Paint Inspection Gauge (PIG)

Paint Inspection Gauge (PIG) is a destructive test gauge used to measure the thickness of coating even if it is single or multiple layer. This test method used even on coatings on wood, concrete, plastic and other non-metallic substrates. The relevance of PIG is coming in the industrial coating industry, when conventional electro-magnetic coating thickness measurement methods fails. For example, coating thickness of Micaceous Iron Oxide (MIO) paint can not be measured using normal electro-magnetic DFT gauge because MIO is magnetic and would cause errors in reading.

This method also found relevance in situations like in a multi coat system, applied earlier without proper DFT of each coats recorded, this method can be helpful. As this is a destructive method, the proper repair of coating after testing is vital. Let's see how it works..

Method of Operation:

1.???? A reference line of a contrasting colour is drawn on the painted surface to be tested

2.???? Pressure applied to force the blade through paint to the substrate and then cut across the reference line

3.???? Measurements can be viewed through microscope in which a graticule scale engraved on the lenses

1. Readings obtained from the graticule scale can be compared with the chart supplied with each gauge and it gives the DFT in μm

This is a few information about the PIG..