JPS5729114A - Metering control method - Google Patents

Abstract

PURPOSE:To exercise adequate metering control over a fluid by finding an overmetering vaue in advance by measuring the operation response time of metering facilities at the beginning of metering. CONSTITUTION:Metering facilities consist of a tank 2 stored with a fluid 1, a valve 3 cutting off a flow passage, a flow rate measuring instrument 4, a pump 5 sending the fluid at a constant flow speed, and a tank 6 receiving the metered fluid 1. An arithmetic device 7 outputs metering start signals 9 and 10 to the valve 3 and pump 5 to find the time when the fluid 1 reaches the measuring instrument 4 after passing through the valve 3 at the point in time when the 1st flow-rate signal 8 from the measuring instrument 4 is detected. Then, the time from when the signal 8 is detected until when the flow speed reaches a constant speed is measured to find the flow rate from the beginning of the opening operation of the valve 3 until the full open state. An elapse time from the beginning of metering is used to find a metering speed, and the corrected flow rate at the beginning of metering is found to calculate a temporary metering target value SC. Once the metered value reaches the target value SC, metering stop signals 11 and 12 are outputted to the valve 3 and pump 5. The metering facilities, on receiving the signals 11 and 12, flows the fluid by the corrected rate until the complete stop, and then stops when the real metering target value is obtained.