Dynamic Characteristics of Cavity-Mounted Pressure Sensors and Restoration of the Pressure Signals

(1st Report: Application of the Orifice Model)

Abstract

This paper proposes a restoration method for the pneumatic pressure signal distorted due to dynamics of a cavity-mounted pressure sensing system, in order to obtain the “correct” or true pressure waveform to be sensed directly at the measuring point. Restoration is performed in the time domain by computing the output waveform of the “inverse transfer function” for the sensing system whose input is the actual, distorted signal from the system. For a relatively short (or thin) hole, restoration is to evaluate the left-hand side of a second order nonlinear differential equation itself. The restored pressure signal form has excellent agreement with the directly measured original one over a wide range of signal frequencies and amplitudes, or, despite overshoot and delay to a step-like change of the pressure.