In this method, a diamond indenter resonated by a piezoelectric ceramic at an ultrasonic frequency is used to penetrate into the test material's surface by applying a specific test load.
As opposed to a conventional Vickers wherein indentation diagonals are optically measured, here, the frequency shift (proportional to the size of the test indentation produced by the Vickers diamond) is evaluated and electronically converted to a hardness value within seconds.
The basic relation in comparison to the definition of the Vickers hardness value is mathematically shown in equation .
Rebound (Known as Leeb)
In this method, the velocity of a propelled impact body is measured directly prior and after the impact onto the test material’s surface. The ratio between both measured velocities specifies the hardness of the material. The harder the material, the less the rebound velocity and the smaller the impression will be on the material.
The Leeb hardness value is determined by using equation 
Regardless of the type of portable instrument used, the hardness value of the material is electronically measured and instantly displayed on the portable screen.
We perform the test in accordance with ASTM 1038: Standard Test Method for Portable Hardness Testing by the Ultrasonic Contact Impedance Method