from the liquid inlet and outlet of the water measuring cup, the rising slope of the water measuring chamber liquid level pressure sensor value curve decreases, forming an inflection point with the previous rising curve; When the numerical curves of the sample chamber liquid level pressure sensor and the water measuring chamber liquid level pressure sensor both rise significantly and form an inflection point, close the sample chamber water supply and drainage valve, the water measuring chamber water supply and drainage valve, and the water reservoir control valve, open the sample chamber air intake valve and the water measuring chamber air intake valve, and remove the sample chamber cover and the water measuring chamber cover; Inject a known mass m into the sample cup cs1 of water, and record the pressure P measured by the sample chamber liquid level pressure sensor cs1 Repeat the above operation 10 times, and the amount of water injected each time does not exceed one tenth of the total volume of the sample cup. Finally, P cs1 , P cs2 , P cs3 ,……,P cs10 , and the corresponding m cs1 、m cs2 、m cs3 ,……,m cs10 , calibrate the measuring cup in the same way and get P cr1 , P cr2 , P cr3 ,……,P cr10 , and the corresponding m cr1 、m cr2 、m cr3 ,……,m cr10 , the relationship curve between the mass of water added to the sample cup and the value of the sample chamber liquid level pressure sensor and the relationship curve between the mass of water added to the measuring cup and the value of the water chamber liquid level pressure sensor are obtained by least squares fitting; Open the sample chamber water supply and drainage valve, the water measuring chamber water supply and drainage valve, and the water reservoir control valve, so that the water in the sample cup passes through the sample cup liquid inlet and outlet, the sample chamber liquid level pressure measurement channel, the sample chamber connecting channel, the sample chamber connecting channel port, the sample chamber water supply and drainage valve inlet, the sample chamber water supply and drainage valve outlet, the sample chamber water supply and drainage valve connecting channel port, and the sample chamber water supply and drainage valve connecting channel to enter the common liquid path channel, and the water in the measuring water cup passes through the measuring water cup liquid inlet and outlet, the water measuring chamber liquid level pressure measurement channel, the water measuring chamber connecting channel, the water measuring chamber connecting channel port, the water measuring chamber water supply and drainage valve inlet, the water measuring chamber water supply and drainage valve outlet, the water measuring chamber water supply and drainage valve connecting channel port, and the water measuring chamber water supply and drainage valve connecting channel to enter the common liquid path channel, and the water discharged from the sample cup and the measuring water cup converges and flows into the water reservoir through the common liquid path channel port, the water reservoir control valve inlet, the water reservoir control valve outlet, the water reservoir control valve connecting channel port, the water reservoir control valve connecting channel, the water reservoir connecting channel, and the water reservoir connecting channel port; S2: Preparation before measurement: record the sample mass m s , pour the sample into the sample cup, and rotate and tighten the sample chamber cover and the water chamber cover; Record the temperature t measured by the water storage tank temperature sensor, and obtain the density ρ of water at the corresponding temperature t. The known formula is: m = ρS s h (1) P = ρgh (2) in: m is the mass of water in the sample cup, S s is the bottom area of ​​the sample cup, h is the height of the water in the sample cup, P is the pressure of the water in the sample cup, and g is the gravitational acceleration. According to formula (1) and formula (2), the relationship curve between the liquid level height of the sample cup and the value of the liquid level pressure sensor in the sample chamber is obtained, and its slope is k s ; Similarly, the relationship curve between the liquid level height of the measuring cup and the value of the liquid level pressure sensor in the measuring chamber is obtained, and its slope is k r ; S3: Vacuum the two chambers: Open the sample chamber air extraction valve and the water measuring chamber air extraction valve, close the sample chamber air intake valve, the water measuring chamber air intake valve, the sample chamber water supply and drainage valve, the water measuring chamber water supply and drainage valve and the water reservoir control valve, and read the sample chamber liquid level pressure sensor value P bs And the water level pressure sensor value P br , start the micro oil-free vacuum pump; The gas in the sample cavity passes through the sample cavity gas path port and sequentially enters the sample cavity gas path common channel, the sample cavity gas extraction valve gas extraction channel, the sample cavity gas extraction valve gas extraction channel outlet, the sample cavity gas extraction valve inlet, the sample cavity gas extraction valve outlet, the sample cavity gas extraction valve exhaust channel inlet and the sample cavity gas extraction valve exhaust channel in the gas-liquid guide integrated module body; The gas in the water measuring cavity passes through the water measuring cavity gas path opening and sequentially enters the water measuring cavity gas path common channel, the water measuring cavity air pumping valve air pumping channel, the water measuring cavity air pumping valve air pumping channel outlet, the water measuring cavity air pumping valve inlet, the water measuring cavity air pumping valve outlet, the water measuring cavity air pumping valve air release channel inlet and the water measuring cavity air pumping valve air release channel in the gas-liquid guiding integrated module body; The two air flows enter the common exhaust channel, and are discharged in sequence through the common exhaust channel outlet, the micro oil-free vacuum pump exhaust port, the micro oil-free vacuum pump exhaust port, the micro oil-free vacuum pump exhaust channel inlet, the micro oil-free vacuum pump exhaust channel, and the micro oil-free vacuum pump exhaust channel outlet; When the sample chamber liquid level pressure sensor value is less than P bs -101000Pa and the water level pressure sensor value of the water chamber is less than P br When the pressure is -101000Pa, the sample chamber and the water measuring chamber reach a vacuum state, and the micro oil-free vacuum pump, the sample chamber exhaust valve and the water measuring chamber exhaust valve are closed; S4: Liquid inlet to the water measuring cup: Open the water reservoir control valve and the water measuring chamber water supply and drainage valve, so that the water in the water reservoir passes through the water reservoir connecting channel, the water reservoir control valve connecting channel, the water reservoir control valve connecting channel port, the water reservoir control valve outlet, enters the water reservoir control valve, the water reservoir control valve inlet, the common liquid path channel port, the common liquid path channel, the water measuring chamber water supply and drainage valve connecting channel, the water measuring chamber water supply and drainage valve connecting channel port, the water measuring chamber water supply and drainage valve outlet, enters the water measuring chamber water supply and drainage valve, the water measuring chamber water supply and drainage valve inlet, the water measuring chamber connecting channel port, the water measuring chamber connecting channel, the water measuring chamber liquid level pressure measurement channel, the water measuring chamber liquid path port and the water measuring cup liquid inlet and outlet, and enters the water measuring cup; When the water level pressure sensor of the water measuring chamber measures that the water level in the water measuring cup reaches the scale line of the water measuring cup, the water reservoir control valve and the water supply and drainage valve of the water measuring chamber are closed; S5: water measuring chamber air intake: open the water measuring chamber air intake valve, so that the atmosphere enters the water measuring chamber through the common air intake channel entrance, the common air intake channel, the water measuring chamber air intake valve air intake channel, the water measuring chamber air intake valve entrance, the water measuring chamber air intake valve, the water measuring chamber air intake valve outlet, the water measuring chamber air intake valve vent channel entrance, the water measuring chamber air intake valve vent channel, the water measuring chamber air path common channel and the water measuring chamber air path port; S6: liquid entering the sample cup: when the water measuring chamber liquid level pressure sensor measures that the pressure above the liquid surface of the water measuring cup reaches atmospheric pressure, the water measuring chamber water supply and drainage valve and the sample chamber water supply and drainage valve are opened, and the water in the water measuring cup passes through the water measuring chamber liquid level pressure measurement channel, the water measuring chamber connecting channel, the water measuring chamber connecting channel port, the water measuring chamber water supply and drainage valve inlet, the water measuring chamber water supply and drainage valve outlet, the water measuring chamber water supply and drainage valve connecting channel port, the water measuring chamber water supply and drainage valve connecting channel, the common liquid path channel, the sample chamber water supply and drainage valve connecting channel, the sample chamber water supply and drainage valve connecting channel port, the sample chamber water supply and drainage valve outlet, the sample chamber water supply and drainage valve inlet, the sample chamber connecting channel port, the sample chamber connecting channel, the sample chamber liquid level pressure measurement channel, the sample chamber liquid path port and the sample cup liquid inlet and outlet in sequence; When the liquid level reaches the sample chamber liquid inlet and outlet, the sample chamber liquid level pressure sensor value reaches P s0 When the water level pressure sensor value P is recorded r0 ; When the sample chamber liquid level pressure sensor measures that the water level in the sample cup reaches the sample cup scale line, close the sample chamber water supply and drainage valve and the water measuring chamber water supply and drainage valve, and record the sample chamber liquid level pressure sensor value P at this time. s1 And the water level pressure sensor value P r1 ; S7: Sample cavity air intake: Open the sample cavity air intake valve to allow the atmosphere to enter the sample cavity through the common air intake channel entrance, the common air intake channel, the sample cavity air intake valve air intake channel, the sample cavity air intake valve entrance, the sample cavity air intake valve, the sample cavity air intake valve outlet, the sample cavity air intake valve exhaust channel entrance, the sample cavity air intake valve exhaust channel, the sample cavity air path common channel and the sample cavity air path port in sequence; S8: Two-chamber water return: Open the sample chamber water supply and drainage valve, the water measuring chamber water supply and drainage valve and the water reservoir control valve to return the water in the sample cup and the water measuring cup to the water reservoir through the original route; S9: Calculate the density value: Change value of the sample chamber liquid level pressure sensor: ΔP s =P s1 –P s0 The slope k of the curve between the liquid level height of the sample cup and the value of the liquid level pressure sensor in the sample chamber is s , and the liquid level change in the sample cup is: Δh s =k s ×ΔP s Change value of the water level pressure sensor in the water measuring chamber: ΔP r =P r1 –P r0 The slope k of the curve between the liquid level height of the measuring cup and the value of the liquid level pressure sensor in the measuring chamber is r , and the change in the liquid level of the measuring cup is: Δh r =k r ×ΔP r The bottom area S of the sample cup s and the bottom area S of the measuring cup r Calculate the sample volume V s for: V s =|Δh s |×S s –|Δh r |×S r The maximum theoretical density of the sample ρ s for: r s =m s / V s 。

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