WO2024103916A1

WO2024103916A1 - Differential pressure sensor core body test tool and testing method thereof

Info

Publication number: WO2024103916A1
Application number: PCT/CN2023/116387
Authority: WO
Inventors: 何方; 张娜; 张海军; 李永清; 李洪儒; 张治国; 刘妍; 刘波; 李颖; 祝永峰; 单鹤南; 金琦; 刘文斌; 裴晓雷; 李林峰; 周聪
Original assignee: 国机传感科技有限公司; 沈阳仪表科学研究院有限公司
Priority date: 2022-11-16
Filing date: 2023-09-01
Publication date: 2024-05-23
Also published as: CN115597772B; CN115597772A

Abstract

Provided in the present application are a differential pressure sensor core body test tool and a testing method thereof. The method comprises: mounting differential pressure sensor core bodies between an upper mounting part and a lower mounting part of the tool, and fastening the upper mounting part and the lower mounting part, so as to ensure that the differential pressure sensor core bodies are in a clamped state; and then, by means of gas inlets provided on the outer side of the differential pressure sensor core body test tool, injecting test gas having a set pressure so as to test the differential pressure sensor core bodies so as to obtain a test result. By means of using the upper mounting part and the lower mounting part to clamp the differential pressure sensor core bodies, and providing inside the upper mounting part and inside the lower mounting part vent holes and gas guide holes which are communicated with each other, the present application can simultaneously test a plurality of differential pressure sensor core bodies after a tester injects the test gas into the gas inlets, thus solving the problems of high mounting and clamping workloads for differential pressure sensor core bodies and liable gas leakage due to a plurality of gas feeding pipe joints, and improving the test precision and efficiency.

Description

A differential pressure sensor core testing tool and testing method thereof

This application claims priority to a Chinese patent application filed with the State Intellectual Property Office on November 16, 2022, with application number 202211429771.3 and invention name “A differential pressure sensor core testing tool and testing method thereof”, the entire contents of which are incorporated by reference in this application.

Technical Field

The present application relates to the field of pressure testing devices, and in particular to a differential pressure sensor core testing tool and a testing method thereof.

Background technique

The differential pressure sensor core test tooling is an indispensable device in the differential pressure sensor core test. The quality of the test tooling design determines the accuracy and efficiency of the differential pressure sensor core test.

At present, most of the differential pressure sensor core test fixtures use a single core test structure. Each test fixture can only test one sensor core at a time. If multiple differential pressure sensor cores are to be tested at the same time, multiple identical test fixtures must be used. The workload of installing the differential pressure sensor core is very large, and the test efficiency is not high. What is more serious is that due to the use of multiple single core test fixtures, there are a lot of intake pipe joints. Multiple joints need to be connected in series and in parallel, and there are stresses between them. The temperature of the differential pressure sensor core test can be as low as -60℃ and as high as 200℃ or above. Due to the large number of intake pipe joints and the stress between them, the intake pipe joints may leak, which in turn affects the test accuracy of the differential pressure sensor core and may even cause the failure of the entire test.

On the one hand, the existing tooling also assembles one end of multiple differential pressure sensor cores on a structural part, sharing one air inlet, while the other end of the differential pressure sensor core still adopts a one-to-one connection structure. Although this test tooling can partially improve the test efficiency, since the test tooling still has a large number of air inlet pipe joints, the air inlet may still have the problem of air leakage.

The above solution cannot completely solve the problems of large workload of fixture installation for differential pressure sensor core test, low test efficiency, and air leakage of intake pipe joint affecting test accuracy, and even causing test failure.

On the other hand, the current testing methods for differential pressure sensor cores are not unified, and there are problems such as poor testing results and low testing efficiency. The existence of these problems will inevitably affect the product quality and production efficiency of the differential pressure sensor core.

In summary, it is of great significance to invent a differential pressure sensor core testing tool with high testing efficiency, easy assembly, simple operation and convenient use, and a set of optimized differential pressure sensor core testing methods.

Summary of the invention

The embodiment of the present application provides a differential pressure sensor core test fixture and a test method thereof to solve the problems of existing single core structure test fixtures and test fixtures with one end assembled on a structural member, sharing an air inlet, and a one-to-one connection structure at the other end, which have a large core assembly workload, low test efficiency, and many air inlet pipe joints that are prone to leakage, affecting test accuracy, and even causing test failure.

In a first aspect, an embodiment of the present application provides a differential pressure sensor core testing tool, the tool comprising: a lower mounting groove and an upper mounting groove that can be buckled with each other, and a plurality of guide shafts; when the lower mounting groove and the upper mounting groove are buckled, a plurality of holes are formed on two opposite sides; the lower mounting groove and the upper mounting groove each include two long side plates and a short side plate;

The guide shaft vertically penetrates the upper mounting groove and is installed on the lower mounting groove; a guide shaft through hole for the guide shaft to pass through is provided at the bottom of the upper mounting groove; a guide shaft fixing seat for installing the guide shaft is provided at the bottom of the lower mounting groove; the position of the guide shaft through hole corresponds to the guide shaft fixing seat; a linear bearing is also provided in the guide shaft through hole, and the guide shaft passes through the linear bearing;

The guide shaft fixing seat is a cylindrical groove structure; in the direction of the short side plate of the lower mounting groove, the guide shaft fixing seats are connected by a plate-like structure;

The upper installation groove is provided with a plurality of upper differential pressure sensor core test seats, and the upper differential pressure sensor core test seats are provided with upper vent holes; a plurality of lower differential pressure sensor core test seats are provided at the four corners of the lower installation groove and the long side plate of the lower installation groove, and the positions of the upper differential pressure sensor core test seats correspond to those of the lower differential pressure sensor core test seats; the number of the upper differential pressure sensor core test seats is the same as the number of differential pressure sensor cores to be tested;

Two lower positioning pin seats are respectively arranged on the short side plates of the lower mounting groove; two upper positioning pin seats are respectively arranged on the short side plates of the upper mounting groove; the positions of the upper positioning pin seats correspond to those of the lower positioning pin seats;

A lower vent hole is provided on the lower differential pressure sensor core test seat; the number of the lower differential pressure sensor core test seats is the same as the number of the differential pressure sensor cores to be tested;

The lower mounting groove and the upper mounting groove are both provided with air inlets in a direction parallel to the hole;

One of the air inlets penetrates through one long side plate of the lower mounting slot and terminates at the other long side plate of the lower mounting slot;

Another air inlet penetrates through one long side plate of the upper mounting slot and terminates at the other long side plate of the upper mounting slot;

The two air inlets are also connected with valves respectively, one end of the valve is connected to the air inlet, and the other end is connected to the gas pressure controller;

A plurality of differential pressure sensor cores to be measured are installed between the lower mounting groove and the upper mounting groove; an upper air guide hole is also provided on the short side plate of the upper mounting groove, and a lower air guide hole is also provided on the short side plate of the lower mounting groove; one air inlet is respectively connected to the upper air vent and the upper air guide hole in a sealed state; the other air inlet is respectively connected to the lower air vent and the lower air guide hole in a sealed state;

One end of the differential pressure sensor core to be tested is a positive cavity, and the other end is a negative cavity; the differential pressure sensor core to be tested includes 4 resistors, and the signals of the 4 resistors are led out through signal output lines; the differential pressure sensor core to be tested has 5 signal output lines.

The test fixture also includes an adjustable DC power supply to provide power to the differential pressure sensor core under test.

In some embodiments of the present application, the tooling further includes two lead screws;

The upper mounting groove is also provided with two screw through holes for the screw to pass through, and the screw through holes are located between the guide shaft through holes in the direction of the short side plate of the upper mounting groove;

A lead screw nut having an internal thread structure matching the external thread of the lead screw is arranged at a position covering the lead screw through hole on the upper mounting groove, the lead screw nut covers the lead screw through hole and is fixed on the upper mounting groove;

The lower mounting groove is provided with an upper tapered roller bearing mounting seat and a lower tapered roller bearing mounting seat; the upper tapered roller bearing mounting seat and the lower tapered roller bearing mounting seat are both cylindrical groove structures;

An upper tapered roller bearing is installed in the upper tapered roller bearing mounting seat, and a lower tapered roller bearing is installed in the lower tapered roller bearing mounting seat;

The lead screw is screwed into the lead screw nut through a thread, passes through the upper tapered roller bearing and the lower tapered roller bearing in sequence, and the lead screw and the lower tapered roller bearing are locked together through a fixing nut at the bottom end of the lead screw.

In some embodiments of the present application, keyways are further provided on the two lead screws, and a sprocket is respectively sleeved on each of the two lead screws, and a keyway structure matching the keyway on the lead screw is provided on the sprocket; a square key is provided in the space enclosed by the keyway on the sprocket and the keyway on the lead screw, and the sprocket and the lead screw are connected through the square key;

A chain is sleeved between the two sprocket wheels, and the chain is meshed with the sprocket wheels.

In some embodiments of the present application, a rocker wheel is further provided on one of the two lead screws;

The center of the rocking wheel is a circular ring structure, and a keyway structure matching the keyway on the lead screw is arranged inside the circular ring. A square key is arranged in the space enclosed by the keyway on the rocking wheel and the keyway on the lead screw, and the rocking wheel and the lead screw are connected by the square key. The tester can move the upper mounting groove up and down by rotating the rocking wheel to make the upper mounting groove and the lower mounting groove in a buckled or separated state. In this embodiment, the rocking wheel can be installed on any of the two lead screws.

In some embodiments of the present application, an internal thread is provided in the lower positioning pin seat;

The upper positioning pin seat and the lower positioning pin seat are positioned by positioning pins;

One end of the positioning pin is provided with an external thread matched with the internal thread of the lower positioning pin seat;

The locating pin is connected to the lower locating pin seat through threads.

In a second aspect, an embodiment of the present application provides a differential pressure sensor core testing method, which is applied to any differential pressure sensor core testing tool in the first aspect, and the method includes:

Obtain all the differential pressure sensor cores to be tested; one end of the differential pressure sensor core to be tested is a positive cavity, and the other end is a negative cavity;

Install the same cavity end of all the differential pressure sensor cores to be tested in the lower installation groove, and install the other cavity end of all the differential pressure sensor cores to be tested in the upper installation groove;

Tighten the upper mounting groove and the lower mounting groove to ensure that all the differential pressure sensor cores to be tested are in a clamped state;

Adjust the position of the test fixture so that the upper mounting groove and the lower mounting groove are at the same horizontal plane;

Inject test gas of set pressure into the gas inlet to test the differential pressure sensor core to be tested.

In some embodiments, the step of testing the differential pressure sensor core to be tested further includes:

Mechanical fatigue screening test, temperature shock aging screening test, electrical shock aging screening test, overload test, bidirectional static pressure error test, static performance test, temperature compensation test, temperature compensation verification test, stability test.

In some embodiments, the mechanical fatigue screening test method comprises:

At room temperature, install the core of the differential pressure sensor to be tested, connect the two air inlets to the fatigue generator, one of which is connected to the positive cavity of the differential pressure sensor core, and the other is connected to the negative cavity of the differential pressure sensor core. Adjust the output of the fatigue generator to the full-scale pressure of the differential pressure sensor core to be tested, set the pressurization and decompression time interval to 2 seconds, and pressurize and decompress the two air inlets alternately for 5000 times each.

In some embodiments, the temperature shock weathering screening test method comprises:

Put the test fixture of the differential pressure sensor core to be tested into the high and low temperature test chamber, control the temperature of the high and low temperature test chamber, and after each temperature point stabilizes, control the high-precision digital multimeter to measure the output signal of the differential pressure sensor core to be tested, control the insulation resistance tester to measure the insulation resistance of the differential pressure sensor core to be tested, and control the leakage current tester to measure the leakage current of the differential pressure sensor core to be tested; wherein, the temperature rise and fall rate is maintained at 5℃/min, and the test temperature points and temperature stabilization time are set according to the following process:

Keep at 25℃ for 2 hours; keep at -55℃ for 2 hours; keep at +150℃ for 2 hours, and make 4 sets of temperature cycles;

Keep at 25℃ for 1.5 hours; keep at -55℃ for 2 hours, keep at +150℃ for 2 hours, and perform 5 sets of temperature cycles;

Keep at 25℃ for 1.5 hours; keep at -55℃ for 12 hours; keep at 25℃ for 2 hours; keep at 150℃ for 12 hours; keep at 25℃ for 12 hours, and perform 2 sets of temperature cycles.

In some embodiments, the electrical shock weathering screening test method comprises:

Place the test fixture with the differential pressure sensor core to be tested into the high and low temperature test chamber, and then control the high and low temperature test chamber to stabilize its temperature at 60°C. Control the output voltage of the adjustable DC power supply according to the following process:

S1: Control the output voltage of the adjustable DC power supply so that it outputs the upper limit power supply voltage of the differential pressure sensor core to be tested and maintain it for 2 hours;

S2: Control the output voltage of the adjustable DC power supply so that it outputs the rated power supply voltage of the differential pressure sensor core to be tested and maintains it for 4 hours;

S3: Control the output voltage of the adjustable DC power supply so that it outputs the lower limit power supply voltage of the differential pressure sensor core to be tested, and maintain it for 2 hours;

S4: Execute S1 to S3 process 3 times, and cut off the power for 1 hour;

S5: Repeat the S4 process 5 times;

S6: Control the high-precision digital multimeter to measure the output signal of the differential pressure sensor core to be tested, control the insulation resistance tester to measure the insulation resistance of the differential pressure sensor core to be tested, and control the leakage current tester to measure the leakage current of the differential pressure sensor core to be tested.

In some embodiments, the static performance test method includes: positive cavity static performance test without static pressure, positive cavity static performance test with static pressure, negative cavity static performance test without static pressure, and negative cavity static performance test with static pressure; the content of the performance test includes the nonlinearity, temperature hysteresis, repeatability, and comprehensive accuracy of the differential pressure sensor core to be tested.

The process of the positive cavity static performance test without static pressure includes:

The air inlet communicating with the positive cavity of the differential pressure sensor core to be tested is connected to the gas pressure controller, and the air inlet communicating with the negative cavity of the differential pressure sensor core to be tested is connected to the atmosphere. The output of the gas pressure controller is adjusted to apply full-scale pressures of 0%, 20%, 40%, 60%, 80%, 100%, 80%, 60%, 40%, 20%, and 0% to the positive cavity of the differential pressure sensor core to be tested in sequence, and control the high-precision digital multimeter to measure and record the output value of the differential pressure sensor core to be tested; repeat the above-mentioned pressurization test process twice, and test 3 times in total, record the output value of the differential pressure sensor core to be tested, and calculate the nonlinearity, temperature hysteresis, repeatability, and comprehensive accuracy static performance indicators of the positive cavity of the differential pressure sensor core to be tested without static pressure.

The process of positive cavity static pressure static performance testing includes:

The air inlet of the upper mounting groove and the air inlet of the lower mounting groove are connected to the same gas pressure controller, and the output of the gas pressure controller is adjusted to the pressure required by the static pressure index of the differential pressure sensor core to be tested. Static pressure is applied to the two air inlets at the same time. After reaching the static pressure, the air inlet valve connected to the negative cavity of the differential pressure sensor core to be tested is closed, and the air inlet connected to the positive cavity of the differential pressure sensor core to be tested continues to be pressurized. On the basis of the static pressure, the differential pressure full scale of 0%, 20%, 40%, 60%, 80%, 100%, 80%, 60%, 40%, 20%, and 0% pressures are additionally applied to the positive cavity of the differential pressure sensor core to be tested in sequence, and the high-precision digital multimeter is controlled to measure and record the output value of the differential pressure sensor core to be tested; repeat the above-mentioned pressurization test process twice, a total of 3 tests, record the output value of the differential pressure sensor core to be tested, and calculate the nonlinearity, temperature hysteresis, repeatability, and comprehensive accuracy static performance indicators under the static pressure of the positive cavity of the differential pressure sensor core to be tested.

The process of negative cavity non-static pressure static performance test includes:

The air inlet communicating with the negative cavity of the differential pressure sensor core to be tested is connected to a gas pressure controller, and the air inlet communicating with the positive cavity of the differential pressure sensor core to be tested is connected to the atmosphere. The output of the gas pressure controller is adjusted to apply full-scale pressures of 0%, 20%, 40%, 60%, 80%, 100%, 80%, 60%, 40%, 20%, and 0% to the negative cavity of the differential pressure sensor core to be tested in sequence, and a high-precision digital multimeter is controlled to measure and record the output value of the differential pressure sensor core to be tested; the above-mentioned pressurization test process is repeated twice, and the test is conducted 3 times in total, and the output value of the differential pressure sensor core to be tested is recorded, and the nonlinearity, temperature hysteresis, repeatability, and comprehensive accuracy static performance indicators of the negative cavity of the differential pressure sensor core to be tested without static pressure are calculated.

The process of negative cavity static pressure static performance test includes:

The air inlet of the upper mounting groove and the air inlet of the lower mounting groove are connected to the same gas pressure controller, and the output of the gas pressure controller is adjusted to the pressure required by the static pressure index of the differential pressure sensor core to be measured. Static pressure is applied to the two air inlets at the same time. After reaching the static pressure, the valve of the air inlet connected to the positive cavity of the differential pressure sensor core to be measured is closed, and the air inlet connected to the negative cavity of the differential pressure sensor core to be measured continues to be pressurized. On the basis of the static pressure, the negative cavity of the differential pressure sensor core to be measured is additionally applied with differential pressure full range 0%, 20%, 40%, 60%, 80%, 100%, 80%, 60%, 40%, 20%, 0% pressure in sequence, to control the high-precision digital multimeter The output value of the differential pressure sensor core to be tested is measured and recorded; the above pressurization test process is repeated twice, for a total of 3 tests, the output value of the differential pressure sensor core to be tested is recorded, and the nonlinearity, temperature hysteresis, repeatability, and comprehensive accuracy static performance indicators of the negative cavity under static pressure of the differential pressure sensor core to be tested are calculated.

In some embodiments, the temperature compensation test method includes:

Place the test fixture of the differential pressure sensor core to be tested in a high and low temperature test chamber, connect the air inlet connected to the positive cavity of the differential pressure sensor core to be tested to the gas pressure controller, and connect the air inlet connected to the negative cavity of the differential pressure sensor core to be tested to the atmosphere, control the high and low temperature test chamber to stabilize its temperature at -55°C, 25°C, and 150°C, respectively. After maintaining each temperature point for 2 hours, control the gas pressure controller to output 0MPa, test and record the output value of the differential pressure sensor core to be tested at zero point and the resistance values of the four resistors; control the gas pressure controller to output full-scale pressure, test and record the full-scale output of the differential pressure sensor core to be tested and the resistance values of the four resistors after stabilization, and unload the pressure at the end of the test;

According to the output of the differential pressure sensor core to be tested at the three temperature points recorded in the above test and the four resistor values, the compensation resistance value is calculated by the temperature compensation formula.

It can be seen from the above technical solution that the beneficial effects of this application are:

1) The present application provides a differential pressure sensor core testing tool and a testing method thereof, which installs the differential pressure sensor core to be tested between the upper mounting groove and the lower mounting groove of the tool, and tightens the upper mounting groove and the lower mounting groove to ensure that the differential pressure sensor core to be tested is in a clamped state, and then injects the test gas through the air inlet provided outside the differential pressure sensor core testing tool to test the differential pressure sensor core to obtain the test result. The present application clamps the differential pressure sensor core to be tested by using the upper mounting groove and the lower mounting groove, and mutually interpenetrating air vents and air guide holes are provided inside the upper mounting groove and the lower mounting groove, and the upper mounting groove and the lower mounting groove each have only one air inlet, so that after the tester injects the test gas into the air inlet, multiple differential pressure sensor cores to be tested can be tested at the same time, solving the problem of large workload of differential pressure sensor core installation and multiple air inlet pipe joints prone to air leakage, and improving the accuracy and efficiency of differential pressure sensor core testing.

2) A guide shaft and a positioning pin are used to guide and position the upper mounting groove and the lower mounting groove for engagement and separation, which can greatly improve the docking accuracy between the upper mounting groove and the lower mounting groove, ensure the accurate engagement and separation of the upper mounting groove and the lower mounting groove, thereby ensuring that the differential pressure sensor core to be tested can be accurately and smoothly pressed into the upper differential pressure sensor core test seat and the lower differential pressure sensor core test seat.

3) The guide shaft is inserted into the linear bearing structure to convert the linear motion into rolling motion, which greatly reduces the friction between the guide shaft and the upper mounting groove during relative motion, making the movement of the upper mounting groove more labor-saving and smooth.

4) The structure of using a chain to drive the sprocket and then drive the lead screw can ensure that the two lead screws rotate synchronously, so that the upper mounting groove can be raised and lowered horizontally and smoothly, ensuring that the core of the differential pressure sensor to be tested is synchronously pressed into the upper mounting groove and the lower mounting groove of the test fixture.

5) The use of tapered roller bearings can ensure the smooth rotation of the screw, making the movement of the mounting slot on the tooling fixture more labor-saving and smooth.

6) The use of a rocker drive makes the installation and removal of the differential pressure sensor core to be tested more convenient and labor-saving.

7) The mechanical fatigue screening test, temperature shock aging screening test, and electrical shock aging screening test methods can effectively release the stress generated during the production process of the differential pressure sensor core and improve the various performances of the differential pressure sensor core.

8) Mechanical fatigue screening test and temperature shock aging screening test can be used to effectively detect and eliminate differential pressure sensor cores with diaphragm damage and oil leakage in the early stage of differential pressure sensor core testing; electrical shock aging screening test can be used to effectively detect differential pressure sensor cores with unqualified electrical parameters in the early stage of differential pressure sensor core testing, which can improve the testing efficiency of differential pressure sensor cores, improve the product quality of differential pressure sensor cores, and reduce production costs.

9) Using the temperature compensation test method to perform temperature compensation on the differential pressure sensor core can greatly improve the measurement accuracy of the differential pressure sensor core.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the technical solution of the present application, the drawings required for use in the embodiments are briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

FIG1 is a three-dimensional view of a differential pressure sensor core testing tool provided in an embodiment of the present application;

FIG2 is a cross-sectional view of a differential pressure sensor core testing tool provided in an embodiment of the present application;

FIG3 is a side view of a differential pressure sensor core testing tool provided in an embodiment of the present application;

FIG4 is a top view of a differential pressure sensor core testing tool provided in an embodiment of the present application;

FIG5 is a schematic diagram of the structure of the lower mounting slot in an embodiment of the present application;

FIG6 is a schematic diagram of the structure of the upper mounting groove in the embodiment of the present application;

FIG. 7 is a schematic diagram of an exploded structure of the lead screw in an embodiment of the present application.

Illustration: 1-upper mounting groove, 2-guide shaft, 3-lower mounting groove, 4-differential pressure sensor core to be tested, 5-first sealing ring, 6-second sealing ring, 7-air inlet, 8-linear bearing, 9-screw, 10-rocker, 11-chain, 12-upper tapered roller bearing, 13-lower tapered roller bearing, 14-upper tapered roller bearing mounting seat, 15-lower tapered roller bearing mounting seat, 16-screw nut, 17-fixing nut, 18-sprocket, 21-guide shaft fixing seat, 23-lower differential pressure sensor core test seat, 24-lower positioning pin seat, 26-guide shaft through hole, 27-screw through hole, 28-upper differential pressure sensor core test seat, 29-upper positioning pin seat.

Detailed ways

The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments. It should be noted that, in the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other. The technical solutions in the embodiments of the present application will be clearly described below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments of the present application, other embodiments obtained by ordinary technicians in this field without making creative work belong to the scope of protection of the present application.

It should be noted that the brief description of terms in this application is only for the convenience of understanding the embodiments described below, and is not intended to limit the embodiments of this application. Unless otherwise specified, these terms should be understood according to their ordinary and common meanings.

At present, most of the differential pressure sensor core test tools adopt a single core test structure. Each test tool can only test one differential pressure sensor core at a time. If multiple differential pressure sensor cores are to be tested at the same time, multiple identical test tools must be used. The workload of core installation is very large, and the test accuracy and efficiency are not high.

One end of multiple differential pressure sensor cores are assembled on a structural part and share one air inlet, while the other end of the differential pressure sensor core still adopts a one-to-one connection structure. Although the use of a test fixture with multiple air inlets can partially improve the test efficiency, since the test fixture still has a large number of air inlet pipe joints, the air inlet may still have the problem of air leakage.

In order to solve the above problems, in the first aspect, the present application provides a differential pressure sensor core testing tool, which includes a lower mounting groove 3 and an upper mounting groove 1 that can be snapped together, and a plurality of guide shafts 2. The upper mounting groove 1 and the lower mounting groove 3 are used to clamp a plurality of differential pressure sensor cores 4 to be tested, and the positive cavity and the negative cavity of the differential pressure sensor core 4 to be tested can fully contact with the test gas to achieve a good test effect.

The differential pressure sensor core 4 to be tested is a device for measuring the difference between two pressures, with one end being a positive cavity and the other end being a negative cavity; the differential pressure sensor core 4 to be tested includes four resistors inside, and the signals of the four resistors are led out through signal output lines; the differential pressure sensor core 4 to be tested has five signal output lines.

As shown in FIG. 1 and FIG. 3 , when the upper mounting groove 1 and the lower mounting groove 3 are buckled together, a plurality of holes are formed on two opposite sides to reduce the weight of the test fixture.

In some embodiments, the lower mounting groove 3 and the upper mounting groove 1 are both provided with air inlets 7 in a direction parallel to the hole.

One of the air inlets 7 passes through one long side plate of the lower mounting groove 3 and ends at the other long side plate of the lower mounting groove 3 .

Another air inlet 7 passes through one long side plate of the upper mounting groove 1 and ends at the other long side plate of the upper mounting groove 1 .

The two air inlets 7 are also connected to valves respectively, one end of the valve is connected to the air inlet 7, the air inlet 7 is used to inject test gas of set pressure into the test tooling, and the other end of the valve is connected to the outlet of the gas pressure controller through a pipeline.

The guide shaft 2 can be a cylindrical body with a smooth surface, which plays a guiding and positioning role when the upper mounting groove 1 and the lower mounting groove 3 are buckled. During the installation of the guide shaft 2, the guide shaft 2 vertically penetrates the upper mounting groove 1 and is installed in the lower mounting groove 3.

In some embodiments of the present application, a guide shaft fixing seat 21 for installing the guide shaft 2 is provided at the bottom of the lower mounting groove 3; the guide shaft fixing seat 21 is a cylindrical groove structure. After the guide shaft 2 is inserted into the guide shaft fixing seat 21, in order to prevent the guide shaft 2 from loosening and causing the upper mounting groove 1 and the lower mounting groove 3 to be unable to be accurately positioned, in this embodiment, the guide shaft 2 can also be fixed in the guide shaft fixing seat 21 by a fixing component, and the guide shaft 2 can also be fixed in the guide shaft fixing seat 21 by an interference fit method.

Corresponding to the guide shaft fixing seat 21 of the lower mounting groove 3 , a guide shaft through hole 26 through which the guide shaft 2 passes is provided at the bottom of the upper mounting groove 1 ; the position of the guide shaft through hole 26 corresponds to the guide shaft fixing seat 21 .

In some embodiments, as shown in Figure 5, the lower mounting groove 3 and the upper mounting groove 1 each include two long side plates and a short side plate, and a total of several lower differential pressure sensor core test seats 23 are arranged on the four corners of the lower mounting groove 3 and the long side plates of the lower mounting groove 3. The number of the lower differential pressure sensor core test seats 23 is the same as the number of the differential pressure sensor cores 4 to be tested, and is used to clamp the differential pressure sensor core 4 to be tested.

As shown in FIG6 , corresponding to the lower differential pressure sensor core test seat 23, the upper mounting groove 1 is also provided with a plurality of upper differential pressure sensor core test seats 28, the upper differential pressure sensor core test seats 28 correspond to the position of the lower differential pressure sensor core test seat 23, and the number of the upper differential pressure sensor core test seats 28 is the same as the number of the differential pressure sensor cores 4 to be tested. When the tester clamps the differential pressure sensor cores 4 to be tested, the same end of all the differential pressure sensor cores 4 to be tested will be installed in the lower differential pressure sensor core test seat 23, for example, the positive cavity of all the differential pressure sensor cores 4 to be tested; when the upper mounting groove 1 and the lower mounting groove 3 are buckled, the upper differential pressure sensor core test seat 28 on the upper mounting groove 1 will be buckled with the other end of all the differential pressure sensor cores 4 to be tested, for example, the negative cavity of all the differential pressure sensor cores 4 to be tested. So that all the differential pressure sensor cores 4 to be tested are in a clamped state.

There are two installation situations in the above embodiment. The first one is that the positive cavities of all differential pressure sensor cores 4 to be tested are installed in the lower installation groove 3, that is, the positive cavities of all differential pressure sensor cores 4 to be tested are assembled in the lower differential pressure sensor core test seat 23, and the negative cavities of all differential pressure sensor cores 4 to be tested are assembled in the upper differential pressure sensor core test seat 28. The second one is that the positive cavities of all differential pressure sensor cores 4 to be tested are installed in the upper installation groove 1, that is, the positive cavities of all differential pressure sensor cores 4 to be tested are assembled in the upper differential pressure sensor core test seat 28, and the negative cavities of all differential pressure sensor cores 4 to be tested are assembled in the lower differential pressure sensor core test seat 23.

It should be noted that this embodiment only needs to ensure that the same end of all the differential pressure sensor cores 4 to be tested is located in one installation groove. For example, the positive cavities of all the differential pressure sensor cores 4 to be tested are installed in the lower installation groove 3, and the negative cavities of all the differential pressure sensor cores 4 to be tested are installed in the upper installation groove 1.

In some embodiments of the present application, as shown in FIG. 2 , a linear bearing 8 is further provided in the guide shaft through hole 26. 2 passes through the linear bearing 8 to make the relative movement between the guide shaft 2 and the upper mounting groove 1 smooth and stable. The linear bearing 8 is a linear motion device used for linear travel in conjunction with a cylindrical shaft. When installing the linear bearing 8, the linear bearing 8 can also be passed through the guide shaft through hole 26 and fixed to the upper mounting groove 1 by a hexagon socket bolt. The structure of the guide shaft 2 being inserted into the linear bearing 8 converts the linear motion into rolling motion, reduces the friction force when the guide shaft 2 and the upper mounting groove 1 move relative to each other, and makes the clamping process of the differential pressure sensor core 4 to be measured more labor-saving.

In some embodiments, as shown in FIG3 , a first sealing ring 5 is further provided at the lower end of the differential pressure sensor core 4 to be tested, and a second sealing ring 6 is further provided at the upper end of the differential pressure sensor core 4 to be tested, so as to produce a buffering effect on the differential pressure sensor core 4 to be tested when tightened. On the other hand, the first sealing ring 5 and the second sealing ring 6 can also play a sealing effect when testing the differential pressure sensor core 4 to be tested.

5 and 6, two lower positioning pin seats 24 are respectively arranged on the short side plates of the lower mounting groove 3, and the guide shaft fixing seats 21 are connected by a plate-like structure in the direction of the short side plates. Two upper positioning pin seats 29 are respectively arranged on the short side plates of the upper mounting groove 1; the upper positioning pin seats 29 correspond to the positions of the lower positioning pin seats 24.

In some embodiments of the present application, an internal thread is provided in the lower positioning pin seat 24, and an external thread matching the internal thread of the lower positioning pin seat 24 is provided at the lower end of the positioning pin, and the lower end of the positioning pin is connected to the lower positioning pin seat 24 via the thread.

After the upper mounting groove 1 and the lower mounting groove 3 are buckled, the upper end of the locating pin enters the upper locating pin seat 29, further improving the docking accuracy of the upper mounting groove 1 and the lower mounting groove 3, ensuring that all differential pressure sensor cores 4 to be tested can be accurately pressed into the test fixture.

As shown in FIG. 7 , in some embodiments of the present application, the test fixture further includes two lead screws 9 , which are cylindrical structures, slightly thinner at the top and bottom ends, and thicker in the middle, with a keyway provided at the top end and an external thread structure provided at the bottom end.

In some embodiments, as shown in Figures 1-3, the upper mounting groove 1 is also provided with two screw through holes 27 for the screw 9 to pass through; the screw through hole 27 is located between the two guide shaft through holes 26 in the short side plate direction of the upper mounting groove 1; a screw nut 16 with an internal thread structure compatible with the external thread of the screw 9 is provided on the upper mounting groove 1 at a position covering the screw through hole 27, and the screw nut 16 covers the screw through hole 27 and is fixed on the upper mounting groove 1.

In some embodiments of the present application, the lower mounting groove 3 is further provided with an upper tapered roller bearing mounting seat 14 and a lower tapered roller bearing mounting seat 15; the upper tapered roller bearing mounting seat 14 and the lower tapered roller bearing mounting seat 15 are cylindrical groove structures.

An upper tapered roller bearing 12 is installed in the upper tapered roller bearing mounting seat 14, and a lower tapered roller bearing 13 is installed in the lower tapered roller bearing mounting seat 15; the force direction of the upper tapered roller bearing 12 is downward, and the force direction of the lower tapered roller bearing 13 is upward.

The inner and outer rings of the upper tapered roller bearing 12 and the lower tapered roller bearing 13 both have tapered tracks.

The lead screw 9 is screwed into the lead screw nut 16 through a thread, passes through the upper tapered roller bearing 12 and the lower tapered roller bearing 13 in sequence, and the lead screw 9 and the lower tapered roller bearing 13 are locked together by a fixing nut 17 at the bottom end of the lead screw 9.

In some embodiments of the present application, a keyway is also provided on the two lead screws 9, and a sprocket 18 is respectively provided on the two lead screws 9, and a keyway structure matching the keyway on the lead screw 9 is provided on the sprocket 18, and a square key is provided in the space enclosed by the keyway on the sprocket 18 and the keyway on the lead screw 9, and the sprocket 18 is connected to the lead screw 9 through the square key, and the lead screw 9 and the sprocket 18 can realize synchronous rotation. The sprocket 18 is installed at the same height of the two lead screws 9, and a chain 11 is provided between the two sprockets 18, and the chain 11 is sleeved on the outside of the two sprockets 18 to form a structure similar to a conveyor belt. The chain 11 is meshed with the sprocket 18, and when the chain 11 rotates, the sprocket 18 will also drive the lead screw 9 to rotate synchronously. In this embodiment, the chain 11 drives the sprocket 18, and then drives the lead screw 9, so that the upper mounting groove 1 is stably raised and lowered, ensuring that all the differential pressure sensor cores 4 to be tested are synchronously pressed into the test fixture.

In some embodiments of the present application, referring to FIG. 4 , a rocker 10 is further provided on one of the two lead screws 9 . The center of the rocking wheel 10 is a circular ring structure, and a keyway structure matching the keyway on the lead screw 9 is arranged inside the circular ring. A square key is arranged in the space enclosed by the keyway on the rocking wheel 10 and the keyway on the lead screw 9, and the rocking wheel 10 and the lead screw 9 are connected by the square key. The tester can move the upper mounting groove 1 up and down by rotating the rocking wheel 10 to make the upper mounting groove 1 and the lower mounting groove 3 in a buckled or separated state. In this embodiment, the rocking wheel 10 can be installed on any of the two lead screws 9.

In some embodiments of the present application, a lower air vent is provided on the lower differential pressure sensor core test seat 23 and an upper air vent is provided on the upper differential pressure sensor core test seat 28; an upper air guide hole is also provided on the short side plate of the upper mounting groove 1, and a lower air guide hole is also provided on the short side plate of the lower mounting groove 3.

Furthermore, since the upper mounting groove 1 and the lower mounting groove 3 on the test fixture are respectively provided with an air inlet 7, for the above two air inlets 7, one of the air inlet 7 forms a closed through-state with the upper air vent and the upper air guide hole, and the other air inlet 7 forms a closed through-state with the lower air vent and the lower air guide hole. This ensures that the test gas is injected from the air inlet 7, passes through the upper air guide hole, the upper air vent or the lower air guide hole, the lower air vent, and reaches the differential pressure sensor core 4 to be tested for testing. It is ensured that there is only one air inlet 7 for each of the upper mounting groove 1 and the lower mounting groove 3, which facilitates the injection of the test gas and reduces the risk of leakage of the test fixture joint.

It should be noted that in actual processing, after drilling the upper air guide holes that pass through the short side plates on both sides on the upper mounting groove 1, and after drilling the lower air guide holes that pass through the short side plates on both sides on the lower mounting groove 3, the upper air guide hole openings on the short side plates on both sides of the upper mounting groove 1, and the lower air guide hole openings on the short side plates on both sides of the lower mounting groove 3 can be sealed and blocked by welding to ensure that one air inlet 7 forms a closed through-state with the lower air vent and the lower air guide hole, and the other air inlet 7 forms a closed through-state with the upper air vent and the upper air guide hole; in this embodiment, the lower differential pressure sensor core test seat 23 is used to test the differential pressure to be measured. One cavity of the sensor core 4, the upper differential pressure sensor core test seat 28 is used to test the other cavity of the differential pressure sensor core 4 to be tested, to ensure that when the differential pressure sensor core 4 to be tested is clamped by the upper mounting groove 1 and the lower mounting groove 3, both upper and lower ends of the differential pressure sensor core 4 to be tested can be fully contacted by the test gas, as for which cavity of the differential pressure sensor core 4 to be tested by the lower differential pressure sensor core test seat 23 and the upper differential pressure sensor core test seat 28 respectively, no limitation is made here, but it must be ensured that the same cavity end of all differential pressure sensor cores 4 to be tested is pressed into the lower differential pressure sensor core test seat 23 and the upper differential pressure sensor core test seat 28.

In some embodiments of the present application, the method of using the above-mentioned test fixture is as follows: rotate the wheel 10 clockwise, and the lead screw 9 rotates clockwise synchronously under the drive of the wheel 10, thereby driving the chain 11 and the sprocket 18 to rotate, the upper mounting groove 1 slowly rises, and the lower mounting groove 3 is separated from the upper mounting groove 1. When the distance between the lower mounting groove 3 and the upper mounting groove 1 reaches the distance for installing the differential pressure sensor core 4 to be tested, stop rotating the wheel 10, and install a preset number of differential pressure sensor cores 4 to be tested inside the lower differential pressure sensor core test seat 23. The number of differential pressure sensor cores 4 to be tested should be equal to the number of lower differential pressure sensor core test seats 23. Then rotate the wheel 10 counterclockwise, and slowly lower the upper mounting groove 1 until the differential pressure sensor core 4 to be tested is pressed into the upper differential pressure sensor core test seat 28, that is, the clamping of the differential pressure sensor core 4 to be tested is completed. Finally, inject the test gas into the test fixture through the air inlet 7 to complete the test of the differential pressure sensor core 4 to be tested.

The disassembly process of the differential pressure sensor core 4 to be measured is the reverse process of the above-mentioned installation process, which will not be described in detail here.

In some embodiments of the present application, valves are respectively connected to the two air inlets 7, one end of the valve is connected to the air inlet 7, and the other ends of the two valves are connected to a gas pressure controller through a three-way common air inlet interface, so that the gas pressure controller can provide gas of a certain pressure to the air inlet 7 simultaneously or in different time periods.

In some embodiments of the present application, the valve may be a solenoid valve, a hydraulic valve, a pneumatic valve or other valve structures.

In some embodiments of the present application, the test fixture further includes an adjustable DC power supply to provide power to the differential pressure sensor core 4 to be tested.

In a second aspect, the present application also provides a differential pressure sensor core testing method, which is applied to any of the above Differential pressure sensor core test tooling, the method includes:

S100: Acquire all differential pressure sensor cores to be tested.

S200: Install the same cavity end of all the differential pressure sensor cores to be tested in the lower installation groove 3, and install the other cavity end of all the differential pressure sensor cores to be tested in the upper installation groove 1.

S300: Tighten the upper mounting groove 1 and the lower mounting groove 3 to ensure that all the differential pressure sensor cores to be tested are in a clamped state.

S400: Adjust the position of the test fixture so that the upper installation slot 1 and the lower installation slot 3 are at the same horizontal plane.

S500: injecting a test gas of a set pressure into the air inlet 7 to test the differential pressure sensor core to be tested.

In some embodiments of the present application, the differential pressure sensor core is tested in the order of mechanical fatigue screening test, temperature shock aging screening test, electrical shock aging screening test, overload test, bidirectional static pressure error test, static performance test, temperature compensation test, compensation resistance welding, temperature compensation verification test and stability test.

For ease of description, the following test process is explained by taking the example that the positive cavity ends of all differential pressure sensor cores 4 to be tested are assembled in the lower differential pressure sensor core test seat 23, and the negative cavity ends of all differential pressure sensor cores 4 to be tested are assembled in the upper differential pressure sensor core test seat 28.

The process of the above mechanical fatigue screening test is as follows: at room temperature, the differential pressure sensor core 4 to be tested is installed, and two air inlets 7 are connected to the fatigue generator, one of the air inlets 7 is connected to the positive cavity of the differential pressure sensor core 4 to be tested, and the other air inlet 7 is connected to the negative cavity of the differential pressure sensor core 4 to be tested, and the fatigue generator output is adjusted to the full-scale pressure of the differential pressure sensor core to be tested, and the pressurization and decompression time interval is set to 2 seconds. After the two air inlets 7 are pressurized and decompressed 5,000 times each, the tooling is disassembled, and the differential pressure sensor core 4 to be tested with damaged diaphragms and oil leakage is removed, and the lower differential pressure sensor core test seat 23 and the upper differential pressure sensor core test seat 28 where the removed differential pressure sensor core 4 is located are blocked with plugs to prevent leakage, and the mechanical fatigue screening of the differential pressure sensor core 4 to be tested is completed.

The process of the temperature shock aging screening test is as follows: put the test fixture of the differential pressure sensor core 4 to be tested into a high and low temperature test chamber, control the high and low temperature test chamber to change the temperature at a certain temperature change rate, and after stabilization at each temperature point, control the high-precision digital multimeter to measure the output signal of the differential pressure sensor core 4 to be tested, control the insulation resistance tester to measure the insulation resistance of the differential pressure sensor core 4 to be tested, and control the leakage current tester to measure the leakage current of the differential pressure sensor core 4 to be tested. Among them, the temperature rise and fall rate is maintained at 5°C/min, and the test temperature points and temperature stabilization time are set according to the following process:

Keep at 25℃ for 2 hours; keep at -55℃ for 2 hours; keep at +150℃ for 2 hours, and perform 4 sets of temperature cycles.

Keep at 25℃ for 1.5 hours; keep at -55℃ for 2 hours; keep at +150℃ for 2 hours, and perform 5 sets of temperature cycles.

After the temperature shock aging screening test, disassemble the tooling, remove the differential pressure sensor core 4 to be tested that is leaking oil or has unqualified electrical parameters, and use plugs to seal the lower differential pressure sensor core test seat 23 and the upper differential pressure sensor core test seat 28 where the removed differential pressure sensor core 4 to be tested is located to prevent air leakage, thereby completing the temperature shock aging screening test for the differential pressure sensor core 4 to be tested.

The process of the above-mentioned electric shock aging screening test is as follows: put the test tooling assembled with the differential pressure sensor core 4 to be tested into a high and low temperature test chamber, and then control the high and low temperature test chamber to stabilize its temperature at 60°C, and control the output voltage of the adjustable DC power supply according to the following process:

S1: Control the output voltage of the adjustable DC power supply so that it outputs the upper limit power supply voltage of the differential pressure sensor core 4 to be tested, and maintain it for 2 hours.

S2: Control the output voltage of the adjustable DC power supply so that it outputs the rated power supply voltage of the differential pressure sensor core 4 to be tested, and maintain it for 4 hours.

S3: Control the output voltage of the adjustable DC power supply so that it outputs the lower limit power supply voltage of the differential pressure sensor core 4 to be tested, and maintain it for 2 hours.

S4: Repeat S1 to S3 for 3 times and cut off the power supply for 1 hour.

S5: Repeat the S4 process 5 times.

S6: Control the high-precision digital multimeter to measure the output signal of the differential pressure sensor core 4 to be tested, control the insulation resistance tester to measure the core insulation resistance of the differential pressure sensor core 4 to be tested, and control the leakage current tester to measure the core leakage current of the differential pressure sensor core 4 to be tested.

S7: Disassemble the tooling, remove the differential pressure sensor core 4 to be tested whose electrical parameters are unqualified, and use plugs to seal the lower differential pressure sensor core test seat 23 and the upper differential pressure sensor core test seat 28 where the removed differential pressure sensor core 4 to be tested is located to prevent air leakage, thereby completing the electric shock aging screening test of the differential pressure sensor core 4 to be tested.

The mechanical fatigue screening test, temperature shock aging screening test, and electrical shock aging screening test methods can effectively release the stress generated during the production process of the differential pressure sensor core 4 to be tested, and improve various performance indicators of the differential pressure sensor core 4 to be tested.

The process of the overload test is as follows: at room temperature, the differential pressure sensor core 4 to be tested is installed, and the zero-point output of the differential pressure sensor core 4 to be tested is first tested as a reference standard for overload error. The overload test includes a positive cavity overload test and a negative cavity overload test.

Positive cavity overload test: the air inlet 7 of the lower mounting slot 3 is connected to the gas pressure controller, and the air inlet 7 of the upper mounting slot 1 is connected to the atmosphere. The output of the gas pressure controller is adjusted to twice the full-scale pressure of the differential pressure sensor core 4 to be tested. Pressurize and maintain for 5 minutes and then release the pressure. Test and record the zero-point output value after overload, compare the output change of the zero point of the differential pressure sensor core 4 to be tested before and after the overload test, and calculate the positive cavity overload error.

Negative cavity overload test: the air inlet 7 of the upper mounting slot 1 is connected to the gas pressure controller, and the air inlet 7 of the lower mounting slot 3 is connected to the atmosphere. The output of the gas pressure controller is adjusted to twice the full-scale pressure of the differential pressure sensor core 4 to be tested. Pressurize and maintain for 5 minutes and then release the pressure. Test and record the zero-point output value after overload, compare the change in the zero-point output of the differential pressure sensor core 4 to be tested before and after the overload test, and calculate the negative cavity overload error.

The process of the above-mentioned bidirectional static pressure error test is as follows:

Before the static pressure test, the zero point and full-scale output of the differential pressure sensor core 4 to be tested are first tested as a reference standard for static pressure error.

The air inlet 7 of the upper mounting groove 1 and the air inlet 7 of the lower mounting groove 3 are connected to the same gas pressure controller, and the output of the gas pressure controller is adjusted to the pressure required by the static pressure index of the differential pressure sensor core 4 to be tested. Static pressure is applied to the two air inlets 7 at the same time, and the zero-point output value when the static pressure is applied is tested and recorded. The change in the zero-point output of the differential pressure sensor core 4 to be tested before and after the static pressure test is compared, and the zero-point static pressure error is calculated.

The air inlet 7 of the upper mounting groove 1 and the air inlet 7 of the lower mounting groove 3 are connected to the same gas pressure controller, and the output of the gas pressure controller is adjusted to the pressure required by the static pressure index of the differential pressure sensor core 4 to be tested. Static pressure is applied to the two air inlets 7 at the same time. After reaching the static pressure, the valve of the air inlet 7 of the upper mounting groove 1 is closed, and the air inlet 7 of the lower mounting groove 3 continues to be pressurized to the full-scale pressure. The full-scale output value when the static pressure is applied is tested and recorded, and the full-scale output change of the differential pressure sensor core 4 to be tested before and after the static pressure test is compared, and the full-scale static pressure error is calculated.

The above-mentioned static performance tests include positive cavity static performance test without static pressure, positive cavity static performance test with static pressure, negative cavity static performance test without static pressure, and negative cavity static performance test with static pressure; the content of the performance test includes the nonlinearity, temperature hysteresis, repeatability, and comprehensive accuracy of the differential pressure sensor core 4 to be tested.

Static performance test of positive cavity without static pressure:

At room temperature, the air inlet 7 connected to the positive cavity of the differential pressure sensor core 4 to be measured is connected to the gas pressure controller, and the air inlet 7 connected to the negative cavity of the differential pressure sensor core 4 to be measured is connected to the atmosphere. The output of the gas pressure controller is adjusted to provide the differential pressure sensor to be measured. The positive cavity of the sensor core 4 is applied with full-scale pressures of 0%, 20%, 40%, 60%, 80%, 100%, 80%, 60%, 40%, 20%, and 0% in sequence, and the high-precision digital multimeter is controlled to measure and record the output value of the differential pressure sensor core 4 to be tested; the above-mentioned pressurization test process is repeated twice, and the test is conducted 3 times in total, and the output value of the differential pressure sensor core 4 to be tested is recorded, and the nonlinearity, temperature hysteresis, repeatability, and comprehensive accuracy static performance indicators of the positive cavity of the differential pressure sensor core 4 to be tested without static pressure are calculated.

Positive cavity static pressure static performance test:

At room temperature, the air inlet 7 of the upper mounting groove 1 and the air inlet 7 of the lower mounting groove 3 are connected to the same gas pressure controller, and the gas pressure controller output is adjusted to the pressure required by the static pressure index of the differential pressure sensor core 4 to be measured. Static pressure is applied to the two air inlets 7 at the same time. After the static pressure is reached, the valve of the air inlet 7 connected to the negative cavity of the differential pressure sensor core 4 to be measured is closed, and the air inlet 7 connected to the positive cavity of the differential pressure sensor core 4 to be measured continues to be pressurized. On the basis of the static pressure, an additional pressure is applied to the positive cavity of the differential pressure sensor core 4 to be measured. Apply differential pressure of full scale 0%, 20%, 40%, 60%, 80%, 100%, 80%, 60%, 40%, 20%, 0% pressure for the first time, control the high-precision digital multimeter to measure and record the output value of the differential pressure sensor core 4 to be tested; repeat the above pressurization test process twice, for a total of 3 tests, record the output value of the differential pressure sensor core 4 to be tested, and calculate the nonlinearity, temperature hysteresis, repeatability, and comprehensive accuracy static performance indicators of the differential pressure sensor core 4 to be tested under positive cavity static pressure.

Negative cavity no static pressure static performance test:

At room temperature, the air inlet 7 connected to the negative cavity of the differential pressure sensor core 4 to be tested is connected to the gas pressure controller, and the air inlet 7 connected to the positive cavity of the differential pressure sensor core 4 to be tested is connected to the atmosphere. The output of the gas pressure controller is adjusted to apply full-scale pressures of 0%, 20%, 40%, 60%, 80%, 100%, 80%, 60%, 40%, 20%, and 0% to the negative cavity of the differential pressure sensor core 4 to be tested in sequence, and control the high-precision digital multimeter to measure and record the output value of the differential pressure sensor core 4 to be tested; repeat the above-mentioned pressurization test process twice, for a total of 3 tests, record the output value of the differential pressure sensor core 4 to be tested, and calculate the nonlinearity, temperature hysteresis, repeatability, and comprehensive accuracy static performance indicators of the negative cavity of the differential pressure sensor core 4 to be tested without static pressure.

Negative cavity static pressure static performance test:

At room temperature, the air inlet 7 of the upper mounting groove 1 and the air inlet 7 of the lower mounting groove 3 are connected to the same gas pressure controller, and the gas pressure controller output is adjusted to the pressure required by the static pressure index of the differential pressure sensor core 4 to be measured. The two air inlets 7 are pressurized at the same time. After reaching the static pressure, the valve of the air inlet 7 connected to the positive cavity of the differential pressure sensor core 4 to be measured is closed, and the air inlet 7 connected to the negative cavity of the differential pressure sensor core 4 to be measured continues to be pressurized. On the basis of the static pressure, the negative cavity of the differential pressure sensor core 4 to be measured is additionally pressurized. Apply differential pressure of full scale 0%, 20%, 40%, 60%, 80%, 100%, 80%, 60%, 40%, 20%, 0% pressure for the first time, control the high-precision digital multimeter to measure and record the output value of the differential pressure sensor core 4 to be tested; repeat the above pressurization test process twice, for a total of 3 tests, record the output value of the differential pressure sensor core 4 to be tested, and calculate the nonlinearity, temperature hysteresis, repeatability, and comprehensive accuracy static performance indicators of the negative cavity of the differential pressure sensor core 4 under static pressure.

The above temperature compensation test process is:

The test tooling of the assembled differential pressure sensor core 4 to be tested is placed in a high and low temperature test chamber, the air inlet 7 communicating with the positive cavity of the differential pressure sensor core 4 to be tested is connected to the gas pressure controller, and the air inlet 7 communicating with the negative cavity of the differential pressure sensor core 4 to be tested is connected to the atmosphere, and the high and low temperature test chamber is controlled to stabilize its temperature at -55°C, 25°C, and 150°C, respectively. After maintaining each temperature point for 2 hours, the gas pressure controller is controlled to output 0MPa, and the output value of the differential pressure sensor core 4 to be tested and the resistance values of the four resistors at the zero point are tested and recorded; the gas pressure controller is controlled to output the full-scale pressure, and the full-scale output of the differential pressure sensor core 4 to be tested and the resistance values of the four resistors are tested and recorded after stabilization, and the pressure is unloaded at the end of the test.

According to the output of the differential pressure sensor core 4 to be tested and the four resistance values at the three temperature points recorded in the above test, the compensation resistance value is calculated by the temperature compensation formula, and the sensor tooling is disassembled.

The above compensation resistance welding process is:

The compensation resistance value obtained according to the temperature compensation test is the welding compensation resistance of the differential pressure sensor 4 to be tested.

The above-mentioned temperature compensation verification test process is as follows: install the differential pressure sensor core 4 to be tested after welding the compensation resistor into the test fixture, put it into the high and low temperature test chamber, connect the air inlet 7 of the lower mounting groove 3 to the gas pressure controller, and connect the air inlet 7 of the upper mounting groove 1 to the atmosphere. Control the high and low temperature test chamber so that its temperature is controlled according to the program of -55℃, 25℃, 150℃, and 25℃, and keep each temperature point constant for two hours each. At each temperature point, control the gas pressure controller to output the zero pressure and full-scale pressure of the differential pressure sensor core 4 to be tested, control the high-precision digital multimeter to measure the zero output and full-scale output value of the differential pressure sensor core 4 to be tested, and calculate the sensitivity of the differential pressure sensor core 4 to be tested.

According to the zero-point output value of the differential pressure sensor core 4 under the temperature conditions of -55°C, 25°C and 150°C, the zero-point temperature drift of the differential pressure sensor core 4 under the temperature conditions of -55°C, 25°C and 150°C is calculated.

The sensitivity temperature drift of the differential pressure sensor core 4 to be tested is calculated according to the sensitivity output values of the differential pressure sensor core 4 to be tested under the temperature conditions of -55°C, 25°C and 150°C.

The temperature hysteresis of the differential pressure sensor core 4 to be tested is calculated according to the difference between the two 25° C. zero-point outputs in the above test.

The above stability test includes zero-point stability test and full-scale stability test. The test process is as follows:

Zero point stability test: control the high and low temperature test box to make its temperature controlled according to the program of -55℃, 25℃, and 150℃, and keep each temperature point constant for 8 hours. Test the zero point output of the differential pressure sensor core 4 to be tested at each temperature point, record it every 1 hour, and calculate the zero point stability of the differential pressure sensor core 4 to be tested based on the test data.

Full-scale stability test: The air inlet 7 of the lower mounting groove 3 is connected to the gas pressure controller, and the air inlet 7 of the upper mounting groove 1 is connected to the atmosphere. The high and low temperature test chamber is controlled so that its temperature is controlled according to the program of -55℃, 25℃, and 150℃, and each temperature point is kept constant for 8 hours each. At each temperature point, the full-scale pressure of the differential pressure sensor core 4 to be tested is applied to the air inlet 7 of the lower mounting groove 3, and the full-scale output of the differential pressure sensor core 4 to be tested is tested. Record once every 1 hour, and calculate the full-scale stability of the differential pressure sensor core 4 to be tested based on the test data.

It can be seen from the above scheme that the differential pressure sensor core testing tool and its testing method provided by the present application are to install the differential pressure sensor core 4 to be tested between the upper mounting groove 1 and the lower mounting groove 3 of the tool, and tighten the upper mounting groove 1 and the lower mounting groove 3 to ensure that the differential pressure sensor core 4 to be tested is in a clamped state. Then, the test gas is injected through the air inlet 7 arranged outside the differential pressure sensor core testing tool to test the differential pressure sensor core 4 to be tested and obtain the test result. The present application clamps the differential pressure sensor core by using the upper mounting groove 1 and the lower mounting groove 3, and provides airtight and mutually interpenetrating vents and air guide holes inside the upper mounting groove 1 and the lower mounting groove 3, so that after the tester injects the test gas into the air inlet, multiple differential pressure sensor cores 4 to be tested can be tested at the same time, thereby improving the test accuracy and efficiency and solving the problem of multiple air inlets and easy leakage of joints.

The "multiple embodiments", "some embodiments", "one embodiment" or "embodiment" mentioned throughout this specification means that the specific features, components or characteristics described in conjunction with the embodiment are included in at least one embodiment. Therefore, the phrases "in multiple embodiments", "in some embodiments", "in at least another embodiment" or "in an embodiment" appearing throughout this specification do not necessarily refer to the same embodiment. In addition, in one or more embodiments, specific features, components or characteristics may be combined in any suitable manner. Therefore, without limitation, the specific features, components or characteristics shown or described in conjunction with one embodiment may be combined in whole or in part with the features, components or characteristics of one or more other embodiments. Such modifications and variations are intended to be included within the scope of this application.

Similar parts between the embodiments provided in this application can be referenced to each other. The specific implementation methods provided above are only a few examples under the general concept of this application and do not constitute a limitation on the protection scope of this application. For those skilled in the art, any other implementation methods expanded based on the scheme of this application without creative work belong to the protection scope of this application.

Claims

A differential pressure sensor core testing tool, characterized in that the tool comprises: a lower mounting groove (3) and an upper mounting groove (1) that can be buckled with each other, and a plurality of guide shafts (2); when the lower mounting groove (3) and the upper mounting groove (1) are buckled, a plurality of holes are formed on two opposite sides; the lower mounting groove (3) and the upper mounting groove (1) each comprise two long side plates and a short side plate;

The guide shaft (2) vertically passes through the upper mounting groove (1) and is installed on the lower mounting groove (3); a guide shaft through hole (26) for the guide shaft (2) to pass through is provided at the bottom of the upper mounting groove (1); a guide shaft fixing seat (21) for installing the guide shaft (2) is provided at the bottom of the lower mounting groove (3); the position of the guide shaft through hole (26) corresponds to the guide shaft fixing seat (21); a linear bearing (8) is also provided in the guide shaft through hole (26), and the guide shaft (2) passes through the linear bearing (8);

The guide shaft fixing seat (21) is a cylindrical groove structure; in the direction of the short side plate of the lower mounting groove (3), the guide shaft fixing seats (21) are connected by a plate-like structure;

The upper installation groove (1) is provided with a plurality of upper differential pressure sensor core test seats (28), and the upper differential pressure sensor core test seats (28) are provided with upper vent holes; a plurality of lower differential pressure sensor core test seats (23) are provided on the four corners of the lower installation groove (3) and the long side plate of the lower installation groove (3), and the positions of the upper differential pressure sensor core test seats (28) and the lower differential pressure sensor core test seats (23) correspond to each other; the number of the upper differential pressure sensor core test seats (28) is the same as the number of the differential pressure sensor cores (4) to be tested;

Two lower positioning pin seats (24) are respectively arranged on the short side plates of the lower mounting groove (3); two upper positioning pin seats (29) are respectively arranged on the short side plates of the upper mounting groove (1); the positions of the upper positioning pin seats (29) correspond to those of the lower positioning pin seats (24);

A lower vent hole is provided on the lower differential pressure sensor core test seat (23); the number of the lower differential pressure sensor core test seats (23) is the same as the number of the differential pressure sensor cores (4) to be tested;

The lower mounting groove (3) and the upper mounting groove (1) are both provided with air inlets (7) in a direction parallel to the hole;

One of the air inlets (7) penetrates through a long side plate of the lower mounting groove (3) and terminates at another long side plate of the lower mounting groove (3);

Another air inlet (7) penetrates through a long side plate of the upper mounting groove (1) and terminates at another long side plate of the upper mounting groove (1);

The two air inlets (7) are also respectively connected to a valve, one end of the valve is connected to the air inlet (7), and the other end is connected to a gas pressure controller;

A plurality of the differential pressure sensor cores (4) to be measured are installed between the lower mounting groove (3) and the upper mounting groove (1); an upper air guide hole is also provided on the short side plate of the upper mounting groove (1), and a lower air guide hole is also provided on the short side plate of the lower mounting groove (3); one of the air inlets (7) is respectively connected to the upper air vent and the upper air guide hole in a sealed state; another of the air inlets (7) is respectively connected to the lower air vent and the lower air guide hole in a sealed state;

One end of the differential pressure sensor core (4) to be measured is a positive cavity, and the other end is a negative cavity; the differential pressure sensor core (4) to be measured includes four resistors inside, and signals of the four resistors are led out through signal output lines; the differential pressure sensor core (4) to be measured has five signal output lines;

The test fixture also includes an adjustable DC power supply;

Wherein, at room temperature, when the test fixture performs a mechanical fatigue screening test, the two air inlets (7) are respectively connected to the fatigue generator, one of the air inlets (7) is connected to the positive cavity of the differential pressure sensor core (4) to be tested, and the other air inlet (7) is connected to the negative cavity of the differential pressure sensor core (4) to be tested; the output of the fatigue generator is the full-scale pressure of the differential pressure sensor core (4), and the pressurization and depressurization time interval of the fatigue generator is 2 seconds;

When performing a mechanical fatigue screening test, the test fixture is configured to alternately pressurize and depressurize the two air inlets (7) through the fatigue generator 5,000 times each.
The differential pressure sensor core testing tool according to claim 1, characterized in that the tool further comprises two lead screws (9);

The upper mounting groove (1) is also provided with two screw through holes (27) for the screw (9) to pass through, and the screw through holes (27) are located between the guide shaft through holes (26) in the short side plate direction of the upper mounting groove (1);

A screw nut (16) having an internal thread structure adapted to the external thread of the screw (9) is arranged at a position on the upper mounting groove (1) covering the screw through hole (27); the screw nut (16) covers the screw through hole (27) and is fixed on the upper mounting groove (1);

The lower mounting groove (3) is provided with an upper tapered roller bearing mounting seat (14) and a lower tapered roller bearing mounting seat (15); the upper tapered roller bearing mounting seat (14) and the lower tapered roller bearing mounting seat (15) are both cylindrical groove structures;

An upper tapered roller bearing (12) is installed in the upper tapered roller bearing mounting seat (14), and a lower tapered roller bearing (13) is installed in the lower tapered roller bearing mounting seat (15);

The lead screw (9) is screwed into the lead screw nut (16) through a thread, passes through the upper tapered roller bearing (12) and the lower tapered roller bearing (13) in sequence, and the lead screw (9) and the lower tapered roller bearing (13) are locked together at the bottom end of the lead screw (9) through a fixing nut (17).
The differential pressure sensor core testing tool according to claim 2 is characterized in that the two lead screws (9) are also provided with keyways, and the two lead screws (9) are respectively provided with a sprocket (18), and the sprocket (18) is provided with a keyway structure adapted to the keyway on the lead screw (9); a square key is provided in the space enclosed by the keyway on the sprocket (18) and the keyway on the lead screw (9), and the sprocket (18) and the lead screw (9) are connected via the square key;

A chain (11) is sleeved between the two sprocket wheels (18), and the chain (11) is meshed with the sprocket wheels (18).
The differential pressure sensor core testing tool according to claim 2, characterized in that a rocker (10) is further provided on one of the two lead screws (9);

The center of the rocking wheel (10) is a circular ring structure, and a keyway structure matching the keyway on the lead screw (9) is arranged inside the circular ring; a square key is arranged in the space enclosed by the keyway on the rocking wheel (10) and the keyway on the lead screw (9), and the rocking wheel (10) and the lead screw (9) are connected via the square key.
The differential pressure sensor core testing tool according to claim 1, characterized in that an internal thread is provided in the lower positioning pin seat (24);

The upper positioning pin seat (29) and the lower positioning pin seat (24) are positioned by a positioning pin;

One end of the positioning pin is provided with an external thread matched with the internal thread of the lower positioning pin seat (24);

The positioning pin is connected to the lower positioning pin seat (24) via threads.
A differential pressure sensor core testing method, applied to the differential pressure sensor core testing tool as claimed in any one of claims 1 to 5, characterized in that the method comprises:

Obtaining all differential pressure sensor cores (4) to be tested; one end of the differential pressure sensor core (4) to be tested is a positive cavity, and the other end is a negative cavity;

The same cavity end of all the differential pressure sensor core bodies (4) to be measured is installed in the lower installation groove (3), and the other cavity end of all the differential pressure sensor core bodies (4) to be measured is installed in the upper installation groove (1);

Tightening the upper mounting groove (1) and the lower mounting groove (3) to ensure that all the differential pressure sensor cores (4) to be measured are in a clamped state;

Adjusting the position of the test fixture so that the upper mounting groove (1) and the lower mounting groove (3) are located at the same horizontal plane;

Injecting a test gas of a set pressure into the air inlet (7) to perform a mechanical fatigue screening test on the differential pressure sensor core (4) to be tested;

Wherein, at room temperature, when the test fixture performs a mechanical fatigue screening test, the differential pressure sensor core (4) to be tested is clamped, the two air inlets (7) are connected to the fatigue generator, one of the air inlets (7) is connected to the positive cavity of the differential pressure sensor core (4) to be tested, and the other air inlet (7) is connected to the negative cavity of the differential pressure sensor core (4) to be tested, the output of the fatigue generator is adjusted to the full-scale pressure of the differential pressure sensor core (4) to be tested, the time interval of pressurization and depressurization is set to 2 seconds, and the two air inlets (7) are alternately pressurized and depressurized 5000 times each.
The differential pressure sensor core testing method according to claim 6, characterized in that the method further comprises:

The differential pressure sensor core (4) to be tested is subjected to a temperature shock aging screening test, an electrical shock aging screening test, an overload test, a bidirectional static pressure error test, a static performance test, a temperature compensation test, a temperature compensation verification test, and a stability test.
The differential pressure sensor core testing method according to claim 7 is characterized in that the temperature shock aging screening test method comprises:

The test fixture assembled with the differential pressure sensor core (4) to be tested is placed in a high and low temperature test chamber, and the temperature of the high and low temperature test chamber is controlled. After each temperature point is stabilized, a high-precision digital multimeter is controlled to measure the output signal of the differential pressure sensor core (4) to be tested, an insulation resistance tester is controlled to measure the insulation resistance of the differential pressure sensor core (4) to be tested, and a leakage current tester is controlled to measure the leakage current of the differential pressure sensor core (4) to be tested; wherein the temperature rise and fall rate is maintained at 5°C/min, and the test temperature points and temperature stabilization time are set according to the following process:

Keep at 25℃ for 2 hours; keep at -55℃ for 2 hours; keep at +150℃ for 2 hours, and make 4 sets of temperature cycles;

Keep at 25℃ for 1.5 hours; keep at -55℃ for 2 hours, keep at +150℃ for 2 hours, and perform 5 sets of temperature cycles;

Keep at 25℃ for 1.5 hours; keep at -55℃ for 12 hours; keep at 25℃ for 2 hours; keep at 150℃ for 12 hours; keep at 25℃ for 12 hours, and perform 2 sets of temperature cycles.
The differential pressure sensor core testing method according to claim 7 is characterized in that the electric shock aging Screening test methods include:

The test fixture assembled with the differential pressure sensor core (4) to be tested is placed in a high and low temperature test chamber, and then the high and low temperature test chamber is controlled to stabilize its temperature at 60° C. The output voltage of the adjustable DC power supply is controlled according to the following process:

S1: Controlling the output voltage of the adjustable DC power supply so that it outputs the upper limit power supply voltage of the differential pressure sensor core (4) to be tested, and maintaining it for 2 hours;

S2: Controlling the output voltage of the adjustable DC power supply so that it outputs the rated power supply voltage of the differential pressure sensor core (4) to be tested, and maintaining this voltage for 4 hours;

S3: controlling the output voltage of the adjustable DC power supply so that it outputs the lower limit power supply voltage of the differential pressure sensor core (4) to be measured, and maintaining it for 2 hours;

S4: Repeat S1 to S3 for 3 times, and then cut off the power supply for 1 hour.

S5: Repeat the S4 process 5 times;

S6: Control the high-precision digital multimeter to measure the output signal of the differential pressure sensor core (4) to be tested, control the insulation resistance tester to measure the insulation resistance of the differential pressure sensor core (4) to be tested, and control the leakage current tester to measure the leakage current of the differential pressure sensor core (4) to be tested.
The differential pressure sensor core testing method according to claim 7 is characterized in that the static performance testing method includes: a positive cavity static performance test without static pressure, a positive cavity static performance test with static pressure, a negative cavity static performance test without static pressure, and a negative cavity static performance test with static pressure; the content of the performance test includes the nonlinearity, temperature hysteresis, repeatability, and comprehensive accuracy of the differential pressure sensor core (4) to be tested;

The process of the positive cavity no-static-pressure static performance test includes:

The air inlet (7) communicating with the positive cavity of the differential pressure sensor core (4) to be tested is connected to a gas pressure controller, and the air inlet (7) communicating with the negative cavity of the differential pressure sensor core (4) to be tested is connected to the atmosphere; the output of the gas pressure controller is adjusted to apply full-scale pressures of 0%, 20%, 40%, 60%, 80%, 100%, 80%, 60%, 40%, 20%, and 0% to the positive cavity of the differential pressure sensor core (4) to be tested in sequence, and a high-precision digital multimeter is controlled to measure and record the output value of the differential pressure sensor core (4) to be tested;

Repeat the above-mentioned pressurization test process twice, for a total of three tests, record the output value of the differential pressure sensor core (4) to be tested, and calculate the nonlinearity, temperature hysteresis, repeatability, and comprehensive accuracy static performance indicators of the differential pressure sensor core (4) to be tested without static pressure in the positive cavity;

The process of the positive cavity static pressure static performance test includes:

The air inlet (7) of the upper mounting groove (1) and the air inlet (7) of the lower mounting groove (3) are connected to the same gas pressure controller, and the output of the gas pressure controller is adjusted to the pressure required by the static pressure index of the differential pressure sensor core (4) to be measured. The two air inlets (7) are simultaneously pressurized. After the static pressure is reached, the valve of the air inlet (7) connected to the negative cavity of the differential pressure sensor core (4) to be measured is closed, and the air inlet (7) connected to the positive cavity of the differential pressure sensor core (4) to be measured continues to be pressurized. On the basis of the static pressure, the differential pressure sensor core (4) to be measured is pressurized. 4) is additionally applied with differential pressure of 0%, 20%, 40%, 60%, 80%, 100%, 80%, 60%, 40%, 20%, 0% of the full scale in the positive cavity, and the high-precision digital multimeter is controlled to measure and record the output value of the differential pressure sensor core (4) to be tested; the above-mentioned pressurization test process is repeated twice, and the test is performed three times in total, and the output value of the differential pressure sensor core (4) to be tested is recorded, and the nonlinearity, temperature hysteresis, repeatability, and comprehensive accuracy static performance indicators of the differential pressure sensor core (4) to be tested under the static pressure of the positive cavity are calculated;

The process of the negative cavity no static pressure static performance test includes:

The air inlet (7) communicating with the negative cavity of the differential pressure sensor core (4) to be tested is connected to a gas pressure controller, and the air inlet (7) communicating with the positive cavity of the differential pressure sensor core (4) to be tested is connected to the atmosphere, and the output of the gas pressure controller is adjusted to sequentially apply full-scale pressures of 0%, 20%, 40%, 60%, 80%, 100%, 80%, 60%, 40%, 20%, and 0% to the negative cavity of the differential pressure sensor core (4) to be tested, and control a high-precision digital multimeter to measure and record the output value of the differential pressure sensor core (4) to be tested; repeat the above-mentioned pressurization test process twice, and test three times in total, record the output value of the differential pressure sensor core (4) to be tested, and calculate the nonlinearity, temperature hysteresis, repeatability, and comprehensive accuracy static performance indicators of the negative cavity of the differential pressure sensor core (4) to be tested without static pressure;

The process of the negative cavity static pressure static performance test includes:

The air inlet (7) of the upper mounting groove (1) and the air inlet (7) of the lower mounting groove (3) are connected to the same gas pressure controller, and the gas pressure controller output is adjusted to the pressure required by the static pressure index of the differential pressure sensor core (4) to be measured. The two air inlets (7) are simultaneously pressurized. After the static pressure is reached, the valve of the air inlet (7) connected to the positive cavity of the differential pressure sensor core (4) to be measured is closed, and the air inlet (7) connected to the negative cavity of the differential pressure sensor core (4) to be measured continues to be pressurized. On the basis of the static pressure, the differential pressure sensor core (4) to be measured is pressurized. 4) is additionally applied with differential pressure full scale 0%, 20%, 40%, 60%, 80%, 100%, 80%, 60%, 40%, 20%, 0% pressure in sequence to the negative cavity, and a high-precision digital multimeter is controlled to measure and record the output value of the differential pressure sensor core (4) to be tested; the above-mentioned pressurization test process is repeated twice, and the test is performed three times in total, and the output value of the differential pressure sensor core (4) to be tested is recorded, and the nonlinearity, temperature hysteresis, repeatability, and comprehensive accuracy static performance indicators of the negative cavity of the differential pressure sensor core (4) to be tested under static pressure are calculated.
The differential pressure sensor core testing method according to claim 7, characterized in that the temperature compensation testing method comprises:

The test fixture assembled with the differential pressure sensor core (4) to be tested is placed in a high and low temperature test chamber, the air inlet (7) communicating with the positive cavity of the differential pressure sensor core (4) to be tested is connected to a gas pressure controller, and the air inlet (7) communicating with the negative cavity of the differential pressure sensor core (4) to be tested is connected to the atmosphere, and the high and low temperature test chamber is controlled to stabilize the temperature at -55°C, 25°C, and 150°C, respectively. After maintaining each temperature point for 2 hours, the gas pressure controller is controlled to output 0MPa, and the output value of the differential pressure sensor core (4) to be tested and the resistance values of the four resistors at zero point are tested and recorded; the gas pressure controller is controlled to output full-scale pressure, and after stabilization, the full-scale output of the differential pressure sensor core (4) to be tested and the resistance values of the four resistors are tested and recorded, and the pressure is unloaded after the test ends;

According to the output of the differential pressure sensor core (4) to be tested at the three temperature points recorded in the above test and the four resistance values, the compensation resistance value is calculated by using a temperature compensation formula.