There are three standards currently in force that refer directly to the quality (purity) and the analysis of compressed air: ISO 8573/ISO 12500/ISO 7183.
The one used most is ISO 8573. This standard defines the methods and tests to be used to determine the contaminants present in compressed air.
Classification of contaminants according to ISO:
Solid particulate
Residual humidity
Residual oil (including vapour) content
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