Multiple Gauges for In Situ Measurements of Pressure and Particle Velocity in Condensed Materials

Abstract

In situ measurements of pressure and particle velocity have always been crucial in the development of theoretical models and formulation of equations of state for both inert and reactive materials. Formerly, measurements were made with separate gauge stations placed between layers of investigated material stacked in the direction of shock propagation. This arrangement not only generates a disturbance in the flow field but also causes interruption in the chemical reaction process being monitored. The introduction of multiple gauge packages placed on an inclined surface has eliminated most of the problems encountered with separate in line gauge stations. Such multiple gauges provide the capability of measuring changes in pressure and particle velocity at depth intervals much smaller than those between separate gauge stations. In addition each consecutive gauge element is not engulfed in the flow wake of the preceding one. The multiple element gauges described here are ideal for monitoring rapid changes in pressure and particle velocity in processes such as transition to detonation or phase transformation. With this arrangement in a single experiment one can have as many as twelve signal traces from within a very thin depth in a sample. 20 refs., 9 figs.