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4.1 The dissipation factor of natural muscovite mica, as determined by this test method, is of practical importance as a measure of the electrical energy lost as heat in the mica serving as the dielectric substance of capacitors, or in other applications in which the electric field is applied perpendicular to the plane of cleavage. The dissipation factor is particularly important in applications using mica at radio frequencies and in some less extensive audio frequency applications. This test method is suitable for specification acceptance and dielectric-loss control tests (see the of Test Methods D150).4.2 Relative Permittivity (Dielectric Constant)—The permittivity of natural muscovite mica is a measure of its relative ability to store electrostatic energy. Since the relative permittivity perpendicular to the cleavage plane is fairly uniform, regardless of origin, its practical significance is mainly for identification purposes, special uses, research, and design. If a loss index is desired, the value of the permittivity must be known (see the of Test Methods D150).1.1 This test method covers the determination of the dissipation factor and the relative permittivity of natural block mica having thicknesses between 0.007 and 0.030 in. (0.18 and 0.77 mm) and mica films or capacitor splits between 0.0008 and 0.004 in. (0.02 and 0.10 mm) in thickness.1.2 The values stated in inch-pound units are to be regarded as the standard. The values in parentheses are for information purposes only.1.3 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. A specific warning statement is given in Section 7 and 6.1.1.NOTE 1: Procedures for the measurement of dissipation factor and permittivity are given in IEC Publication 60371-2, but the details of the procedure are somewhat different from those specified in this test method.1.4 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.

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ASTM D1126-17 Standard Test Method for Hardness in Water Active 发布日期 :  实施日期 : 

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ASTM D1687-17 Standard Test Methods for Chromium in Water Active 发布日期 :  实施日期 : 

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ASTM D1691-17 Standard Test Methods for Zinc in Water Active 发布日期 :  实施日期 : 

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5.1 A major factor affecting the life of insulating materials is thermal degradation. Other factors, such as moisture and vibration, are able to cause failures after the material has been weakened by thermal degradation.5.2 Electrical insulation is effective in electrical equipment only as long as it retains its physical and electrical integrity. Thermal degradation is able to be characterized by weight change, porosity, crazing, and generally a reduction in flexibility, and is usually accompanied by an ultimate reduction in dielectric breakdown voltage.1.1 This test method provides a procedure for evaluating thermal endurance of flexible sheet materials by determining dielectric breakdown voltage at room temperature after aging in air at selected elevated temperatures. Thermal endurance is expressed in terms of a temperature index.1.2 This test method is applicable to such solid electrical insulating materials as coated fabrics, dielectric films, composite laminates, and other materials where retention of flexibility after heat aging is of major importance (see Note 4).1.3 This test method is not intended for the evaluation of rigid laminate materials nor for the determination of thermal endurance of those materials which are not expected or required to retain flexibility in actual service.1.4 The values stated in acceptable metric units are to be regarded as the standard. The values in parentheses are for information only.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. For a specific hazard statement, see 10.1.1.6 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.

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ASTM D3373-17 Standard Test Method for Vanadium in Water Active 发布日期 :  实施日期 : 

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ASTM D3543-17 Standard Test Method for Metal Glide Adhesion Active 发布日期 :  实施日期 : 

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