Toshniwal digital ultrasonic concrete tester [duct] is supplied by toshcon jesco [india]. It is a rugged, light and easy to operate instrument and uses a non-destructive technique for concrete testing. The technique includes the detection of velocity of ultrasonic pulses using the solid concrete block. The velocity of these pulses depends on the density, reinforcement and elastic properties of the material used in the structure. The quality of concrete blocks is related to their elastic stiffness, so that measurement of ultrasonic pulse velocity in such concrete blocks can often be used to indicate their quality and elastic properties. This instrument requires power of 230 v ±15%, 50-60 hz or on 6v-10 v battery. A four-digit seven-segment display indication is given on the front panel. The instrument has accuracy of ±0.1 ms for the entire range of 0.1 to 999.9 microseconds. Hold control is given for easy operation, which displays the last reading. The instrument has the facility to display waveform on the screen of an oscilloscope. Toshniwal duct finds its applications in determining :
The homogeneities of concrete,
Presence of voids,
Cracks or other imperfections,
Changes in the concrete which may occur with time or through the action of fire or chemical attack,
Comparison of the concrete structure strength with a known sample.