Test method for pressure instrument temperature influence test

Abstract

The invention relates to a test method for a pressure instrument temperature influence test. The method comprises the following steps: placing a detected pressure gauge in a heat preservation chamber of a high-low temperature test box; the actual temperature and the actual pressure in the heat preservation chamber are obtained, the temperature in the heat preservation chamber is controlled to be increased or decreased, and a pressure generator is controlled to increase or decrease the pressure in the heat preservation chamber; when the actual temperature and the actual pressure in the heat preservation chamber respectively reach the target temperature and the target pressure, entering a heat preservation and pressure maintaining stage; in the indicating value detection stage, the pressure generator is controlled to enable the actual pressure in the heat preservation chamber to reach different verification points, and then a photo file of the detected pressure gauge is obtained through the visual device; and obtaining indicating value data based on the photo file, and associating the indicating value data corresponding to each verification point with the file name of the photo file. According to the invention, full automation of the pressure gauge temperature influence test process is realized, and the detection efficiency is greatly improved.

Description

Technical Field

[0001] The invention relates to the technical field of pressure instrument type evaluation, in particular to a test method for a pressure instrument temperature influence test. Background Art

[0002] The type evaluation of pressure instruments (hereinafter referred to as "type evaluation") is a type test conducted on new products to verify whether the trial-produced pressure instruments can meet the requirements of technical specifications. During the type evaluation process, performance and stability tests need to be conducted on multiple pressure instrument samples of one or more models. Only products that pass the type test and meet the requirements can be officially put into production and put on the market. The type evaluation must be conducted by a qualified metrology and verification agency, and the corresponding certification certificate must be issued.

[0003] The object of type evaluation is the sample (i.e. the pressure gauge under test), and the temperature influence test is an indispensable and important part of type evaluation. The temperature influence test is divided into two parts: low temperature performance test and high temperature performance test. The low temperature performance test requires that the sample be kept warm and maintained for a specified time (usually 3 hours) under the conditions of -40°C environment and medium temperature, and then the indication accuracy of the sample is tested in accordance with the "Regulations" (i.e. indication test). The specific steps include: raising the pressure of the sample to the pressure of each calibration point, tapping and reading, and maintaining the pressure for 3 minutes after obtaining the tapping displacement, and then reducing the pressure to the pressure of each calibration point, tapping and reading again, obtaining the tapping displacement and calculating the return error. The calibration point pressure is usually the corresponding pressure of each large scale line on the pressure gauge under test. Similarly, the high temperature performance test is carried out under the conditions of 70°C environment and medium temperature according to the same testing process.

[0004] According to the requirements of the "Regulations" and "Type Evaluation Outline", when the temperature reaches -40°C or 70°C, the sample pressure should be pre-increased to 75% of its range, and then maintained for a specified time (usually 3 hours). After the insulation is completed, the indication test is carried out, and the instrument under test and the medium are required to always maintain the corresponding temperature (-40°C or 70°C).

[0005] At present, most of the testing devices place the pressure gauge under test in a high and low temperature test chamber, first cool it down to -40°C and keep it warm for 3 hours, then take out the sample and perform indication test at room temperature. Subsequently, the sample is put back into the test cabinet again, heated to 70°C and kept warm, and then the high temperature indication test is completed at room temperature. In this way, some devices are connected to the pressure device outside the high and low temperature cabinet. However, since the pressure, pressure maintenance during 3 hours, indication test, etc. all require manual operation and manual reading, not only does it require continuous adjustment of the pressure device to control the pressure within the error range, but also the inspector needs to read the indication of multiple (usually 3) gauges under test through the observation window during the indication test. There are many disadvantages, such as high labor intensity, low efficiency, data accuracy cannot be guaranteed, and the test data cannot be traced. In addition, the indication test under room temperature conditions is inconsistent with the requirements of the "Regulations" and needs to be improved and perfected urgently. Summary of the invention

[0006] To this end, the present invention provides a testing method for temperature influence test of pressure gauge, which realizes full automation of temperature influence test process of pressure gauge, and can complete photographing and reading of indication of each calibration point without manual intervention, thereby greatly improving detection efficiency.

[0007] In order to solve the above technical problems, the present invention provides a test method for a temperature influence test of a pressure instrument, the test method comprising: The pressure gauge to be inspected is placed in the insulation chamber of the high and low temperature test chamber, and the pressure gauge to be inspected is connected to the digital pressure gauge and the pressure generator through a medium pipeline, and a visual device and a tapping device are allocated to each of the pressure gauges to be inspected, and the visual device is used to take a photo of the pressure gauge to be inspected; Acquiring the actual temperature and the actual pressure in the insulation chamber, and controlling the temperature in the insulation chamber to increase or decrease according to the difference between the actual temperature and the preset target temperature; and controlling the pressure generator to increase or decrease the pressure in the insulation chamber according to the difference between the actual pressure and the preset target pressure; When the actual temperature and the actual pressure in the insulation chamber reach the target temperature and the target pressure respectively, the insulation chamber enters the insulation and pressure holding stage; After the heat preservation and pressure preservation stage, an indication detection stage is performed, wherein the pressure generator is controlled so that the actual pressure in the heat preservation chamber reaches different calibration points, and then a photo file of the pressure gauge under test is obtained through the visual device, wherein the photo file includes the indication information of the dial pointer; wherein the photo file includes a first sample photo corresponding to each of the calibration points, and a second sample photo obtained after the pressure gauge under test is tapped by the tapping device at each of the calibration points; Based on the photo file, the indication data is obtained, and the indication data corresponding to each of the calibration points is associated with the file name of the photo file.

[0008] In one embodiment of the present invention, when the actual temperature and the actual pressure in the insulation chamber reach the target temperature and the target pressure respectively, the insulation and pressure maintenance stage is entered, including: When the actual temperature and the actual pressure in the insulation chamber reach the corresponding target temperature and the target pressure, the temperature and / or the pressure in the insulation chamber are controlled and adjusted to maintain stability, and the insulation timing is started at the same time; During the heat preservation and pressure preservation stage, an alarm is triggered when the temperature and / or pressure in the heat preservation chamber exceeds an error range.

[0009] In one embodiment of the present invention, after the heat preservation and pressure preservation stage, a value indication detection stage is performed, including: When the accumulated time of the heat preservation timing reaches the preset time, the pressure generator is controlled to release the pressure, so that the medium pressure displayed by the digital pressure gauge returns to zero, and the indication detection stage is carried out.

[0010] In one embodiment of the present invention, the preset time is 3 hours.

[0011] In one embodiment of the present invention, the target temperature is -40°C or 70°C.

[0012] In one embodiment of the present invention, when the actual temperature in the insulation chamber reaches -40°C±2°C or 70°C±2°C, the pressure generator is controlled to pre-boost the pressure of the pressure gauge under test to 75% of its measuring range.

[0013] In one embodiment of the present invention, after controlling the pressure generator so that the actual pressure in the insulation chamber reaches different calibration points, obtaining a photo file of the pressure gauge under test through the visual device includes: At zero pressure, controlling the visual device to take a first sample zero pressure point photo of the pressure gauge under inspection; Controlling the pressure generator to gradually increase the pressure to the first calibration point, and controlling the visual device to take the first sample photo of the pressure gauge under inspection; Control the tapping device to tap the pressure gauge under inspection so that the dial pointer shakes slightly, and after the tapping is completed, control the visual device to take a photo of the second sample; Repeat the above operation, gradually increase the pressure to each calibration point, and obtain the corresponding first sample photo and second sample photo at each calibration point during the pressure increase process; After the pressure is increased, the pressure is gradually reduced to each calibration point, and the corresponding first sample photo and second sample photo are respectively obtained at each calibration point during the pressure reduction process until the pressure returns to zero, and the last sample zero pressure point photo is obtained.

[0014] In one embodiment of the present invention, when the pressure is increased to the maximum pressure test point, the pressure is maintained for 3 minutes.

[0015] In one embodiment of the present invention, the high and low temperature test chamber also includes a refrigeration unit and a hot air generator. The refrigeration unit includes an evaporator copper tube arranged in the insulation layer, which is used to cool the insulation chamber; the hot air generator is connected to the insulation chamber through a pipeline, and transports hot air to the inside of the insulation chamber to increase the temperature of the insulation chamber.

[0016] In one embodiment of the present invention, the visual device includes an industrial camera configured corresponding to each of the pressure gauges to be inspected.

[0017] The above technical solution of the present invention has the following advantages compared with the prior art: The test method for the temperature influence test of a pressure instrument described in the present invention fully automates the traditional manually operated temperature influence test process of the pressure gauge, including processes such as temperature control, pressure adjustment, photographing, indication detection and data preservation, and can complete the photographing and indication reading of each calibration point without manual intervention, greatly improving the detection efficiency. The indication data of each calibration point is saved through the association of photo files, and all detection data have images as intuitive basis, which is convenient for traceability and review. The system can call back photos of any data point to ensure the transparency of the detection process and the traceability of the data. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to make the contents of the present invention more clearly understood, the present invention is further described in detail below based on specific embodiments of the present invention in conjunction with the accompanying drawings.

[0019] Figure 1 The present invention is a flow chart of a test method for a pressure instrument temperature influence test.

[0020] Figure 2 It is a front view of the automatic detection system for temperature influence test of pressure instrument of the present invention.

[0021] Figure 3 It is a top view of the automatic detection system for temperature influence test of pressure instrument of the present invention.

[0022] Figure 4 It is a side view of the automatic detection system for temperature influence test of pressure instrument of the present invention.

[0023] Description of the Figures in the Specification: 1. Camera; 2. Camera mounting base; 3. Insulation chamber; 4. Mounting base; 5. Evaporator copper tube; 6. Insulation layer; 7. High and low temperature test cabinet; 8. Standard digital pressure gauge; 9. Host computer; 10. Electrical auxiliary cabinet; 11. Pressure generator; 12. Pressure generator cabinet; 13. Medium pipeline; 14. Lighting; 15. Insulation chamber door; 16. Observation window; 17. Insulating glass; 18. Camera cabinet; 20. Threaded joint; 21. Sample mounting seat; 22. Hot air generator; 23. Refrigeration unit; 24. Controller; 25. Camera data cable; 26. Pressure gauge under test; 27. Controller cable. DETAILED DESCRIPTION

[0024] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0025] In the present invention, if directions (up, down, left, right, front and back) are described, it is only for the convenience of describing the technical solution of the present invention, and does not indicate or imply that the technical features referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, it cannot be understood as a limitation of the present invention.

[0026] In the present invention, "several" means one or more, "multiple" means more than two, "greater than", "less than", "exceed" and the like are understood to exclude the number itself; "above", "below", "within" and the like are understood to include the number itself. In the description of the present invention, if there is a description of "first" or "second", it is only used for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0027] In the present invention, unless otherwise clearly defined, the words "set", "install", "connect" and the like should be understood in a broad sense, for example, they can be directly connected or indirectly connected through an intermediate medium; they can be fixedly connected or detachably connected or integrally formed; they can be mechanically connected or electrically connected or able to communicate with each other; they can be the internal connection of two elements or the interaction relationship between two elements. Those skilled in the art can reasonably determine the specific meanings of the above words in the present invention in combination with the specific content of the technical solution.

[0028] Reference Figure 1 As shown, a test method for a temperature influence test of a pressure instrument, the test method comprising: S1. Place the pressure gauge 26 to be tested in the insulation chamber 3 of the high and low temperature test chamber, connect the pressure gauge 26 to be tested with the digital pressure gauge and the pressure generator 11 through the medium pipeline 13, and assign a visual device and a tapping device to each of the pressure gauges 26 to be tested. The visual device is used to take photos of the pressure gauge 26 to be tested.

[0029] In this embodiment, the high and low temperature test box further includes a refrigeration unit 23 and a hot air generator 22. The refrigeration unit 23 includes an evaporator copper tube 5 arranged in the insulation layer 6, which is used to cool the insulation chamber 3; the hot air generator 22 is connected to the insulation chamber 3 through a pipeline, and delivers hot air to the inside of the insulation chamber 3 to achieve the heating of the insulation chamber 3. The visual device includes an (industrial) camera 1 configured corresponding to each of the pressure gauges 26 to be inspected. A lighting lamp 14 is also provided on the top of the insulation chamber 3 to illuminate the pressure gauges 26 to be inspected. The lighting lamp 14 provides the brightness environment required for taking pictures.

[0030] When setting up specific settings, refer to Figures 2 to 4 As shown, a temperature sensor is arranged in the insulation chamber 3; a sample mounting seat 21 is also provided at the bottom of the insulation chamber 3, a mounting base plate 4 is mounted on the sample mounting seat 21, a threaded joint 20 for mounting the pressure gauge 26 to be tested is arranged on the mounting base plate 4, and the threaded joint 20 is connected to the medium pipeline 13.

[0031] In addition, the insulation chamber 3 includes an insulation chamber door 15, and an observation window 16 is provided on the insulation chamber door 15. The observation window 16 includes at least one layer of transparent heat-insulating glass 17 with heating function. The transparent heat-insulating glass 17 with heating function can not only prevent the glass from frosting or fogging to affect observation, but also play a heat insulation role.

[0032] A camera cabinet 18 is installed outside the observation window 16, and each camera 1 is installed on the camera mounting base plate 2 of the camera cabinet 18, and each pressure gauge 26 to be inspected matches one camera 1. A lighting lamp 14 for illuminating the pressure gauge 26 to be inspected is also provided on the top of the insulation chamber 3. The lighting lamp 14 provides the brightness environment required for taking pictures. The camera cabinet 18 provides a stable installation platform for the camera 1, while preventing external interference from affecting the shooting effect. The lighting lamp 14 optimizes the shooting environment, ensures the clarity of the image taken under different conditions, and provides support for data collection of the visual device.

[0033] The design of the observation window 16 facilitates real-time viewing of the equipment operating status and improves the convenience of operation. The camera 1 configured in front of the observation window 16 can take pictures of the sample through the glass.

[0034] The high and low temperature test chamber can accurately control the temperature between -40°C and 70°C through the refrigeration unit 23 and the hot air generator 22 to meet the test requirements. The pressure generator 11 is used in conjunction with a digital pressure gauge to monitor and adjust the medium pressure in real time to ensure that the pressure is stable and the error range is controllable during the test. The tapping device can use an existing electromagnet-driven tapping device.

[0035] In this embodiment, the high and low temperature test chamber, the digital pressure gauge, and the pressure generator 11 are connected to the control system through a data line, so that the temperature and the medium pressure can be controlled by the control system. The control system includes a host computer 9 and a controller 24. The pressure generator 11 is connected to the controller 24 through a cable, and the camera 1 is connected to the host computer 9 through the data line of the camera 1. The camera 1 is controlled by the host computer 9 to take pictures, and the pictures are saved in the specified location of the host computer 9. The host computer 9 sends a control instruction to the controller 24, and the controller 24 receives the instruction and then controls the pressure generator 11 to increase, maintain or reduce the pressure. The controller 24 is a PLC or a single-chip microcomputer.

[0036] S2. Acquire the actual temperature and the actual pressure in the insulation chamber 3, and control the temperature of the insulation chamber 3 to increase or decrease according to the difference between the actual temperature and the preset target temperature; and control the pressure generator 11 to increase or decrease the pressure in the insulation chamber 3 according to the difference between the actual pressure and the preset target pressure.

[0037] Specifically, the target temperature is -40°C or 70°C; when the actual temperature in the insulation chamber 3 reaches -40°C±2°C or 70°C±2°C, the pressure generator 11 is controlled to pre-boost the pressure of the tested pressure gauge 26 to 75% of its range.

[0038] S3. When the actual temperature and the actual pressure in the insulation chamber 3 reach the target temperature and the target pressure respectively, the temperature and pressure insulation stage is entered.

[0039] Specifically, when the actual temperature and the actual pressure in the insulation chamber 3 reach the corresponding target temperature and the target pressure, the temperature and / or the pressure in the insulation chamber 3 are controlled and adjusted to maintain stability, and the insulation timing is started at the same time; During the heat preservation and pressure preservation stage, an alarm is triggered when the temperature and / or pressure in the heat preservation chamber 3 exceeds an error range.

[0040] S4, after the heat preservation and pressure preservation stage, when the heat preservation time reaches the preset time, the pressure generator 11 is controlled to release the pressure, so that the medium pressure displayed by the digital pressure gauge returns to zero, and the indication detection stage is carried out. The preset time is 3 hours.

[0041] After controlling the pressure generator 11 so that the actual pressure in the insulation chamber 3 reaches different calibration points, a photo file of the pressure gauge 26 under test is obtained through the visual device, and the photo file includes the indication information of the dial pointer; wherein the photo file includes a first sample photo corresponding to each of the calibration points, and a second sample photo obtained after tapping the pressure gauge 26 under test through the tapping device at each of the calibration points.

[0042] Specifically, at zero pressure, the visual device is controlled to take a first sample zero pressure point photo of the pressure gauge 26 under inspection; Control the pressure generator 11 to gradually increase the pressure to the first test point, and control the visual device to take the first sample photo of the pressure gauge 26 under test; Control the tapping device to tap the pressure gauge 26 to make the dial pointer shake slightly, and after the tapping is completed, control the visual device to take a photo of the second sample; Repeat the above operation, gradually increase the pressure to each calibration point, and obtain the corresponding first sample photo and second sample photo at each calibration point during the pressure increase process; After the pressure is increased, the pressure is gradually reduced to each calibration point. At each calibration point in the process of reducing the pressure, the corresponding first sample photo and second sample photo are obtained respectively, until the pressure returns to zero, and the last sample zero pressure point photo is obtained. In addition, when the pressure is increased to the highest pressure calibration point, the pressure must be maintained for 3 minutes.

[0043] The tapping device simulates manual tapping of the case, allowing the pointer to swing to eliminate the friction hysteresis effect and ensure the accuracy of the reading. Each calibration point takes photos before and after the tapping, and compares and analyzes the movement of the pointer, so as to more accurately calculate the measurement error of the pressure gauge.

[0044] S5. Based on the photo file, obtain the indication data, and associate the indication data corresponding to each of the calibration points with the file name of the photo file. By clicking on the data, the corresponding photo file can be popped up to review the indication data. After the test is completed, the indication data and the photo file are both saved. When querying the indication data obtained from the test of each sample, the corresponding photo can be displayed synchronously to achieve traceability of the indication data.

[0045] It can be understood that the tapping displacement of each calibration point can be obtained by combining the indication data of the second sample photo obtained after the tapping device taps the pressure gauge 26 to be tested with the indication data of the first sample photo.

[0046] The indication data of each calibration point is saved through the association of photo files. All test data have images as intuitive basis, which is convenient for traceability and review. The system can call back photos of any data point to ensure the transparency of the test process and the traceability of the data.

[0047] For example, after the pressure value at each calibration point stabilizes, the system controls the camera to take photos of the pressure gauge being tested. Each photo contains the pressure gauge dial and its pointer position. The photo file naming rules include information such as the test time, pressure calibration point, tapping status (front or back), etc. All photo files are saved in directories according to the sample number. The file name of each photo is mapped to the corresponding test point indication data and saved in the system database. In the query interface, the test data can be quickly located by sample number, test time or pressure point. Click the indication data to synchronously call out the corresponding photo, showing the pointer position and scale lines on the photo.

[0048] In addition, the system automatically marks the detection points that exceed the error range and prompts the user to recheck. During the photo review process, the user can calibrate the displayed value. After the correction, the system automatically records the modification operation and time, and retains the original data and photos.

[0049] Specifically, each photo file is parsed through the visual processing process of the host computer 9 to obtain the indicated value of the sample pointer, and the indicated value data is displayed at a specific position on the test page through the program of the host computer 9. For example, the specific process is as follows: The visual device takes a picture of the inspected pressure gauge 26 in a zero-pressure state and saves the picture.

[0050] The software processes the photo: locates the dial, cuts out the part outside the dial, performs grayscale processing (divides the grayscale value of the photo into 0-255 levels according to the logarithmic relationship), removes noise by filtering, and binarizes the image to make the photo appear clear in black and white. Find the pointer in the processed photo and mark the first center line of the pointer.

[0051] First calibration point detection: Add pressure to the pressure gauge 26 to be tested. When the pressure reaches the corresponding pressure value of the first calibration point, stop adding pressure and keep the pressure stable for a while so as to take a photo. Take a photo of the gauge to be tested at this time and save it. Process the photo and mark the second center line of the pointer.

[0052] A coordinate system is established with the intersection of the first center line and the second center line as the origin; the scale area in the photo is identified and the scale lines are calibrated; and the pressure value pointed to by the pointer is calculated based on the angle between the scale lines and the center line.

[0053] Continue to pressurize the meter under test until it reaches each preset pressure value, and repeat the following steps: Take a photo of the meter under test at each pressure point; process the photo, mark the center line of the pointer, and calculate the pressure value of the pointer through the coordinate system; compare the calculated pressure value (P1) with the applied system pressure value (P2) and the pressure value manually read on the photo (P3); if the error of the pressure point is within the allowable range, continue to test the next pressure point; if the error exceeds the allowable range, it is judged that the meter under test does not meet the accuracy standard; Recording and display of test results: After the test is completed at the last preset pressure point, if the errors of all points are within the allowable range, the accuracy of the meter under test is judged to be up to standard; otherwise, the accuracy is judged to be not up to standard.

[0054] During the test, all indications (P1) are displayed in real time on the computer screen; click on any indication to view the corresponding real-time photo. If there is a deviation between P1 and P3, it can be manually modified and the modification record is kept. During the test, multiple tables under test can be tested at the same time to improve the test efficiency. Each table under test is photographed by an independent camera 1, and the data is recorded and processed separately.

[0055] This process ensures the accuracy, efficiency and reliability of testing, while providing data traceability and verification capabilities.

[0056] It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0057] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0058] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0059] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0060] Finally, it should be noted that the above specific implementation methods are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A test method for temperature influence test of pressure instrument, characterized in that: The test method includes: The pressure gauge to be inspected is placed in the insulation chamber of the high and low temperature test chamber, and the pressure gauge to be inspected is connected to the digital pressure gauge and the pressure generator through a medium pipeline, and a visual device and a tapping device are allocated to each of the pressure gauges to be inspected, and the visual device is used to take a photo of the pressure gauge to be inspected; Acquiring the actual temperature and the actual pressure in the insulation chamber, and controlling the temperature in the insulation chamber to increase or decrease according to the difference between the actual temperature and the preset target temperature; and controlling the pressure generator to increase or decrease the pressure in the insulation chamber according to the difference between the actual pressure and the preset target pressure; When the actual temperature and the actual pressure in the insulation chamber reach the target temperature and the target pressure respectively, the insulation chamber enters the insulation and pressure holding stage; After the heat preservation and pressure preservation stage, an indication detection stage is performed, wherein the pressure generator is controlled so that the actual pressure in the heat preservation chamber reaches different calibration points, and then a photo file of the pressure gauge under test is obtained through the visual device, wherein the photo file includes the indication information of the dial pointer; wherein the photo file includes a first sample photo corresponding to each of the calibration points, and a second sample photo obtained after the pressure gauge under test is tapped by the tapping device at each of the calibration points; Based on the photo file, the indication data is obtained, and the indication data corresponding to each of the calibration points is associated with the file name of the photo file.

2. A test method for a pressure instrument temperature influence test according to claim 1, characterized in that: When the actual temperature and the actual pressure in the insulation chamber reach the target temperature and the target pressure respectively, the insulation and pressure maintenance stage is entered, including: When the actual temperature and the actual pressure in the insulation chamber reach the corresponding target temperature and the target pressure, the temperature and / or the pressure in the insulation chamber are controlled and adjusted to maintain stability, and the insulation timing is started at the same time; During the heat preservation and pressure preservation stage, an alarm is triggered when the temperature and / or pressure in the heat preservation chamber exceeds an error range.

3. A test method for a pressure instrument temperature influence test according to claim 2, characterized in that: After the heat preservation and pressure preservation stage, the indication detection stage is carried out, including: When the accumulated time of the heat preservation timing reaches the preset time, the pressure generator is controlled to release the pressure, so that the medium pressure displayed by the digital pressure gauge returns to zero, and the indication detection stage is carried out.

4. The test method for temperature influence test of pressure instrument according to claim 1, characterized in that: The preset time is 3 hours.

5. The test method for temperature influence test of pressure instrument according to claim 1, characterized in that: The target temperature is -40°C or 70°C.

6. The test method for temperature influence test of pressure instrument according to claim 1, characterized in that: When the actual temperature in the insulation chamber reaches -40°C±2°C or 70°C±2°C, the pressure generator is controlled to pre-boost the pressure of the pressure gauge under test to 75% of its measuring range.

7. The test method for temperature influence test of pressure instrument according to claim 1, characterized in that: After controlling the pressure generator so that the actual pressure in the insulation chamber reaches different calibration points, obtaining a photo file of the pressure gauge under test through the visual device includes: At zero pressure, controlling the visual device to take a first sample zero pressure point photo of the pressure gauge under inspection; Controlling the pressure generator to gradually increase the pressure to the first calibration point, and controlling the visual device to take the first sample photo of the pressure gauge under inspection; Control the tapping device to tap the inspected pressure gauge so that the dial pointer shakes slightly, and after the tapping is completed, control the visual device to take a photo of the second sample; Repeat the above operation, gradually increase the pressure to each calibration point, and obtain the corresponding first sample photo and second sample photo at each calibration point during the pressure increase process; After the pressure is increased, the pressure is gradually reduced to each calibration point, and the corresponding first sample photo and second sample photo are respectively obtained at each calibration point during the pressure reduction process until the pressure returns to zero, and the last sample zero pressure point photo is obtained.

8. The test method for temperature influence test of pressure instrument according to claim 1, characterized in that: When the pressure is increased to the maximum pressure calibration point, maintain the pressure for 3 minutes.

9. The test method for temperature influence test of pressure instrument according to claim 1, characterized in that: The high and low temperature test box also includes a refrigeration unit and a hot air generator. The refrigeration unit includes an evaporator copper tube arranged in the insulation layer, which is used to cool the insulation chamber; the hot air generator is connected to the insulation chamber through a pipeline and transports hot air into the insulation chamber to increase the temperature of the insulation chamber.

10. A test method for temperature influence test of pressure instrument according to claim 1, characterized in that: The visual device includes an industrial camera configured corresponding to each of the pressure gauges to be inspected.

Images