A device for localizing and function of a sprue of a pipeline pig

摘要

1,174,048. Testing for leaks. SHELL INTERNATIONALE RESEARCH MAATSCHAPPIJ N.V. Dec.20, 1966 [Dec. 22, 1965; Jan.26, 1966], No. 56900/66. Heading G1S. In a method of testing a tube for leaks, microphone is urged through the tube with the flowing material to pick up ultrasonic vibrations caused by leaks. The signal from the pick-up is fed through a selective amplifier which only picks up selected peak frequencies. External sources of ultrasonic vibrations may be attached at intervals to the pipe to aid location.