The Elcometer NDT VG10 Ultrasonic Velocity Gauge (part number VG10) is a handheld gauge for determining the speed of sound (velocity) of a material. Knowing a material's sound velocity is needed to calibrate thickness gauges accurately and to check whether a component is homogeneous, since variations in velocity can reveal differences in material condition. The VG10 reads velocity directly: placing the transducer probe on the material displays the speed of sound at that point, and on a sample of known thickness it can be used to assess homogeneity.

Measurement uses Pulse-Echo mode over a range of 0.63 to 500mm, with ±0.01mm accuracy, 0.01mm resolution and a velocity calibration range of 1250 to 10,000m/s. A dual element transducer (1 to 10MHz) is used, with automatic V-path correction and manual probe zero via the integrated probe disk. The gauge takes 4 readings per second in manual mode, or 16 per second in high speed scan mode, where the operator drags the probe across the material and the gauge displays the fastest velocity recorded once the probe is lifted.

Results are shown on a multi-function 4.5 digit LCD with 12.7mm high digits, in metres per second or inches per microsecond, with a scan bar indicating reading stability and a backlight (on/off/auto) for poor light. The aluminium housing is tough and impact, water, dust and petroleum product resistant, with up to 200 hours of battery life from 2 AA cells. Note that this model has been discontinued; contact BAMR, South Africa's authorised distributor, for a current replacement recommendation.