Verification Regulation of the Pressure Transmitter

JJG 882-2004 Pressure Transmitter Verification Procedure JJG882-2004 Standard download decompression password: www.bzxz.net
This procedure applies to the finalization and identification (or prototype test), initial verification, subsequent verification and in-use inspection of pressure (including positive and negative gauge pressure, differential pressure and absolute pressure) transmitters.

National Metrology Verification Regulation of the People's Republic of China JJG882-2004
Pressure Transmitter
Transmitter
2004-06-04 Issued
2004-12-01. Implementation
General Administration of Quality Supervision, Inspection and Quarantine
JJG882—2004
Verification Regulation of
the Pressure Transmitter
JJG882—2004
Replaces JJG882—1994
This regulation was approved by the General Administration of Quality Supervision, Inspection and Quarantine on June 4, 2004, and came into effect on December 1, 2004.
Responsible unit: National Pressure Metrology Technical Committee Main drafting unit: Shanghai Metrology and Testing Technology Research Institute Participating drafting unit: Hangzhou Tianyuan Instrument Co., Ltd. This regulation entrusts the National Pressure Metrology Technical Committee to be responsible for interpreting this regulation Main drafter:
Zhu Jialiang
Tu Limeng
Participating drafter:
JJG882—2004
(Shanghai Metrology and Testing Technology Research Institute) (Shanghai Metrology and Testing Technology Research Institute ) (Hangzhou Tianyuan Instrument Co., Ltd.)
Scope·
References
Overview·
4 Metrological performance requirements
4.1 Measurement error
Static pressure influence·
5 General technical requirements
5.1 Appearance...·
Sealing·
Insulation resistance
5.4 Insulation strength·
6 Measuring instrument control
Type identification (or prototype test)
JJG882—2004
6.2 Initial calibration, subsequent calibration and in-use inspection Appendix A Equipment connection method for pressure transmitter calibration Appendix B
Test items and methods for type verification (or prototype test) Appendix C
Pressure transmitter calibration record format
Appendix D Uncertainty analysis example
Appendix E
Calibration certificate, calibration result notice (inside page) format (1)
1 Scope
JJG8822004
Verification procedure for pressure transmitter
This procedure is applicable to the finalization qualification (or prototype test), initial verification, subsequent verification and in-service inspection of pressure (including positive and negative gauge pressure, differential pressure and absolute pressure) transmitters. References
This regulation refers to the following documents:
JJF1015-2002 General Specification for Type Evaluation and Type Approval of Measuring InstrumentsJJF1016-2002 Guidelines for Compilation of Type Evaluation Outline of Measuring InstrumentsJG8751994 Verification Procedure for Digital Pressure Gauges
GB/T17614.1-1998 Transmitters for Industrial Process Control Systems Part 1: Performance Evaluation MethodsGB/T17626.3-1998 Radio Frequency Electromagnetic Field Radiation Immunity TestWhen using this regulation, attention should be paid to using the current valid versions of the above references. 3 Overview
Pressure transmitter is an instrument that converts pressure variables into a transmittable standardized output signal, and there is a given continuous function relationship (usually a linear function) between its output signal and pressure variables. It is mainly used for the measurement and control of industrial process pressure parameters. Differential pressure transmitters are often used for flow measurement. There are two major types of pressure transmitters: electric and pneumatic. The standardized output signals of electric are mainly direct current signals of 0mA~10mA and 4mA~20mA (or 1V~5V). The standardized output signals of pneumatic are mainly gas pressures of 20kPa~100kPa. Other standardized output signals with special provisions are not excluded. Pressure transmitters usually consist of two parts: a pressure sensing unit and a signal processing and conversion unit. Some transmitters have added display units, and some also have field bus functions. The structural principle of the pressure transmitter is shown in Figure 1. Pressure transmitters can be divided into capacitive, resonant, piezoresistive, force (torque) balance, inductive and strain gauge types according to their principles.
Display unit
Pressure (or differential pressure) signal
Pressure sensing unit
Signal processing
And conversion unit
Figure 1 Principle block diagram of pressure transmitter
-Fieldbus
Output signal (mA, V or kPa)
Measuring performance requirements
Measurement error
JJG882-2004
The measurement error of pressure transmitter is divided according to the accuracy grade and shall not exceed the provisions of Table 1. Table 1 Accuracy grade and maximum allowable error and hysteresis Accuracy grade
0.2(0.25)
Maximum allowable error/%
±0.2(±0.25)www.bzxz.net
Note: The maximum allowable error and hysteresis are expressed as a percentage of the output range. 4.2 Hysteresis
Hysteresis 1%
0.16(0.20)
For the pressure transmitter that is calibrated for the first time, its hysteresis shall not exceed the provisions of Table 1. For the pressure transmitter that is subsequently calibrated and inspected during use, its hysteresis shall not exceed the absolute value of the maximum allowable error. 4.3 Static pressure influence
The static pressure influence is only applicable to differential pressure transmitters. And it is measured by the change in the output lower limit value and the range. 4.3.1 The static pressure influence of the force-balanced differential pressure transmitter shall not exceed the provisions of Table 2. Table 2 Static pressure influence requirements for force-balanced differential pressure transmitters Accuracy grade
Pw≤6.4 (Gain pressure range ≤6kPa)
Lower limit value
and range
Note: w
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