This standard applies to the gas source used in industrial automation instruments. GB/T 4830-1984 Pressure range and quality of gas source for industrial automation instruments GB/T4830-1984 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Pressure range and quality of air supply for the industrial process.neasurementand control instrumentscntsThis standard applies to the air supply used by industrial automation instruments. Definitions
1.1 Online pressure
The gas pressure transported by the pipeline network from the purification device outlet to the receiving end 1.2 Lower limit of ambient temperature
The lowest temperature of the place where the entire system, including the purification device outlet, pipeline network and instruments, is located. 2 Pressure range
UDC 681.2:621-50bZxz.net
GB4830-84
2.1 The pressure range of the gas source element at the outlet of the purification device is 300~500kPa and 500~800k (3-5k5f/cm and 58 kgf,cm2).
2.2 Pressure range of the gas source layer at the instrument input end
2.2.1 The nominal value of the gas source layer at the instrument input end is 140, 260, 350, 550 and 700kP1 (1.4, 2.G, 3.5, 5.5 and 7.0 kgf/cm2).
2.2.2 The allowable return range of the gas source pressure at the instrument input end is ±10 of its nominal value. 3 Quality
Test method and formula charts are shown in Appendix A (Supplement) and Appendix B (Supplement). 3.1 Dew point
The dew point of the gas source under the line pressure should be at least 10℃ lower than the lower limit of the ambient temperature. 3.2 Dust particle size
The dust particle size in the gas source should not be greater than 3μn.
3.3 Oil content
The oil content in the gas source should not be greater than +10mg/m2 (8ppmw). 3.4 Pollutants
There should be no obvious pollutants or vapors in the gas source. Note: Under the circumstances, the supply system quality assurance, design, inspection and use of the "National Bureau of Standards 1984-12-25 issued 198511-01 implementation A.1 Test date GB4830-84 Appendix A Gas source quality test (supplement) Check and monitor whether the gas source quality meets the standard requirements A.2
The equipment used to test the dynamic resistance must be identified, calibrated and calibrated by the relevant departments according to the regulations and requirements. A.3
Test items
Dust content.
Oil.
Test method
Point test method:
Precise change of less than -10\. (Ppm, value) The trace water analyzer is used for measurement, and the obtained data is estimated according to the relevant formula (curve or grid).
A.4.2 Test method for dust content:
Counting is based on the principle of light emission.
A.4.3 Test method for oil content
Sampling method: carbon dioxide absorption method,
Analysis method: spectrophotometry.
Test system business diagram:
U-type various dresses warm collection| |tt||Flow meter
A row of air
Spectrophotometer [-
B.1 Water content unit conversion formula
GR4830-84
Appendix B
Related formulas and charts
(Supplement)
The volume ratio of micro-moisture content in the air, parts per million, PPn, and the dew point temperature are obtained: B11
PHeo=cp.10 6
Where: FH,o
- Saturated vapor pressure corresponding to its dew point humidity, mmHg: - Total positive pressure, that is, standard atmospheric pressure, calculated at 760mmHg: - Measured water content, volume percentage, Ppm. The dew point temperature can be obtained by looking up the table with the value of o.
B.1.2 Relationship curve between pressure dew point and atmospheric pressure dew point (see attachment) B.2 Conversion formula of oil content unit
Conversion formula of oil content unit weight percentage ppw and mg.m\ D
Where: C- Measured oil content, oil content weight percentage, ppmw! D- Measured oil content, mg/im3;
- Air specific gravity under (25℃, 760mmHg) humid state, kg/m. 1.205
GB 4830—84
GB4830—84
Additional Notes:
This standard was proposed by the Machinery Industry of the People's Republic of China and is under the jurisdiction of Shanghai Institute of Industrial Automation Instrumentation of the Machinery Industry. This standard was drafted by the Working Group for the Development of "Industrial Automation Instrument Gas Source Pressure Specification and Quality Standard" (National Standard). The drafter of this standard is Zheng Xia, a member of the Ministry of Planning. The standard was entrusted to Chongqing Institute of Industrial Automation Instrumentation of the Ministry of Machinery Industry for interpretation. The gas source pressure specification, dew point and particle size specified in the standard are consistent with IEC Publication 654-2 (1979) No. 1JEC65B (Secret) No. 42, and the oil content is consistent with the United States ANS1M11.1-1975-; according to the current situation in my country, the gas source specification is supplemented.
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