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

A pressure sensor, a pressure controller and a flow controller in which the pressure can be detected accurately regardless of temperature variation by correcting temperature drift of the pressure sensor automatically. The temperature drift corrector of a pressure type flow controller comprises an upstream side pressure sensor (10) interposed between an orifice (4) and a control valve (22) and detecting the upstream side pressure P1. The pressure type flow controller for controlling flow rate at the orifice (4) by opening/closing the control valve (22) while operating the flow rate at the orifice (4) based on the upstream side pressure P1 comprises a temperature sensor (14) for measuring the fluid temperature, a memory means (64) for storing the relation between the fluid temperature T and the output drift of the upstream side pressure sensor (10), and means for correcting temperature drift by operating the output drift of the upstream side pressure sensor (10) from the data of the memory means (64) when the fluid temperature T is varied and eliminating the output drift of the upstream side pressure sensor (10) by the output drift thus operated. According to the arrangement, temperature drift of the pressure sensor is corrected automatically and accurate flow control is ensured.