When performing the Ultrasonic Hardness Test while testing thinner materials, in the 2-5mm range, an excellent solution is to stack the specimens to increase thickness. The goal is to bring the thickness over 5mm (0.2″). This will drastically improve your accuracy.

The same concept applies to the specimen’s weight. In order to optimize accuracy, the weight of the specimen should be over 300g. Should your specimens be lighten than 300g, a stacking option may be highly beneficial to meet this weight requirement. This too will improve your testing result accuracy.