| 摘要 |
PURPOSE:To detect the leakage of a fluid accurately with a high sensitivity and a high reliability, by using a weight flow rate obtained by correcting a fluid density, which is changed dependently upon the pressure and the temperature of the fluid in the system, to calculate a differential flow rate. CONSTITUTION:Flow meters 11A-11C and thermometers 12A-12C are arranged in a system inlet piping 4A, a system outlet piping 4B, and a waste water piping 4C in the outlet side of a filter demineralizer 3 respectively. Flow rate signals due to flow meters 11A-11C are corrected with density in correcting operators 13A-13C by fluid temperature signals due to thermometers 12A-12C at respective measure points, and a correct differential flow rate signal, namely, a signal S3 corresponding to an accurate weight flow rate value is always obtained in a differential flow rate operator 14 on a basis of these corrected flow rate signals. When this differential flow rate signal S3 exceeds a preliminarily set value, valves 5A and 5B are closed by a signal S4 outputted from a leakage discriminator 15 to isolate the system. |
