Some standard content:
National Metrology Technical Specification of the People's Republic of China JJF1183—2007
Calibration Specification of the Temperature Transnitter2007 - 11 - 21 Issued
Implementation on 2008-05-21
Issued by the General Administration of Quality Supervision, Inspection and Quarantine JIF1183-—2007
Calibration Specification ofthe Temperature Transmitter
JJF1183—2007
Replaces JJG829—1993
This specification was approved by the General Administration of Quality Supervision, Inspection and Quarantine on November 21, 2007, and came into effect on May 21, 2008.
Responsible unit: National Temperature Metrology Technical Committee Main drafting unit: Shanghai Metrology and Testing Technology Research Institute Participating drafting unit: Dajin City Planning and Reclamation Supervision and Inspection Science Research Institute The National Temperature Metrology Technical Committee is responsible for interpreting this specification Main drafter:
JJF 1183—2007
Zhu Jialiang (Shanghai Institute of Metrology and Testing Technology) Co-drafters:
Liu Wei (Tianjin Institute of Metrology Supervision and Testing Science) Li Xiaozhong (Tianjin Institute of Metrology Supervision and Testing Science) Pan Chenyan (Shanghai Institute of Metrology and Testing Technology) Yao Lifang (Shanghai Institute of Metrology and Testing Technology) 1. Scope·
2 References·
3 Overview·
4 Metrological characteristics·
4.1 Measurement error·
4.2 Safety performance
5 Calibration conditions
5.1 Calibrator and other equipment
5.2 Environmental conditions·
5.3 Power supply
6 Calibration items and calibration methods
6.1 Calibration items·
6. 2 Calibration method...
6.3 Data processing principles
7 Expression of calibration results·
JJF1183—2007
Appendix A Equipment connection method for temperature transmitter calibration
Appendix B Requirements and measurement methods affecting metrological performance of DZ series and modular temperature transmitters (11) Appendix C Requirements for calibration using thermocouple instrument calibrators Appendix D Calibration record format
Appendix E Reference format for the inner pages of the calibration report
Appendix F Uncertainty analysis example
1 Scope
JJF1183—2007
Temperature transmitter calibration specification
This specification applies to the calibration of temperature transmitters (hereinafter referred to as transmitters) whose sensors are thermocouples or thermal resistors. Transmitters include those with and without temperature sensors. 2 References
This specification references the following documents:
GB/T16839.2—1997 Thermocouple Part 2: Tolerance JJG128-20H3 Second-class standard mercury thermometer verification procedure JJG141-2000 Verification procedure for working precious metal thermocouples JJG229—1998 Verification procedure for industrial platinum and copper thermal resistors JJG351-1996 Verification procedure for working cheap metal thermocouples JB/T8622—1997 Technical conditions and graduation table for industrial platinum thermal resistors JB/T8623—1997 Technical conditions and graduation table for industrial copper thermal resistors When using this specification, attention should be paid to the use of the current valid versions of the above references. 3 Overview
Temperature transmitter is an instrument that converts temperature variables into a standardized output signal that can be transmitted. Mainly used for the measurement and control of industrial process temperature parameters. Transmitters with sensors usually consist of two parts: a transmitter and a signal converter. The sensor is mainly a thermocouple or a thermal resistor: the signal converter is mainly composed of a measuring unit, a signal processing unit and a conversion unit (since the graduation tables of industrial thermal resistors and thermocouples are standardized, the signal converter is also called a transmitter when it is an independent product). Some transmitters have added display units, and some have field bus functions. As shown in Figure 1, the display unit
thermal resistor
or thermocouple
measuring unit
signal processing
and conversion unit
Figure 1 Transmitter principle frame
field bus
output signal (mA or Y)
If the transmitter consists of two sensors used to measure the temperature difference, there is a given continuous function relationship between the output signal and the temperature difference, which is also called a temperature differential transmitter. There is a given continuous function relationship (usually a linear function) between the output signal of the transmitter and the temperature variable. The output signal of the transmitter produced in the early stage has a linear function relationship with the resistance value (or voltage value) of the temperature sensor. The standardized output signal is mainly a DC signal of 0mA~10mA and 4mA~20mA (or 1V·5V)1
JFF 1183—2007
Other standardized output signals with special provisions are not excluded. Temperature transmitters can be divided into two-wire and four-wire systems according to the supply wiring method. Transmitters are electric unit combination instrument series (DDZ-Ⅱ type, DDZ-Ⅲ type and DDZ~S type) and miniaturized modular, multi-functional intelligent types. The former does not have a sensor; the latter two types of transmitters can be easily combined with thermocouples or thermal resistors to form a transmitter with a sensor. 4 Metrological characteristics
4.1 Measurement error
The measurement error of the transmitter is the error generated when converting the temperature into a standardized output signal. 8) The maximum permissible error of the transmitter (signal converter) without a sensor is divided according to the accuracy level. Under standard conditions, the relationship between the accuracy level of the transmitter and the maximum permissible error is specified in Table 1. Table 1 Accuracy level and maximum permissible error
Accuracy level
Maximum permissible error (%FS)
Note: The maximum permissible error is expressed as a percentage of the output range. When the input temperature variable is in a linear function relationship with the output signal, the maximum permissible error can be expressed as a percentage of the input range. bh) The maximum permissible error of the transmitter with a sensor consists of two parts: the thermal resistor or thermocouple charge difference and the signal converter tolerance, which is the sum of the absolute values of the two. The tolerances of thermal resistors and thermocouples are shown in JB/T 8622-1997, JB/T862:3-1997 and GB/T 16839.2-1997. Note: For transmitters with sensors, the maximum allowable error within the measurement range can be expressed as temperature or as a percentage of the input range.
4.2 Safety performance
4.2.1 Insulation resistance
When the ambient temperature is 15℃~35t and the relative humidity is 45%-75%, the insulation resistance between each group of terminals (including the housing) of the transmitter should not be less than the specified value in Table 2. 4.2.2 Insulation strength
When the ambient temperature is 15℃~35 and the relative humidity is 45%~75%, the test voltage (frequency is 50Hs) specified in Table 3 is applied between each group of terminals (including the housing) of the transmitter for 1 minute, and there should be no breakdown or arcing. Transmitters with sensors are not subject to this test. 2
Test location
Input, output terminals short-circuited-housing
Power supply terminal-housing
Input, output terminals short-circuited--power supply terminalInput terminal-output terminal
Test location
Input, output terminals short-circuited-housing
Power supply terminal-housing
Input, output terminals short-circuited--power supply terminalInput terminal-output terminal
5 Calibration conditions
5.1 Standards and other equipment
JJF 1183--2007
Table 2 Technical requirements for insulator resistance
Technical requirements
Insulation strength test voltage
Test voltage/V
12V--48V
Applicable to one-wire transmitter
Applicable to four-wire transmitter
Applicable only to transmitter with input and output isolation220V
Applicable to two-wire transmitter
Applicable to four-wire transmitter
Applicable only to transmitter with input and output isolation
The standard instruments and supporting equipment required for calibration can be selected from Table 4 according to the type of transmitter to be calibrated. In order to improve the calibration capability, the expanded uncertainty introduced by the standard instruments and supporting equipment should be as small as possible compared with the absolute value of the maximum allowable error of the transmitter to be calibrated.
5.2 Environmental conditions
Ambient temperature 15℃~-35℃; relative humidity <85%. In order to ensure that the calibration has the smallest possible uncertainty, it is recommended that the calibration should be carried out under the following standard environmental conditions. These conditions are also conducive to providing an explanation of whether the instrument meets the metrological characteristics when the user makes a request. a) Ambient temperature 20℃±2% (0.1~0.2 grade transmitter); 20±5% (0.5.-2.5 grade transmitter)
b) Relative humidity 45%75%.
c) Except for the geomagnetic field, there should be no external magnetic field around the transmitter that affects its normal operation. 3
Instrument name
DC low potential
JJF 11832007
Table 4 Standard instruments and supporting equipment
Technical requirements
Differential meter or standard DC 0.02 level, 0.05 level voltage source for calibration thermocouple input
DC resistance box
Compensation wire and obzxz.net
Thermostat
Special connecting wire
DC ammeter
DC voltmeter
Standard resistor
AC voltage regulator
DC voltage regulator
Second-class platinum resistance standard
Device or second-class Mercury thermometer standard device, second-class standard platinum, 10-platinum thermocouple standard device, insulation resistance meter, voltage withstand tester, 0.01 grade and 0.02 grade compensation wire should match the input thermocouple graduation number, and have a correction value of 10℃30℃ after verification. The temperature deviation of the 0℃ delay device does not exceed +0.1℃, and its resistance should meet the requirements of the manufacturer's instructions. When the three-wire connection is used, the difference in resistance between the wires should be as small as possible. When the resistance value is not clearly specified, a copper wire can be cut into segments of equal length (not exceeding 1m). UmA~30mA 0.01~ 0.015 0V-5V, 0V~50V 0.01~0.05 1000 (2502)
Not less than 0.05 level
220V, 50H, stability
1%, power not less than 1kW
12V~48V, tolerance +1%
Conform to the requirements of JJ229-1998 or
JJG128-203 for standard instruments and supporting equipment
Conform to JJG351-1996 or
JIG 141-2000 Requirements for standard instruments and supporting equipment: DC voltage 100V, 500V Output voltage: AC 0V.-1500V Output power: not less than 0.25kW Transmitter (without sensor) Calibration of thermal resistance input Transmitter (without sensor) with automatic compensation of reference end temperature Transmitter (without sensor) Dedicated connection line for calibration Connecting wire between DC resistance box and transmitter terminal Measurement standard of transmitter output signal DC voltmeter is used alone as the measurement standard of transmitter electrical output signal ：Combined with standard resistor to replace DC ammeter as measurement standard of transmitter current output signal AC power supply of transmitter DC power supply of transmitter Input standard for calibration of humidity transmitter with thermocouple Auxiliary standard for calibration of temperature transmitter with thermocouple Insulation strength of measuring transmitter Output impedance of measuring transmitter is not more than 100n o℃ Thermostat or ice point bath for transmitter with sensor 5.3 Power supply Working power supply of transmitter: JJF 1183—2007
For AC powered transmitters, the voltage variation shall not exceed 11% of the rated value, and the frequency variation shall not exceed ±1% of the rated value; for DC powered transmitters, the voltage variation shall not exceed ±1% of the rated value. 6 Calibration items and calibration methods
6.1 Calibration items
a) The calibration items for transmitters are differential pressure and insulation resistance. b) Newly manufactured transmitters without sensors shall also be subjected to insulation strength and insulation resistance. c) For DDZ system transmitters, the calibration items shall be subjected to the following tests: accuracy, power supply influence and transmission current component. 6.2 Calibration methods
6.2.1 Measurement error 6.2.1.1 Calibration of calibration pipes and connections.
Transmitter with sensor:
Standard thermometer:
b) Power on
until it can be connected to the load characteristic temperature source (constant temperature bath or thermocouple calibration furnace; when calibrating the inverter, the preheating time is 3 for the transmitter connected to the manufacturer's manual;
e) Small adjustment before calibration. (The adjustment must be carried out within a specified time of 15 minutes; it must be carried out under suitable conditions) Transmitters without sensors can be adjusted using modified signal guides to make them consistent with the ideal limit values and ratio limits for the input range of the transmitter, and then make the above adjustments to the corresponding values and keep them as close as possible to the temperature control system. Before calibration, adjust the transmitter with sensor according to the client's input specifications and range. The above adjustment can be made to the transmitter alone with the sensor turned on. If the measurement result still cannot meet the client's requirements, readjust it in the calibration furnace. It is not allowed to adjust the zero point and full range during the measurement. Note: 1. The general transmitter can be adjusted by adjusting the "zero point" and "full range". 2. For the transmitter with field bus, the "zero point" and "full range" of the input part and the output part must be adjusted by the three-way operator (or adapter) according to the requirements of the manual to complete the adjustment work. At the same time, the damping body of the transmitter should be adjusted to the minimum. 6.2.1.2 Calibration
Selection of calibration points: The selection of calibration points should be evenly distributed according to the range, and generally should include at least 5 points including the upper limit, lower limit and near 50% of the range: Transmitters of level 0.2 and above should have at least 7 points. 5
JJF 1183—2007
a) When calibrating a transmitter with a sensor, the measurement sequence can start from the lower limit temperature of the measurement range, and then measure from bottom to top. At each test point, the temperature in the temperature source should be sufficiently stable before measurement can be carried out (generally not less than 30 minutes): the indication of the standard thermometer and the output of the transmitter should be read repeatedly 6 times in turn. Calculate the measurement error according to formula (1):
AA, = A- A(t - n) + Ao]
Where: AA,-
- The measurement error of each calibrated point of the transmitter (expressed as the output quantity), mA or VA. — The average value of the actual output of the calibrated point of the transmitter, mA or V; The output range of the transmitter, mA or V
The input range of the transmitter, ?;
Au——The theoretical lower limit of the transmitter output, mA or V; —… The average temperature value measured by the standard thermometer, C; to——The lower limit of the transmitter input range, ℃. (1)
b) When calibrating a transmitter without a sensor, the signal value corresponding to each calibrated point should be input steadily from the lower limit, and the output value should be read and recorded until the upper limit; then the input signal should be input steadily in the opposite direction to each calibrated point in turn, and the output value should be read and recorded until the lower limit. This is one cycle, and three cycles of measurement must be performed. When approaching the calibrated point, the input signal should be slow enough to avoid overshoot. Note: When calibrating a transmitter with thermocouple input (which has automatic reference end temperature compensation), in order to obtain an integer standard output value, the input signal of each calibrated point should be the corresponding electrical value of the calibrated point minus the compensation wire correction value. The measurement error is calculated according to formula (2):
[A(2 +- t)+ A]
AA. = Ag -
Where: A, - the actual input value of the calibrated point of the transmitter, the average of multiple measurements, mA or V; A, - the output range of the transmitter, mA or V; the input range of the transmitter, ;
An - the theoretical lower limit of the transmitter output, mA or V: 1, - the input temperature value of the transmitter, that is, the temperature value corresponding to the simulated thermal resistor (or thermocouple), C: t. =Lower limit of the transmitter input range, °C; =Correction value of compensation wire, mV;
S = Temperature measurement points and slope of thermocouple characteristic curve, which can be regarded as constant for a certain temperature measurement point, mV/C
6.2.1.3 Processing of measurement results
The measurement error can be expressed in output units, overflow units, or as a percentage of input (or output).
Since the output of the transmitter is usually a linear function of temperature, the conversion between them can be carried out according to formula (3): JF1183-2007
Wu Zhong: A = Error expressed by input temperature, C (3)
Note: The output of some products in the DDZ series transmitter is a linear function of the thermocouple millivolt signal (or the resistance signal of the thermal resistor). At this time: Formula (1) - Formula (3) The main should be replaced by the base volt number (or electrical signal) 6.2.2 Measurement of insulation resistance
Disconnect the transmitter power supply, use the insulation resistance meter to measure the position specified in Table 2, and the reading should be stable for 5s: 6.2.3 Measurement of insulation strength
Disconnect the transmitter power supply, connect each pair of wiring to the two poles of the withstand voltage tester in turn according to the provisions of Table 3, slowly and steadily increase the voltage to the specified value, maintain for 1 minute, and observe whether there is breakdown and arcing. Then, slowly and steadily reduce the voltage to zero. || tt||Note: To protect the transmitter from breakdown during the test, a voltage tester with alarm current setting can be used during the test. The setting value is generally 51mA (special requirements are preferred). When using this instrument, whether the alarm is used is used as the basis for judging whether the insulation is qualified or not:
6.3 Data processing principles
Data processing principles during measurement results and error calculation: The number of digits retained after the decimal point should be limited to 10~20
of the maximum allowable error of the rounded error transmitter (equivalent to taking one more decimal place than the maximum allowable error). In case of uncertainty In the calculation process of calibration, in order to avoid rounding errors, 2 to 3 significant digits can be retained. However, the final expanded uncertainty can only retain 1-2 significant digits. The measurement result is given by the arithmetic mean of multiple measurements, and its last digit should be aligned with the effective compensation digit of the expanded uncertainty. 7 Expression of calibration results
The calibration report should at least include the following information: a) Title, such as "Calibration Certificate" or "Calibration Report" b) Laboratory name and address;
c) Location of calibration (if the calibration is not performed in the laboratory space): d) Unique identification of the certificate or report 1) The name and address of the organization sending the calibration documents; 2) A description and clear identification of the object being calibrated; 3) The date on which the calibration was carried out and, if relevant to the validity and application of the calibration results, the date on which the object was received; 4) If relevant to the validity and application of the calibration results, a description of the sampling procedure: 5) Identification of the technical specification on which the calibration is based, including its name and code; 6) A description of the traceability and validity of the quantity standards used for this calibration; 7) A description of the calibration environment; 8) The date on which the calibration was carried out and, if relevant to the validity and application of the calibration results, a description of the sampling procedure: 9) The name and address of the organization sending the calibration documents; 10) The name and address of the organization sending the calibration documents; 11) The name and address of the organization sending the calibration documents; 12) The name and address of the organization sending the calibration documents; 13) The name and address of the organization sending the calibration documents; 14) The name and address of the organization sending the calibration documents; 15) The name and address of the organization sending the calibration documents; 16) The name and address of the organization sending the calibration documents; 17) The name and address of the organization sending the calibration documents; 18) The name and address of the organization sending the calibration documents; 19) The name and address of the organization sending the calibration documents; 20) The name and address of the organization sending the calibration documents; 21) The name and address of the organization sending the calibration documents; 22) The name and address of the organization sending the calibration documents; 23) The name and address of the organization sending the calibration documents; 24) The name and address of the organization sending the calibration documents; 25) The name and address of the organization sending the calibration documents; 26) The name and address of the organization sending the calibration documents; 27) The name and address of the organization sending the calibration documents; 28) The name and address of the organization sending the calibration documents; 29) The name and address of the organization sending the calibration documents; 1183--2007
I) Description of calibration results and their measurement uncertainty: m) Signature, position or equivalent identification of the issuer of the calibration certificate or calibration report, and the date of issuance; n) Statement that the calibration results are only valid for the object being calibrated; o) Statement that the certificate or report shall not be partially reproduced without the written approval of the laboratory. Among them:
"Description of the traceability and validity of the measurement standards used in this calibration" should include the name, model specifications, measurement scope and uncertainty (or accuracy grade, maximum tolerance), validity period, etc. of the standard instrument. "Description of the calibration environment" should include the status of the power supply; the transmitter with a sensor
should also explain the protection of the casing during calibration and the temperature rise and fall test period. The “Explanation of the calibration results and their measurement accuracy” should give the output mean value or the converted temperature value corresponding to each measured value (the corresponding error can also be extracted, such as the extended METROL uncertainty of the Hsriand calibration point of a transmitter and the replacement of the fixed value).3 Data processing principles
Data processing principles in the measurement results and error calculation process: The number of digits retained after the decimal point should be limited to 10~20
of the maximum allowable error of the transmitter (equivalent to taking one more decimal place than the maximum allowable error). In the calculation process of uncertainty, in order to avoid rounding errors, 2 to 3 significant digits can be retained. However, the final expanded uncertainty can only retain 1--2 significant digits. The measurement result is given by the arithmetic mean of multiple measurements, and its last digit should be aligned with the effective compensation digit of the expanded uncertainty. 7 Expression of calibration results
The calibration report shall include at least the following information: a) Title, such as "Calibration Certificate" or "Calibration Report" b) Name and address of the laboratory; c) Location where the calibration was performed (if the calibration is not performed in a laboratory environment); d) Unique identification of the certificate or report (such as number), identification of each page and total number of pages; d) Name and address of the sending organization; d) Description and clear identification of the object to be calibrated; e) Date of calibration, and if it is related to the validity and application of the calibration results, the date of receipt of the object to be calibrated should be stated; h) If it is related to the validity and application of the calibration results, the sampling procedure should be explained: 1) Identification of the technical specification on which the calibration is based, including name and code; i) Traceability and validity of the standard used for this calibration; k) Description of the calibration environment; 1183--2007
I) Description of calibration results and their measurement uncertainty: m) Signature, position or equivalent identification of the issuer of the calibration certificate or calibration report, and the date of issuance; n) Statement that the calibration results are only valid for the object being calibrated; o) Statement that no partial reproduction of the certificate or report is allowed without the written approval of the laboratory. Among them:
The "Description of the traceability and validity of the measurement standards used in this calibration" should include the name, model specifications, measurement scope and uncertainty (or accuracy grade, maximum tolerance), validity period, etc. of the standard instrument. The "Description of the calibration environment" should include the status of the power supply; the transmitter with a sensor should also explain the protection of the casing during calibration and the temperature rise and fall test period. The "Description of the calibration results and their measurement accuracy" should give the output average value corresponding to each measured value or the converted temperature value (the corresponding error can also be extracted, such as the expansion of the HSI calibration point of a transmitter, the METROL uncertainty and the replacement of the solid state.3 Data processing principles
Data processing principles in the measurement results and error calculation process: The number of digits retained after the decimal point should be limited to 10~20
of the maximum allowable error of the transmitter (equivalent to taking one more decimal place than the maximum allowable error). In the calculation process of uncertainty, in order to avoid rounding errors, 2 to 3 significant digits can be retained. However, the final expanded uncertainty can only retain 1--2 significant digits. The measurement result is given by the arithmetic mean of multiple measurements, and its last digit should be aligned with the effective compensation digit of the expanded uncertainty. 7 Expression of calibration results
The calibration report shall include at least the following information: a) Title, such as "Calibration Certificate" or "Calibration Report" b) Name and address of the laboratory; c) Location where the calibration was performed (if the calibration is not performed in a laboratory environment); d) Unique identification of the certificate or report (such as number), identification of each page and total number of pages; d) Name and address of the sending organization; d) Description and clear identification of the object to be calibrated; e) Date of calibration, and if it is related to the validity and application of the calibration results, the date of receipt of the object to be calibrated should be stated; h) If it is related to the validity and application of the calibration results, the sampling procedure should be explained: 1) Identification of the technical specification on which the calibration is based, including name and code; i) Traceability and validity of the standard used for this calibration; k) Description of the calibration environment; 1183--2007
I) Description of calibration results and their measurement uncertainty: m) Signature, position or equivalent identification of the issuer of the calibration certificate or calibration report, and the date of issuance; n) Statement that the calibration results are only valid for the object being calibrated; o) Statement that no partial reproduction of the certificate or report is allowed without the written approval of the laboratory. Among them:
The "Description of the traceability and validity of the measurement standards used in this calibration" should include the name, model specifications, measurement scope and uncertainty (or accuracy grade, maximum tolerance), validity period, etc. of the standard instrument. The "Description of the calibration environment" should include the status of the power supply; the transmitter with a sensor should also explain the protection of the casing during calibration and the temperature rise and fall test period. The "Description of the calibration results and their measurement accuracy" should give the output average value corresponding to each measured value or the converted temperature value (the corresponding error can also be extracted, such as the expansion of the HSI calibration point of a transmitter, the METROL uncertainty and the replacement of the solid state.
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