An Ultrasonic Stroboscope for Measuring Sound Wave-Length in Liquids

Abstract
A stroboscopic method discussed by Bär for using a sound wave as a light shutter and viewing the same wave train with the modulated light is modified so as to permit observations to be made with a very simple optical system without lenses. This results in a method of measuring relative or absolute acoustic wave‐lengths in liquids with a precision limited only by that of measuring lengths of the order of a meter and the spacing of lines on a photographic plate.