PRESSURE SENSOR

摘要

A pressure sensor (1) for pressure measurement in a combustion chamber or the like includes a photoelastic medium (6) such as quartz means for directing polarised light through said photoelastic medium (6) and detector means (12) for detecting the change in polarisation of the light after it is passed through said photoelastic medium (6). In use the pressure sensor is disposed so that the photoelastic medium (6) is subject to pressure in the combustion chamber, changes in pressure acting on the medium causes changes in the light transmission properties and hence affect the light detected by the detecting means (12), thus producing a signal indicative of the pressure in said combustion chamber to which the medium is subjected.