Hardness measurements are one of the most common methods used to evaluate mechanic properties of materials. Unlike stationary hardness testers, where hardness is determined based on an optical measurement of indentation, portable hardness testers utilize the Ultrasonic Contact Impedance method. Special probe with a diamond indenter and a vibrating rod is pressed into the material. The hardness measurement is displayed and analyzed based on ultrasonic wave reflection. Hardness measurements can be useful in evaluating material degradation or to confirm that thermal treatment or welds were performed properly.