The UPV2100 Ultrasonic Pulse Velocity Tester calculates the sound wave velocity based on the propagation distance and time of the received ultrasonic pulses, and then evaluates the performance of solid materials and detects defects such as cracks. The ultrasonic speed depends on the density and elasticity of the material, as well as the presence of defects such as cracks, which determine the strength and quality of the material.