TDR system and method for detecting leakage of a liquid

摘要

A leak detection system and method are disclosed in which an electrical circuit uses time domain reflectometry techniques to monitor one or more leak detection cables for impedance changes which are caused when a cable is contacted by a leaking liquid. The circuit of the system includes an electrical pulse generator means for generating a single electrical launch pulse, and for selectively transmitting the launch pulse down one of the cables. A delay means responsive to the launch pulse produces a reset signal upon the transmission of the launch pulse. A sensing means connected to a selected cable produces a trip signal upon receiving a reflected launch pulse which exceeds one or more predetermined thresholds. A latch means connected to the sensing means latches (sets) upon receiving the trip signal and unlatches upon receiving the reset signal. A counter means which is responsive to the reset signal and the trip signal measures a time difference therebetween. A controller means causes the pulse generator means to generate the launch pulse, determines the predetermined thresholds, and generates a fault status signal in response to the setting of the latch means. The predetermined thresholds are determined for each cable in an autoreferencing step performed by the controller means.