Accession Number : ADA318059

Title :   Acoustic Emission Methods for the Detection of Leaks in Underground Storage Tanks and Pipelines.

Descriptive Note : Final rept. Aug 87-Apr 88,

Corporate Author : PELAGOS CORP SAN DIEGO CA

Personal Author(s) : Buck, John S.

PDF Url : ADA318059

Report Date : OCT 1996

Pagination or Media Count : 69

Abstract : The objective of this Small Business Innovative Research (SBIR) Phase 1 study was to investigate the feasibility of applying advanced acoustic emission (AE) instrumentation and methodology to the detection of small leaks in large underground fuel storage tanks (USTs) and associated pipelines. This technology has been successfully used to test for leaks in the floors of large above-ground petrochemical storage tanks. Laboratory testing was conducted by mounting two acoustic sensors to a leak test apparatus. As the leak hole size, hydrostatic pressure head, and surrounding soil types were varied, the acoustic signal levels within 16 frequency bands were monitored. A leak source emits a characteristic acoustic signature that travels through both the storage vessel walls and liquid until it arrives at the monitoring sensors. Software routines were developed to distinguish this signal from random unrelated background noise using two distinct leak detection approaches, activity detection and location detection. Experimental results showed a minimum detection leak rate of approximately 0.4 gal/hr. Continued laboratory development to improve the detection sensitivity was recommended. This would be followed by field test evaluation.

Descriptors :   *LEAKAGE(FLUID), *ACOUSTIC DETECTION, *LEAK DETECTORS, *ACOUSTIC EMISSIONS, TEST AND EVALUATION, LABORATORY TESTS, AIR FORCE RESEARCH, FIELD TESTS, SENSITIVITY, PIPELINES, ACOUSTIC SIGNALS, FUEL TANKS, MAN COMPUTER INTERFACE, ACOUSTIC SIGNATURES, STORAGE TANKS, ANALOG TO DIGITAL CONVERTERS, JET ENGINE FUELS, SOUND PRESSURE, BACKGROUND NOISE, ACOUSTIC DETECTORS, HYDROSTATIC PRESSURE.

Subject Categories : Acoustic Detection and Detectors
      Fluidics and Fluerics

Distribution Statement : APPROVED FOR PUBLIC RELEASE