Velocity gages are instruments used to determine the speed of sound (velocity) of an unknown material or, as a device, to assess the homogeneity of a component of known thickness. Placing the transducer probe on the material the gauge will display the speed of sound of the material at that point. The high speed scan mode allows the operator to drag the probe across the material and when the probe is lifted from the material, the gauge displays the fastest velocity recorded during the scan.