The Persoz Elcometer Pendulum Hardness Tester is a simple-to-use instrument for assessing the hardness of specimens such as coated panels. This hardness tester works on the principle that the damping time of a pendulum oscillating on a specimen indicates the hardness of the specimen. The amplitude of the oscillation reduces more quickly on soft specimens than on hard specimens. The Persoz test measures the time taken for the amplitude of oscillation to decrease from 12° to 4°.