JJG Petroleum 31-1994 Integrated Temperature Transmitter JJG Petroleum 31-1994 Standard Download Decompression Password: www.bzxz.net

China National Petroleum and Natural Gas Corporation
Departmental Metrology Verification Regulation
Integrated Temperature Transmitter
JJG (Petroleum) 31-94
Verification Regulation of
IntegratedTemperatureTransmitter
JJG (Petroleum) 31--94
This verification regulation was approved by China National Petroleum and Natural Gas Corporation on January 18, 1995, and will be implemented on July 1, 1995. Responsible unit: Petroleum Industry Metrology Professional Standardization Technical Committee Drafting unit: China National Petroleum and Natural Gas Corporation Metrology and Testing Institute The drafting unit is responsible for interpreting the technical provisions of this regulation. The main drafter of this regulation:
Li Xiurong (Metrology and Testing Institute of China National Petroleum Corporation) Participating drafters:
Xie Youzhi (Heilongjiang Metrology and Verification Institute) Zhang Jian (Metrology and Testing Institute of China National Petroleum Corporation) Wang Weixuan (Metrology and Testing Institute of China National Petroleum Corporation) Ding Yumei (Metrology and Testing Institute of China National Petroleum Corporation) II
Technical requirements
Verification conditions
Verification items and verification methods
Calculation of verification results
Processing of verification results and verification cycle
Appendix 1
Appendix 2
Format of the back of the verification certificate·
Format of the verification record of the indication of the temperature transmitter
Appendix 3· Temperature transmitter drift characteristic calibration record format Appendix 4
Appendix 5
Appendix 6
Appendix 7
Temperature transmitter indication stability calibration record format... Temperature transmitter transmission circuit indication calibration method... Temperature transmitter transmission circuit indication calibration record format.1
(2)
Format on the back of temperature transmitter transmission circuit indication calibration certificate·(20)JJG(Petroleum)31—94
Total 20 pages
Integrated temperature transmitter calibration procedure
No. 1
This calibration procedure is applicable to the calibration of two-wire integrated temperature transmitters (hereinafter referred to as transmitters) that are newly manufactured, in use and after repair. Overview
1 Integrated temperature transmitter refers to a transmitter that can be directly installed on site, with the transmitter circuit directly installed in the junction box of the temperature sensing element, and an integrated structure formed through the shell and the connecting pipe. The transmitter adopts a two-wire signal transmission method, that is, the transmitter power line is also used as a signal line, and the output signal is a standard 4-20mADC. Its structural schematic diagram is shown in (a) and (b) of Figure 1. Among them, (a) the transmitter circuit adopts discrete components and is composed of several printed circuit boards: (b) the transmitter circuit adopts IC technology and is composed of a module.
Figure! Integrated temperature transmitter structure diagram 1 Junction box: 2 Transmitter circuit; 3 Fixing bolt: 4 Protective arm: 5- Temperature sensing element Page 2 of 20
2 Appearance:
2 Technical requirements
JJG (Petroleum) 31--94
2.1 The appearance of the transmitter should be complete, without rust and damage, the movable parts should be flexible and reliable, and the fasteners should not be loose
2.2 The nameplate of the transmitter should have the manufacturer, name, model, range, accuracy level, production number, explosion-proof level and factory date of the transmitter 2.3 The internal parts and circuit parts of the transmitter should be neat and tidy, and the wiring should be firm and reliable 2.4 The wiring terminals and adjustment knobs of the transmitter should have clear and legible words or symbols.
3 The transmitter must have zero point and full range adjustment devices. 4 The accuracy grade and basic error value of the transmitter shall comply with the provisions of Table 1. Other special accuracy grades and basic errors shall comply with the provisions of the factory technical documents. Table 1
Accuracy grade
Basic error
(relative to full-scale output)
5 The zero time drift of the transmitter in 1h at the specified calibration temperature shall not exceed 2% of the absolute value of the allowable basic error in Article 4
6 When the ambient temperature of the transmitter changes by 1°C, the temperature source drift shall not exceed the absolute value of the basic error specified in Article 4
7 The output stability of the transmitter shall not exceed the absolute value of the basic error specified in Article 4.
JJG (Petroleum) 31—94
8 Verification environment conditions:
Verification conditions
Total 20 pages
Page 3
8.1 Ambient temperature: 0.1~0.3 level, 203℃; other levels, 20±5℃.
The temperature fluctuation of ambient temperature within 1h shall not exceed 1℃. 8.2 Relative humidity: <80%
8.3 Atmospheric pressure: 86~106kPa.
9 Storage time:
Before the verification of the transmitter, it should be placed at the verification environment temperature for more than 2h before the verification can be carried out.
10 The requirements for various constant temperature fields used for verification of the transmitter shall comply with the provisions of Table 2. Table 2
Low-temperature tank
Application range
100～30
Zhao temperature～95
90~300
Temperature difference in horizontal direction
Calibration equipment and requirements:
Any
Lubrication temperature difference between two points in the effective working area
Using medium
Alcohol, liquid nitrogen
Transformer oil
The absolute value of the allowable basic error of the calibration standard shall not be greater than 1 of the absolute value of the allowable error of the transmitter being tested
The absolute value of the allowable basic error of the calibration measuring instrument shall not be greater than the absolute value of the allowable error of the transmitter being tested
11.3. For the calibration standards, measuring instruments and supporting equipment used for -30~300℃ transmitters, please refer to Table 3. Other measuring ranges shall be selected as required. Page 4 of 20
Instruments
·First-class mercury thermometer
Second-class mercury thermometer
Standard low-temperature tank
Standard water meter
Standard oil level
Ice point meter
Reading telescope
True current digital voltage
<current) meter
Precision phoenix box
DC standard current and voltage source
True current regulated power supply
AC regulated power supplywww.bzxz.net
High and low humidity box
30～+300 C
Graduation value 0.05℃
30~+300℃
Graduation value 0.1℃
100~+30℃
Room temperature~95℃
90~200℃.200~300
Accuracy above 0.005%
0~9999Q
Accuracy (0.005~0.01)%
0~10V, accuracy 0.02%
0~30Vpc+ ripple less than 0.5%
220Vc3kVA. Stability 1%
40~130C
Humidity fluctuation less than 1℃
JJG (petroleum) 31-94
13 groups
9 groups
JJG (petroleum) 31--94
IV. Verification items and verification methods
The verification items of the transmitter shall be in accordance with Table 4.
Inspection and safety items
Verification category
Newly manufactured
In use
Repaired
Note: "+" indicates that it should be verified, "\" indicates that it is not necessary to verify. Appearance inspection:
Total 20 pages3
Page 5
Visual inspection The transmitter should meet the requirements of Article 2 of this regulation. 14 Indication verification:
Stability
Before verification, turn on the measuring instrument and transmitter power supply, and preheat for 15~30 minutes before the indication verification. The indication verification system of the temperature transmitter is shown in Figure 2.7
Temperature transmitter indication verification system
1-Temperature measuring element: 2-Standard temperature: 3-Standard thermometer: 4---Transmission circuit; 5-DC digital ammeter: 6-DC regulated power supply: 7-DC digital voltmeter; 8-Precision resistance boxPage 6 of 20 pages
JJG (Petroleum) 31--94
14.2 For transmitters with standard signal input, check the transmission circuit according to Appendix 5 After the indication verification, the integrated indication verification is then carried out. If there are special requirements, the zero point and upper limit value can be fine-tuned.
14.3 For the transmitter with non-standard signal input, the zero point and the upper limit value of the measurement can be adjusted directly in the lower limit temperature field and the upper limit temperature field. In the following verifications, no further adjustment is allowed.
14.4 Insert the temperature measuring element of the integrated transmitter and the standard thermometer into the standard temperature field, and use the standard thermometer to measure the actual temperature value of the temperature field. 14.5 The number of verification points is determined according to the measurement range and accuracy level requirements of the transmitter. Within the verification range, the minimum number of verification points should not be less than 5 points. 14.6 During verification, the verification should be carried out point by point from the lower temperature limit point to the upper temperature limit point. When verifying each temperature point, the output value of the transmitter under test at the temperature verification point and the indication of the standard thermometer should be read after the temperature of the constant temperature field is stable. 14.7 When the lower limit temperature of the transmitter is below zero, the verification work should be carried out in a low temperature tank. During verification, the verification should be carried out point by point from room temperature to the lower temperature limit value. 14.8 Temperature transmitter indication verification is usually only performed once. 15 Zero time drift verification:
The transmitter is connected to the verification system according to Figure 2 or Figure 3: After the transmitter is preheated for the specified time, under the condition of constant room temperature, the zero output value is recorded every 15 minutes, and the recording is continued for 1 hour from the beginning.
16 Temperature drift characteristic verification:
16.1 When verifying the temperature drift characteristic of the transmitter circuit, connect it according to Figure 3. At the verification ambient temperature, the transmitter circuit uses a standard signal source to give the corresponding values ​​of the zero output and full-scale output of the transmitter circuit, and records the zero and full-scale output values ​​of the transmitter circuit, and performs three times in a row.
16.2 Place the transmitter circuit in a temperature-controlled box, keep it at the temperature specified in the transmitter circuit output technical conditions for 1 hour, and read the zero output value and full-scale output value at the specified temperature (high or low temperature) three times in succession. 17 Stability verification:
JJG(Right Oil)31--94
Total 20 pages
Page 7
Newly manufactured and repaired transmitters should be subjected to stability verification for 48 hours of continuous operation. During the verification, the transmitter should be preheated for the time specified in Article 14.1, and the output value of a certain verification point (any point between 20% and 90% of the full scale) of the transmitter should be recorded every 8 hours.
Figure 3 Standard signal source of the temperature transmitter indication drift characteristic calibration system; 2--Temperature transmitter circuit; 3--Secret resistor box: 4--DC digital voltmeter: 5--DC digital ammeter: 6--DC regulated power supply V. Calculation of calibration results
18 Calculate the various performance indicators of the transmitter according to the data obtained from the above calibration. The calculation formulas used are based on the measurement method of using a DC digital voltmeter. If a DC digital ammeter is used, the voltage symbols in all calculation formulas and record tables should be replaced with current symbols.
19 Transmitter accuracy calculation method:
19.1 Calculate the basic error (accuracy) of the transmitter according to the data obtained from the calibration in Article 14. When the transmitter is calibrated once, the indication error of each calibration point is calculated point by point, and the maximum value of the measurement error is taken as the basic error of the transmitter. 19.2 Actual temperature of the temperature field 1. Calculation method: a. The calculation formula for measuring temperature using a first-class standard mercury thermometer
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