PRESSURE GAUGE

PURPOSE:To obtain a pressure gauge free of a temperature error by providing a strain inducer which has the 1st and 2nd quartz strain gauges on the 1st and 2nd bellows where reference pressure and pressure to be measured are introduced, and then finding the difference in natural oscillation frequency between those two quartz strain gauges. CONSTITUTION:In a housing 11 made of a thin material, bellows 12 and 13 where reference voltage and pressure to be measured are in troduced are provided, and a comma-patterned strain inducer 14 is fitted over the bellows by clamping bodies 19 and 19'. The body 14 is provided with quartz strain gauges 17 and 17 bonded by bonding bodies 17 and 17', and the center part of the strain-motive body 14 is fitted to a supporting body 18 by a clamping body 20 such as a screw. Thus, a pressure gauge is constituted and when the pressure to be measured is introduced into the bellows 13, the strain inducer body 14 generates strain which corresponds to the difference from the reference voltage to vary the natural oscillation frequencies of quartz strain gauges 15 and 16 by the strain. Therefore, the difference between the natural oscillation frequencies of those gauges 15 and 16 is found to obtain the difference between the pressure to be measured and reference voltage.