| 摘要 |
PURPOSE:To detect the occurrence of leak in a pipeline without performing mechanical processing on the pipe by a simple means to which a sound sensor capable of detecting supersonic waves being propagated through the wall of the pipeline is additionally provided. CONSTITUTION:The outputs of sound sensors 11, 12 provided at the upper stream and lower stream sides of a pipeline 10 are amplified (a) and converted into digital signals by an A/D converter (b), and (n) pieces each of signal Xi sampled at an interval of very short time are stored in data buffers I , II in sequence. Signal Xi taken out from the data buffers I , II (n) pieces each are added to a leak occurrence detection index calculation circuit (c), and a leak occurrence detection index (LEAK) is calculated. The leak occurrence detection circuit gives (n) pieces of signal Xi to a correlation circuit (d) and calculates a correlation value gammak, and then a coefficient alphak is calculated in a coefficient circuit (e), and based on those calculated values, a variance alphae<2> is calculated by a variance circuit (f), and further the calculation of a leak occurrence detection index is carried out by an index calculation circuit (g). |
