C. T. Lane

The Thermophone as a Source of Sound in Liquid Helium and Liquid Hydrogen

Although the thermophone effect, the generation of sound waves by a varying heat source, has long been known in gases and has proved to be useful in a precision sound source for calibrating microphones, no mention of its use in liquids has come to our attention. In some recent experiments, described in this paper, we have observed this effect in liquid helium I and liquid hydrogen. Suggestions are made for its use as a simple sound source for audiofrequency velocity and absorption measurements in these liquids.