意义和目的
4.1 – most commonly coating thickness gauge does not apply to all the combination of base material thickness and material. The limitations of a particular instrument is usually described by their manufacturers. In choosing to use the instrument and the required accuracy of measurement, should be examined to measure the substrate material and coating combination and the change of substrate and coating.

4.2 磁的 – The magnetic type measuring instrument measures the magnetic force between the magnet and the coating or its substrate, or the reluctance of the magnetic flux path through the coating and the substrate. These thickness gauges are designed to measure the thickness of non-magnetic coatings on magnetic substrates. Some of them will also measure the thickness of nickel coatings on magnetic or non-magnetic substrates. 6

4.3 Eddy Current – The eddy current type thickness gauge is an electronic instrument used to measure the impedance change of the eddy current induction coil caused by the change of coating thickness. Only when the electrical conductivity of the coatings and the conductivity of the substrate is obviously not at the same time, in order to use them.

4.4 精确 – The accuracy of the measurement depends on the instrument, the foil, its calibration and standardization, and the operating conditions. Accuracy is also affected by the interference of listed in section 5, such as part geometry (curvature), magnetic permeability and electric conductivity, and surface roughness.

笔记 2: Under ideal conditions, the coating thickness can be determined to within ±10% of its true thickness or ±2.5μm (or ±0.0001 in), whichever is greater. See Appendix X2 for exceptions.

Determination of Coating Thickness by Magnetic Field Method or Eddy Current Method (电场法)

范围
1.1 this practice include the use of magnetic and type eddy current thickness instrument (gauge) of the coating on metal (IE。, conductive) substrate nondestructive thickness measurement. The substrate can be ferrous or non-ferrous metal. The coating or plating under test can be conductive or insulating, ferrous or non-ferrous metals.

1.2 The more specific use of these instruments is covered by Practice D7091 and the following test methods published by ASTM: Test Methods B244, B499 and B530.

1.3 单位 – values in SI units shall be deemed to be standard. Values given in the brackets are inches – pound unit mathematical transformation, for reference only, 不被视为标准.

1.4 according to the practice of measurement to accord with the requirement of printing of ISO 2178 在 1982.

1.5 本标准无意解决与其使用相关的所有安全问题 (如果有的话). 本标准的使用者有责任建立适当的安全机制, 健康和环境实践，并在使用前确定监管限制的适用性.

1.6 这个国际标准就是技术性贸易壁垒, 根据世界贸易组织委员会发布的 “关于制定国际标准, 决定原则的指导方针和建议” 建立国际公认的标准化原则.