Acoustic leak location and detection system

Claim 1

An acoustic leak detection and location system for a storage tank having access openings, for detecting and locating the presence of a leak in the storage tank by sensing signas emitted from a noise source therein, comprising, in combination: a pair of sensors spaced apart a fixed predetermined distance on a horizontal support member, said member and said sensors located within said tank and supported from a vertical mounting member extending through one of said access openings into said tank, said sensors sensing the presence of a noise source by receiving signals which are emitted from said noise source and producing output electric signals representative of the received signals, means for simultaneously varying by substantially equal amounts the relative phase relation of said output signals of said sensors, electronic circuit means including signal multiplier means connected to said sensors through cable means for receiving the sensor output signals and providing a continuous output signal which is a function of the instantaneous product of the signal outputs of the sensors and wherein the time average of said instantaneous product is at a maximum value when said noise source is equidistant from said sensors and is located in the central plane normal to the axis of said support member.

Claim 13

A method of detecting and determining the location of a leak in a storage tank by employing a probe assembly having a pair of sensors mounted a spaced fixed predetermined distance apart on a horizontal support arm and wherein said tank has access openings in the top thereof, and said probe assembly receives signals emitted from a noise source which is indicative of the presence of said leak, comprising the steps of: (a) eliminating substantially all loud environmental noise; (b) lowering said probe assembly into said tank through one of said access openings so that said sensors extend in a horizontal plane substantially into said tank; (c) activating said sensors to monitor a predetermined area within said tank for noise sources; (d) monitoring the output signals from said sensors for maximum signal level as a function of the instantaneous product of the sensor output signals; (e) recording on a scale representation of said storage tank being monitored a direction line extending through said one of said access openings and a central plane normal to the horizontal axis of said support arm to the extremities of said storage tank; and (f) repeating the foregoing steps (b) through (e) for at least a second access opening of said storage tank, whereupon the intersection of the direction lines from steps (e) and (f) will locate said leak.

Claim 14

A method of detecting and determining the location of a leak in a storage tank by employing a probe assembly having a pair of sensors mounted a spaced fixed predetermined distance apart on a horizontal support arm and wherein said tank has access openings in the top thereof, and said probe assembly receives signals emitted from a noise source which is indicative of the presence of said leak, comprising the steps of: (a) eliminating substantially all loud environmental noise; (b) lowering said probe assembly into said tank through one of said access openings so that said sensors extend in a horizontal plane substantially into said tank; (c) activating said sensors to monitor a predetermined area within said tank for noise sources; (d) monitoring the output signals from said sensors for maximum signal level as a function of the instantaneous product of the sensor output signals; (e) recording on a scale representation of said storage tank being monitored a direction line extending through said one of said access openings and a central plane normal to the horizontal axis of said support arm to the extremities of said storage tank; and (f) repeating the foregoing steps (b) through (e) for at least a second access opening of said storage tank, whereupon the intersection of the direction lines from steps (e) and (f) will locate said leak.