Pressure calibration device

Abstract

The utility model discloses a pressure calibration device which comprises a pressure probe, a circuit board and a wire. The pressure probe comprises a diode and a wrapping body, and the diode is located in the wrapping body; the circuit board comprises a constant current source module, a voltage sensor and a microprocessor, and the input end of the microprocessor is electrically connected with the output end of the voltage sensor; the lead comprises an anode lead and a cathode lead, the first end of the anode lead is electrically connected with the anode of the output end of the constant current source module and the anode of the input end of the voltage sensor, and the second end of the anode lead is electrically connected with the anode lead of the diode; the first end of the cathode wire is electrically connected with the cathode of the output end of the constant current source module and the cathode of the input end of the voltage sensor, and the second end of the cathode wire is electrically connected with the cathode lead of the diode. According to the pressure calibration device provided by the invention, the diode is applied to the pressure probe of the pressure calibration device, so that low-cost, efficient and rapid pressure measurement and calibration can be realized.

Description

TECHNICAL FIELD

[0001] The present application relates to Large cavity press TECHNICAL FIELD, in particular to a pressure calibration device. BACKGROUND

[0002] A cubic press is a high-temperature and high-pressure equipment, which is often used for synthesizing superhard materials such as diamond and cubic boron nitride. Under the driving of a hydraulic system, a GPa-level pressure is applied to the material inside an assembly by 6 working anvils. When it is applied to material synthesis, the pressure precision requirement is extremely high, and pressure fluctuation will affect the crystal structure, particle size distribution and performance index of the synthesized material, resulting in unstable product quality and reduced qualified rate.

[0003] When a cubic press is installed and debugged, key components are repaired or replaced, pressure is abnormal or fluctuates, and high-precision experiments or production are carried out, pressure calibration is needed to obtain the relationship between the liquid pressure output by the hydraulic system and the pressure applied to the sample by the anvil, so as to facilitate the operator to accurately adjust and control the pressure according to the process requirements, ensure that each synthesis is carried out under the same pressure condition, and improve the consistency and stability of product quality.

[0004] The prior art lacks a pressure calibration technology with low cost and simple implementation. SUMMARY

[0005] The present application provides a pressure calibration device to solve the problem that the prior art lacks a pressure calibration technology with low cost and simple implementation.

[0006] In view of the above problems, the present application is proposed to provide a pressure calibration device that overcomes the above problems or at least partially solves the above problems.

[0007] The present application provides a pressure calibration device, comprising a pressure probe, a circuit board and a wire;

[0008] The pressure probe comprises a diode and a wrapping body, and the diode is located in the wrapping body;

[0009] The circuit board comprises a constant current source module, a voltage sensor and a microprocessor, and the input end of the microprocessor is electrically connected with the output end of the voltage sensor;

[0010] The wire comprises a positive wire and a negative wire, the first end of the positive wire is electrically connected with the positive pole of the output end of the constant current source module and the positive pole of the input end of the voltage sensor respectively, and the second end of the positive wire is electrically connected with the positive pole lead of the diode; the first end of the negative wire is electrically connected with the negative pole of the output end of the constant current source module and the negative pole of the input end of the voltage sensor respectively, and the second end of the negative wire is electrically connected with the negative pole lead of the diode.

[0011] Optionally, the package body comprises a block of pyrophyllite, a first encapsulation tube, a second encapsulation tube and a third encapsulation tube.

[0012] The block of pyrophyllite comprises a first surface and a second surface, and a through hole, the first surface and the second surface are oppositely arranged, and the through hole penetrates the block of pyrophyllite in a direction perpendicular to the first surface.

[0013] The first encapsulation tube is arranged in the through hole, and the diode is arranged in the first encapsulation tube.

[0014] The second encapsulation tube is arranged in the through hole and located at a side of the first encapsulation tube close to the first surface, and an inner wall of the second encapsulation tube wraps the anode lead of the diode.

[0015] The third encapsulation tube is arranged in the through hole and located at a side of the first encapsulation tube close to the second surface, and an inner wall of the third encapsulation tube wraps the cathode lead of the diode.

[0016] Optionally, the package body further comprises a first conductive sheet and a second conductive sheet, the first conductive sheet is arranged on the first surface of the package body, a side of the first conductive sheet close to the first surface is electrically connected with the anode lead of the diode, and a side of the first conductive sheet away from the first surface is electrically connected with the second end of the anode lead.

[0017] The second conductive sheet is arranged on the second surface of the package body, a side of the second conductive sheet close to the second surface is electrically connected with the cathode lead of the diode, and a side of the second conductive sheet away from the second surface is electrically connected with the second end of the cathode lead.

[0018] Optionally, the material of the first encapsulation tube is magnesium oxide, boron nitride or aluminum oxide; the material of the second encapsulation tube is magnesium oxide, boron nitride or aluminum oxide; and the material of the third encapsulation tube is magnesium oxide, boron nitride or aluminum oxide.

[0019] Optionally, in a direction perpendicular to the first surface of the package body, the distance between the first surface and the second surface of the package body is 32.5 mm.

[0020] Optionally, the circuit board further comprises an anode terminal and a cathode terminal, the anode terminal is electrically connected with the anode of the output end of the constant current source module and the anode of the input end of the voltage sensor respectively, the cathode terminal is electrically connected with the cathode of the output end of the constant current source module and the cathode of the input end of the voltage sensor respectively; the first end of the anode lead is electrically connected with the anode terminal; and the first end of the cathode lead is electrically connected with the cathode terminal.

[0021] Optionally, the positive terminal comprises a first pin and a second pin, and the negative terminal comprises a third pin and a fourth pin; the first pin is electrically connected with the positive electrode of the output end of the constant current source module, the second pin is electrically connected with the positive electrode of the input end of the voltage sensor, and the first end of the positive electrode lead wire is connected with the first pin and the second pin respectively; the third pin is electrically connected with the negative electrode of the output end of the constant current source module, the fourth pin is electrically connected with the negative electrode of the input end of the voltage sensor, and the first end of the negative electrode lead wire is connected with the third pin and the fourth pin respectively.

[0022] Optionally, the circuit board further comprises a transmission interface, the positive terminal and the negative terminal are arranged in the transmission interface, and the lead wire further comprises a transmission connector, the first end of the positive electrode lead wire and the first end of the negative electrode lead wire are arranged on the transmission connector, and in the state that the transmission interface is connected with the transmission connector, the first end of the positive electrode lead wire is electrically connected with the positive terminal, and the first end of the negative electrode lead wire is electrically connected with the negative terminal.

[0023] Optionally, the display screen is further arranged, and the input end of the display screen is electrically connected with the output end of the microprocessor.

[0024] Optionally, the lead wire further comprises a terminal, and the terminal is provided with a first port, a second port, a third port and a fourth port, wherein the first port is electrically connected with the second port, and the third port is electrically connected with the fourth port.

[0025] The positive electrode lead wire comprises a first sub-lead wire segment and a second sub-lead wire segment, and the negative electrode lead wire comprises a third sub-lead wire segment and a fourth sub-lead wire segment, wherein the first end of the first sub-lead wire segment is the first end of the positive electrode lead wire, and the second end of the first sub-lead wire segment is fixedly connected with the first port; the first end of the second sub-lead wire segment is detachably electrically connected with the second port, and the second end of the second sub-lead wire segment is the second end of the positive electrode lead wire.

[0026] The first end of the third sub-lead wire segment is the first end of the negative electrode lead wire, the second end of the third sub-lead wire segment is fixedly connected with the third port, the first end of the fourth sub-lead wire segment is detachably connected with the fourth port, and the second end of the fourth sub-lead wire segment is the second end of the negative electrode lead wire.

[0027] The technical scheme provided in the application has at least the following technical effects or advantages:

[0028] The pressure calibration device provided by the application, the pressure calibration device provided by the embodiment of the application, the diode is applied to the pressure probe of the pressure calibration device, the pressure probe is used to bear the pressure output by the high-pressure equipment, such as a cubic press or a two-surface press, the constant current source module is used to apply a constant current to the diode, the PN junction is arranged in the diode, the band gap of the PN junction changes linearly with the borne pressure, so that the voltage between the two ends of the diode changes linearly with the pressure input by the high-pressure equipment, the voltage sensor is used to collect the voltage between the two ends of the diode under different pressure conditions, and the microprocessor can be used to determine the specific pressure output by the high-pressure equipment to the pressure probe according to the voltage-pressure characteristic curve of the PN junction and the voltage value between the two ends of the diode collected by the voltage sensor. The high-pressure equipment usually adopts a hydraulic system to input pressure, and the microprocessor can also be used to receive the oil pressure of the hydraulic system of the high-pressure equipment and associate the oil pressure with the pressure output by the high-pressure equipment, so as to calibrate the pressure of the high-pressure equipment. The pressure calibration device provided by the embodiment of the application applies the diode to the pressure probe, and low-cost, efficient and rapid pressure measurement and calibration can be realized.

[0029] The above description is only a summary of the technical scheme of the application, in order to more clearly understand the technical means of the application, the content of the specification can be implemented, and in order to make the above and other purposes, characteristics and advantages of the application more obvious and easy to understand, the following specific embodiments of the application are described. BRIEF DESCRIPTION OF DRAWINGS

[0030] By reading the detailed description of the preferred embodiments below, various other advantages and benefits will become clear to those of ordinary skill in the art. The drawings are only for the purpose of illustrating the preferred embodiments and are not considered limiting the application. Moreover, the same reference symbols are used throughout the drawings to represent the same parts. In the drawings:

[0031] Figure 1 A line frame diagram of one example of the pressure calibration device provided by the embodiment of the application;

[0032] Figure 2 A structure diagram of one example of the pressure probe provided by the embodiment of the application;

[0033] Figure 3 A structure diagram of another example of the pressure probe provided by the embodiment of the application;

[0034] Figure 4 A line frame diagram of another example of the pressure calibration device provided by the embodiment of the application;

[0035] Figure 5 A standard curve of the voltage of the diode changing with the pressure in the constant current mode;

[0036] Figure 6A key structure diagram of a pressure calibration device provided by the embodiment of the present application is shown in the figure.

[0037] Figure 7 A result diagram of pressure calibration of a cubic press by the pressure calibration device provided by the embodiment of the present application is shown in the figure. DETAILED DESCRIPTION

[0038] Exemplary embodiments of the present disclosure will be described in detail with reference to the drawings.

[0039] Various structure diagrams according to the embodiment of the present application are shown in the drawings. These diagrams are not drawn to scale, in which certain details are exaggerated for clarity of presentation and can omit certain details. The shapes of various regions, layers shown in the drawings and their relative size, position relationship are only exemplary, and in actuality, there can be deviations due to manufacturing tolerances or technical limitations, and the skilled in the art can additionally design regions / layers with different shapes, sizes, relative positions according to actual needs.

[0040] In order to better understand the above technical solutions, the above technical solutions will be described in detail below in combination with specific embodiments, and it should be understood that the embodiments of the present disclosure and the specific features in the embodiments are detailed descriptions of the technical solutions of the present application, and are not limitations of the technical solutions of the present application. In the case of no conflict, the technical features in the embodiments of the present application and the embodiments can be combined with each other.

[0041] When a cubic press is installed and debugged, repaired or replaced with key components, the pressure appears abnormal or fluctuates, and high-precision experiments or production are carried out, pressure calibration is needed to obtain the relationship between the liquid pressure output by the hydraulic system and the pressure applied to the sample by the anvil.

[0042] In view of this, the present application provides a pressure calibration device, please refer to Figure 1 , Figure 1A line frame diagram of a pressure calibration device provided by the embodiment of the application, the pressure calibration device comprising a pressure probe 101, a circuit board 102 and a wire 103; the pressure probe 101 comprising a diode 1011 and a wrapping body 1012, the diode 1011 being located in the wrapping body 1012; the circuit board 102 comprising a constant current source module 1021, a voltage sensor 1022 and a microprocessor 1023, an input end of the microprocessor 1023 being electrically connected with an output end of the voltage sensor 1022; the wire 103 comprising a positive wire 1031 and a negative wire 1032, a first end of the positive wire 1031 being electrically connected with a positive pole of an output end of the constant current source module 1021 and a positive pole of an input end of the voltage sensor 1022 respectively, a second end of the positive wire 1031 being electrically connected with a positive pole lead wire 205 of the diode 1011; a first end of the negative wire 1032 being electrically connected with a negative pole of the output end of the constant current source module 1021 and a negative pole of the input end of the voltage sensor 1022 respectively, a second end of the negative wire 1032 being electrically connected with a negative pole lead wire 206 of the diode 1011.

[0043] The pressure calibration device provided by the embodiment of the application applies the diode 1011 to the pressure probe 101 of the pressure calibration device, the pressure probe 101 is used to bear the pressure output by the high-pressure equipment, such as a cubic press or a two-surface press, the constant current source module 1021 is used to apply a constant current to the diode 1011, the diode 1011 is provided with a PN junction, the forbidden band width of the PN junction linearly changes with the borne pressure, so that the voltage across the diode 1011 linearly changes with the pressure input by the high-pressure equipment, the voltage sensor 1022 is used to collect the voltage across the diode 1011 under different pressure conditions, and the microprocessor 1023 can be used to determine the specific pressure output by the high-pressure equipment to the pressure probe 101 according to the voltage-pressure characteristic curve of the PN junction and the voltage value across the diode 1011 collected by the voltage sensor 1022, the high-pressure equipment usually adopts a hydraulic system to input pressure, and the microprocessor 1023 can also be used to receive the oil pressure of the hydraulic system of the high-pressure equipment and associate the oil pressure with the pressure output by the high-pressure equipment, so as to calibrate the pressure of the high-pressure equipment.

[0044] In some optional embodiments, as Figure 2As shown, the package 1012 includes a chunk of pyrophyllite 201, a first encapsulation tube 202, a second encapsulation tube 203, and a third encapsulation tube 204; the chunk of pyrophyllite 201 includes a first surface 2011, a second surface 2012, and a through hole 2013, the first surface 2011 is oppositely arranged with the second surface 2012, and the through hole 2013 penetrates the chunk of pyrophyllite 201 in a direction perpendicular to the first surface 2011; the first encapsulation tube 202 is arranged in the through hole 2013, and the diode 1011 is arranged in the first encapsulation tube 202; the second encapsulation tube 203 is arranged in the through hole 2013 and located on a side of the first encapsulation tube 202 close to the first surface 2011, and an inner wall of the second encapsulation tube 203 wraps the positive lead 205 of the diode 1011; the third encapsulation tube 204 is arranged in the through hole 2013 and located on a side of the first encapsulation tube 202 close to the second surface 2012, and an inner wall of the third encapsulation tube 204 wraps the negative lead 206 of the diode 1011.

[0045] The pressure calibration device provided by the embodiment of the present application has the first encapsulation tube 202 for wrapping and protecting the positive lead 205, improves the pressure transmission efficiency of the cavity, has the second encapsulation tube 203 for wrapping and protecting the diode 1011, improves the pressure transmission efficiency of the cavity, ensures that the diode 1011 is in a good hydrostatic pressure environment, and has the third encapsulation tube for wrapping and protecting the negative lead 206, improves the pressure transmission efficiency of the cavity.

[0046] In some examples, the material of the first encapsulation tube 202 is magnesium oxide, boron nitride, or aluminum oxide; the material of the second encapsulation tube 203 is magnesium oxide, boron nitride, or aluminum oxide; and the material of the third encapsulation tube 204 is magnesium oxide, boron nitride, or aluminum oxide. The materials of the first encapsulation tube 202, the second encapsulation tube 203, and the third encapsulation tube 204 can be the same or different in pairs.

[0047] In some examples, the chunk of pyrophyllite 201 of the package 1012 is a regular hexahedron, the first surface 2011 is a top plane of the chunk of pyrophyllite 201, the second surface 2012 is a bottom plane of the chunk of pyrophyllite 201, and the through hole 2013 penetrates the chunk of pyrophyllite 201 in a direction perpendicular to the first surface 2011 of the chunk of pyrophyllite 201.

[0048] For example, the chunk of pyrophyllite 201 is a regular hexahedron with an edge length of 32.5 mm, and the distance between the first surface 2011 and the second surface 2012 of the chunk of pyrophyllite 201 is 32.5 mm in a direction perpendicular to the first surface 2011 of the chunk of pyrophyllite 201.

[0049] The package 1012 and the diode 1011 form a whole hexahedral pressure probe 101. When the pressure probe 101 is used for pressure calibration of the cubic press, the specific use method and working principle are as follows: the pressure probe 101 is placed in the cubic press to be calibrated, the constant current source module 1021 is started to apply a constant current to the diode 1011, the hydraulic system of the cubic press is started, the hydraulic system drives the anvil of the cubic press to extrude the pressure probe 101, as the output pressure of the anvil increases, the band gap of the PN changes under the force, the voltage between the two ends of the PN changes linearly, the voltage sensor 1022 collects the voltage between the two ends of the PN and then outputs to the microprocessor 1023, the microprocessor 1023 can determine the pressure borne by the PN according to the voltage-pressure characteristic curve of the PN junction and the voltage value transmitted by the voltage sensor 1022, thereby determining the output pressure of the anvil of the cubic press, and combining the oil pressure value of the hydraulic system of the cubic press, the relationship between the oil pressure of the hydraulic system of the cubic press and the output pressure of the anvil of the cubic press can be obtained, thereby realizing the pressure calibration of the cubic press.

[0050] In some optional embodiments, as shown in FIG. 1, the package 1012 further comprises a first conductive sheet and a second conductive sheet. Figure 3 The first conductive sheet is arranged on the first surface 2011 of the package 1012, the side of the first conductive sheet close to the first surface 2011 is electrically connected with the positive lead 205 of the diode 1011, and the side of the first conductive sheet away from the first surface 2011 is electrically connected with the second end of the positive lead 1031. The second conductive sheet is arranged on the second surface 2012 of the package 1012, the side of the second conductive sheet close to the second surface 2012 is electrically connected with the negative lead 206 of the diode 1011, and the side of the second conductive sheet away from the second surface 2012 is electrically connected with the second end of the negative lead 1032.

[0051] The first conductive sheet is used to conduct the positive lead 1031 and the positive lead 205 of the diode 1011, and the second conductive sheet is used to conduct the negative lead 1032 and the negative lead 206 of the diode 1011. When the pressure calibration device is applied to high-voltage equipment, the first conductive sheet and the second conductive sheet can avoid the connection between the lead 103 and the diode 1011 from being disconnected under the tangential stress, thereby preventing the pressure calibration from failing.

[0052] In some optional embodiments, the circuit board 102 further comprises a positive terminal and a negative terminal, the positive terminal is electrically connected with the positive terminal of the output end of the constant current source module 1021 and the positive terminal of the input end of the voltage sensor 1022, respectively, and the negative terminal is electrically connected with the negative terminal of the output end of the constant current source module 1021 and the negative terminal of the input end of the voltage sensor 1022, respectively. The first end of the positive lead 1031 is electrically connected with the positive terminal, and the first end of the negative lead 1032 is electrically connected with the negative terminal.

[0053] The circuit board 102 can adopt a flexible circuit board 102, and the constant current source module 1021 and the voltage sensor 1022 are connected with the conductive wire 103 through the positive electrode terminal and the negative electrode terminal, so as to ensure the reliability of the connection, the accuracy of the signal transmission, and also help to protect the circuit from the influence of overcurrent, overvoltage and other faults

[0054] In some optional embodiments, the positive electrode terminal includes a first pin and a second pin, and the negative electrode terminal includes a third pin and a fourth pin; the first pin is electrically connected with the positive electrode of the output end of the constant current source module 1021, the second pin is electrically connected with the positive electrode of the input end of the voltage sensor 1022, and the first end of the positive electrode conductive wire 1031 is connected with the first pin and the second pin respectively; the third pin is electrically connected with the negative electrode of the output end of the constant current source module 1021, the fourth pin is electrically connected with the negative electrode of the input end of the voltage sensor 1022, and the first end of the negative electrode conductive wire 1032 is connected with the third pin and the fourth pin respectively.

[0055] In some optional embodiments, the circuit board 102 further includes a transmission interface, and the positive electrode terminal and the negative electrode terminal are arranged in the transmission interface; the conductive wire 103 further includes a transmission joint, and the first end of the positive electrode conductive wire 1031 and the first end of the negative electrode conductive wire 1032 are arranged on the transmission joint; in the state that the transmission interface is connected with the transmission joint, the first end of the positive electrode conductive wire 1031 is electrically connected with the positive electrode terminal, and the first end of the negative electrode conductive wire 1032 is electrically connected with the negative electrode terminal.

[0056] Since the pressure output by the high-pressure device usually reaches the GPa level, after the pressure probe 101 is used for pressure calibration of the high-pressure device, obvious deformation usually occurs and the pressure probe 101 cannot be applied to the pressure calibration of the high-pressure device again, while the circuit board 102 is usually not damaged during use, so it can be repeatedly used; the transmission joint on the conductive wire 103 and the transmission interface on the circuit board 102 are connected to form a detachable connection, when the used pressure probe 101 cannot be used again, the transmission joint on the conductive wire 103 is pulled out from the transmission interface on the circuit board 102, and a new pressure probe 101 is replaced.

[0057] In some optional embodiments, the wire 103 further comprises a terminal, and the terminal is provided with a first port, a second port, a third port and a fourth port, wherein the first port is electrically connected with the second port, and the third port is electrically connected with the fourth port; the positive wire 1031 comprises a first sub-wire 103 segment and a second sub-wire 103 segment, and the negative wire 1032 comprises a third sub-wire 103 segment and a fourth sub-wire 103 segment, wherein the first end of the first sub-wire 103 segment is the first end of the positive wire 1031, and the second end of the first sub-wire 103 segment is fixedly connected with the first port; the first end of the second sub-wire 103 segment is detachably electrically connected with the second port, and the second end of the second sub-wire 103 segment is the second end of the positive wire 1031; the first end of the third sub-wire 103 segment is the first end of the negative wire 1032, and the second end of the third sub-wire 103 segment is fixedly connected with the third port; the first end of the fourth sub-wire 103 segment is detachably connected with the fourth port, and the second end of the fourth sub-wire 103 segment is the second end of the negative wire 1032.

[0058] The detachable connection between the pressure probe 101 and the circuit board 102 is realized through the terminal. When the used pressure probe 101 cannot be used again, the third sub-wire 103 segment corresponding to the third interface is disconnected, the fourth sub-wire 103 segment is disconnected, a new pressure probe 101 is replaced, the third sub-wire 103 segment of the new pressure probe 101 is connected with the third interface, and the fourth sub-wire 103 segment is connected with the fourth interface.

[0059] In some optional embodiments, as shown in FIG. 4, Figure 4 The display screen 401 is further provided, and an input end of the display screen 401 is electrically connected with an output end of the microprocessor 1023, so as to receive the calculation result output by the microprocessor 1023 and realize dynamic high-pressure measurement visualization. The display screen 401 can be arranged outside the circuit board 102 or integrated on the circuit board 102, and the specific mounting position of the display screen 401 is not limited in the present application.

[0060] The display screen 401 can be an OLED display, and the specific structure and type of the display screen 401 are not limited in the present application.

[0061] The following will specifically introduce how to use the pressure calibration device provided in the above embodiments to calibrate the pressure of the cubic press.

[0062] The following will specifically introduce how to use the pressure calibration device provided in the above embodiments to calibrate the pressure of the cubic press.

[0063] When calibrating the pressure of the cubic press and obtaining the relationship between the liquid pressure output by the hydraulic system and the pressure applied to the sample by the anvil.

[0064] The common pressure calibration methods in the prior art include phase change method of pressure calibration substance and piezoresistive effect pressure calibration. The phase change method of pressure calibration substance is to use the phase change characteristics of the pressure calibration substance at a known pressure to indirectly calibrate the actual pressure in the cavity of the press by detecting the external pressure parameter corresponding to the phase change point. Specifically, the pressure calibration substance is placed in the sample cavity, the press gradually increases the external oil pressure at a constant rate by a hydraulic system or mechanical loading to apply pressure to the sample cavity, and the oil pressure value and the resistance signal of the pressure calibration substance are monitored and recorded in real time. By recording the theoretical pressure value of the pressure calibration substance at the phase change point and the external oil pressure value of the press, a pressure correction curve can be established for the pressure calibration of the experiment. This technology has high experimental precision, accurate measurement, does not require complex sensors, low cost and is suitable for extreme high-pressure environments. However, this technology relies on pressure calibration substances with known and clear phase change points, and the number of available materials under high pressure is limited. This technology can only measure the cavity pressure at the phase change point of the pressure calibration substance, and cannot dynamically measure the change of the cavity pressure during the pressurization process. In addition, in order to establish a high-precision correction curve, repeated experiments at different pressure points are required, which is time-consuming and requires high stability of the equipment.

[0065] The piezoresistive effect pressure calibration of manganese copper wire is based on the characteristic that the resistance of manganese copper alloy (such as manganese copper and constantan) changes with the applied pressure, and the pressure is indirectly calibrated by measuring the resistance change.

[0066] Specifically, the manganese copper wire is embedded as a pressure sensor in the pressure transmission medium, and the pressure is uniformly transmitted to the manganese copper wire through the pressure transmission medium. By measuring the resistance change (ΔR) of the manganese copper wire, combined with the known piezoresistive coefficient (K), the pressure value of the cavity is inversely deduced.

[0067] The disadvantage of this technology is that the diameter of the manganese copper wire is only a few tens of microns to ensure that the measured resistance is obvious enough, so insulation wrapping treatment is required. During the experiment, the experiment is prone to failure due to tangential stress fracture, and the non-linear effect of the piezoresistive coefficient of manganese copper increases with increasing pressure, which requires high-order correction. Therefore, this technology has poor operation convenience and high failure rate.

[0068] The pressure calibration device provided by the embodiment of the present application is used to calibrate the cubic press. First, a plurality of diodes of the same batch are purchased in batches. The diodes of the same batch have basically the same curve of voltage change with pressure in the constant current mode due to the same material and process. After assembling one diode with the wrapping body and connecting it with the circuit board, it is placed in the pressure cavity of the cubic press for pressure calibration using the prior art. A constant current is applied to the diode by the constant current source module, the cubic press is started, and the voltage of the diode is collected by the voltage sensor while the cubic press inputs pressure to the pressure probe, so that the voltage of the diode changes with the pressure as shown in FIG. 2. Figure 5The standard curve shown is the voltage-pressure variation of the diode (model 1N5408) in constant current mode. The voltage U can be obtained from this curve. F The formula for U as a function of pressure P is... F = -44.22P + 634.38. Furthermore, diodes of different models, types, and batches vary in voltage U under constant current mode due to differences in their PN junction crystal plane type, manufacturing process, etc. F The slope and intercept of the curve will differ depending on the pressure P.

[0069] After obtaining the standard curve of the diode's voltage versus pressure in constant current mode, it can be used for pressure calibration during the installation and commissioning of a new six-sided press, equipment maintenance or replacement of key components, when pressure abnormalities or fluctuations occur, and when conducting high-precision experiments or production. The specific calibration method is as follows:

[0070] The first step involves assembling the diode and the encapsulation to obtain the pressure probe. The diode is then connected to the constant current source module and voltage sensor on the circuit board to obtain a complete pressure calibration device. Its key system architecture is as follows: Figure 6 As shown.

[0071] The second step is to set the oil pressure curve of the hydraulic system of the six-sided top press and place the pressure probe of the pressure calibration device assembled in the first step into the pressure chamber of the six-sided top press.

[0072] The third step is to start the constant current source module 601 to provide a constant current to the diode 602. The current is in the mA range and is adjustable, with a default value of 1mA.

[0073] The fourth step is to start the six-sided top press. The hydraulic system provides power to the top hammer of the six-sided top press according to the oil pressure curve, driving the top hammer to apply pressure to the pressure probe. During this process, the voltage sensor 603 collects the potential difference across the diode 602, and at the same time, the magnitude of the collected potential difference is input into the microprocessor 604.

[0074] Step 5, the microprocessor 604 is based on Figure 5 The standard curve of the voltage change of diode 602 with pressure in constant current mode and the received potential difference are calculated by a pre-set function to obtain the pressure applied by the hammer to the pressure probe, and then output to the display screen for display.

[0075] The sixth step involves inputting the hydraulic pressure curve of the six-sided top press system into the microprocessor 604. Based on the calculated pressure applied by the top hammer to the pressure probe at multiple moments and the corresponding oil pressure at each moment, the microprocessor 604 obtains the following... Figure 7The curve of the cavity pressure of the cubic press shown varies with the oil pressure of the hydraulic system, and the result is transmitted to the display screen 605 for display, thus obtaining the pressure calibration curve of the cubic press.

[0076] In the seventh step, the cubic press is calibrated by using the phase transition method of the pressure calibration substance, such as Bi, Tl, Te, Ba, and the result is still as shown in the figure. Figure 7 The pressure values calibrated by the pressure calibration substances, such as Bi, Tl, Te, and Ba, coincide with the pressure calibration curve obtained by using the pressure calibration device provided in the above embodiment, proving that the result of calibrating the cubic press by using the pressure calibration device provided in the above embodiment is accurate.

[0077] In summary, the pressure calibration device provided in the embodiments of the present application has the following technical problems and advantages when applied to the pressure calibration of the cubic press:

[0078] (1) Based on the PN junction, the forward voltage (U F ) - pressure has the nature of an approximate line in a certain pressure range, and the forward voltage has high sensitivity to pressure changes, so that dynamic measurement of the cavity pressure in a certain pressure range can be realized, and the problem that high-pressure measurement range and resolution cannot be considered together can be solved.

[0079] (2) The standard semiconductor PN junction can be used as a pressure probe, and the material cost is lower than that of the pressure calibration substances (such as Bi, Tl, Te, and Ba) and manganese copper wire, the complex mechanical structure is saved, and the manufacturing cost is significantly reduced.

[0080] (3) The PN junction semiconductor material has low manufacturing cost, and the pressure probe can be directly replaced when damaged, which can avoid the problem that the mechanical sensor needs to be frequently calibrated due to material aging or stress relaxation.

[0081] (4) By integrating the constant current source module 601, the pressure sensor, and the microprocessor 604, the integrated design of the sensor and the signal processing can be realized, the volume is reduced to millimeter level, and the problem of insufficient miniaturization and integration is solved.

[0082] (5) By using the microprocessor 604 and the display screen, the voltage signal caused by the pressure is directly converted into a pressure signal output, dynamic high-pressure measurement visualization is realized, the time cost of manual calculation is saved, and the accuracy is high.

[0083] (6) By the overall system design, the integrated design of the sensor and the signal processing is realized, and low-cost, efficient, and rapid pressure measurement and calibration are realized.

[0084] Finally, it should be noted that the above embodiments are merely used to describe and illustrate, but not to limit the technical solutions of the present application; even though the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or equivalently replace some or all of the technical features thereof; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

[0085] In the description provided herein, a large number of specific details are illustrated. However, it can be understood that the embodiments of the present application can be practiced without these specific details. In some instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure the understanding of this description.

Claims

1. A pressure calibration device, characterized by, The pressure probe, the circuit board and the lead wire are included; The pressure probe includes a diode and a package, and the diode is located in the package; The circuit board includes a constant current source module, a voltage sensor and a microprocessor, and an input end of the microprocessor is electrically connected with an output end of the voltage sensor; The lead wire includes a positive lead wire and a negative lead wire, a first end of the positive lead wire is electrically connected with a positive pole of an output end of the constant current source module and a positive pole of an input end of the voltage sensor respectively, and a second end of the positive lead wire is electrically connected with a positive pole lead wire of the diode; a first end of the negative lead wire is electrically connected with a negative pole of the output end of the constant current source module and a negative pole of the input end of the voltage sensor respectively, and a second end of the negative lead wire is electrically connected with a negative pole lead wire of the diode.

2. The pressure calibration device of claim 1, wherein, The package includes a pyrophyllite block, a first encapsulation tube, a second encapsulation tube and a third encapsulation tube; The pyrophyllite block includes a first surface, a second surface and a through hole, the first surface and the second surface are oppositely arranged, and the through hole penetrates the pyrophyllite block in a direction perpendicular to the first surface; The first encapsulation tube is arranged in the through hole, and the diode is arranged in the first encapsulation tube; The second encapsulation tube is arranged in the through hole and located on a side of the first encapsulation tube close to the first surface, and an inner wall of the second encapsulation tube wraps the positive pole lead wire of the diode; The third encapsulation tube is arranged in the through hole and located on a side of the first encapsulation tube close to the second surface, and an inner wall of the third encapsulation tube wraps the negative pole lead wire of the diode.

3. The pressure calibration device of claim 2, wherein, The package further includes a first conductive sheet and a second conductive sheet, the first conductive sheet is arranged on the first surface of the package, a side of the first conductive sheet close to the first surface is electrically connected with the positive pole lead wire of the diode, and a side of the first conductive sheet away from the first surface is electrically connected with the second end of the positive lead wire; the second conductive sheet is arranged on the second surface of the package, a side of the second conductive sheet close to the second surface is electrically connected with the negative pole lead wire of the diode, and a side of the second conductive sheet away from the second surface is electrically connected with the second end of the negative lead wire. The material of the first encapsulation tube is magnesium oxide, boron nitride or aluminum oxide; the material of the second encapsulation tube is magnesium oxide, boron nitride or aluminum oxide; and the material of the third encapsulation tube is magnesium oxide, boron nitride or aluminum oxide.

4. The pressure calibration device of claim 2, wherein, In a direction perpendicular to the first surface of the package, the distance between the first surface and the second surface of the package is 32.5 mm.

5. The pressure calibration device of claim 2, wherein, The circuit board further includes a positive terminal and a negative terminal, the positive terminal is electrically connected with the positive pole of the output end of the constant current source module and the positive pole of the input end of the voltage sensor respectively, the negative terminal is electrically connected with the negative pole of the output end of the constant current source module and the negative pole of the input end of the voltage sensor respectively; the first end of the positive lead wire is electrically connected with the positive terminal; and the first end of the negative lead wire is electrically connected with the negative terminal.

6. The pressure calibration device of claim 1, wherein, ​ 7. The pressure calibration device of claim 6, wherein, The positive terminal comprises a first pin and a second pin, and the negative terminal comprises a third pin and a fourth pin; the first pin is electrically connected with the positive pole of the output end of the constant current source module, the second pin is electrically connected with the positive pole of the input end of the voltage sensor, and the first end of the positive lead wire is connected with the first pin and the second pin respectively; the third pin is electrically connected with the negative pole of the output end of the constant current source module, the fourth pin is electrically connected with the negative pole of the input end of the voltage sensor, and the first end of the negative lead wire is connected with the third pin and the fourth pin respectively.

8. A pressure calibration device as claimed in claim 6 or 7, characterised in that, The circuit board further comprises a transmission interface, the positive terminal and the negative terminal are arranged in the transmission interface, and the lead wire further comprises a transmission connector, the first end of the positive lead wire and the first end of the negative lead wire are arranged on the transmission connector, and in the state that the transmission interface is connected with the transmission connector, the first end of the positive lead wire is electrically connected with the positive terminal, and the first end of the negative lead wire is electrically connected with the negative terminal.

9. The pressure calibration device of claim 1, wherein, Further comprising a display screen, the input end of the display screen is electrically connected with the output end of the microprocessor.

10. The pressure calibration device of claim 1, wherein, The lead wire further comprises a wiring terminal, the wiring terminal is provided with a first port, a second port, a third port and a fourth port, wherein the first port is electrically connected with the second port, and the third port is electrically connected with the fourth port; The positive lead wire comprises a first sub-lead wire segment and a second sub-lead wire segment, and the negative lead wire comprises a third sub-lead wire segment and a fourth sub-lead wire segment, wherein the first end of the first sub-lead wire segment is the first end of the positive lead wire, and the second end of the first sub-lead wire segment is fixedly connected with the first port; the first end of the second sub-lead wire segment is detachably electrically connected with the second port, and the second end of the second sub-lead wire segment is the second end of the positive lead wire; The first end of the third sub-lead wire segment is the first end of the negative lead wire, and the second end of the third sub-lead wire segment is fixedly connected with the third port; the first end of the fourth sub-lead wire segment is detachably connected with the fourth port, and the second end of the fourth sub-lead wire segment is the second end of the negative lead wire.

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