Water-leakage detecting apparatus and method which are little influenced

Abstract

A sensor detects a vibration generated due to water leakage. An integration circuit integrates time intervals for which a signal obtained by absolute-value amplifying an output signal from the sensor exceeds a predetermined level within a predetermined period of time. The integration circuit performs the integration a plurality of times. A detection circuit selects a minimum value of a plurality of integration values obtained by the plurality of measurements as an integration value obtained when the influence of unrelated noise is at a minimum and compares the minimum value with a preset reference value. When the minimum value exceeds the reference value, the detection circuit determines the presence of water leakage, and when the minimum value is smaller than the reference value, determines the absence of water leakage.