Winthrop K. Brown

Passive acoustic detection of pipeline pigs

The present invention determines the presence of a pig in a pipeline and the condition of the pig, as regards to the material the pig may be pushing, by passive acoustic detectors which determine the acoustic characteristics for the pipe and the pig. From these a computer is used to determine from changes in these characteristics the nature of the materials picked up by the pig or the condition of the pig and the pipe.

Sonic leak detector and method

Sonic type leak detector system for liquid storage tanks or the like. It uses a hydrophone to convert sonic waves in the liquid to electrical signals. The electrical signals are divided by two band pass filters. The division is into one band which contains any leak signals, and another band which contains only noise signals. Then both bands are blanked whenever the noise signal amplitude exceeds a predetermined amount. There is a differential amplifier that acts on the outputs of both band pass filters to amplify the difference after averaging of each, whenever signals are not blanked. And, there is an indicator to show when a leak is present. The indicator is actuated whenever the output of the differential amplifier exceeds a predetermined amplitude.