Comb gauge

The tests for determining wet film thickness are primarily intended for paint, but can also be used for the much thicker gel coats. A wheel gauge or a comb gauge may be used neither will give more than an approximate measurement, hence the fairly wide range of... 

Examples include the wheel, Pfund, notch, and comb gauges. The appropriate ASTM standards can be found in refs. [62,63]. 

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