Coating thickness tester

Coating thickness tester

A quick and inexpensive method of measuring coating thickness
The coating thickness tester is sometimes referred to as a Calo® tester or ball crater equipment depending on the thickness tester manufacturer. Such coating thickness testers provide a quick and inexpensive method of measuring coating thickness.

Coating thickness tester - Basics
A rotating steel sphere of known diameter (Ø ball) is pressed onto the surface of a coated test piece or component. When diamond paste is applied to the contact area a crater is abraded through the coating to the substrate. See an impression of a coating thickness test below.

Coating thickness measurement using a Calo® tester or ball crater thickness tester

The distances x and y are measured using an optical microscope and then the thickness of the coating t is calculated using a simple equation. Usually simple analysis software is provided with the Calo® tester / ball crater thickness tester that calculates the coating thickness and allows the user to capture and store images of the ball crater for future reference. This is particularly useful when the coating equipment is part of a production department.