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ISO 8573-7 does not have a numerical specification, however, alert and action limits should be created to ensure microbial load in compressed air testing is appropriate for its application

Hi Nourddine, Trace Analytics is an analytical laboratory accredited to performed a series of specialized analyses for a variety of gas/air components. Depending on the specifics of the analysis, different laboratory methods are used. The most common analytical methods used are gas chromatography-mass spectrometry for gas concentration and gas contaminants, gravimetry for oil and particulate contamination, and direct reading color reaction tube for water vapor. I hope this helps!