Abstract
This paper deals with the effect of the pressure sensing orifice-cavity ensemble (PSOCE) on the transfer characterstics of the pneumatic transmission line. The following results are obtained. (1) When the pressure transfer gain characteristics of a pneumatic rectangular line terminated with a long line are measured by the cavity mounted transducers, they vary sinusoidally and do not coincide with those measured by the flush mounted transducers. (2) The amplitude of the gain variation depends on the input pressure amplitude, the diameter and the length of the pressure sensing orifice, and the volume of the pressure sensing cavity. (3) The period of the gain variation depends mainly on the input-output distance of the test line. (4) The PSOCE of a large diameter and short length orifice and of a small volume cavity should be used to minimize the PSOCE effects. (5) The theory taking account of the effects of these parameters has a good correlation with the experimental results.
