【国外标准】 Standard Methods for Sampling and Testing Untreated Mica Paper Used for Electrical Insulation

7.1 Accurate determination of thickness is important for identification purposes. Thickness is related to weight and must be known in order to calculate apparent density and the dielectric strength.7.2 Thickness variation affects the quality of roll winding and is useful in judging the uniformity of mica paper particularly with respect to dielectric breakdown voltage, impregnation time, and thickness of the end product.1.1 These methods cover procedures for sampling and testing untreated mica paper to be used as an electrical insulator or as a constituent of a composite material used for electrical insulating purposes.1.2 The procedures2 appear in the following order:    ASTM    MethodProcedures Sections ReferencesApparent Density 12 ...Aqueous Extract Conductivity 32 and 33 D202Conditioning 4 D685Dielectric Strength 16 – 19 D149Impregnation Time 20 – 24 D202Moisture Content 26 – 28 D644Roll Quality 25 ...Sampling 3 ...Tensile Strength 13 – 15 D828Thickness 6 – 10 D374Weight 11 D646Weight Variability 29 – 31 ...1.3 The values stated in inch-pound units are to be regarded as the standard.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.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.