ASTM D8446-22 - Standard Test Method for Water Vapor Content in Compressed Air Using Electronic Moisture Analyzers

1.1 This test method covers the determination of the water vapor content in compressed air using portable or in-situ electronic moisture analyzers. Such analyzers commonly use sensing cells based on phosphorus pentoxide, P₂O₅, aluminum oxide, Al₂O₃, or silicon piezoelectric-type cells or laser-based technologies.

1.2 This test method is applicable for the range of condensation temperatures from –80 °C to 60 °C.

1.3 Testing is often performed at reduced pressure from the full pressure of the system or source of compressed air depending on the capability of the specific analyzer. Testing above 2000 kPa may introduce additional uncertainty because of changes in the relationship between water vapor pressure and actual moisture content at elevated pressures.

1.4 Units—The values stated in SI units are to be regarded as the standard. No other units of measurement are included in this standard.

1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.