This standard applies to the calibration of temperature circuit detectors (hereinafter referred to as circuit detectors) with a measuring range of (-60 to 300)°C using thermocouples, thermal resistors, and semiconductor resistors as temperature sensors (hereinafter referred to as sensors). JJF 1171-2007 Calibration specification for temperature circuit detectors JJF1171-2007 Standard download decompression password: www.bzxz.net
This standard applies to the calibration of temperature circuit detectors (hereinafter referred to as circuit detectors) with a measuring range of (-60 to +300)°C using thermocouples, thermal resistors, and semiconductor resistors as temperature sensors (hereinafter referred to as sensors).

National Metrology Technical Specification of the People's Republic of China JJF1171-2007
Calibration Specification fonTemperature Itinerant Detecting Instrument2007—02—28Promulgated
Implementation on 2007-08-28
Promulgated by the General Administration of Quality Supervision, Inspection and Quarantine JJF1171-2007
Calibration Specification for
Temperature Itinerant Detecting Instrument JJF1171—2007
Replaces JJG718—1991
This specification was approved by the General Administration of Quality Supervision, Inspection and Quarantine on February 28, 2007, and came into effect on August 28, 2007.
Responsible unit: National Technical Committee on Temperature Metrology Main drafting unit: Shandong Institute of Metrology China Institute of Testing Technology
Participating drafting units: Xi'an Xihang Tianding Electronic Instrument Co., Ltd. Tai'an Panran Measurement and Control Technology Co., Ltd.
Beijing Conster Technology Co., Ltd.
This specification is interpreted by the National Technical Committee on Temperature Metrology Main drafters of this specification:bZxz.net
JJF1171—2007
Sun Shulan (Shandong Institute of Metrology) Wei Shoufang (China Institute of Testing Technology Test Technology Research Institute) Wei Jing (Shandong Institute of Metrology) Fu Zhiyong (China Test Technology Research Institute) Participating drafters:
Hu Xueliu (Xi'an Xihang Tianding Electronic Instrument Co., Ltd.) Xu Jun (Tai'an Panran Measurement and Control Technology Co., Ltd.) He Xin (Beijing Conster Technology Co., Ltd.) Zheng Zhonghui (Xi'an Xihang Tianding Electronic Instrument Co., Ltd.) Drafting
2 References...
3 Overview·
4 Metrological characteristics·
4.1 Functional inspection
4.2 Safety performance inspection||t t||4.3 Measurement error
5 Calibration conditions.
5.1 Calibration conditions
5.2 Environmental conditions·
6 Calibration method
6.1 Appearance inspection
Inspection of display function
Inspection of inspection cycle:
6.4 Inspection of insulation resistance
Inspection of insulation strength·
6.6 Measurement error calibration
Expression of calibration results··
8 Recalibration time interval
Appendix A Original record format Formula
JJF1171—2007
Appendix B
Format of the inner pages of the calibration certificate
Appendix C Examples of uncertainty analysis of measurement results
1 Scope
JJF1171—2007
Calibration specification for temperature circuit detectors
This specification applies to the calibration of temperature circuit detectors (hereinafter referred to as circuit detectors) with thermocouples, thermal resistors, and semiconductor resistors as temperature sensors (hereinafter referred to as sensors) and a measuring range of (-60～+300)℃. HENH
References
JJG617—1996 "Verification Procedure for Digital Temperature Indicator and Regulator") GB/T13639—1992 "Analog Input Digital Indicator for Industrial Process Measurement and Control System" When using this specification, the currently valid version of the referenced document should be used. The inspection instrument consists of a measuring display instrument and a group of sensors. Sensor?
4 Metrological characteristics
4.1 Functional inspection
4.1.1 Appearance
The main typical structure is shown in the figure
A/D conversion
Typical structure diagram of inspection meter
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1
The appearance and structure of the inspection meter should be intact, and the text symbols, signs, graphics, numbers and physical quantity codes that describe the functions should comply with the corresponding standards and should be clear and correct. There should be no obvious dents, trauma, cracks and deformation on the surface of the inspection meter, and the metal parts should not have rust and other mechanical damage. The switches and buttons of various parts of the inspection meter should be flexible and reliable. The metal (or plastic) package of the inspection meter sensor must be well sealed, and the lead connectors must have good contact. The protective tube and lead wire used by the sensor should be able to withstand the corresponding operating temperature. 4.1.2 Display function
JJF1171—2007
The inspection of the display function of the inspection instrument should be carried out when the power is on. The displayed numbers and images should be clear and without overlapping characters. The brightness should be uniform, and there should be no missing strokes or no measurement units. The decimal point and status display should be correct. For inspection instruments with a negative temperature measurement range, when displaying temperatures below 0C, the inspection instrument should display the polarity symbol of "1": when the measurement range is exceeded or the sensor fails, the overload symbol and the corresponding channel number should be displayed. If there is an alarm device, the alarm signal should be issued at the same time. 4.1.3 Inspection cycle
On the premise that each channel meets the measurement error requirements, the time used from the first channel inspection to the last channel is a inspection cycle. The inspection cycle should meet the indicator requirements given in the inspection instrument manual. 4.1.4 Inspection instruments with printing functions should not have the phenomenon of wrong printing, missing printing or unclear printing. 4.2 Safety performance inspection
4.2.1 Insulation resistance
Under the condition of ambient temperature (1535)℃ and humidity 45%~75%RH, the insulation resistance between the power terminal housing of the patrol meter and the sensor-power terminal shall meet the requirements of Table 1. Table 1
Technical requirements for insulation resistance between terminals
Test location
Power terminal-housing
Sensor-power terminal
4.2.2 Insulation strength
Technical requirements
≥20MQ
Under the condition of ambient temperature (15～35)℃ and humidity 45%～75%RH, the test voltage with a frequency of 50Hz specified in Table 2 is applied between the power terminal-housing sensor-power for 1min. There should be no breakdown corona and spark, and the patrol meter should be able to work normally. Table 2 Test voltage
Test part
Power supply terminal-housing
Sensor-power supply terminal
4.3 Measurement error
Test voltage/V
The difference between the indication of each channel of the patrol meter and the actual temperature is the measurement error of the patrol meter. Expressed in one of the following two forms.
Expressed in the range and quantization unit related to the measured value: Amx =± (a %FS + bd)
Where: Amx
Maximum allowable measurement error, ℃:
Accuracy level of the patrol meter;
Range of the patrol meter, C;
Quantization error generated in the digitization process, generally 1; The value represented by the last word of the output information, . 4.3.2 Expressed directly in the measured value:
Where: K-
--allowable measurement error limit, ℃.
Calibration conditions
Calibration conditions
Calibration standards, see Table 3.
JJF1171—2007
Amx=±K
Table 3 Calibration standards
Name of standard
Standard mercury thermometer
Standard mercury-based thermometer
Measuring range
-30~+300)C
(-60~0)℃
See Table 4.
Calibration equipment,
Technical performance
Table 4 Equipment
Technical performance
Constant temperature oil tank
Constant temperature water tank
Alcohol low temperature tank
Freezing point meter
Reading telescope
Mgohmmeter
Withstand voltage tester
5.2 Environmental conditions
Measuring range
(95~300)℃
Room temperature~95℃
Room temperature 80℃||tt ||Working area
Horizontal temperature difference
Working area
Maximum temperature difference
Magnification more than 5 times
Standard instrument
Other standards with accuracy level not lower than the above requirements can also be used
Temperature fluctuation
±0.05t/10min
±0.05/10min
±0.05C/10min
Rated voltage is 500V, 10.Level 0
Output voltage is higher than 1500V, power is not less than 0.25kW, minimum scale value is not greater than 0.1s
Environmental conditions during calibration are (20±5)℃, humidity is 45%～75%RH. Purpose
Temperature source
Measure zero point
Reading device
Measure insulation resistance
Measure insulation strength
Measurement inspection cycle
The power supply voltage change does not exceed 1% of the rated voltage, and the power supply frequency change does not exceed 1% of the rated frequency. 6
Calibration method
6.1 Appearance inspection
The appearance of the inspection instrument is inspected by visual inspection.
6.2 Inspection of display function
Turn on the power supply of the inspection instrument, check the switches of each part, and the key operation should be flexible and reliable, and should have the corresponding function under the specified state.
JJF1171-—2007
Insert the inspection meter sensor directly from room temperature into a thermostatic bath below zero degrees. At this time, it should be clearly observed that the inspection meter indication changes from air temperature to negative temperature value, and displays the polarity symbol of "-" and the corresponding channel number and temperature value. Then insert the inspection meter sensor into the upper limit temperature, and the inspection meter should clearly display the overload symbol and the corresponding channel number. When any channel sensor is disconnected, the inspection meter should send out an alarm signal. This item can be selected from all channels for single-point assessment, or it can be carried out simultaneously with the measurement error. 6.3 Inspection of inspection cycle
The inspection cycle of the inspection meter can be carried out at any temperature within the measurement range. In the normal inspection state, the inspection meter starts the stopwatch at the same time when the first channel number and the corresponding temperature value are displayed, and stops timing when the last channel number and the corresponding temperature value are displayed. Try to measure the average value of the 9 measurements of the NS original as the inspection cycle of the inspection meter.
6.4 Inspection of insulation resistance
The insulation resistance of the inspection instrument is inspected with a light ohm meter with a rated voltage of 500VM. During the inspection, the external power supply is double-disconnected, and the inspection position is measured.
The power switch of the inspection instrument is turned on, and then the position and test voltage specified in Table 2 are measured. 6.5 Insulation strength inspection
When inspecting, the inspection instrument is disconnected from the external power supply and the power switch of the inspection instrument is turned on. The measurement is carried out according to the position and test voltage specified in Table 2. During the measurement, the withstand voltage test voltage is gradually and steadily increased from zero to the specified value, and maintained. 6.6 Measurement error
6.6.1 Preheating,
Finally, the test voltage is steadily reduced to zero. Turn on the power supply of the patrol meter and preheat for 30 minutes. For the patrol meter with adjustable zero point (or lower limit value) and range, adjust the zero point of each channel according to the instructions before calibration. 6.6.2 Select calibration points (or lower limit value) and range. During the calibration process, the calibration points of the patrol meter should not be evenly distributed on the integral points of the entire measuring range, including the zero point and the upper and lower limit values. In special cases, 6.6.3 The calibration sequence should not be less than 5 points. The calibration points can be selected according to user requirements, and the value should not be less than 3 calibration points.
First calibrate the zero point, and then calibrate the upper or lower limit point by point.
6.6.4 Calibration of the zero point
The calibration of the zero point indication should be carried out in the ice point device.
6.6.5 Calibration of other temperature points
Insert the instrument into the ice point device, and after the indication is stable, the calibration of other temperature points is carried out in a constant temperature bath. Place the inspection instrument sensor in a glass test tube, the inner diameter of which should be compatible with the diameter and width of the sensor. During calibration, insert the glass tube containing the sensor into the medium, with a depth of not less than 300mm. In order to eliminate the convection of air in the glass test tube, the tube mouth should be plugged with cotton. Keep the temperature of the thermostat constant at the point to be calibrated. The temperature deviation from the calibration point shall not exceed ±0.2℃ (based on the indication of the standard instrument). After stabilization for 20 minutes, start reading. The reading order is as follows: standard-→calibrated 1-calibrated 2→····-→calibrated n-standard 4
standard—→calibrated 1-→calibrated 2-.
JJF1171—2007
→calibrated n→standard
When reading, let the inspection instrument inspect all channels for two cycles (that is, measure the displayed value of each channel at least twice), and record or print the temperature value displayed on each channel. Take the difference between the average value of the two readings of each channel and the actual temperature to determine the measurement error of the calibration point. The time interval between the two readings must be greater than or equal to the inspection cycle of the calibrated inspection instrument. During the reading process, the bath temperature should be constant or rise slowly and evenly. The bath temperature change during the entire reading process should not exceed 0.5℃ (if the bath temperature changes by more than 0.5℃ during the reading process, the patrol meter should be recalibrated at the temperature point). Use the same method to calibrate other points in turn. When calibrating with a constant temperature water bath or an alcohol low-temperature bath, glass test tubes are not required for sensors with good sealing. The sensor can be directly inserted into the bath for calibration after being fixed. #人度SB0876.6.6 Actual temperature and measurement error are used to calculate the actual temperature using the following formula
Where: t
actual temperature ℃;
the average value of the four readings of the calibrator
the correction value of the calibrator at the calibration temperature point, ℃The calculation formula for the measurement error of the patrol meter is as follows: At-
the measured reading of a certain
channel of the patrol meter under inspection
the average value of the measurement of a certain
channel of the patrol meter under inspection
calibration Expression of results
The certificate should give the following information: the accuracy mark of the certificate; the name and address of the calibration unit that issues the calibration certificate to the calibrated instrument; description and clear identification of the instrument: the identification of the technical specification on which the calibration is based; the measurement error of each calibration point and the uncertainty of the measurement result, and should also include a description of the calibration environment and the traceability and validity of the measurement standard used for this calibration. 8
Recalibration time interval
The recalibration time interval of the inspection instrument can be determined by the user according to the specific usage, HINA
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more than 1 year.
It is recommended that the longest recalibration time interval is not
Appendix A
Calibration unit:
Instrument name
Manufacturer
Name of standard instrument
Measuring range
Calibration basis
Calibration date
Calibration point/℃
Average value
Corrected value
Actual value
JJF1171 —2007
Original record format
Standard instrument number
Uncertainty (or
Accuracy grade)
Standard thermometer indication/℃
Patrol meter measurement error/C
Average value
Corrected value
Actual value
Patrol meter measurement error/C
Insulation resistance
Calibrator||tt| |Valid until
Address:
Certificate No.
Factory No.
Valid until
Indication of each channel of the inspected patrol meter/C
Display function
Verifier
Insulation strength
Inspection cycle
Indication of standard thermometer/
Appendix B
Main measuring equipment used for calibration:||tt| |Name of standard instrument
Standard instrument number
Environmental conditions for calibration
Uncertainty of measurement result:
1. Measurement error
Measurement error
Channel number
Calibration point/
2. Appearance inspection
3. Display function inspection
4. Inspection cycle inspection
5. Insulation resistance inspection
6.Insulation strength inspection
JJE1171—2007
Calibration certificate page format
Measurement range
Temperature:
Certificate number:
Uncertainty or accuracy level
Grade or maximum allowable error
Calibration result
Measurement error/℃
Note: Articles 2 to 6 should fill in whether the inspection result meets the requirements of the relevant provisions of the specification. Humidity:
The inspection/calibration certificate is valid until
Appendix C
Measurement method
JJF1171—2007
Example of uncertainty analysis of measurement results
This method is applicable to the uncertainty analysis of the measurement results of the temperature circuit detector calibrated by the second-class standard mercury thermometer (taking the measurement results of the ith channel of the temperature circuit detector with a resolution of 0.1℃ at the temperature calibration point of 200℃ as an example). S
C.2 Mathematical model
-Measurement error of a channel of the inspected patrol instrument, ℃; where: At:
t;——Measurement average value of the channel of the inspected patrol instrument,——Average value of the four readings of the standard instrument
Correction of standard mercury thermometer
List the sources of each uncertainty component according to the mathematical model 0.3
The sources of uncertainty of the standard device when measuring the temperature of the guest point are shown in Table C.1. The sources of uncertainty of the standard device when measuring the temperature of each point Input quantity
Measurement repeatability (including the source of the patrol instrument itself
The source of the slot C.4 Evaluation of standard uncertainty of each input quantity C.4.1 Calculation of uncertainty (al)
UBLISHING
C.4.1.1 Calculation of uncertainty component u (am) for repeated measurements Select three sufficiently stable temperature detectors (numbered 1, 2 as the measured objects, repeat the measurement at 200℃ within one week, and obtain 10 measurement values ​​each The difference between the low-frequency detection readings is shown in Table C.2.
Table C.2 Observed values ​​obtained by repeated measurements (taking the resolution of 0.1℃ as an example) Number of readings
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