Primary standard metal container and its method of verification and use

Abstract

The application provides a first-class standard metal measuring cylinder and a method for calibrating and using the same. The first-class standard metal measuring cylinder comprises a support, a cylinder body located at the top of the support and composed of an upper cone, a cylinder and a lower cone which are in communication with each other, a liquid inlet mechanism located at the bottom of the lower cone, a constant volume mechanism located at the inclined surface of the upper cone, and a fine adjustment mechanism for fine adjustment of the volume of the cylinder body 2, wherein the fine adjustment volume includes the volume changed due to deformation of the cylinder body 2 after liquid is introduced through the liquid inlet mechanism. The first-class standard metal measuring cylinder can determine the nominal volume of the calibration medium at one time through cooperation of the constant volume mechanism and the fine adjustment mechanism, and the operation process of the staff in determining the nominal volume of the calibration medium is simplified.

Description

Technical Field

[0001] This invention relates to the field of measuring instruments, and more specifically to a first-class standard metal measuring instrument and its calibration and usage methods. Background Technology

[0002] Standard metal measuring instruments are widely used in the calibration of fuel dispensers, volumetric tubes, and flow meters for volume measurement. The objects being calibrated involve people's livelihoods, trade settlements, and many other practical applications in daily life, so their accuracy is crucial.

[0003] According to JJG2024-1989 "Verification System Block Diagram for Volumetric Measuring Instruments," a Class I metal measuring instrument standard device is used to verify Class II and lower-level standard metal measuring instruments. Currently, the Class I metal measuring instrument standard device uses the Class I standard metal measuring instrument as the main standard device, and the volume of its internal verification medium (such as circulating water) is usually used as the verification standard for other levels of standard metal measuring instruments. For example, when verifying the capacity of a Class II standard metal measuring instrument, firstly, the verification medium (e.g., a volume of 50 L) from the Class I standard metal measuring instrument is injected into the Class II standard metal measuring instrument being tested. The volume corresponding to the liquid level height H0 in the Class II standard metal measuring instrument is 50 L. Then, a certain volume of verification medium (e.g., a volume of 100 mL) is continued to be injected into the Class II standard metal measuring instrument, and the change in its liquid level height is read, thereby calculating its measuring neck graduation value V. f Finally, using the calibrated Class II standard metal measuring instruments H0 and V... f Temperature correction is applied to the volume of fuel dispensers, volumetric pipes, flow meters, and other working measuring instruments to perform calibration work.

[0004] Determining whether the calibration medium in a first-class standard metal measuring vessel reaches its nominal volume, such as 50 L, is the primary technical issue in measuring with this instrument. Typically, to ensure this, the operator's line of sight must be level with the 50 L mark on the vessel, and the operator must manually control the addition or removal of liquid. Specifically, if the liquid level is above the 50 L mark, the discharge valve must be manually operated to release excess calibration medium and adjust the level down to the 50 L mark; if the liquid level is below the 50 L mark, the inlet valve must be manually operated to add calibration medium and adjust the level back to the 50 L mark.

[0005] Because first-class standard metal measuring instruments require high accuracy, the JJG259-2005 "Standard Metal Measuring Instruments" verification procedure stipulates that their maximum permissible error is ±0.005%. This often leads to operators frequently controlling the inflow and outflow of liquid in these instruments to determine the nominal volume of the verification medium, resulting in a cumbersome operating procedure. Therefore, there is an urgent need for a first-class standard metal measuring instrument that can quickly determine the nominal volume of the verification medium. Summary of the Invention

[0006] The present invention aims to provide a first-class standard metal measuring instrument and its calibration and usage methods, which can solve the above-mentioned technical problems.

[0007] According to one aspect of the present invention, a first-class standard metal measuring instrument is provided, comprising: a support 1; a measuring instrument body 2 located at the top of the support 1 and composed of an upper cone, a cylindrical body and a lower cone that are in communication with each other; a liquid inlet mechanism located at the bottom of the lower cone; a volume-fixing mechanism located on the inclined surface of the upper cone; and a fine-tuning mechanism for fine-tuning the volume of the measuring instrument body 2, wherein the fine-tuned volume includes the volume of the measuring instrument body 2 changed due to deformation after liquid is introduced through the liquid inlet mechanism.

[0008] Preferably, the volume-regulating mechanism includes: a volume-regulating tube 5, the inner surface of which is covered with an elastic rubber layer; the volume-regulating tube 5 further includes: a lower tube 51 with a constant cross-sectional area, connected to the inclined surface; and an upper tube 52 with a variable cross-sectional area, disposed at the top of the lower tube 51; and a control terminal for controlling the upper tube 52 to be in a first state or a second state and the liquid inlet speed of the liquid inlet mechanism according to the liquid level height of the first-class standard metal volumetric instrument, wherein: when the upper tube 52 is in the first state, the cross-sectional area of ​​the upper tube 52 is equal to the cross-sectional area of ​​the lower tube 51; when the upper tube 52 is in the second state, the cross-sectional area of ​​the upper tube 52 is greater than the cross-sectional area of ​​the lower tube 51.

[0009] Preferably, when the liquid level in the first-class standard metal measuring instrument is lower than the first liquid level sensor 92, the control terminal controls the upper tube body 52 to be in the second state and controls the liquid inlet mechanism to perform rapid liquid inlet at more than 3 times the rated speed; when the liquid level in the first-class standard metal measuring instrument is between the first liquid level sensor 92 and the second liquid level sensor 91, the control terminal controls the upper tube body 52 to be in the second state and controls the liquid inlet mechanism to perform medium-speed liquid inlet at the rated speed; when the liquid level in the first-class standard metal measuring instrument reaches the second liquid level sensor 91, the control terminal controls the upper tube body 52 to be in the first state and controls the liquid inlet mechanism to perform slow liquid inlet at less than 0.2 times the rated speed, and after a delay of 5 seconds, the control terminal controls the upper tube body 52 to be in the first state and controls the liquid inlet mechanism to stop liquid inlet.

[0010] Preferably, the measuring instrument body 2 further includes: a first temperature sensor 6, located on the outer surface of the splash guard 8 of the measuring instrument body 2, for monitoring the ambient temperature of the measuring instrument body 2; and a second temperature sensor 3, located inside the measuring instrument body 2, for monitoring the liquid temperature of the calibration medium inside the measuring instrument body 2. The control terminal judges the measurement results of the first temperature sensor 6 and the second temperature sensor 3. If the calibration requirements are not met, the control terminal sends a command to the electric three-way valve 12 to close the water inlet channel, stopping the calibration work, and displays the unmet requirement on the control terminal. The calibration requirements are: using a first-class standard... When calibrating a Class II standard metal measuring instrument, the ambient temperature should be between 15℃ and 25℃, and the difference between the ambient temperature and the liquid temperature should not exceed 5℃. Alternatively, when calibrating a Class III standard metal measuring instrument using a Class I standard metal measuring instrument, the ambient temperature should be between 10℃ and 30℃, and the difference between the ambient temperature and the liquid temperature should not exceed 5℃. When the control terminal sends a command to the electric three-way valve 12 to open the drain channel and inject water into the Class II or Class III standard metal measuring instrument, the control terminal automatically records the measurement result of the second temperature sensor 3 and uses it as the temperature value of the calibration medium for data processing of the calibration result: when the liquid temperature is t℃, the volume V of the calibration medium is... t for: In the formula: t is the temperature of the liquid, and β is the volumetric expansion coefficient of the first-class standard metal measuring instrument. This is the nominal volume of the first-class standard metal measuring instrument at 20°C.

[0011] Preferably, the upper tube 52 includes: a plurality of arc members 521 with the same curvature, each of the plurality of arc members 521 being independent of each other, each having a gravity member 53 at its top, and each having a rotating member 54 at its bottom connected to the lower tube 51; and a telescopic ring 55 with a variable cross-sectional area, composed of a plurality of blades 551 respectively fixedly connected to the plurality of arc members 521, the plurality of blades 551 being connected by a plurality of connecting mechanisms, wherein: the plurality of connecting mechanisms include adjusting holes 553 respectively disposed on the plurality of blades 551; and a rotation controlled by the control terminal. Adjusting element 552; the adjusting holes 553 of adjacent blades among the plurality of blades 551 overlap and are connected to the adjusting element 552 through snap teeth; the telescopic ring 55 also drives the upper tube body 52 to a first state or a second state according to the rotation of the adjusting element 552, wherein: when the upper tube body 52 is in the first state, the cross-sectional area formed by the aggregation of the plurality of arc elements 521 is equal to the cross-sectional area of ​​the lower tube body 51; when the upper tube body 52 is in the second state, the cross-sectional area formed by the dispersion of the plurality of arc elements 521 is greater than the cross-sectional area of ​​the lower tube body 51.

[0012] Preferably, the fine-tuning mechanism 11 includes: a fine-tuning hole communicating with the measuring instrument body 2, and the fine-tuning hole having a first annular groove at one end away from the measuring instrument body 2; an elastic component including a plurality of elastic elements embedded in the first annular groove; a fine-tuning member 111 adapted to the fine-tuning hole, and the fine-tuning member 111 having a plurality of second annular grooves with the same spacing and adapted to the first annular groove; an adjusting handwheel 113 for rotating to drive the fine-tuning member (111) to move inward or outward; and a fixing pin 114 for fixing the positioning of the adjusting handwheel 113.

[0013] According to another aspect of the present invention, a method for calibrating a first-class standard metal volumetric instrument is provided, comprising: determining the original weight of the first-class standard metal volumetric instrument; injecting a calibration medium of a specific density into the volumetric instrument body 2 through a liquid inlet mechanism until the calibration medium is discharged by a volume-fixing mechanism and the injection is stopped; fine-tuning the volume of the volumetric instrument body 2 such that the difference between the actual weight of the first-class standard metal volumetric instrument and the original weight is equal to the product of the specific density and the calibration volume of the first-class standard metal volumetric instrument, wherein the fine-tuned volume includes the volume of the volumetric instrument body 2 changed due to deformation after liquid is injected through the liquid inlet mechanism.

[0014] According to another aspect of the present invention, a method for using a first-class standard metal measuring instrument is provided, comprising: keeping the position of the fine-tuning mechanism unchanged; injecting a calibration medium of a specific density into the measuring instrument body 2 through the liquid inlet mechanism until the calibration medium is discharged by the volume-fixing mechanism and then stopping the injection; injecting the calibration medium in the first-class standard metal measuring instrument into other measuring instruments as the basis for the capacity calibration of the other measuring instruments.

[0015] Preferably, the test medium is introduced into the upper tube 52 through the lower tube 51 of the constant volume tube 5 until the test medium is discharged from the upper tube 52; the upper tube 52 is controlled to be in the first state or the second state and the liquid inlet speed of the liquid inlet mechanism is controlled according to the liquid level height of the first-class standard metal volumetric instrument.

[0016] Preferably, the control terminal controls the telescopic ring 55, thereby driving the upper tube 52, composed of multiple arc elements 521, to be in a first state or a second state. Specifically: when the first-class standard metal measuring instrument has completed liquid filling, the upper tube 52 is in the first state, and the cross-sectional area formed by the aggregation of the multiple arc elements 521 is equal to the cross-sectional area of ​​the lower tube 51; when the first-class standard metal measuring instrument is filling with liquid and the liquid level is lower than the second liquid level sensor 91, the upper tube 52 is in the second state, and the cross-sectional area formed by the dispersion of the multiple arc elements 521 is greater than the cross-sectional area of ​​the lower tube 51.

[0017] In traditional first-class standard metal measuring instruments, operators often need to frequently control the inflow and outflow of liquid to determine the nominal volume of the test medium, making the operation process cumbersome. This invention provides a first-class standard metal measuring instrument, its calibration method, and its usage method. Its volume-fixing mechanism and fine-tuning mechanism work together to allow the first-class standard metal measuring instrument to determine the nominal volume of the test medium in a single operation, simplifying the operator's process for determining the nominal volume of the test medium. Attached Figure Description

[0018] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention. In the drawings:

[0019] Figure 1 A schematic diagram of a first-class standard metal measuring instrument according to an embodiment of the present invention is shown;

[0020] Figure 2 A schematic diagram of the liquid level change at port 5 of the constant volume tube according to an embodiment of the present invention is shown;

[0021] Figure 3 A schematic diagram of the liquid surface microstructure at port 5 of the constant volume tube according to an embodiment of the present invention is shown;

[0022] Figure 4 A schematic diagram of the liquid surface tension at port 5 of the constant volume tube according to an embodiment of the present invention is shown;

[0023] Figure 5 A schematic diagram of surface tension analysis at port 5 of the constant volume tube according to an embodiment of the present invention is shown;

[0024] Figure 6 A schematic diagram of the liquid surface force analysis at port 5 of the constant volume tube according to an embodiment of the present invention is shown;

[0025] Figure 7 A schematic diagram of the upper tube 52 in a first state according to an embodiment of the present invention is shown;

[0026] Figure 8 A schematic diagram of the upper tube 52 in a second state according to an embodiment of the present invention is shown;

[0027] Figure 9 A schematic diagram of the telescopic ring 55 in a first state according to an embodiment of the present invention is shown;

[0028] Figure 10 A schematic diagram showing the telescopic ring 55 in a second state according to an embodiment of the present invention is shown.

[0029] Figure 11A side view of a fine-tuning device according to another embodiment of the present invention is shown;

[0030] Figure 12 A schematic diagram of the fixing of a fine-tuning device according to another embodiment of the present invention is shown;

[0031] Figure 13 A flowchart illustrating a method for verifying a first-class standard metal measuring instrument according to an embodiment of the present invention is shown; and

[0032] Figure 14 A flowchart illustrating the method of using a first-class standard metal measuring instrument according to an embodiment of the present invention is shown. Detailed Implementation

[0033] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0034] Reference will now be made in detail to various embodiments of the invention, examples of which are shown in the accompanying drawings and described below. For ease of interpretation and precise definition in the appended claims, the terms “upper,” “lower,” “inner,” and “outer” are used to describe features with reference to their location in the exemplary embodiments shown in the figures.

[0035] Figure 1 A schematic diagram of a first-class standard metal measuring instrument according to an embodiment of the present invention is shown.

[0036] like Figure 1 As shown, according to an embodiment of the present invention, the first-class standard metal measuring instrument includes: a support 1; a measuring instrument body 2, located at the top of the support 1, and composed of an upper cone, a cylindrical body and a lower cone that are interconnected; a liquid inlet mechanism located at the bottom of the lower cone; a volume-fixing mechanism located on the inclined surface of the upper cone; and a fine-tuning mechanism for fine-tuning the volume of the measuring instrument body 2, wherein the fine-tuned volume includes the volume of the measuring instrument body 2 changed due to deformation after liquid is introduced through the liquid inlet mechanism.

[0037] The determination of the nominal volume of the calibration medium in traditional first-class standard metal measuring instruments relies primarily on frequent manual addition or removal of liquid by operators to reach the nominal volume, making the operation process cumbersome. Furthermore, it mainly depends on visually observing whether the liquid level matches the graduation mark on the measuring neck of the instrument, which inevitably introduces significant reading errors, thus affecting the nominal volume of the calibration medium. This invention provides a first-class standard metal measuring instrument with an added volume-fixing mechanism and a fine-tuning mechanism. The volume-fixing mechanism allows for the one-time determination of the nominal volume of the calibration medium when using the first-class standard metal measuring instrument. The fine-tuning mechanism is mainly used to adjust the volume of the measuring instrument body 2 to compensate for volume errors caused by manufacturing defects or deformation due to the entry of the calibration medium during calibration, thereby ensuring that the volume of the calibration medium is the nominal volume. Furthermore, since the volume error generated during the manufacturing of first-class standard metal measuring instruments is relatively small and can be ignored, the volume adjusted by the fine-tuning mechanism corresponds to the volume change of the main body 2 of the measuring instrument due to deformation after liquid is introduced through the liquid inlet mechanism. The advantage of doing so is that it simplifies the operation process for staff to determine the nominal volume.

[0038] According to an embodiment of the present invention, the first-class standard metal measuring instrument further includes multiple vent holes 7, a splash guard 8, and a measuring neck 10, which are disposed at the top of the upper cone to facilitate liquid filling. Further, the liquid filling mechanism includes an electric three-way valve 12 and a control terminal for controlling the liquid filling speed of the calibration medium; a level 4 is disposed on the cylindrical body for monitoring whether the first-class standard metal measuring instrument is tilted during use; if tilting occurs, it is adjusted using a leveling screw 14; the first-class standard metal measuring instrument also includes a liquid discharge mechanism disposed at the bottom of the lower cone, which further includes an electric three-way valve 12 and a control terminal for remotely controlling the liquid discharge of the first-class standard metal measuring instrument.

[0039] According to an embodiment of the present invention, the volume-regulating mechanism includes: a volume-regulating tube 5, the inner surface of which is covered with an elastic rubber layer; the volume-regulating tube 5 further includes a lower tube body 51 with a constant cross-sectional area, communicating with the inclined surface; and an upper tube body 52 with a variable cross-sectional area, disposed at the top of the lower tube body 51; and a control terminal for controlling the upper tube body 52 to be in a first state or a second state and the liquid inlet speed of the liquid inlet mechanism according to the liquid level height of the first-class standard metal volumetric instrument, wherein: when the upper tube body 52 is in the first state, the cross-sectional area of ​​the upper tube body 52 is equal to the cross-sectional area of ​​the lower tube body 51; when the upper tube body 52 is in the second state, the cross-sectional area of ​​the upper tube body 52 is greater than the cross-sectional area of ​​the lower tube body 51.

[0040] Because the constant-volume tube 5 of the first-class standard metal measuring instrument is relatively thin, gas resistance during the entry of the test medium can cause difficulties in the liquid inlet mechanism; during the discharge of the test medium, its discharge speed is also relatively slow, reducing the efficiency of determining the nominal volume of the test medium. This invention provides a first-class standard metal measuring instrument with an added constant-volume tube 5 made of stainless steel. This constant-volume tube 5 mainly utilizes the principle of communicating vessels to ensure that the liquid level of the test medium in the measuring neck 10 of the first-class standard metal measuring instrument is level with the liquid level of the test medium in the constant-volume tube 5. When the test medium flows out from the top of the constant-volume tube 5, the volume of the test medium reaches the nominal volume. Even if liquid continues to be added, excess test medium will still flow out, ensuring the accuracy of the nominal volume of the test medium. Furthermore, the constant-volume tube 5 is divided into a lower tube body 51 with a constant cross-sectional area and an upper tube body 52 with a variable cross-sectional area. During the entry of the test medium, the upper tube 52 is in a second state, where its cross-sectional area can increase to reduce gas resistance. Similarly, during the discharge of the test medium, the upper tube 52 can also be in a second state, with an increased cross-sectional area, accelerating the discharge speed. Furthermore, when the test medium flows out from the top of the constant volume tube 5, the upper tube 52 is in a first state, with its cross-sectional area equal to that of the lower tube 51. The elastic rubber layer prevents leakage of the test medium, ensuring the accuracy of determining the nominal volume of the test medium. Moreover, this first-class standard metal measuring instrument also includes a control terminal that controls whether the upper tube 52 is in the first or second state and the liquid inlet speed of the liquid inlet mechanism based on the liquid level height of the instrument. This approach ensures both the accuracy of determining the nominal volume of the test medium and improves the efficiency of this determination.

[0041] Taking circulating water as an example, when the second level sensor 91 and the first level sensor 92 detect that the circulating water has reached the preset level, they send a signal to the electric three-way valve 12 to close the inlet, and then the electric three-way valve immediately closes. According to the principle of communicating vessels, the liquid level in the measuring neck 10 will be consistent with the liquid level in the constant volume tube 5. Under the combined action of the surface tension of the circulating water, gravity, and the potential energy of the liquid surface in the measuring neck, the liquid level in the constant volume tube 5 is in a stable state. At this time, the liquid level in the constant volume tube 5 only changes within the range of 1 drop of circulating water. Figure 2 As shown, when there is more than one water droplet, the water droplet will flow out under the combined action of surface tension and gravity. The effective volume of a first-class standard metal measuring instrument is the actual volume between the height of the electric three-way valve 12 and the constant volume tube 5, such as 50L.

[0042] like Figure 3As shown, due to the different intermolecular distances between liquids and gases, the attractive and repulsive forces between their molecules are not equal. The intermolecular forces on the liquid surface layer are particularly pronounced, resulting in surface tension. This surface tension causes the liquid surface to tend to contract, forming a convex liquid surface at the opening of the constant-volume tube 5. A schematic diagram of its surface tension is shown below. Figure 4 As shown. Figure 5 As shown, for an imaginary line element ΔL on the liquid surface, the magnitude of the surface tension ΔF on the left and right sides should be proportional to the length ΔL of the line element, i.e., ΔF = γΔL. When the line element ΔL on the liquid surface increases, the surface tension ΔF increases, where the proportionality coefficient γ is the surface tension coefficient of the liquid.

[0043] Based on the above principles, such as Figure 6 As shown, when the cross-sectional area of ​​the water droplet is smaller than the cross-sectional area of ​​the opening of the constant-volume tube 5, the sum of its surface tension and its gravity equals the supporting force. At this time, the surface tension keeps the water droplet in an arc shape, and the supporting force provided by the constant-volume tube is balanced with gravity. When the cross-sectional area of ​​the water droplet is equal to the cross-sectional area of ​​the opening, the surface tension keeps the water droplet in an arc shape, the supporting force reaches its maximum, and it is balanced with gravity. When the cross-sectional area of ​​the water droplet is larger than the cross-sectional area of ​​the opening, the water droplet is on the verge of collapse. The supporting force can only support the water droplet above the tube. The water droplet exceeding the tube is bound by the surface tension. At this time, gravity, supporting force, and surface tension are about to become unbalanced. If a small amount of circulating water is added on top of this water droplet, its liquid surface will bulge outward. The surface tension cannot provide the gravity of the water droplet exceeding the tube, breaking the balance of forces, and the water droplet collapses and flows out. Therefore, the liquid level change in the constant-volume tube 5 only varies within the range of 1 drop of water.

[0044] Measurements showed that the mass of one drop of water is less than 50 mg, and its volume is less than 0.05 mL. The smaller the diameter of the volumetric tube, the smaller the water droplet at the tube opening. For a 50 L volumetric instrument, the error is within ±0.0001%; ​​for a 20 L volumetric instrument, the error is within ±0.00025%; for a 10 L volumetric instrument, the error is within ±0.0005%. Even for the smallest 1 L volumetric instrument, using a smaller diameter volumetric tube results in a smaller water droplet volume, while still ensuring an error within ±0.0005%. These errors are far less than the maximum permissible error value (±0.005%) specified in the verification procedure of JJG 259 "Standard Metal Volumetric Instruments".

[0045] Those skilled in the art should know that setting the volumetric tube 5 as cylindrical is only one example of this solution. In practical applications, technicians can set the volumetric tube 5 of different shapes that conform to the principle of communicating vessels according to different specifications and different uses of measuring instruments.

[0046] According to an embodiment of the present invention, when the liquid level of the first-class standard metal measuring instrument is lower than the first liquid level sensor 92, the control terminal controls the upper tube body 52 to be in the second state and controls the liquid inlet mechanism to perform rapid liquid inlet at more than 3 times the rated speed; when the liquid level of the first-class standard metal measuring instrument is between the first liquid level sensor 92 and the second liquid level sensor 91, the control terminal controls the upper tube body 52 to be in the second state and controls the liquid inlet mechanism to perform medium-speed liquid inlet at the rated speed; when the liquid level of the first-class standard metal measuring instrument reaches the second liquid level sensor 91, the control terminal controls the upper tube body 52 to be in the first state and controls the liquid inlet mechanism to perform slow liquid inlet at less than 0.2 times the rated speed; after a delay of 5 seconds, the control terminal controls the upper tube body 52 to be in the first state and controls the liquid inlet mechanism to stop liquid inlet.

[0047] During the process of the test medium entering the constant volume tube 5, if the liquid level is low and the inflow rate of the test medium is slow, the efficiency of determining the nominal volume of the test medium will be reduced; if the liquid level is high and the inflow rate of the test medium is fast, too much test medium will be discharged, resulting in waste. This invention provides a first-class standard metal volumetric instrument, which can control the state of the upper tube 52 and whether and how much liquid is being introduced by the inflow mechanism by detecting the liquid level using the second liquid level sensor 91 and the first liquid level sensor 92. The advantage of this design is that it improves the efficiency of determining the nominal volume of the test medium while effectively preventing waste of the test medium.

[0048] Specifically, two liquid level sensors 9 are installed at appropriate heights on the metering neck 10. When water needs to be added to the first-class standard metal measuring vessel, the control terminal sends a command to the electric three-way valve 12 to open the water inlet channel. At this time, the electric three-way valve 12 controls the water inlet channel to be fully opened, and the liquid is added rapidly at more than three times the rated speed. When the liquid level reaches the position of the first liquid level sensor 92, the first liquid level sensor 92 sends a command to the electric three-way valve 12 to close the water inlet channel through the control terminal. At this time, the electric three-way valve 12 closes the water inlet channel by 50% and adds liquid at a medium speed at the rated speed. When the liquid level reaches the position of the second liquid level sensor 91, the second liquid level sensor 91 sends a command to the electric three-way valve 12 to close the water inlet channel through the control terminal. At this time, the electric three-way valve 12 closes the water inlet channel by 90% and adds liquid slowly at less than 0.2 times the rated speed. After a 5-second delay after the liquid level reaches the position of the second liquid level sensor 91, the control terminal controls the electric three-way valve 12 to close, stopping the liquid addition. As can be seen, the present invention controls the water injection speed by using the second liquid level sensor 91 and the first liquid level sensor 92, thereby avoiding large overshoot when the electric three-way valve 12 is closed. This improves the efficiency of staff in determining the nominal volume of the test medium and effectively prevents the waste of the test medium.

[0049] Those skilled in the art should know that the above-described method of controlling the state of the upper tube 52 and whether the liquid inlet mechanism is feeding liquid and the feeding speed by detecting the liquid level height through the second liquid level sensor 91 and the first liquid level sensor 92 is only an example of this solution. In practical applications, technicians can flexibly adjust the above proportions according to different types and capacities of measuring instruments.

[0050] According to an embodiment of the present invention, the measuring instrument body 2 further includes: a first temperature sensor 6 located on the outer surface of the splash guard 8 of the measuring instrument body 2, used to monitor the ambient temperature of the measuring instrument body 2; and a second temperature sensor 3 located inside the measuring instrument body 2, used to monitor the liquid temperature of the calibration medium inside the measuring instrument body 2. The control terminal judges the measurement results of the first temperature sensor 6 and the second temperature sensor 3. If the calibration requirements are not met, the control terminal sends a command to the electric three-way valve 12 to close the water inlet channel, stopping the calibration work, and displays the unmet requirement on the control terminal. The calibration requirements are: using... When calibrating a Class II standard metal measuring instrument using a Class I standard metal measuring instrument, the ambient temperature should be between 15℃ and 25℃, and the difference between the ambient temperature and the liquid temperature should not exceed 5℃. Alternatively, when calibrating a Class III standard metal measuring instrument using a Class I standard metal measuring instrument, the ambient temperature should be between 10℃ and 30℃, and the difference between the ambient temperature and the liquid temperature should not exceed 5℃. When the control terminal sends a command to the electric three-way valve 12 to open the drain channel and inject water into the Class II or Class III standard metal measuring instrument, the control terminal automatically records the measurement result of the second temperature sensor 3 and uses it as the temperature value of the calibration medium for data processing of the calibration result: when the liquid temperature is t℃, the volume V of the calibration medium is... t for: In the formula: t is the temperature of the liquid, and β is the volumetric expansion coefficient of the first-class standard metal measuring instrument. This is the nominal volume of the first-class standard metal measuring instrument at 20°C.

[0051] During the process of the calibration medium entering the second- or third-class standard metal measuring vessel, temperature differences will cause the calibration medium to have a certain coefficient of expansion, resulting in volume errors during the calibration process and reducing the accuracy of calibrating the second- or third-class standard metal measuring vessels. In this embodiment, by monitoring the ambient temperature of the measuring vessel body 2 and the liquid temperature of the calibration medium, it is determined whether the first-class standard metal measuring vessel meets the calibration requirements, whether the calibration work should be carried out or stopped, and the actual volume of the first-class standard metal measuring vessel at t ℃ is calculated. The advantage of this is that it reduces the volume errors caused by the calibration medium during the calibration process.

[0052] Figure 7-8 A schematic diagram showing the upper tube 52 in a first state and a second state according to an embodiment of the present invention is provided. Figure 9-10 A schematic diagram showing the telescopic ring 55 in a first state and a second state according to an embodiment of the present invention is shown.

[0053] like Figure 7-10As shown, according to an embodiment of the present invention, the upper tube 52 includes: a plurality of arc members 521 with the same curvature, each of the plurality of arc members 521 being independent of each other, each having a gravity member 53 at its top and each having a rotating member 54 at its bottom connected to the lower tube 51; and a telescopic ring 55 with a variable cross-sectional area, composed of a plurality of blades 551 respectively fixedly connected to the plurality of arc members 521, the plurality of blades 551 being connected by a plurality of connecting mechanisms, wherein: the plurality of connecting mechanisms include adjusting holes 553 respectively disposed on the plurality of blades 551; and a control terminal 15 An adjusting member 552 controls rotation; the adjusting holes 553 of adjacent blades among the plurality of blades 551 overlap and are connected to the adjusting member 552 through snap teeth; the telescopic ring 55 also drives the upper tube body 52 to a first state or a second state according to the rotation of the adjusting member 552, wherein: when the upper tube body 52 is in the first state, the cross-sectional area formed by the aggregation of the plurality of arc members 521 is equal to the cross-sectional area of ​​the lower tube body 51; when the upper tube body 52 is in the second state, the cross-sectional area formed by the dispersion of the plurality of arc members 521 is greater than the cross-sectional area of ​​the lower tube body 51.

[0054] To enable the upper tube 52 to automatically expand its cross-sectional area under conditions of high gas resistance and automatically shrink its cross-sectional area under conditions of low gas resistance, this invention provides a first-class standard metal measuring instrument. The upper tube 52 of this first-class standard metal measuring instrument is composed of multiple arc members 521 with the same cross-section and curvature. Furthermore, the sum of the curvatures of the multiple arc members 521 is exactly 360°, and the combination of the multiple arc members 521 forms the upper tube 52. Further, the control terminal can control the telescopic ring 55 to drive the multiple arc members 521 to expand or shrink their cross-sectional area according to different conditions.

[0055] The state of reducing the cross-sectional area is called the first state. In the first state, the control terminal controls the adjusting component 552 to rotate counterclockwise. The locking teeth on the adjusting component 552 engage with the locking teeth on the inner wall of the adjusting hole 553 and displace, thereby driving the overlapping blades 551 to move with a smaller cross-sectional area. Correspondingly, the telescopic ring 55 contracts, and multiple arc components 521 converge, with their cross-sectional area equal to the cross-sectional area of ​​the lower pipe body 51. The vertical cross-section is rectangular. This shape is used to determine the nominal volume of the test medium when the gas resistance is low. The state of expanding the cross-sectional area is called the second state. In the second state, the control terminal controls the adjusting component 552 to rotate clockwise. The teeth on the adjusting component 552 mesh with the teeth on the inner wall of the adjusting hole 553 and displace, thereby driving the overlapping blades 551 to move with an increased cross-sectional area. Correspondingly, the telescopic ring 55 expands. Due to the gravity component 53 at the top, the multiple arc components 521 are subjected to gravity and the tension of the telescopic ring 55, and are then dispersed by the rotating component 54. Their cross-sectional area is larger than that of the lower tube body 51, and the vertical cross-section is an inverted isosceles trapezoid. This shape is used to reduce gas resistance when there is high gas resistance. The advantage of this setting is that the first and second states of the upper tube body 52 can be set according to different specific needs. On the one hand, it improves the efficiency of determining the nominal volume of the test medium, and on the other hand, it ensures the accuracy of determining the nominal volume of the test medium.

[0056] Those skilled in the art should understand that designing the upper tube 52 and the lower tube 51 with the same cross-sectional area in a first state and a different cross-sectional area in a second state is merely an example of this solution. Workers can design the ratio between their cross-sectional areas and their respective states according to specific needs. Furthermore, technicians can flexibly choose objects of different shapes to replace multiple arc-shaped components 521, as long as the above functions can be achieved, they are all within the protection scope of this invention.

[0057] like Figure 11-12 As shown, according to an embodiment of the present invention, the fine-tuning mechanism 11 includes: a fine-tuning hole communicating with the measuring instrument body 2, and the fine-tuning hole having a first annular groove at one end away from the measuring instrument body 2; an elastic component including a plurality of elastic elements embedded in the first annular groove; a fine-tuning member 111 adapted to the fine-tuning hole, and the fine-tuning member 111 having a plurality of second annular grooves with the same spacing and adapted to the first annular groove; an adjusting handwheel 113 for rotating to drive the fine-tuning member 111 to move inward or outward; and a fixing pin 114 for fixing the positioning of the adjusting handwheel 113.

[0058] Because the volume of the main body 2 of a first-class standard metal measuring instrument often exhibits errors during manufacturing and use, it affects the accuracy of determining the nominal volume of the calibration medium. This invention provides a first-class standard metal measuring instrument with a specially designed fine-tuning device, including a fine-tuning hole and a matching fine-tuning element 111. When fine-tuning is not required, the adjusting handwheel 113 is fixed by a fixing pin 114, and the sealing ring 112 prevents leakage of the calibration medium. When fine-tuning is required, the fine-tuning element 111 is moved inward or outward. Due to the smooth surface of the first annular groove and the multiple elastic elements at the bottom, the fine-tuning element 111 can be displaced and engaged within the fine-tuning hole. Furthermore, multiple first annular grooves are arranged within multiple equally spaced second annular grooves. This spacing can be set according to the specific needs of the operator, ensuring the accuracy of the displacement distance of the fine-tuning element 111, thereby ensuring the accuracy of precisely adjusting the volume of the main body 2 of the measuring instrument. The advantage of doing this is that by precisely adjusting the volume of the main body 2 of the measuring instrument, the accuracy of determining the nominal volume of the calibration medium is improved.

[0059] The fine-tuning mechanism 11 is mainly used in the calibration of first-class standard metal measuring instruments. When the nominal volume of the measuring instrument does not meet the requirements of the calibration procedure of JJG259 "Standard Metal Measuring Instruments", the fine-tuning mechanism 11 adjusts its nominal volume to the range specified in the procedure. That is, by adjusting the fine-tuning mechanism 11, the volume error generated during the manufacturing and use of the first-class standard metal measuring instrument, as well as the volume error caused by deformation due to the entry of the calibration medium into the measuring instrument body 2, is eliminated, thus ensuring that the volume of the calibration medium is the nominal volume. After the calibration is passed, the fine-tuning mechanism 11 will fix the position of its adjusting handwheel 113 by the fixing pin 114. During the use of the measuring instrument, the fine-tuning mechanism 11 will not make any further adjustments, thus ensuring that the nominal volume of the measuring instrument does not change. The volume of the calibration medium inside the measuring instrument can be ensured to be equal to its nominal volume by using the fixed-volume tube, greatly simplifying the operation process for personnel to determine the nominal volume.

[0060] In addition, the main body 2 of the measuring instrument is equipped with a splash guard 8 and a measuring neck 10, which are located at the top of the upper cone. The splash guard 8 is sealed with a cover and has an exhaust hole 7 on the side. This prevents foreign objects from falling in during storage and use and affecting the nominal volume of the measuring instrument, and also facilitates smooth venting during liquid filling. The measuring neck 10 has a small cross-sectional area, which meets the requirements of the verification procedure of JJG 259 "Standard Metal Measuring Instruments". The effective volume of the measuring instrument can be easily controlled by the slight change in the liquid level height. That is, the nominal volume of the measuring instrument can be accurately controlled by the constant volume tube 5 and the measuring neck 10.

[0061] The present invention also provides a method for verifying first-class standard metal measuring instruments. Figure 13 A flowchart illustrating the verification method for a first-class standard metal measuring instrument according to an embodiment of the present invention is shown. See also... Figure 13As shown, the specific implementation steps of the verification method for this first-class standard metal measuring instrument are as follows:

[0062] Step S1302: Determine the original weight of the first-class standard metal measuring instrument.

[0063] Step S1304: Inject the test medium of a specific density into the volumetric body 2 through the liquid inlet mechanism until the volumetric mechanism discharges the test medium and then stops the injection.

[0064] Step S1306: Fine-tune the volume of the measuring instrument body 2 so that the difference between the actual weight of the first-class standard metal measuring instrument and the original weight is equal to the product of the specific density and the verification volume of the first-class standard metal measuring instrument, wherein the fine-tuned volume includes the volume of the measuring instrument body 2 changed due to deformation after liquid is introduced through the liquid inlet mechanism.

[0065] The traditional calibration process for first-class standard metal measuring instruments is subject to volume errors arising from manufacturing processes and deformation caused by the entry of the calibration medium into the instrument body 2, reducing the accuracy of determining the nominal volume of the calibration medium. This invention provides a calibration method for first-class standard metal measuring instruments, which incorporates a volume-fixing mechanism and a fine-tuning mechanism. The volume-fixing mechanism determines the volume of the calibration medium during calibration by using the weight difference before and after liquid introduction and the density of the calibration medium. Even with volume errors arising from manufacturing processes and deformation caused by the entry of the calibration medium, the fine-tuning mechanism adjusts the volume of the instrument body 2 based on the obtained volume of the calibration medium to offset these errors, thereby ensuring that the volume of the calibration medium is the nominal volume. Furthermore, since the volume error generated during the manufacturing of first-class standard metal measuring instruments is relatively small and can be ignored, the volume adjusted by the fine-tuning mechanism corresponds to the volume change of the main body 2 of the measuring instrument due to deformation after liquid is introduced through the liquid inlet mechanism. The advantage of doing so is that it improves the accuracy of determining the nominal volume of the calibration medium.

[0066] Specifically, the procedure for this verification method includes:

[0067] 1. Weigh the original weight of a first-class standard metal measuring instrument using a balance;

[0068] 2. The test medium is injected into the volumetric body 2 through the inlet channel of the electric three-way valve 12 until the liquid level reaches the position of the second liquid level sensor 91. After a delay of 5 seconds, the control terminal sends a command to the electric three-way valve 12 to close the inlet channel, and the constant volume tube automatically discharges the excess test medium at the same time.

[0069] 3. Measure the temperature of the test medium;

[0070] 4. Weigh the first-class standard metal measuring vessel filled with the test medium using a balance, calculate the mass of the test medium inside the measuring vessel, divide it by the density of the test medium, and then calculate the actual volume of the first-class standard metal measuring vessel.

[0071] 5. If there is an error between the actual volume and the nominal volume, the actual volume of the measuring instrument shall be adjusted by the fine-tuning mechanism 11 so that the error of the actual volume of the first-class standard metal measuring instrument meets the requirements of the verification procedure of JJG 259 "Standard Metal Measuring Instruments".

[0072] The present invention also provides a method for using a first-class standard metal measuring instrument. Figure 14 A flowchart illustrating the method of using a first-class standard metal measuring instrument according to an embodiment of the present invention is shown. See also: Figure 14 As shown, the specific implementation steps of the method for using this first-class standard metal measuring instrument are as follows:

[0073] Step S1402: Keep the position of the fine-tuning mechanism unchanged.

[0074] Step S1404: Inject a test medium of a specific density into the volumetric body 2 through the liquid inlet mechanism until the volumetric mechanism discharges the test medium and then stops the injection.

[0075] Step S1406: Inject the calibration medium from the first-class standard metal measuring instrument into other measuring instruments as the basis for calibrating the capacity of the other measuring instruments.

[0076] Determining the nominal volume of the calibration medium in traditional first-class standard metal measuring instruments mainly relies on frequent manual addition or removal of liquid by operators to reach the nominal volume, making the operation process rather cumbersome. This invention provides a method for using a first-class standard metal measuring instrument, which incorporates a volume-fixing mechanism and a fine-tuning mechanism. The volume-fixing mechanism allows for the one-time determination of the nominal volume of the calibration medium when using the instrument. Furthermore, the calibration medium with the aforementioned nominal volume can then serve as the basis for calibrating the capacity of other measuring instruments. The advantage of this approach is that it simplifies the operator's process for determining the nominal volume.

[0077] Specifically, the process of using this method includes:

[0078] 1. Based on the level 4 and leveling screw 14, adjust the first-class standard metal measuring instrument to the horizontal position, connect the water inlet pipe, drain pipe and power supply of the control terminal, and set the position of the adjustment handwheel 113 of the fine adjustment device to be prohibited from being adjusted during use;

[0079] 2. The control terminal sends a command to the electric three-way valve to open the water inlet channel, and begins to fill the second-class standard metal measuring vessel with water;

[0080] 3. The second temperature sensor 3 and the first temperature sensor 6 start measuring the temperature. The control terminal judges in real time whether the temperature meets the requirements. If it does not meet the requirements, the control terminal prompts "Ambient temperature does not meet the requirements" and sends a command to the electric three-way valve to close the water inlet channel and stop the calibration.

[0081] 4. After the second liquid level sensor 91 and the first liquid level sensor 92 detect the liquid level of the test medium, the control terminal sequentially issues commands to reduce and close the water inlet channel. The volume control mechanism automatically discharges the excess test medium. At this time, the volume of the test medium in the measuring vessel is equal to the nominal volume of the measuring vessel.

[0082] 5. Once the second-class standard metal measuring instrument is ready, the control terminal sends a command to the electric three-way valve to open the drainage channel, injecting the calibration medium into the second-class standard metal measuring instrument. At the same time, the control terminal records the temperature value of the temperature sensor and converts it according to the preset density value.

[0083] 6. After the liquid level sensor 13 detects that the calibration medium has been discharged, there is a 2-minute delay. The control terminal then issues a command to close the drainage channel. At this time, the first-class standard metal measuring instrument has completed one calibration and is in a ready state, waiting for the water filling work of the next calibration task.

[0084] The method for using the first-class standard metal measuring instrument provided by this invention eliminates the need for manual operation by staff, thus ensuring the accuracy of the measuring instrument and simplifying the operation for staff.

[0085] According to an embodiment of the present invention, the test medium is introduced into the upper tube 52 through the lower tube 51 of the constant volume tube 5 until the test medium is discharged from the upper tube 52; the upper tube 52 is controlled to be in a first state or a second state and the liquid inlet speed of the liquid inlet mechanism is controlled according to the liquid level height of the first-class standard metal volumetric instrument.

[0086] This invention provides a method for using a first-class standard metal volumetric instrument. The instrument includes a set-volume tube 5, which utilizes the principle of communicating vessels to ensure that the liquid level of the testing medium in the first-class standard metal volumetric instrument is equal to its height in the set-volume tube 5. When the testing medium flows out from the top of the set-volume tube 5, its nominal volume is reached. Even if liquid continues to be added, excess testing medium will still flow out, ensuring the accuracy of the nominal volume. Furthermore, the first-class standard metal volumetric instrument also includes a control terminal that controls the upper tube body 52 to be in a first or second state and the liquid inlet speed of the inlet mechanism based on the liquid level in the instrument. This improves the efficiency of determining the nominal volume of the testing medium.

[0087] According to an embodiment of the present invention, the control terminal controls the telescopic ring 55, thereby driving the upper tube 52 composed of multiple arc members 521 to be in a first state or a second state, wherein: when the first-class standard metal measuring instrument has completed liquid filling, the upper tube 52 is in the first state, and the cross-sectional area formed by the aggregation of the multiple arc members 521 is equal to the cross-sectional area of ​​the lower tube 51; when the first-class standard metal measuring instrument is filling with liquid and the liquid level is lower than the second liquid level sensor 91, the upper tube 52 is in the second state, and the cross-sectional area formed by the dispersion of the multiple arc members 521 is greater than the cross-sectional area of ​​the lower tube 51.

[0088] How to automatically expand the cross-sectional area of ​​the upper tube 52 when the gas resistance is high and automatically shrink the cross-sectional area when the gas resistance is low is the technical problem to be solved by this solution. The present invention provides a method for using a first-class standard metal measuring instrument, which includes a control terminal that can control the telescopic ring 55 to drive multiple arc components 521 to expand or shrink the cross-sectional area according to different situations. The state of reduced cross-sectional area is referred to as the first state. In the first state, the telescopic ring 55 is compressed, and multiple arc elements 521 converge, with its cross-sectional area equal to that of the lower tube 51. The vertical cross-section is rectangular. This configuration is used to determine the nominal volume of the test medium when the test medium enters the volumetric body 2 through the liquid inlet mechanism and the volumetric mechanism discharges the test medium. The state of expanded cross-sectional area is referred to as the second state. In the second state, the telescopic ring 55 expands, and multiple arc elements 521 disperse, with its cross-sectional area greater than that of the lower tube 51. The vertical cross-section is an inverted isosceles trapezoid. This configuration is used to reduce gas resistance when the test medium enters the volumetric body 2 through the liquid inlet mechanism and the volumetric mechanism does not discharge the test medium. The advantage of this configuration is that the first and second states of the upper tube 52 can be set according to different specific needs, which improves the efficiency of determining the nominal volume of the test medium and ensures the accuracy of determining the nominal volume of the test medium.

[0089] In the traditional use of first-class standard metal measuring instruments, operators often need to frequently control the inflow and outflow of liquid to determine the nominal volume of the test medium, making the operation process cumbersome. This invention provides a first-class standard metal measuring instrument, its calibration method, and its usage method. Its volume-fixing mechanism and fine-tuning mechanism can work together to allow the first-class standard metal measuring instrument to determine the nominal volume of the test medium in a single operation, simplifying the operation process for operators when determining the nominal volume of the test medium.

[0090] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0091] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A first order standard metal measure, characterized in that, The first-class standard metal measuring cylinder comprises: a support (1); a measuring cylinder body (2) located on the top of the support (1) and composed of an upper cone, a cylinder and a lower cone which are in communication with each other; a liquid inlet mechanism located at the bottom of the lower cone; a constant volume mechanism located on the inclined surface of the upper cone; and a fine adjustment mechanism for fine adjustment of the volume of the measuring cylinder body (2), wherein the fine-adjusted volume includes the volume changed due to deformation of the measuring cylinder body (2) after liquid is introduced through the liquid inlet mechanism; wherein the constant volume mechanism comprises: a constant volume tube (5) with an inner surface covered with an elastic rubber layer; the constant volume tube (5) further comprises: a lower tube body (51) with an unchanged cross-sectional area, which is in communication with the inclined surface; and an upper tube body (52) with a variable cross-sectional area, which is arranged on the top of the lower tube body (51); and a control terminal for controlling the upper tube body (52) to be in a first state or a second state and the liquid inlet speed of the liquid inlet mechanism according to the liquid level height of the first-class standard metal measuring cylinder, wherein: when the upper tube body (52) is in the first state, the cross-sectional area of the upper tube body (52) is equal to the cross-sectional area of the lower tube body (51); and when the upper tube body (52) is in the second state, the cross-sectional area of the upper tube body (52) is greater than the cross-sectional area of the lower tube body (51).

2. The first-class standard metal measuring cylinder according to claim 1, wherein: in the case that the liquid level height of the first-class standard metal measuring cylinder is lower than a first liquid level sensor (92), the control terminal controls the upper tube body (52) to be in the second state and controls the liquid inlet mechanism to perform rapid liquid inlet at more than 3 times the rated speed; in the case that the liquid level height of the first-class standard metal measuring cylinder is between the first liquid level sensor (92) and a second liquid level sensor (91), the control terminal controls the upper tube body (52) to be in the second state and controls the liquid inlet mechanism to perform medium-speed liquid inlet at the rated speed; in the case that the liquid level height of the first-class standard metal measuring cylinder reaches the second liquid level sensor (91), the control terminal controls the upper tube body (52) to be in the first state and controls the liquid inlet mechanism to perform slow liquid inlet at not more than 0.2 times the rated speed; after a delay of 5 s, the control terminal controls the upper tube body (52) to be in the first state and controls the liquid inlet mechanism to stop liquid inlet.

3. The first-class standard metal measuring cylinder according to claim 1, wherein: the measuring cylinder body (2) further comprises: a first temperature sensor (6) located on the outer surface of a splash-proof cover (8) and used for monitoring the ambient temperature of the measuring cylinder body (2); and a second temperature sensor (3) located inside the measuring cylinder body (2) and used for monitoring the liquid temperature of the certified medium in the measuring cylinder body (2), ​ The control terminal judges the measurement results of the first temperature sensor (6) and the second temperature sensor (3), and if the verification work requirement is not met, the control terminal sends a command to the electric three-way valve (12) to close the water inlet channel, stops the verification work, and displays the non-satisfaction item on the control terminal; wherein the verification work requirement is that when the first-class standard metal measuring cylinder is used to verify the second-class standard metal measuring cylinder, the ambient temperature is 15-25 DEG C and the difference between the ambient temperature and the liquid temperature is not more than 5 DEG C, or when the first-class standard metal measuring cylinder is used to verify the third-class standard metal measuring cylinder, the ambient temperature is 10-30 DEG C and the difference between the ambient temperature and the liquid temperature is not more than 5 DEG C; When the control terminal sends an instruction to open the drain passage to the electric three-way valve (12) and water is injected into the secondary standard metal measuring cylinder or the tertiary standard metal measuring cylinder, the control terminal automatically records the measurement result of the second temperature sensor (3) and takes it as the temperature value of the test medium for data processing of the test result: when the liquid temperature is t℃, the volume V of the test medium t is: , wherein: t is the liquid temperature, β is the volume expansion coefficient of the primary standard metal measuring cylinder, is the nominal volume value of the primary standard metal measuring cylinder at 20℃.

4. A primary standard metal measure according to any one of claims 1 to 3, characterised in that, The upper pipe body (52) comprises: A plurality of arc pieces (521) with the same curvature, each of which is independent of each other, and the top of each is provided with a gravity piece (53), and the bottom is connected with the lower pipe body (51) through a rotating piece (54); and A telescopic ring (55) with variable cross-sectional area, which is composed of a plurality of blades (551) fixedly connected with the plurality of arc pieces (521), and the plurality of blades (551) are connected through a plurality of connecting mechanisms, wherein: The plurality of connecting mechanisms comprise adjusting holes (553) arranged on the plurality of blades (551); and An adjusting piece (552) is controlled to rotate through the control terminal; The adjusting holes (553) of adjacent blades in the plurality of blades (551) are connected through the pawl after overlapping with each other and the adjusting piece (552); The telescopic ring (55) also drives the upper pipe body (52) to be in the first state or the second state according to the rotation of the adjusting piece (552), wherein: When the upper pipe body (52) is in the first state, the cross-sectional area formed by the aggregation of the plurality of arc pieces (521) is equal to the cross-sectional area of the lower pipe body (51); When the upper pipe body (52) is in the second state, the cross-sectional area formed by the dispersion of the plurality of arc pieces (521) is greater than the cross-sectional area of the lower pipe body (51).

5. A primary standard metal measure according to any one of claims 1 to 3, characterised in that The fine adjustment mechanism (11) comprises: A fine adjustment hole is communicated with the measuring cylinder body (2), and a first annular groove is arranged at one end away from the measuring cylinder body (2); An elastic assembly comprising a plurality of elastic pieces is embedded in the first annular groove; A fine adjustment piece (111) is matched with the fine adjustment hole, and a plurality of second annular grooves with the same spacing and matched with the first annular groove are arranged on the fine adjustment piece (111); An adjusting hand wheel (113) is used to rotate and drive the fine adjustment piece (111) to move inward or outward; and A fixing pin (114) is used to fix the position of the adjusting hand wheel (113).

6. A method of verification for a primary metal measure according to any one of claims 1 to 5, characterized in that, It comprises: Determining the original weight of the first-class standard metal measuring cylinder; Injecting the verification medium into the measuring cylinder body (2) through the liquid inlet mechanism until the liquid outlet mechanism stops injecting after discharging the verification medium; Fine-tune the volume of the measurer body (2) so that the difference between the actual weight of the primary standard metal measurer and the original weight is equal to the product of the density of the verification medium and the verification volume of the primary standard metal measurer, wherein the fine-tuned volume includes the volume changed due to deformation of the measurer body (2) after liquid is injected through the liquid injection mechanism.

7. A method of using a primary metal measure according to any one of claims 1 to 5, characterised in that, The method comprises: keeping the position of the fine-tuning mechanism unchanged; injecting the verification medium into the measurer body (2) through the liquid injection mechanism until the liquid injection stops after the constant volume mechanism discharges the verification medium; injecting the verification medium in the primary standard metal measurer into other measurers as the basis for capacity verification of the other measurers.

8. The method of using a primary standard metal measure according to claim 7, wherein, Injecting the verification medium into the measurer body (2) through the liquid injection mechanism until the liquid injection stops after the constant volume mechanism discharges the verification medium comprises: injecting the verification medium into the upper tube (52) of the constant volume tube (5) through the lower tube (51) until the upper tube (52) discharges the verification medium; controlling the cross-sectional area of the upper tube (52) according to the liquid level of the primary standard metal measurer, and controlling the liquid injection speed of the liquid injection mechanism.

9. The method of using a primary standard metal measure according to claim 8, wherein, Controlling the cross-sectional area of the upper tube (52) according to the liquid level of the primary standard metal measurer comprises: controlling the telescopic ring (55) to drive the upper tube (52) composed of a plurality of arc pieces (521) to be in the first state or the second state, wherein: when the primary standard metal measurer is full of liquid, the upper tube (52) is in the first state, and the cross-sectional area formed by the plurality of arc pieces (521) aggregated is equal to the cross-sectional area of the lower tube (51); when the primary standard metal measurer is being filled with liquid and the liquid level is lower than the second liquid level sensor (91), the upper tube (52) is in the second state, and the cross-sectional area formed by the plurality of arc pieces (521) dispersed is greater than the cross-sectional area of the lower tube (51).

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