Standard Practice for Measurement of Wet Film Thickness by Notch Gages

1.1 This practice describes the use of thin rigid metal notched gages, also called step or comb gages, in the measurement of wet film thickness of organic coatings, such as paint, varnish, and lacquer.

1.2 Notched gage measurements are neither accurate nor sensitive, but they are useful in determining approximate wet film thickness of coatings on articles where size(s) and shape(s) prohibit the use of the more precise methods given in Methods D1212.

1.3 This practice is divided into the following two procedures:

1.3.1 Procedure A--A square or rectangular rigid metal gage with notched sides is used to measure wet film thicknesses ranging from 3 to 2000 µm (0.5 to 80 mils 1). Such a gage is applicable to coatings on flat substrates and to coatings on articles of various sizes and complex shapes where it is possible to get the end tabs of the gage to rest in the same plane on the substrate.

1.3.2 Procedure B--A circular thin rigid metal notched gage is used to measure wet film thicknesses ranging from 25 to 2500 µm (1 to 100 mils ). Such a gage is applicable to coatings on flat substrates and to coatings on objects of various sizes and complex shapes.

1.4 The values stated in SI units are to be regarded as the standard. The values given 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 and health practices and determine the applicability of regulatory limitations prior to use.