Method of testing a thermal resistance temperature sensor

Abstract

This invention belongs to the field of sensor technology and discloses a testing method for a resistance temperature sensor (RTS). The method includes: testing reference temperatures T1 and T2 of a liquid medium in a static state and determining the fluctuation of the liquid medium; independently testing the RTS under the reference temperatures T1 and T2 in the liquid medium, and correcting the reference temperature measurement value T. 标 ; Change the direction of the driving current and repeat the previous step; calculate the resistance values ​​ΔR1, ΔR2 and the resistance fluctuation values ​​ΔΔR1, ΔΔR2 of the RTD temperature sensor; determine the RTD temperature sensor grade and whether retesting is required. This invention improves the testing efficiency of platinum resistance thermometers in engineering applications by correcting the measured values ​​of the RTD temperature sensor at a reference temperature, calculating the resistance temperature coefficient, and determining the RTD temperature sensor grade.

Description

Technical Field

[0001] This invention belongs to the field of sensor technology and relates to a testing method for a resistance temperature sensor. Background Technology

[0002] Resistance temperature detectors (RTDs) are thermometers that measure temperature based on the principle that the resistance of a conductor or semiconductor changes with temperature. RTDs exhibit errors under varying temperature conditions. Common two-wire temperature measurement methods include the bridge method, constant current source method, and capacitor-resistance charge-discharge method. These methods typically use a "standard resistor" with a known resistance value. In the bridge and constant current source methods, the microcontroller calculates the resistance of the measured RTD based on the voltage division relationship between the measured RTD and the standard resistor in the circuit, as well as the resistance value of the standard resistor. In the capacitor-resistance charge-discharge method, the microcontroller controls the charging and discharging of the measured RTD and the standard resistor into a capacitor, respectively, and calculates the resistance of the measured RTD based on the time of the two RC charge-discharge cycles and the standard resistor value. However, common testing methods require a stable constant temperature environment, expensive equipment, and a stabilization time of more than 10 minutes, resulting in low testing efficiency. Summary of the Invention

[0003] The technical problem solved by this invention is to provide a testing method for a resistance temperature sensor that solves the problem of testing efficiency for platinum resistance thermometers while meeting certain testing accuracy requirements.

[0004] The technical solution of this invention is:

[0005] This invention provides a testing method for a resistance temperature sensor, the method comprising:

[0006] The S100 tests the reference temperatures T1 and T2 of a liquid medium in a static state and determines the fluctuation of the liquid medium.

[0007] S200 independently tests the resistance temperature sensor in a liquid medium with reference temperatures T1 and T2, correcting the reference temperature measurement value T. 标 ;

[0008] S300 changes the direction of the drive current, repeating S200;

[0009] S400 calculates the resistance values ​​ΔR1, ΔR2 and the resistance fluctuation values ​​ΔΔR1, ΔΔR2 of the thermal resistance temperature sensor;

[0010] S500 determines the rating of the resistance temperature sensor and whether a retest is required.

[0011] Furthermore, the method for testing the reference temperature of a liquid medium in a static state in S100 includes:

[0012] S101 sets the maximum permissible temperature fluctuation ΔT of the liquid medium in a static state when temperature T1 is set. 标1max ;

[0013] S102 acquires the resistance value of standard resistor A1 at preset time intervals, for a total of n times, and calculates the average temperature T corresponding to the resistance value of standard resistor A1 for the n times. 标1 ;

[0014] S103 Obtain the resistance value of the standard resistor A1 for the (n+1)th time, and calculate the temperature T corresponding to the resistance value of the standard resistor A1 for the (n+1)th time. 标1-2 ;

[0015] S104 determines whether |T 标1 -T 标1-2 |<ΔT 标1max If yes, the test fluctuation conditions are met; otherwise, proceed to S101 to restart the test.

[0016] S105 sets the maximum permissible temperature fluctuation ΔT of the liquid medium in a static state when temperature T2 is set. 标2max

[0017] S106 acquires the resistance value of standard resistor A1 at preset time intervals, for a total of n times, and calculates the average temperature T corresponding to the resistance values ​​of standard resistor A1 acquired n times. 标2 ;

[0018] S107 Obtain the resistance value of the standard resistor A1 for the (n+1)th time, and calculate the temperature T corresponding to the resistance value of the standard resistor A1 for the (n+1)th time. 标2-2 ;

[0019] S108 determines whether |T 标2 -T 标2-2 |<ΔT 标2max If yes, the test fluctuation conditions are met; otherwise, proceed to S105 to restart the test.

[0020] Furthermore, in step S200, when the reference temperature is T1, the thermal resistance temperature sensor is tested to correct the reference temperature measurement value T. 标 The methods include:

[0021] S201 Obtain the resistance value of the standard resistor A1, and calculate the temperature T′ corresponding to the resistance value of the standard resistor A1. 标1-前 ;

[0022] S202 Obtains the resistance value R′ of the thermal resistance temperature sensor. 测1 Then, obtain the resistance value of the standard resistor A1 again, and calculate the temperature T′ corresponding to the resistance value of the standard resistor A1. 标1-后 ;

[0023] S203 Determines whether |T′ 标1-后 -T′ 标1-前 |<ΔT 标1max If yes, the test conditions are met; otherwise, proceed to S201 to restart the test.

[0024] S204 calculates T′ 标1 =(T′ 标1-前 +T′ 标1-后 ) / 2, where T′ 标1 The resistance value of the standard resistor A1 under the current condition corresponds to the average temperature value.

[0025] S205 Obtain the resistance value of the standard resistor A1, and calculate the temperature T′ corresponding to the resistance value of the standard resistor A1. 标2-前 ;

[0026] S206 Obtain the resistance value R′ of the thermal resistance temperature sensor. 测2 Then, obtain the resistance value of the standard resistor A1 again, and calculate the temperature T′ corresponding to the resistance value of the standard resistor A1. 标2-后 ;

[0027] S207 Determines if |T′ 标2-后 -T′ 标2-前 |<ΔT 标2max If yes, the test conditions are met; otherwise, proceed to S205 to start the test again.

[0028] S208 calculates T′ 标2 =(T′ 标2-前 +T′ 标2-后 ) / 2, where T′ 标2 The resistance value of the standard resistor A1 under the current condition corresponds to the average temperature value.

[0029] Furthermore, S300 reverses the direction of the drive current, tests the resistance temperature sensor at the reference temperature T1, and corrects the reference temperature measurement value T. 标 The methods include:

[0030] S301 Obtains the resistance value R″ of the standard resistor A1. 测1 Calculate the resistance value of the standard resistor A1 corresponding to the temperature T″. 标1-前 ;

[0031] S302 acquires the resistance value of the thermal resistance temperature sensor, acquires the resistance value of the standard resistor A1 again, and calculates the temperature T″ corresponding to the resistance value of the standard resistor A1. 标1-后 ;

[0032] S303 determines whether |T″标1-后 -T″ 标1-前 |<ΔT 标1max If yes, the test conditions are met; otherwise, proceed to S301 to restart the test.

[0033] S304 Calculate T″ 标1 =(T″ 标1-前 +T″ 标1-后 ) / 2, where T″ 标1 The average resistance value of the standard resistor A1 after the conversion of the drive current corresponds to the average temperature.

[0034] S305 Obtains the resistance value of the standard resistor A1 and calculates the temperature T″ corresponding to the resistance value of the standard resistor A1. 标2-前 ;

[0035] S306 Obtains the resistance value R″ of the thermal resistance temperature sensor. 测2 The resistance value of the standard resistor A1 is obtained again, and the temperature T″ corresponding to the resistance value of the standard resistor A1 is calculated. 标2-后 ;

[0036] S307 determines whether |T″ 标2-后 -T″ 标2-前 |<ΔT 标2max If yes, the test conditions are met; otherwise, proceed to S305 and start the test again.

[0037] S308 Calculate T″ 标2 =(T″ 标2-前 +T″ 标2-后 ) / 2, where T″ 标2 The average resistance value of the standard resistor A1 after the conversion of the drive current corresponds to the average temperature.

[0038] Further, the method for S400 to calculate the resistance values ​​ΔR1, ΔR2 and resistance fluctuation values ​​ΔΔR1, ΔΔR2 of the thermal resistance temperature sensor includes:

[0039] S401 according to R′ 测1 and T′ 标1 Calculate ΔR′1, based on R″ 测1 and T″ 标1 Calculate ΔR″1;

[0040] S402 calculates ΔR1 = (ΔR′1 + ΔR″1) / 2, where ΔR1 is the average of ΔR′1 and ΔR″1;

[0041] S403 calculates ΔΔR1=|ΔR′1+ΔR″1| / 2, where ΔΔR1 is the difference;

[0042] S404 according to R″ 测2and T′ 标2 Calculate ΔR′2 based on R″2 and T″. 标2 Calculate ΔR″2;

[0043] S405 calculates ΔR2=(ΔR′2+ΔR″2) / 2, where ΔR2 is the average of ΔR′2 and ΔR″2;

[0044] S406 calculates ΔΔR2=|ΔR′2+ΔR″2| / 2, where ΔΔR2 is the difference.

[0045] Furthermore, the method for determining the rating of the resistance temperature sensor in step S500 includes:

[0046] S501 calculates the temperature coefficient of resistance α of the resistance temperature sensor based on ΔR1 and ΔR2. R ;

[0047] S502 determines the grade of the resistance temperature sensor according to the resistance temperature coefficient and temperature tolerance specified in the Industrial Platinum and Copper Resistance Temperature Detection Procedure JJG 229-2010.

[0048] Furthermore, the method by which S500 determines whether a retest is needed includes:

[0049] S503 determines whether |ΔR1-x1| < 2a·ΔT 标1max And ΔΔR1>a·ΔT 标1max Or |ΔR² - x²| < 2b·ΔT 标1max And ΔΔR2>b·ΔT 标1max Where x1, a, x2, and b are all constants. If they are constants, then a retest is required; otherwise, a retest is not required.

[0050] The beneficial effects of this invention are:

[0051] (1) The temperature sensor testing method provided by the present invention avoids measurement errors caused by the instability of standard resistor and liquid medium temperature by testing the temperature fluctuation range of liquid medium in static state.

[0052] (2) Measure the standard resistance twice before and after the temperature sensor measurement to reduce the error caused by the temperature fluctuation of the constant temperature bath to the temperature sensor.

[0053] (3) The current direction is changed and tested independently to eliminate the error in temperature measurement caused by thermoelectric potential.

[0054] (4) By calculating the temperature coefficient of resistance and determining the grade of the temperature sensor, the testing efficiency of platinum resistance thermometers can be improved in engineering applications. Attached Figure Description

[0055] Figure 1 This is a flowchart of the calibration method for the resistance temperature sensor provided by the present invention;

[0056] Figure 2 This is a flowchart illustrating the testing method for liquid media under reference temperature T1 provided by the present invention.

[0057] Figure 3 This is a flowchart illustrating the testing method for liquid media under reference temperature T2 provided by the present invention.

[0058] Figure 4 This is a flowchart illustrating the method for correcting the temperature measurement value of a thermal resistor at a reference temperature T1 provided by the present invention.

[0059] Figure 5 This is a flowchart illustrating the method for correcting the temperature measurement value of a thermal resistor at a reference temperature T2 provided by the present invention.

[0060] Figure 6 This is a flowchart illustrating the method for calculating the resistance value and resistance fluctuation value of a resistance temperature sensor provided by the present invention.

[0061] Figure 7 This is a schematic diagram of the process for determining the temperature sensor level provided by the present invention. Detailed Implementation

[0062] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0063] In this invention, the terms "first," "second," etc., are primarily used to distinguish different devices, elements, or components (the specific types and structures may be the same or different), and are not intended to indicate or imply the relative importance or quantity of the indicated devices, elements, or components. Unless otherwise stated, "a plurality of" means two or more.

[0064] like Figure 1 As shown in the figure, the testing method for a resistance temperature sensor illustrated in this embodiment includes:

[0065] The S100 tests the reference temperatures T1 and T2 of a liquid medium in a static state and determines the fluctuation of the liquid medium.

[0066] The S200 independently tests the resistance temperature sensor in a liquid medium with reference temperatures T1 and T2, correcting the reference temperature measurement value T. 标 ;

[0067] S300 reverses the direction of the drive current, and repeats S200;

[0068] S400 calculates the resistance values ​​ΔR1, ΔR2 and resistance fluctuation values ​​ΔΔR1, ΔΔR2 of the resistance temperature sensor.

[0069] The S500 determines the rating of the resistance temperature sensor and whether a retest is required.

[0070] like Figure 2 As shown, the method for testing the reference temperature of a liquid medium in a static state includes:

[0071] S101 sets the maximum permissible temperature fluctuation ΔT of the liquid medium in a static state when temperature T1 is set. 标1max ;

[0072] S102 acquires the resistance value of standard resistor A1 every 10 seconds, for a total of 3 times, and calculates the average temperature T corresponding to the 3 resistance values ​​of standard resistor A1. 标1 ;

[0073] S103 obtains the resistance value of the 4th standard resistor A1 and calculates the temperature T corresponding to the resistance value of the 4th standard resistor A1. 标1-2 ;

[0074] S104 determines whether |T 标1 -T 标1-2 |<ΔT 标1max If yes, the test fluctuation conditions are met; otherwise, proceed to S101 to restart the test.

[0075] It should be noted that in this embodiment, the temperature corresponding to the resistance value of the thermal resistor is calculated according to the functional relationship between the resistance value and temperature of the industrial platinum thermal resistor in the verification procedure of industrial platinum and copper thermal resistors JJG 229-2010.

[0076] like Figure 3 As shown, S105 sets the maximum allowable temperature fluctuation ΔT of the liquid medium in a static state at temperature T2. 标2max ;

[0077] S106 acquires the resistance value of standard resistor A1 every 10 seconds, for a total of 3 times, and calculates the average temperature T corresponding to the 3 resistance values ​​of standard resistor A1. 标2 ;

[0078] S107 obtains the resistance value of the 4th standard resistor A1, and calculates the temperature T corresponding to the resistance value of the 4th standard resistor A1. 标2-2 ;

[0079] S108 determines whether |T 标2 -T 标2-2|<ΔT 标2max If yes, the test fluctuation conditions are met; otherwise, proceed to S105 to restart the test.

[0080] By testing the temperature fluctuation range of the liquid medium in a static state, we can ensure that the standard resistor is in normal working condition and the liquid medium used for testing is in a stable state with small temperature fluctuations when correcting the temperature sensor measurement value in the next step.

[0081] like Figure 4 As shown, the resistance temperature sensor was tested at reference temperatures T1 and T2, and the reference temperature measurement value T was corrected. 标 The methods include:

[0082] S201 obtains the resistance value of standard resistor A1 and calculates the temperature T′ corresponding to the resistance value of standard resistor A1. 标1-前 ;

[0083] S202 acquires the resistance value R″ of the resistance temperature sensor. 标1 Obtain the resistance value of standard resistor A1 again, and calculate the temperature T′ corresponding to the resistance value of standard resistor A1. 标1-后 ;

[0084] S203 Determines whether |T′ 标1-后 -T′ 标1-前 |<ΔT 标1max If yes, the test conditions are met; otherwise, proceed to S201 to restart the test.

[0085] S204 calculates T′ 标1 =(T′ 标1-前 +T′ 标1-后 ) / 2, where T′ 标1 This represents the average resistance value of standard resistor A1 at the current temperature.

[0086] like Figure 5 As shown, S205 obtains the resistance value of standard resistor A1 and calculates the temperature T′ corresponding to the resistance value of standard resistor A1. 标2-前 ;

[0087] S206 acquires the resistance value R″ of the resistance temperature sensor. 标2 Obtain the resistance value of standard resistor A1 again, and calculate the temperature T′ corresponding to the resistance value of standard resistor A1. 标2-后 ;

[0088] S207 Determines if |T′ 标2-后 -T′ 标2-前 |<ΔT 标2max If yes, the test conditions are met; otherwise, proceed to S204 and start the test again.

[0089] S208 calculates T′ 标2 =(T′ 标2-前 +T′ 标2-后 ) / 2, where T′ 标2 This represents the average resistance value of standard resistor A1 at the current temperature.

[0090] The resistance of a standard resistor is measured twice, before and after the temperature sensor resistance is measured. The average value of the standard resistor at the corresponding temperature is calculated to reduce the error caused by the temperature fluctuation of the constant temperature bath to the temperature sensor.

[0091] like Figure 4 As shown, the direction of the driving current is reversed, and the resistance temperature sensor is tested at a reference temperature to correct the reference temperature measurement value T. 标 The methods include:

[0092] S301 obtains the resistance value of standard resistor A1 and calculates the temperature T″ corresponding to the resistance value of standard resistor A1. 标1-前 ;

[0093] S302 acquires the resistance value of the resistance temperature sensor and then acquires the resistance value R″ of the standard resistor A1. 测1 Calculate the resistance value of standard resistor A1 corresponding to temperature T″. 标1-后 ;

[0094] S303 determines whether |T″ 标1-后 -T″ 标1-前 |<ΔT 标1max If yes, the test conditions are met; otherwise, proceed to S301 to restart the test.

[0095] S304 Calculate T″ 标1 =(T″ 标1-前 +T″ 标1-后 ) / 2, where T″ 标1 This is the average resistance value of standard resistor A1 at the temperature after the drive current is converted.

[0096] like Figure 5 As shown, S305 obtains the resistance value of standard resistor A1 and calculates the temperature T″ corresponding to the resistance value of standard resistor A1. 标2-前 ;

[0097] S306 acquires the resistance value R″ of the resistance temperature sensor. 测2 Obtain the resistance value of standard resistor A1 again, and calculate the temperature T″ corresponding to the resistance value of standard resistor A1. 标2-后 ;

[0098] S307 determines whether |T″ 标2-后 -T″ 标2-前 |<ΔT 标2maxIf yes, the test conditions are met; otherwise, proceed to S305 and start the test again.

[0099] S308 Calculate T″ 标2 =(T″ 标2-前 +T″ 标2-后 ) / 2, where T″ 标2 This is the average resistance value of standard resistor A1 at the temperature after the drive current is converted.

[0100] The test is repeated by changing the direction of the current drive to eliminate the error in temperature measurement caused by thermoelectric potential.

[0101] like Figure 6 As shown, the methods for calculating the resistance values ​​ΔR1 and ΔR2 and the resistance fluctuation values ​​ΔΔR1 and ΔΔR2 of a resistance temperature sensor include:

[0102] S401 according to R′ 测1 and T′ 标1 Calculate ΔR′1, based on R″ 测1 and T″ 标1 Calculate ΔR″1;

[0103] S402 calculates ΔR1 = (ΔR′1 + ΔR″1) / 2, where ΔR1 is the average of ΔR′1 and ΔR″1;

[0104] S403 calculates ΔΔR1=|ΔR′1+ΔR″1| / 2, where ΔΔR1 is the difference;

[0105] S404 according to R′ 测2 and T′ 标2 Calculate ΔR′2, based on R″ 测2 and T″ 标2 Calculate ΔR″2;

[0106] S405 calculates ΔR2=(ΔR′2+ΔR″2) / 2, where ΔR2 is the average of ΔR′2 and ΔR″2;

[0107] S406 calculates ΔΔR2=|ΔR′2+ΔR″2| / 2, where ΔΔR2 is the difference.

[0108] like Figure 7 As shown, the method for determining the rating of the resistance temperature sensor includes:

[0109] S501 calculates the temperature coefficient of resistance α of the resistance temperature sensor based on ΔR1 and ΔR2. R ;

[0110] S502 is determined according to the resistance temperature coefficient and temperature tolerance specified in the Industrial Platinum and Copper Resistance Temperature Detection Procedure JJG 229-2010;

[0111] S503 determines whether |ΔR1-x1| < 2a·ΔT 标1max And ΔΔR1>a·ΔT 标1max Or |ΔR² - x²| < 2b·ΔT 标1max And ΔΔR2>b·ΔT 标1max ,

[0112] Where x1, a, x2, and b are all constants.

[0113] a is Temperature T1 is the rate of change of electrical resistance.

[0114] b is Temperature T2 is the rate of change of electrical resistance.

[0115] x1 and x2 are the maximum allowable resistance values ​​for temperatures T1 and T2, respectively.

[0116] If yes, then a retest is required; otherwise, a retest is not required.

[0117] It should be noted that, according to the verification procedure for industrial platinum and copper resistance thermometers JJG 229-2010, the determination of the resistance temperature coefficient and temperature tolerance of the resistance thermometer includes: within the effective temperature range, the maximum deviation between the temperature t calculated by the resistance thermometer through the calibration table and the actual temperature, and the determination of the corresponding sensor level based on the maximum deviation and the specified range.

[0118] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A testing method for a resistance temperature sensor, characterized in that, The method includes: The S100 is a reference temperature for testing liquid media in a static state. and And determine the fluctuation of the liquid medium; S200 places the resistance temperature sensor at the reference temperature. and Independent testing was conducted on the liquid medium to correct the reference temperature measurement. ; Wherein, the reference temperature is At that time, the thermal resistance temperature sensor is tested to correct the reference temperature measurement value. The methods include: S201 Obtain Standard Resistor Calculate the resistance value of the standard resistor. The resistance value corresponds to the temperature ; S202 Obtain the resistance value of the thermal resistance temperature sensor. The standard resistor is obtained again. Calculate the resistance value of the standard resistor. The resistance value corresponds to the temperature ; S203 Determine whether If yes, the test conditions are met; otherwise, proceed to S201 to restart the test. S204 Calculation ,in The standard resistor in the current state The resistance value corresponds to the average temperature; Wherein, the reference temperature is At that time, the thermal resistance temperature sensor is tested to correct the reference temperature measurement value. The methods include: S205 Obtain the standard resistor Calculate the resistance value of the standard resistor. The resistance value corresponds to the temperature ; S206 Obtain the resistance value of the thermal resistance temperature sensor. The standard resistor is obtained again. Calculate the resistance value of the standard resistor. The resistance value corresponds to the temperature ; S207 Determine whether If yes, the test conditions are met; otherwise, proceed to S205 to start the test again. S208 Calculation ,in The standard resistor in the current state The resistance value corresponds to the average temperature; S300 changes the direction of the drive current, repeating S200; Wherein, the S300 changes the direction of the drive current at the reference temperature. The resistance temperature sensor was tested to correct the reference temperature measurement value. The methods include: S301 Obtain the standard resistor resistance value Calculate the standard resistance The resistance value corresponds to the temperature ; S302 obtains the resistance value of the thermal resistance temperature sensor, and then obtains the standard resistor. Calculate the resistance value of the standard resistor. The resistance value corresponds to the temperature ; S303 Determines whether If yes, the test conditions are met; otherwise, proceed to S301 to restart the test. S304 Calculation ,in The standard resistor after converting the drive current The resistance value corresponds to the average temperature; S305 Obtain the standard resistor Calculate the resistance value of the standard resistor. The resistance value corresponds to the temperature ; S306 Obtain the resistance value of the thermal resistance temperature sensor. The standard resistor is obtained again. Calculate the resistance value of the standard resistor. The resistance value corresponds to the temperature ; S307 determines whether If yes, the test conditions are met; otherwise, proceed to S305 and start the test again. S308 Calculation ,in The standard resistor after converting the drive current The resistance value corresponds to the average temperature; S400 calculates the resistance value of the thermal resistance temperature sensor. , and resistance fluctuation value ; Specifically, step S400 calculates the resistance value of the resistance temperature sensor. , and resistance fluctuation value The methods include: S401 according to and calculate ,according to and calculate ; S402 Calculation ,in for The average value; S403 Calculation ,in The difference; S404 according to and calculate ,according to and calculate ; S405 Calculation ,in for The average value; S406 Calculation ,in The difference; S500 determines the rating of the resistance temperature sensor and whether a retest is required.

2. The testing method for the resistance temperature sensor as described in claim 1, characterized in that, The method for testing the reference temperature of a liquid medium in a static state using S100 includes: S101 Set Temperature Maximum permissible temperature fluctuation of liquid medium in static state ; S102 obtains a standard resistor at preset intervals. The resistance value was obtained n times, and the standard resistance was calculated n times. The resistance value corresponds to the average temperature. ; S103 obtains the standard resistor for the (n+1)th time. The resistance value is used to calculate the standard resistance for the (n+1)th time. The resistance value corresponds to the temperature ; S104 Determines whether If yes, the test fluctuation conditions are met; otherwise, proceed to S101 to restart the test.

3. The testing method for the resistance temperature sensor as described in claim 2, characterized in that, The method for testing the reference temperature of a liquid medium in a static state using S100 includes: S105 Set Temperature Maximum permissible temperature fluctuation of liquid medium in static state S106 obtains a standard resistor at preset intervals. The resistance value was obtained n times, and the standard resistance was calculated n times. The resistance value corresponds to the average temperature. ; S107 Obtains the standard resistor for the (n+1)th time. The resistance value is used to calculate the standard resistance for the (n+1)th time. The resistance value corresponds to the temperature ; S108 Determines whether If yes, the test fluctuation conditions are met; otherwise, proceed to S105 to restart the test.

4. The testing method for the resistance temperature sensor as described in claim 3, characterized in that, The method for S500 to determine the rating of the resistance temperature sensor includes: S501 according to and Calculate the temperature coefficient of resistance of the aforementioned resistance temperature sensor. ; S502 determines the grade of the resistance temperature sensor according to the resistance temperature coefficient and temperature tolerance specified in the Industrial Platinum and Copper Resistance Temperature Detection Procedure JJG 229-2010.

5. The testing method for the resistance temperature sensor as described in claim 4, characterized in that, The method by which S500 determines whether a retest is needed includes: S503 determines whether and or and ,in All are constants. If they are constants, then a retest is required; otherwise, a retest is not required.

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