| 摘要 |
PURPOSE:To easily detect water leakage by generating an alarm when more than prescribed repetitive time intervals of an object which moves repeatedly according to measuring flow rates are measured continuously. CONSTITUTION:The revolutions of the impeller of a flowmeter are detected with the sensors provided at two points, by which two signals (a), (b) are obtained. The inputting sequence of the signals (a), (b) is detected with an input circuit 11, and a forward-backward decision signal (c) is inputted to an adder-subtractor 12. Further, the signals (a), (b) are ANDed and the pulse intervals T of stepping pulses (d) are time-measured 21. A controller 22 supplies the correction coefft. corresponding to the flow rate of a correction table 23 to the adder-subtractor 12 by the pulse intervals T and the forward-backward decision signal (c), has the outputs thereof integrated by a reversible integrating counter 13; at the same time, when the pulse intervals T are within the prescribed range having been stored in the table 23, it outputs a pulse to the integrating counter 31 which outputs an alarm at a prescribed value, and if they are outside of the range, it resets the counter, so that the water leakage is detected by the alarm output. |
