APPARATUS FOR THE CORRECTION OF TEMPERATURE DRIFT FOR A PRESSURE SENSOR, A PRESSURE CONTROL APPARATUS, AND A PRESSURE-TYPE FLOW RATE CONTROL APPARATUS

摘要

22A pressure sensor, a pressure control apparatus, and a flow rate controlapparatusare provided in which the temperature drift of the pressure sensor isautomaticallycorrected and pressure can be accurately detected in spite of changes intemperature.A pressure-type flow rate control apparatus, in which an apparatus forcorrectingtemperature drift according to the present invention is installed, has anupstream sidepressure sensor 10 provided between an orifice 4 and a control valve 22 fordetecting anupstream side pressure P1, and controls the flow rate of a fluid passingthrough the orifice4 by means of a regulating control valve 22, while calculating the flow rateof the fluidpassing through the orifice 4 from the upstream side pressure P1, wherein theapparatus forcorrecting temperature drift comprises a temperature sensor 14 for measuringthetemperature of the fluid, a memory means 64 for storing a relation between thefluidtemperature T and an output drift of the upstream side pressure sensor 10, andatemperature drift correcting means which calculates the amount of the outputdrift of theupstream side pressure sensor 10 from data in the memory means 64 when thetemperatureT of the fluid changes, and offsets the output drift of the upstream sidepressure sensor 10with the calculated amount of the output drift, thereby correcting thetemperature drift.By means of this arrangement, the temperature drift of the pressure sensor isautomatically corrected, which makes it possible to control accurately theflow rate.