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 varie d and eliminating the output drift of the upstream side pressure sensor (10) b y the output drift thus operated. According to the arrangement, temperature drift of the pressure sensor is corrected automatically and accurate flow control is ensured.