Temperature transmitter response time testing device and method

Abstract

The invention discloses a temperature transmitter response time testing device and method, and relates to the technical field of temperature transmitter calibration, and the device comprises a tested temperature transmitter without a temperature sensor, a data recorder, a change-over switch, a first input signal, and a second input signal. The first input signal and the second input signal are connected to a first input binding post and a second input binding post of the change-over switch respectively. The input signal I and the input signal II are temperature signals of the same type, and the input signal I and the input signal II are thermocouple type potential signals or thermal resistance type resistance signals; an output binding post of the change-over switch is electrically connected with the input end of a tested temperature transmitter, and the output end of the tested temperature transmitter is electrically connected with the input end of a data recorder. According to the invention, the blank of the device and the method for testing the response time of the temperature transmitter without a temperature sensor is filled, and the test device and the method are proved by practice.

Description

Technical Field

[0001] This invention relates to the field of temperature transmitter calibration technology, and in particular to a temperature transmitter response time testing device and method. Background Technology

[0002] A temperature transmitter, also known as a temperature signal converter, is an instrument that converts temperature variables into a standardized analog or digital output signal that can be transmitted. It consists of a measurement unit, a data processing unit, and an electrical output subsystem. It is mainly used for the measurement and control of temperature parameters in industrial processes, and its analog output signal has a continuous functional relationship with the temperature variable. Temperature transmitters include two types: with and without sensors. The temperature sensor is a resistance temperature detector (RTD) or a thermocouple. The temperature transmitters described in this invention refer to the sensorless type.

[0003] The national metrological technical specification JJF1183-2025, "Calibration Specification for Temperature Transmitters," is applicable to the calibration of measurement errors in temperature transmitters whose temperature sensors are thermocouples or resistance temperature detectors (RTDs). The measurement error is the error generated when converting temperature into a standardized output signal. During measurement error calibration, it is essential to ensure that the temperature signal input to the transmitter is stable.

[0004] Response time is a key performance indicator for temperature transmitters in safety-critical applications, including nuclear power, aerospace, weaponry, scientific research, semiconductor manufacturing, food, and pharmaceutical industries. The response time of temperature transmitters with sensors is measured using the interpolation method, as illustrated in invention patents CN110057472B (A Temperature Sensor Thermal Response Time Measurement Device and Method) and CN110617906B (A Temperature Sensor Dynamic Response Calibration Device and Step Time Measurement Method), which can be used to measure the response time of temperature transmitters with sensors.

[0005] For temperature transmitters without temperature sensors, the national standard GB / T17614.2-2015, "Transmitters for Industrial Process Control Systems - Part 2: Inspection and Routine Test Methods," specifies the principle measurement procedure for step response, but does not cover operable test equipment and methods. The measurement procedure specified in GB / T17614.2 is as follows: Apply two steps equivalent to 80% of the output range, preferably from 10% to 90%, and then from 90% to 10%; for each step, the time required for the output to reach and remain within 1% of its steady-state range should be stated, and if there is time lag, rise time, time constant, or overshoot, their values ​​should be specified.

[0006] Invention patent CN111024186B discloses a microwave level gauge step response time measurement device and method; invention patent CN108362436B discloses a pressure / differential pressure transmitter response time testing system and method; invention patent CN113432779B discloses a pressure / differential pressure transmitter response time testing device and testing method; utility model patent CN214200484U discloses a pressure and differential pressure transmitter response time testing device. None of the above contents have significant reference value for the response time testing of temperature transmitters without temperature sensors.

[0007] There is currently a lack of research on the response time testing of temperature transmitters, and there are no suitable testing devices and methods. It is an urgent need for users to test and verify the response time marked on commercially available temperature transmitters. Therefore, this invention proposes a temperature transmitter response time testing device and method. Summary of the Invention

[0008] The purpose of this invention is to address the deficiencies in the existing technology by proposing a temperature transmitter response time testing device and method.

[0009] To achieve the above objectives, the present invention adopts the following technical solution:

[0010] A temperature transmitter response time testing device includes a temperature transmitter under test without a temperature sensor, a data logger, a selector switch, input signal one, and input signal two. Input signal one and input signal two are respectively connected to input terminals one and two of the selector switch. Input signal one and input signal two are temperature signals of the same type, specifically thermocouple-type potential signals or resistance signals of thermistor type. The output terminal of the selector switch is electrically connected to the input terminal of the temperature transmitter under test, and the output terminal of the temperature transmitter under test is connected to the data logger. The instrument's input terminals are electrically connected; the selector switch achieves conduction between its output terminal and either input terminal one or input terminal two via knob three. Input terminal one and input terminal two will not be simultaneously connected to the output terminal; each of the input terminal one, input terminal two, and output terminal contains two contacts, labeled "+" and "-" respectively. When the output terminal is connected to either input terminal one or input terminal two, the conduction occurs between "+" terminals and between "-" terminals, respectively; there is no conduction between "+" and "-" terminals.

[0011] The "+" terminal wire is arranged on the upper layer and the "-" terminal wire is arranged on the lower layer inside the changeover switch. The upper and lower layers are insulated from each other. The knob three of the changeover switch includes a fixed post and a knob post. The fixed post and the knob post are made of insulating rigid material. The knob post includes adjacent insulating grooves and conductive grooves. There are two insulating grooves, which are distributed on both sides of the conductive groove. The conductive groove is electrically connected to the output terminal of the changeover switch. The input terminal one and the input terminal two are connected to the fixed post through wires and then contact the insulating groove or the conductive groove through copper pressure plates.

[0012] Input signal one and input signal two can be implemented by reference thermometer one and reference thermometer two, which are respectively placed in a low-temperature thermostat and a high-temperature thermostat to achieve thermal equilibrium; when the temperature transmitter being measured is a thermocouple-type temperature transmitter, reference thermometer one and reference thermometer two are specifically reference thermocouple one and reference thermocouple two; when the temperature transmitter being measured is a resistance temperature detector (RTD) type temperature transmitter, reference thermometer one and reference thermometer two are reference RTD type thermometers.

[0013] Input signal one and input signal two can also be implemented by temperature signal simulation instruments. When the temperature transmitter under test is a thermocouple type temperature transmitter, input signal one and input signal two are specifically implemented by a temperature calibrator that can output millivolt potential values. When the temperature transmitter under test is a resistance temperature transmitter, input signal one and input signal two are implemented by precision resistance box one and precision resistance box two.

[0014] Preferably, all electrical connection wires used are pure copper wires; the input terminal one, input terminal two, output terminal, copper pressure plate and conductive groove of the changeover switch are all made of pure copper gold-plated material; the upper and lower layers, fixed post and knob post inside the changeover switch are all immersed in insulating heat dissipation lubricating oil.

[0015] Preferably, the data logger can be an oscilloscope.

[0016] A method for testing the response time of a temperature transmitter includes testing the response time of a changeover switch and testing the response time of the temperature transmitter under test, specifically including the following steps:

[0017] Test the response time of the changeover switch:

[0018] S1: Connect input signal one and input signal two, or DC constant voltage source one and DC constant voltage source two, to the input terminals one and two of the changeover switch respectively, and connect the output terminal to the data logger. Stabilize for at least 30 minutes.

[0019] S2: Set the sampling type, range, and sampling frequency of the data logger, start the data logger to begin recording data, rotate knob three to switch between input signal one and input signal two, or DC constant voltage source one and DC constant voltage source two, and stop recording data after the data recorded by the data logger stabilizes;

[0020] S3: Based on the data curve recorded by the data logger, the response time of the changeover switch is measured by plotting. At least three consecutive tests are conducted, and the average value is taken as the final test result. The deviation between each test result and the average value should not exceed 10%. Otherwise, the test should be repeated.

[0021] S4: Determine whether the sampling interval of the data logger is not greater than 1 / 100 of the measured response time of the changeover switch. If not, the sampling frequency of the data logger should be increased, and steps S2 and S3 should be repeated until the requirement is met. Only then will the test result be valid.

[0022] Test the response time of the temperature transmitter under test:

[0023] SS1: Connect input signal one and input signal two to input terminals one and two of the changeover switch respectively. Connect the output terminal of the changeover switch to the input terminal of the temperature transmitter under test. Connect the output terminal of the temperature transmitter under test to the input terminal of the data logger. Stabilize for at least 30 minutes.

[0024] SS2: Set the sampling type, range, and sampling frequency of the data logger, start the data logger to begin recording data, rotate knob three to switch between input signal one and input signal two, and stop recording data after the data recorded by the data logger has stabilized;

[0025] SS3: Based on the data curve recorded by the data logger, the response time of the temperature transmitter under test is measured by plotting. At least three consecutive tests are performed, and the average value is taken as the final test result. The deviation of each test result from the average value is not greater than 10%. Otherwise, the test should be repeated.

[0026] SS4: Determine if the response time of the selector switch is not greater than 1 / 10 of the response time of the measured temperature transmitter. If not, replace the selector switch with one that has a shorter response time and repeat steps SS2 and SS3 until the requirement is met. Only then will the test results be valid. At the same time, determine if the sampling interval of the data logger is not greater than 1 / 100 of the response time of the measured temperature transmitter. If not, increase the sampling frequency of the data logger and repeat steps SS2 and SS3 until the requirement is met. Only then will the test results be valid.

[0027] Preferably, the response time of the changeover switch should be tested at least annually; the step ratio of the response time of the changeover switch should not be less than the step ratio of the response time of the temperature transmitter under test.

[0028] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0029] This invention fills the gap in the testing device and method for the response time of temperature transmitters without temperature sensors, and the testing device and method of this invention have been proven in practice. Attached Figure Description

[0030] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention and do not constitute a limitation thereof.

[0031] Figure 1 This is a schematic diagram of a temperature transmitter response time testing device according to the present invention;

[0032] Figure 2 This is a schematic diagram of the thermocouple-based switching response time testing device of the present invention;

[0033] Figure 3 This is a schematic diagram of the thermocouple-type temperature transmitter response time testing device of the present invention;

[0034] Figure 4 (a) is a schematic diagram of the wiring of the upper "+" pole inside the changeover switch of the present invention;

[0035] Figure 4 (b) is a schematic diagram of the lower "-" pole wiring inside the changeover switch of the present invention;

[0036] Figure 5 This is a schematic diagram of another switching response time testing device according to the present invention;

[0037] Figure 6 This is a schematic diagram of the response time testing device for the resistance temperature transmitter of the present invention.

[0038] Figure 7 This is the measurement result of the negative step response time of the switching switch in this invention;

[0039] Figure 8(a) shows the positive step transient response curve of the thermocouple-type temperature transmitter under test according to the present invention;

[0040] Figure 8(b) shows the measurement results of the positive step response time of the thermocouple-type temperature transmitter under test according to the present invention;

[0041] Figure 9 This is a schematic diagram of another thermal resistance type temperature transmitter response time testing device according to the present invention.

[0042] In the diagram: 1. Low-temperature thermostat; 2. High-temperature thermostat; 3. Reference thermometer one; 4. Reference thermometer two; 5. Precision resistance box one; 6. Precision resistance box two; 7. Knob one; 8. Knob two; 9. Terminal one; 10. Terminal two; 11. Changeover switch; 12. Input terminal two; 13. Input terminal one; 14. Knob three; 15. Output terminal; 16. Temperature transmitter under test; 17. Data logger; 18. 19. Fixed post; 20. Knob post; 21. Copper pressure plate; 22. Insulating groove; 23. Conductive groove; 24. DC constant voltage source one; 25. DC constant voltage source two; 26. Input signal one; 27. Input signal two; 38. Reference thermocouple one; 49. Reference thermocouple two; 10. Changeover switch two; 110. Temperature transmitter of thermocouple under test; 120. Temperature transmitter of resistance temperature under test; 131. Dual-channel data logger. Detailed Implementation

[0043] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention;

[0044] Example 1

[0045] Please see Figures 1-4 A temperature transmitter response time testing device includes a temperature transmitter 16 without a temperature sensor, a data logger 17, a changeover switch 11, an input signal 1 25, and an input signal 2 26.

[0046] The input signal 25 is connected to the input terminal 13 of the changeover switch 11; the input signal 26 is connected to the input terminal 12 of the changeover switch 11.

[0047] The input signal 25 and the input signal 26 are temperature signals of the same type, and the input signal 25 and the input signal 26 are thermocouple-type potential signals or resistance signals of resistance temperature detectors.

[0048] Input signal 25 is realized by reference thermometer 3, and input signal 26 is realized by reference thermometer 4. Reference thermometer 3 is placed in low temperature thermostat 1, and reference thermometer 4 is placed in high temperature thermostat 2, and thermal equilibrium is reached.

[0049] When the temperature transmitter 16 being measured is a thermocouple-type temperature transmitter 161 being measured, the reference thermometer 3 and the reference thermometer 4 are specifically the reference thermocouple 31 and the reference thermocouple 41.

[0050] When the temperature transmitter 16 being measured is a resistance temperature transmitter 162 being measured, the reference thermometer 3 and the reference thermometer 4 are reference resistance thermometers.

[0051] Specifically, in this embodiment, the thermocouple-type temperature transmitter 161 being measured is a PR3101 thermocouple transmitter manufactured by Peyle Electronics GmbH in Denmark, with an input range of 0-100℃ and an output range of 1-5V DC voltage.

[0052] Input signal 1 25 and input signal 2 26 are both standard J-type or K-type thermocouple millivolt potential values, specifically K-type thermocouple potential values;

[0053] Reference thermometer 1 (3) and reference thermometer 2 (4) are specifically reference thermocouple 1 (31) and reference thermocouple 2 (41), both of which are type K thermocouples.

[0054] The low-temperature thermostat 1 is set to 10℃, and the high-temperature thermostat 2 is set to 90℃; the data logger 17 is a digital oscilloscope.

[0055] The output terminal 15 of the selector switch 11 is electrically connected to the input terminal of the temperature transmitter 16 under test, and the output terminal of the temperature transmitter 16 under test is electrically connected to the input terminal of the data logger 17. The selector switch 11 achieves conduction between its output terminal 15 and input terminal 13 or input terminal 2 12 through knob 3 14. Input terminal 13 and input terminal 2 12 will not be simultaneously connected to the output terminal 15. Input terminal 13, input terminal 2 12 and output terminal 15 each contain two contacts, which are marked as "+" and "-" respectively. When the output terminal 15 is connected to input terminal 13 or input terminal 2 12, it is a connection between "+" and "+" terminals and a connection between "-" and "-" terminals respectively. There is no connection between "+" and "-" terminals.

[0056] The "+" terminal wire is arranged on the upper layer and the "-" terminal wire is arranged on the lower layer inside the changeover switch 11. The upper and lower layers are insulated from each other. The knob 14 of the changeover switch 11 includes a fixed post 18 and a knob post 19. The fixed post 18 and the knob post 19 are made of insulating rigid material. The knob post 19 includes adjacent insulating grooves 21 and conductive grooves 22. There are two insulating grooves 21 and they are distributed on both sides of the conductive grooves 22. The conductive grooves 22 are electrically connected to the output terminal 15 of the changeover switch 11. The input terminal 13 and the input terminal 22 are connected to the fixed post 18 through wires and then contact the insulating grooves 21 or conductive grooves 22 through copper pressure plates 20.

[0057] All electrical connection wires used are pure copper wires; the input terminal 13, input terminal 2 12, output terminal 15, copper pressure plate 20 and conductive groove 22 of the changeover switch 11 are all made of pure copper gold-plated material; the upper and lower layers inside the changeover switch 11, the fixing post 18 and the knob post 19 are all immersed in insulating heat dissipation lubricating oil, specifically No. 10 transformer oil with a freezing point ≤ -10℃ is selected.

[0058] Please see Figures 1-5 A method for testing the response time of a temperature transmitter, comprising testing the response time of a changeover switch 11 and testing the response time of the temperature transmitter 16 under test, specifically including the following steps:

[0059] Test the response time of changeover switch 11:

[0060] S1: Connect input signal 1 25 and input signal 2 26, or DC constant voltage source 1 23 and DC constant voltage source 2 24, to input terminals 1 13 and 12 of the changeover switch 11 respectively, and connect output terminal 15 to data logger 17. Stabilize for at least 30 minutes.

[0061] S2: Set the sampling type, range and sampling frequency of the data logger 17, start the data logger 17 to start recording data, rotate knob 3 14 to switch between input signal 1 25 and input signal 2 26, or DC constant voltage source 1 23 and DC constant voltage source 2 24, and stop recording data after the data recorded by the data logger 17 stabilizes.

[0062] S3: Based on the data curve recorded by the data logger 17, the response time of the changeover switch 11 is measured by plotting. At least three consecutive tests are conducted, and the average value is taken as the final test result. The deviation between each test result and the average value is no more than 10%. Otherwise, the test should be repeated.

[0063] S4: Determine whether the sampling interval of the data logger 17 is not greater than 1 / 100 of the measured response time of the changeover switch 11. If not, the sampling frequency of the data logger 17 should be increased, and steps S2 and S3 should be repeated until the requirement is met. Only then will the test result be valid.

[0064] For details, please refer to Figure 2 Input signal 25 and input signal 26 are respectively implemented by K-type thermocouples placed in low-temperature thermostat 1 and high-temperature thermostat 2. The data logger 17 uses a digital oscilloscope to measure the negative step change curve of the potential before and after rotating knob 14 of the selector switch 11. Please refer to [link / reference needed]. Figure 7 The digital oscilloscope in the image has a time range of 2ms / div and a cursor resolution of 0.04ms. Figure 7It can be seen that knob 14 enables transient switching between input signal 25 and input signal 26, with a switching time ≤0.04ms. Three measurements were performed, and the results were all ≤0.04ms. Therefore, the selector switch 11 in this embodiment can be used to test the response time of the temperature transmitter 16 under test, which has a response time ≥0.4ms. The rise time of the digital oscilloscope used, calibrated by the metrology laboratory, is 3.5ns, which is much less than 1 / 100 of the switching time, thus the measurement result can be considered valid.

[0065] Test the response time of the temperature transmitter 16 under test:

[0066] SS1: Connect input signal 1 25 and input signal 2 26 to input terminals 1 13 and 12 of changeover switch 11 respectively; connect output terminal 15 of changeover switch 11 to input terminal of temperature transmitter 16; connect output terminal of temperature transmitter 16 to input terminal of data logger 17; and stabilize for at least 30 minutes.

[0067] SS2: Set the sampling type, range, and sampling frequency of the data logger 17, start the data logger 17 to begin recording data, rotate knob 3 14 to switch between input signal 1 25 and input signal 2 26, and stop recording data after the data recorded by the data logger 17 has stabilized;

[0068] SS3: Based on the data curve recorded by the data logger 17, the response time of the temperature transmitter 16 under test is measured by plotting. At least three consecutive tests are performed, and the average value is taken as the final test result. The deviation between each test result and the average value is not greater than 10%. Otherwise, the test should be repeated.

[0069] SS4: Determine whether the response time of the selector switch 11 is not greater than 1 / 10 of the response time of the measured temperature transmitter 16. If not, replace the selector switch 11 with one that has a shorter response time and repeat steps SS2 and SS3 until the requirement is met. Only then will the test result be valid. At the same time, determine whether the sampling interval of the data logger 17 is not greater than 1 / 100 of the response time of the measured temperature transmitter 16. If not, increase the sampling frequency of the data logger 17 and repeat steps SS2 and SS3 until the requirement is met. Only then will the test result be valid.

[0070] Preferably, the response time of the changeover switch 11 should be tested at least annually; the step ratio of the response time of the changeover switch 11 should not be less than the step ratio of the response time of the temperature transmitter 16 under test.

[0071] Please refer to the details. Figure 3The test results are shown in Figures 8(a) and 8(b). Figure 8(b) shows the time required for the output of the temperature transmitter 16 to reach a step change of 63.2% by plotting, which is a time constant of 1.12 ms. The measurement was repeated twice, and the time constants were 1.08 ms and 1.12 ms, respectively. The average of the three measurements was 1.11 ms, and the maximum deviation was 2.4%. The measurement results meet the maximum deviation requirement for repeatability, and the device used meets the technical specifications. Therefore, the results are considered valid.

[0072] Example 2

[0073] Unlike Example 1, please refer to Figure 5 Another switching response time testing device uses DC constant voltage source 1 23 and DC constant voltage source 24, set to 0.4V and 0.8V respectively. The data logger 17 uses a small signal acquisition card and is connected to the host computer. The sampling parameter is set to a low voltage value for testing.

[0074] See also Figure 6 Input signals 25 and 26 can also be implemented using temperature signal simulation instruments. When the temperature transmitter 16 under test is a thermocouple-type temperature transmitter 161, input signals 25 and 26 are specifically implemented by a temperature calibrator capable of outputting millivolt potential values. When the temperature transmitter 16 under test is a resistance temperature transmitter 162, input signals 25 and 26 are implemented by precision resistance boxes 5 and 6. Specifically, the resistance temperature transmitter 162 is a Pt100 type resistance temperature transmitter manufactured by Phoenix Contact, Germany, with an input range of 0-100℃ and an output range of 0-10V DC voltage. The setting value of precision resistance box 5 is 103.90Ω, and the setting value of precision resistance box 6 is 134.71Ω, corresponding to 10℃ and 90℃ respectively. Test results and... Figure 7 - Similar to Figure 8, so I will not repeat it here.

[0075] Example 3

[0076] Please see Figure 9 A schematic diagram of another response time testing device for a resistance temperature transmitter of the present invention, compared with Embodiment 2. Figure 6The difference lies in that the input terminals 12, 13, and 15 of the second changeover switch 111 each contain four contacts, labeled "+", "-", "+", and "-" respectively. When the output terminal 15 is connected to either input terminal 13 or input terminal 12, the connection is between the corresponding "+" terminals and between the corresponding "-" terminals, respectively; non-corresponding contacts will not conduct. The changeover switch 111 has four layers of wiring internally, with insulation between each layer. The knob 14 of the second changeover switch 111 includes a fixed post 18 and a knob post 19, and also has four layers of insulated wiring contacts. The input terminals 12 and 13 of the second changeover switch 111 can receive input signals and DC constant voltage sources, enabling simultaneous switching between temperature change signals and step signals.

[0077] Compared with Example 2 Figure 6 The difference is that the dual-channel data logger 171 can simultaneously acquire temperature change signals and step signals to determine the step start time, so as to measure the hysteresis time of the temperature transmitter 16 under test by plotting.

Claims

1. A temperature transmitter response time testing device, comprising a temperature transmitter under test (16) without a temperature sensor, a data logger (17), a selector switch (11), input signal one (25) and input signal two (26), characterized in that: The input signal 1 (25) is connected to the input terminal 1 (13) of the changeover switch (11); The second input signal (26) is connected to the second input terminal (12) of the changeover switch (11); The input signal one (25) and input signal two (26) are temperature signals of the same type. The input signal one (25) and input signal two (26) are thermocouple-type potential signals or resistance signals of resistance temperature detectors. The output terminal (15) of the selector switch (11) is electrically connected to the input terminal of the temperature transmitter (16) under test, and the output terminal of the temperature transmitter (16) under test is electrically connected to the input terminal of the data logger (17). The selector switch (11) enables the output terminal (15) to be connected to either input terminal one (13) or input terminal two (12) through knob three (14). Input terminal one (13) and input terminal two (12) will not be connected at the same time. When the output terminal (15) is connected, the input terminal (13), the input terminal (12) and the output terminal (15) are connected simultaneously. Each of the input terminal (13), the input terminal (12) and the output terminal (15) contains two contacts, which are marked as "+" and "-" respectively. When the output terminal (15) is connected to the input terminal (13) or the input terminal (12), the connection is between "+" and "+" and between "-" and "-" respectively. The connection between "+" and "-" will not be established. The "+" terminal wire inside the changeover switch (11) is arranged on the upper layer, and the "-" terminal wire is arranged on the lower layer. The upper and lower layers are insulated from each other. The knob three (14) of the changeover switch (11) includes a fixed post (18) and a knob post (19). The fixed post (18) and the knob post (19) are made of insulating rigid material. The knob post (19) includes adjacent insulating grooves (21) and conductive grooves (22). There are two insulating grooves (21) and they are distributed on both sides of the conductive grooves (22). The conductive grooves (22) are electrically connected to the output terminals (15) of the changeover switch (11). The input terminals one (13) and two (12) are connected to the fixed post (18) through wires and then contact the insulating grooves (21) or conductive grooves (22) through copper pressure plates (20). Input signal one (25) and input signal two (26) are realized by reference thermometer one (3) and reference thermometer two (4) or input signal one (25) and input signal two (26) are realized by temperature signal simulation instrument; The reference thermometer one (3) is placed in the low-temperature thermostat (1), and the reference thermometer two (4) is placed in the high-temperature thermostat (2) to achieve thermal equilibrium. When the temperature transmitter (16) being measured is a thermocouple-type temperature transmitter (161), the reference thermometer one (3) and the reference thermometer two (4) are specifically reference thermocouple one (31) and reference thermocouple two (41). When the temperature transmitter (16) being measured is a resistance temperature transmitter (162), the reference thermometer one (3) and the reference thermometer two (4) are reference resistance thermometers. When the temperature transmitter under test (16) is a thermocouple-type temperature transmitter (161), the input signal one (25) and the input signal two (26) are specifically implemented by a temperature calibrator that can output millivolt potential values; when the temperature transmitter under test (16) is a resistance temperature transmitter (162), the input signal one (25) and the input signal two (26) are implemented by a precision resistance box one (5) and a precision resistance box two (6).

2. The temperature transmitter response time testing device according to claim 1, characterized in that, All wires used for electrical connection are pure copper wires; the input terminal 1 (13), input terminal 2 (12), output terminal (15), copper pressure plate (20) and conductive groove (22) of the changeover switch (11) are all made of pure copper gold-plated material; the upper and lower layers, fixed post (18) and knob post (19) inside the changeover switch (11) are all immersed in insulating heat dissipation lubricating oil.

3. The temperature transmitter response time testing device according to claim 1, characterized in that, The data logger (17) is an oscilloscope.

4. A method for testing the response time of a temperature transmitter, characterized in that, The response time test includes the changeover switch (11) and the response time test of the temperature transmitter under test (16), specifically including the following steps: Test the response time of the changeover switch (11): S1: Connect input signal one (25) and input signal two (26), or DC constant voltage source one (23) and DC constant voltage source two (24) to the input terminals one (13) and two (12) of the changeover switch (11) respectively, and connect the output terminal (15) to the data logger (17) for at least 30 minutes; S2: Set the sampling type, range and sampling frequency of the data logger (17), start the data logger (17) to start recording data, rotate knob three (14) to switch between input signal one (25) and input signal two (26), or DC constant voltage source one (23) and DC constant voltage source two (24), and stop recording data after the data recorded by the data logger (17) stabilizes; S3: Based on the data curve recorded by the data logger (17), the response time of the changeover switch (11) is measured by plotting. At least three consecutive tests are conducted, and the average value is taken as the final test result. The deviation between each test result and the average value is not greater than 10%. Otherwise, the test should be repeated. S4: Determine whether the sampling interval of the data logger (17) is not greater than 1 / 100 of the measured response time of the changeover switch (11). If not, the sampling frequency of the data logger (17) should be increased, and steps S2 and S3 should be repeated until the requirement is met. Only then will the test result be valid. Test the response time of the temperature transmitter (16) under test: SS1: Connect input signal one (25) and input signal two (26) to input terminals one (13) and two (12) of the changeover switch (11) respectively, connect output terminal (15) of the changeover switch (11) to input terminal of the temperature transmitter under test (16), connect output terminal of the temperature transmitter under test (16) to input terminal of the data logger (17), and stabilize for at least 30 minutes; SS2: Set the sampling type, range and sampling frequency of the data logger (17), start the data logger (17) to start recording data, rotate knob three (14) to switch between input signal one (25) and input signal two (26), and stop recording data after the data recorded by the data logger (17) has stabilized; SS3: Based on the data curve recorded by the data logger (17), the response time of the temperature transmitter (16) under test is measured by plotting. At least three consecutive tests are conducted, and the average value is taken as the final test result. The deviation between each test result and the average value is not greater than 10%. Otherwise, the test should be repeated. SS4: Determine whether the response time of the selector switch (11) is not greater than 1 / 10 of the response time of the measured temperature transmitter (16). If not, replace the selector switch (11) with one that has a shorter response time and repeat steps SS2 and SS3 until the requirement is met. Only then will the test result be valid. At the same time, determine whether the sampling interval of the data logger (17) is not greater than 1 / 100 of the response time of the measured temperature transmitter (16). If not, increase the sampling frequency of the data logger (17) and repeat steps SS2 and SS3 until the requirement is met. Only then will the test result be valid.

5. The method for testing the response time of a temperature transmitter according to claim 4, characterized in that, The response time of the changeover switch (11) should be tested at least annually; the step ratio of the response time of the changeover switch (11) should not be less than the step ratio of the response time of the temperature transmitter (16) under test.

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