Test tool and synchronous test method for high static pressure multi-differential pressure sensor

Abstract

The testing tool comprises a high-pressure end positioning plate and a low-pressure end positioning plate, the high-pressure end positioning plate is provided with a convex plane, the low-pressure end positioning plate is provided with a concave plane, and the convex plane is matched with the side surface of the concave plane; the convex plane is hermetically connected with the sensor core upper base, and the concave plane is hermetically connected with the sensor core lower base; the high-pressure end and low-pressure end positioning plate internal oil paths are connected with the high-pressure end and low-pressure end pressure leading ends; the sensor core upper base and the sensor core lower base are provided with a high-pressure end and a low-pressure end of the differential pressure sensor core; at each stable temperature point, different static pressure values are applied to the differential pressure type piston pressure gauge, meanwhile, corresponding differential pressure values are applied to the differential pressure type piston pressure gauge, and a measured value of a differential pressure sensor core is taken to obtain a temperature-static pressure-differential pressure ternary test data matrix; the testing tool is simple in structure, can adapt to testing work under the high static pressure condition, and completes multi-parameter synchronous measurement of the multiple differential pressure sensors under the high static pressure.

Description

Technical Field

[0001] The invention belongs to the technical field of sensor testing, and in particular relates to a testing fixture device and a synchronous testing method for a high static pressure multi-differential pressure sensor. Background Art

[0002] Silicon piezoresistive pressure sensors are widely used in pressure monitoring and control systems in the fields of aerospace, petrochemical, engineering machinery, automatic control, etc. In addition to pressure sensors used for single-point pressure measurement, differential pressure sensors for differential pressure measurement are also an important type. However, for silicon piezoresistive differential pressure sensors, their testing and calibration is a tedious task. Not only the effect of temperature on differential pressure must be considered, but also the effect of static pressure (especially high static pressure) on differential pressure measurement must be considered. That is, it is often necessary to perform multi-parameter synchronous measurement of static pressure, differential pressure and temperature for sensor performance analysis and calibration. The commonly used sensor testing methods make the workload of multi-parameter testing very huge. For this reason, it is an effective means to establish a test fixture suitable for multi-differential pressure sensors and a multi-parameter testing method.

[0003] The test of differential pressure sensor requires the simultaneous introduction of high and low pressure gas or oil. The principle of the corresponding test fixture is that two pressure-inducing devices (high pressure end device and low pressure end device) are used on both sides of the test sensor core to tighten the core and then conduct the test. Under the common low static pressure conditions, the pressure-inducing devices all adopt a flat plate structure, and the positioning structure on it, such as the positioning pin seat, is used to achieve the positioning between the pressure-inducing device and the sensor core. However, under high static pressure and high temperature test environments, slight deformation and misalignment of the flat plate structure will cause the sealing of the pressure-inducing device and the sensor core to decrease, resulting in leakage in the sealed chamber, which will ultimately affect the test results. Summary of the invention

[0004] In order to overcome the shortcomings of the above-mentioned prior art, the purpose of the present invention is to provide a test fixture and a synchronous testing method for high static pressure multi-differential pressure sensors. The test fixture has a simple and reliable structure, can adapt to testing work under high static pressure conditions, and complete multi-parameter synchronous measurement of multiple differential pressure sensors under high static pressure.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] A test fixture for a high static pressure multi-differential pressure sensor, comprising a high-pressure end positioning plate 1 and a low-pressure end positioning plate 2, wherein the high-pressure end positioning plate 1 has a convex plane, and the low-pressure end positioning plate 2 has a concave plane, and the convex plane and the concave plane side cooperate to realize automatic positioning between the high-pressure end positioning plate 1 and the low-pressure end positioning plate 2; the internal oil circuit of the high-pressure end positioning plate 1 is connected to the high-pressure end pressure lead terminal 4, and the convex plane of the high-pressure end positioning plate 1 is sealed and connected to the sensor core upper base 12; the internal oil circuit of the low-pressure end positioning plate 2 is connected to the low-pressure end pressure lead terminal 5, and the concave plane of the low-pressure end positioning plate 2 is sealed and connected to the sensor core lower base 13; the sensor core upper base 12 and the sensor core lower base 13 are in plane contact; the high-pressure end positioning plate 1 and the low-pressure end positioning plate 2 are fastened by fastening bolts 3.

[0007] The high-pressure end positioning plate 1 is processed with a plurality of high-pressure end core body positioning blind holes 6 that cooperate with the upper base 12 of the sensor core body, wherein the high-pressure end oil holes 7 in each core body positioning blind hole 6 are interconnected and connected with the high-pressure end process hole 8 on the side of the high-pressure end positioning plate 1, and the process hole 8 is fastened and sealed by bolts; the low-pressure end positioning plate 2 is processed with a plurality of low-pressure end core body positioning blind holes 9 that cooperate with the lower base 13 of the sensor core body, wherein the low-pressure end oil holes 10 on each core body positioning blind hole 9 are interconnected and connected with the low-pressure end process hole 11 on the side of the low-pressure end positioning plate 2, and the low-pressure end process hole 11 is fastened and sealed by bolts.

[0008] The sensor core upper base 12 and the sensor core lower base 13 have the same structure, both are stepped cylindrical; the upper and lower end faces of the cylinder are both flat, an end face sealing groove 14 is set on the upper end face, and a lead hole 16 is opened on the lower end face; a side sealing groove 15 is set on the side of the cylinder.

[0009] The upper base 12 of the sensor core is installed with the high-pressure end of the differential pressure sensor core 17, and the two are gap-fitted and sealed by an O-ring to form a high-pressure chamber; the lower base 13 of the sensor core is installed with the low-pressure end of the differential pressure sensor core 17, and the two are gap-fitted and sealed by an O-ring to form a low-pressure chamber; the high-pressure end of the differential pressure sensor core 17 is installed with a temperature platinum resistor 18, a differential pressure chip 19 and a static pressure chip 20.

[0010] The differential pressure sensor core 17 and the high-pressure end core positioning blind hole 6 of the sensor core upper base 12 and the low-pressure end core positioning blind hole 9 of the sensor core lower base 13 are sealed and positioned by O-rings.

[0011] A synchronous testing method using a test fixture for high static pressure multi-differential pressure sensors includes the following specific steps:

[0012] S1, lead out the metal lead wires of each differential pressure sensor core 17 from the lead wire hole 16 through the signal wire to ensure that the differential pressure sensor core 17 to be tested is in a working state;

[0013] S2. Place the test fixture in a high and low temperature control box, connect the high-pressure end lead-in terminal 4 of the test fixture to the high-pressure end of the differential pressure piston pressure gauge, and connect the low-pressure end lead-in terminal 5 of the test fixture to the low-pressure end of the differential pressure piston pressure gauge;

[0014] S3, the power lead on each differential pressure sensor core 17 is connected to the positive and negative electrodes of the high-precision digital source meter outside the temperature control box, and the metal signal leads corresponding to the differential pressure chip 19, static pressure chip 20 and temperature platinum resistor 18 on each differential pressure sensor core 17 are connected to the digital multimeter;

[0015] S4. According to the measurement range of the sensor temperature, multiple temperature measurement points are non-uniformly set, and the high and low temperature test chamber is controlled. Starting from the lowest temperature point, the temperature is gradually raised to the set temperature point. After maintaining each temperature point for 1 hour, the display value of the digital multimeter is cyclically observed. When the zero point output of the differential pressure chip 19 and the static pressure chip 20 and the resistance value of the temperature platinum resistor 18 are stable, the subsequent test is started;

[0016] S5. At each stable temperature point, weights are added to the two differential pressure piston flanges of the differential pressure piston pressure gauge to apply different static pressure values. At the same time, at each static pressure value, differential pressure weights are added to the high pressure end of the differential pressure piston pressure gauge to apply the corresponding differential pressure value. After the output value measured by the digital multimeter is stable, the measured values ​​of the leads of the three differential pressure sensor cores 17 are read in turn by the digital multimeter to obtain multiple sets of ternary test data matrices about temperature-static pressure-differential pressure;

[0017] S6. According to the ternary test data matrix, the influence of static pressure on differential pressure and the influence of temperature on differential pressure are analyzed, and drift compensation is completed using a third-order polynomial.

[0018] In the step S5, different static pressure values ​​are applied, starting from 0 MPa, and static pressures of 25% FS, 50% FS, 75% FS and 100% FS are applied respectively; and corresponding differential pressure values ​​are applied, starting from 0 MPa, and differential pressures of 20% FS, 40% FS, 60% FS, 80% FS are applied respectively, until 100% FS.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] According to the requirements of testing and analyzing the impact of differential pressure under high static pressure, the present invention designs a test tooling and a multi-parameter synchronous testing method with simple structure and high reliability based on a single differential pressure sensor core structure; since the present invention adopts a detachable sensor core base structure, the differential pressure sensor core can form an independent test unit, which has the advantages of simulating the real working state and reducing mutual interference between cores; different from the traditional planar structure positioning plate, the present invention adopts a convex plane and a concave plane structure, which has the advantage of automatic positioning of the high and low pressure end positioning plates, and greatly simplifies the fixed structure, and improves the reliability of the test tooling; in addition, the multi-parameter synchronous testing method designed by the present invention can obtain a three-dimensional test data matrix including static pressure, differential pressure and temperature, which provides an effective means for the analysis and calibration of the impact of differential pressure, and through multi-sensor synchronous testing, it can quickly identify and analyze the performance differences of sensors, providing reliable data support for further optimization and improvement of sensor design. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 Schematic diagram of the test tooling of the present invention.

[0022] Figure 2 This is a structural diagram of the high-voltage lead terminal of the present invention.

[0023] Figure 3 This is a structural diagram of the high-voltage end positioning plate of the present invention.

[0024] Figure 4 This is a structural diagram of the low-voltage end positioning plate of the present invention.

[0025] Figure 5 This is a structural diagram of the sensor core base of the present invention.

[0026] Figure 6 This is a structural diagram of the sensor core of the present invention.

[0027] In the attached figure: 1. High-pressure end positioning plate, 2. Low-pressure end positioning plate, 3. Fastening bolts, 4. High-pressure end pressure lead terminal, 5. Low-pressure end pressure lead terminal, 6. High-pressure end core body positioning blind hole, 7. High-pressure end oil hole, 8. High-pressure end process hole, 9. Low-pressure end core body positioning blind hole, 10. Low-pressure end oil hole, 11. Low-pressure end process hole, 12. Sensor core body upper base, 13. Sensor core body lower base, 14. End face sealing groove, 15. Side sealing groove, 16. Lead hole, 17. Sensor core, 18. Temperature platinum resistor, 19. Differential pressure chip, 20. Static pressure chip. DETAILED DESCRIPTION

[0028] In order to make the purpose and technical solution of the present invention clearer and easier to understand. The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. The specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. This embodiment selects the measurement requirements of static pressure 0-40Mpa, differential pressure 0-3Mpa, and temperature range -40 degrees to 125 degrees for testing.

[0029] Reference Figure 1 and Figure 2 A test fixture for high static pressure multi-differential pressure sensor, including a high-pressure end positioning plate 1, a low-pressure end positioning plate 2, a fastening bolt 3, a high-pressure end pressure lead terminal 4, a low-pressure end pressure lead terminal 5, a sensor core upper base 12 and a sensor core lower base 13; a convex plane and four through holes are provided on the high-pressure end positioning plate 1, and the dimensions of both sides of the convex plane meet the matching accuracy requirements; a concave plane and four threaded blind holes are provided on the low-pressure end positioning plate 2, and the dimensions of both sides of the concave plane also meet the matching accuracy requirements, and the convex plane of the high-pressure end positioning plate 1 and the concave plane of the low-pressure end positioning plate 2 are matched to achieve Automatic positioning between the high-pressure end positioning plate 1 and the low-pressure end positioning plate 2; the internal oil circuit of the high-pressure end positioning plate 1 is connected to the high-pressure end pressure lead terminal 4, and the convex plane of the high-pressure end positioning plate 1 is sealed and connected to the upper base 12 of the sensor core; the internal oil circuit of the low-pressure end positioning plate 2 is connected to the low-pressure end pressure lead terminal 5, the low-pressure end pressure lead terminal 5 and the high-pressure end pressure lead terminal 4 have the same structure, and the concave plane of the low-pressure end positioning plate 2 is sealed and connected to the lower base 13 of the sensor core; the upper base 12 of the sensor core and the lower base 13 of the sensor core are in plane contact; the high-pressure end positioning plate 1 and the low-pressure end positioning plate 2 are fastened by four fastening bolts 3.

[0030] Reference Figure 3 The high-pressure end positioning plate 1 is processed with three high-pressure end core body positioning blind holes 6 that match the base 12 on the sensor core body, wherein the high-pressure end oil holes 7 in each high-pressure end core body positioning blind hole 6 are interconnected and connected to the high-pressure end process hole 8 on the side of the high-pressure end positioning plate 1, and the high-pressure end process hole 8 is fastened and sealed by bolts. Figure 4 The low-pressure end positioning plate 2 is processed with three low-pressure end core positioning blind holes 9 that cooperate with the lower base 13 of the sensor core. The low-pressure end oil holes 10 on each low-pressure end core positioning blind hole 9 are interconnected and connected to the low-pressure end process hole 11 on the side of the low-pressure end positioning plate 2. The low-pressure end process hole 11 is sealed by bolts.

[0031] Reference Figure 5 The sensor core upper base 12 and the sensor core lower base 13 have the same structure, both are stepped cylindrical; the upper and lower end faces of the cylinder are both flat, an end face sealing groove 14 is set on the upper end face, and a lead hole 16 is opened on the lower end face; a side sealing groove 15 is set on the side of the cylinder.

[0032] Reference Figure 5 and Figure 6 The upper base 12 of the sensor core is installed with the high-pressure end of the differential pressure sensor core 17, and the two are gap-matched and sealed by an O-ring to form a high-pressure chamber; the lower base 13 of the sensor core is installed with the low-pressure end of the differential pressure sensor core 17, and the two are gap-matched and sealed by an O-ring to form a low-pressure chamber; the high-pressure end of the differential pressure sensor core 17 is installed with a temperature platinum resistor 18, a differential pressure chip 19 and a static pressure chip 20.

[0033] Reference Figure 3 , Figure 4 and Figure 5 The differential pressure sensor core 17 and the high-pressure end core positioning blind hole 6 of the sensor core upper base 12 and the low-pressure end core positioning blind hole 9 of the sensor core lower base 13 are sealed and positioned through O-rings.

[0034] A synchronous testing method using a test fixture for high static pressure multi-differential pressure sensors includes the following specific steps:

[0035] S1. The metal leads of the differential pressure sensor core 17 are led out from the lead holes 16 respectively, and the test fixture is tightened to ensure that the differential pressure sensor core 17 to be tested is in a working state;

[0036] S2. Place the test fixture in a high and low temperature control box, connect the high-pressure lead terminal 4 of the test fixture to the high-pressure end of the differential pressure piston pressure gauge through a stainless steel lead pressure pipe, and connect the low-pressure lead terminal 5 of the test fixture to the low-pressure end of the differential pressure piston pressure gauge through a stainless steel lead pressure pipe;

[0037] S3, the four power leads of each differential pressure sensor core 17 are connected to the positive and negative electrodes of the high-precision digital source meter outside the temperature control box, and the differential pressure chip 19, static pressure chip 20 and temperature platinum resistor 18 installed on each differential pressure sensor core 17 are connected to the digital multimeter through the corresponding six metal signal leads;

[0038] S4. According to the sensor temperature measurement range of -40 to 125 degrees, 6 temperature measurement points are non-uniformly set, namely -40 degrees, 0 degrees, 20 degrees, 40 degrees, 80 degrees and 125 degrees. The high and low temperature test chamber is controlled, starting from the lowest temperature point of -40 degrees, and gradually heated to the set temperature point. After maintaining each temperature point for 1 hour, the display value of the digital multimeter is cyclically observed. When the zero point output of the differential pressure chip 19 and the static pressure chip 20 and the resistance value of the temperature platinum resistor 18 are stable, the subsequent test can be started;

[0039] S5. At each stable temperature point, weights are placed on the two differential pressure piston hanging flanges of the differential pressure piston pressure gauge to apply different static pressure values. Starting from 0 MPa, static pressures of 10 MPa, 20 MPa, 30 MPa, and 40 MPa are applied respectively. At the same time, at each static pressure value, differential pressure weights are placed on the high pressure end of the differential pressure piston pressure gauge to apply corresponding differential pressure values. Starting from 0 MPa, differential pressures of 0.5 MPa, 1 MPa, 1.5 MPa, 2 MPa, 2.5 MPa, and 3 MPa are applied respectively. After the output value measured by the digital multimeter is stable, the measured values ​​of the leads of the three differential pressure sensor cores 17 are read in turn by the digital multimeter to obtain a ternary test data matrix about 6 temperature measuring points, 5 static pressure measuring points, and 7 differential pressure measuring points;

[0040] S6. Based on the 6×5×7 ternary test data matrix, analyze the influence of static pressure on the zero point and sensitivity of differential pressure, as well as the influence of temperature on the zero point and sensitivity of differential pressure. The influence of static pressure is mainly reflected in the static pressure zero point drift, which can be compensated by a third-order polynomial. Temperature has an impact on both the zero point and sensitivity, and a third-order polynomial can be used to compensate for the zero point and sensitivity respectively.

[0041] Advantages of this embodiment: First, through the automatic positioning characteristics of the convex plane and the concave plane, fast and accurate positioning between the high-pressure end positioning plate 1 and the low-pressure end positioning plate 2 is achieved, which is suitable for high static pressure test environment and realizes multi-differential pressure sensor testing under high static pressure; secondly, the detachable sensor core upper base 12 and the sensor core lower base 13 are adopted, so that the differential pressure sensor core 17 forms an independent test unit, which not only simulates the real working state but also the operation of the differential pressure sensor cores 17 does not affect each other; thirdly, this embodiment designs a multi-parameter synchronous testing method, and the obtained three-dimensional test matrix contains static pressure-differential pressure-temperature information, which can accurately reflect the influence of static pressure on differential pressure, and provide an effective means for differential pressure calibration.

Claims

1. A test fixture for high static pressure multi-differential pressure sensors, characterized in that: The invention comprises a high-pressure end positioning plate (1) and a low-pressure end positioning plate (2). The high-pressure end positioning plate (1) has a convex plane, and the low-pressure end positioning plate (2) has a concave plane. The convex plane and the concave plane cooperate with each other to realize automatic positioning between the high-pressure end positioning plate (1) and the low-pressure end positioning plate (2). The internal oil circuit of the high-pressure end positioning plate (1) is connected to the high-pressure end pressure lead terminal (4), and the convex plane of the high-pressure end positioning plate (1) is sealed and connected to the upper base (12) of the sensor core. The internal oil circuit of the low-pressure end positioning plate (2) is connected to the low-pressure end pressure lead terminal (5), and the concave plane of the low-pressure end positioning plate (2) is sealed and connected to the lower base (13) of the sensor core. The upper base (12) of the sensor core is in plane contact with the lower base (13) of the sensor core. The high-pressure end positioning plate (1) and the low-pressure end positioning plate (2) are fastened by fastening bolts (3).

2. The test tool according to claim 1, characterized in that: The high-pressure end positioning plate (1) is processed with a plurality of high-pressure end core body positioning blind holes (6) that match the upper base (12) of the sensor core body, wherein the high-pressure end oil holes (7) in each core body positioning blind hole (6) are interconnected and connected to the high-pressure end process hole (8) on the side of the high-pressure end positioning plate (1), and the high-pressure end process hole (8) is sealed by bolts; the low-pressure end positioning plate (2) is processed with a plurality of low-pressure end core body positioning blind holes (9) that match the lower base (13) of the sensor core body, wherein the low-pressure end oil holes (10) on each core body positioning blind hole (9) are interconnected and connected to the low-pressure end process hole (11) on the side of the low-pressure end positioning plate (2), and the low-pressure end process hole (11) is sealed by bolts.

3. The test tool according to claim 2, characterized in that: The sensor core upper base (12) and the sensor core lower base (13) have the same structure and are both stepped cylindrical; the upper and lower end faces of the cylinder are both flat, an end face sealing groove (14) is provided on the upper end face, and a lead hole (16) is opened on the lower end face; a side sealing groove (15) is provided on the side face of the cylinder.

4. The test tool according to claim 2, characterized in that: The upper base (12) of the sensor core is installed with the high-pressure end of the differential pressure sensor core (17), and the two are gap-matched and sealed by an O-ring to form a high-pressure chamber; the lower base (13) of the sensor core is installed with the low-pressure end of the differential pressure sensor core (17), and the two are gap-matched and sealed by an O-ring to form a low-pressure chamber; the high-pressure end of the differential pressure sensor core (17) is installed with a temperature platinum resistor (18), a differential pressure chip (19) and a static pressure chip (20).

5. The test tool according to claim 4, characterized in that: The differential pressure sensor core (17) and the high-pressure end core positioning blind hole (6) of the sensor core upper base (12) and the low-pressure end core positioning blind hole (9) of the sensor core lower base (13) are sealed and positioned via O-rings.

6. A synchronous testing method using a test fixture for high static pressure multi-differential pressure sensors according to claim 5, characterized in that: The specific steps include: S1, lead out the metal lead wires of each differential pressure sensor core (17) from the lead wire holes (16) through the signal wires to ensure that the differential pressure sensor core (17) to be tested is in a working state; S2. Place the test fixture in a high and low temperature control box, connect the high-pressure end lead-in terminal (4) of the test fixture to the high-pressure end of the differential pressure piston pressure gauge, and connect the low-pressure end lead-in terminal (5) of the test fixture to the low-pressure end of the differential pressure piston pressure gauge; S3, the power leads on each differential pressure sensor core (17) are connected to the positive and negative electrodes of the high-precision digital source meter outside the temperature control box, and the metal signal leads corresponding to the differential pressure chip (19), static pressure chip (20) and temperature platinum resistor (18) on each differential pressure sensor core (17) are connected to the digital multimeter; S4. According to the measurement range of the sensor temperature, a plurality of temperature measurement points are non-uniformly set, and the high and low temperature test chamber is controlled. Starting from the lowest temperature point, the temperature is gradually raised to the set temperature point. After maintaining each temperature point for 1 hour, the display value of the digital multimeter is cyclically observed. When the zero point output of the differential pressure chip (19) and the static pressure chip (20) and the resistance value of the temperature platinum resistor (18) are stable, the subsequent test is started; S5. At each stable temperature point, weights are placed on the two differential pressure piston flanges of the differential pressure piston pressure gauge to apply different static pressure values. At the same time, at each static pressure value, differential pressure weights are placed on the high pressure end of the differential pressure piston pressure gauge to apply the corresponding differential pressure value. After the output value measured by the digital multimeter is stable, the measured values ​​of the leads of the three differential pressure sensor cores (17) are read in turn by the digital multimeter to obtain multiple groups of ternary test data matrices about temperature, static pressure and differential pressure; S6. According to the ternary test data matrix, the influence of static pressure on differential pressure and the influence of temperature on differential pressure are analyzed, and a third-order polynomial is selected to complete drift compensation.

7. The synchronous testing method according to claim 6, characterized in that: In the step S5, different static pressure values ​​are applied, starting from 0 MPa, and static pressures of 25% FS, 50% FS, 75% FS and 100% FS are applied respectively; and corresponding differential pressure values ​​are applied, starting from 0 MPa, and differential pressures of 20% FS, 40% FS, 60% FS, 80% FS are applied respectively, until 100% FS.

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