Elcometer 3095
Buchholz Hardness Tester

Unit for measuring hardness by the indentation of a bevelled disc indenting tool with a sharp edge. This is fitted onto a steel block with two supports providing a constant test load of 500g. When placed on a coating for 30 seconds, the disc leaves a trace that can be observed with the x20 microscope, with graduations every 0.1mm. The indentation length is then recorded. This length of the trace is inversely proportional to the hardness.