Stroboscopic Schlieren system for the visual observation of pulsed ultrasonic waves

The purpose of this communication is to report our recent work employing a Schlieren optical system to make pulsed ultrasonic waves visible in water. The light source for the Schlieren system was a strobe lamp synchronized with the electrical pulses used to drive the ultrasonic transducer. Preliminary experiments described here have shown that a stroboscopic Schileren system has potential use as a nondestructive testing technique. Another possible use would be sound-velocity measurements in liquids and in solids immersed in a liquid.