The hardness tester products you will find at PCE Instruments (PCE) are used for determining surface hardness. Each hardness tester uses a standard method of measurement. The measuring principles of most hardness tester devices are based on either the penetration of a diamond indentor into the material being tested or a calculation related to the force of the rebound after striking the tested material. However, material hardness can also be measured accurately through ultrasonic testing. Each hardness testing method has its benefits and will allow for the precise measurement of material hardness in accordance with the technical specifications of the hardness testing instrument.