A piezo-electric pressure bar gauge

Abstract

A pressure bar gauge is described in which the average stress over the cross-section of the bar is measured by means of an X-cut quartz disk. Bars of duralumin and lead are employed since the acoustic impedances of these materials closely match the value appropriate to longitudinal thickness vibrations in the quartz. The design of a gauge housing, suitable for mounting in the wall of an explosion or shock tube is discussed.