ASTM D 2029:2026

1.1 These test methods describe the determination of the water vapor content of electrical insulating gases by directly or indirectly measuring the dew point and calculating the water vapor content. 1.2 The following three test methods are provided: 1.2.1 Method A describes the automatic chilled mirror method for measurement of dew point as low as -73 °C (-99 °F). 1.2.2 Method B describes the adiabatic expansion method for measuring dew point as low as -62 °C (-80 °F). 1.2.3 Method C describes the capacitance method for measurement of dew point as low as -110 °C (-166 °F). 1.3 This standard will also provide insight into the direct measurement of dew point in electrical insulating gas from in-field servicing of various gas insulating equipment. 1.4 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. For specific warnings, see 8.1.1 , 9.2 , and 10.1.2 . 1.5 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.

29.040.20