초록 ▼

A method and system for multiple microphone photoacoustic leak detection and localization. The leak detection technique uses photoacoustic sounds produced by the interaction of a carbon dioxide (CO2) laser turned to 10.6 microns and a photoactive tracer gas, sulfur hexafluoride (SF.sub.6), emitted b

A method and system for multiple microphone photoacoustic leak detection and localization. The leak detection technique uses photoacoustic sounds produced by the interaction of a carbon dioxide (CO2) laser turned to 10.6 microns and a photoactive tracer gas, sulfur hexafluoride (SF.sub.6), emitted by calibrated leak sources. As the leaked gas is heated by the laser, it expands and launches a photoacoustic sound pulse. The sound pulses generated by the scanning process are recorded across a broad bandwidth by multiple ultra-sensitive microphones. After the photoacoustic pulses arc recorded, the magnitude is compared with background noise measurement at several frequencies for a determination if a leak is present. If the presence of a leak is found, then the location of the leak is determined. The recorded sound is processed by using Matched Field Processing (MFP) as the signal processing technique. The photoacoustic sounds recorded at the microphones are reversed in time through computer simulation that causes the sounds to converge to the apparent point of origin. No synchronization between the acoustic signal processor and the laser scanner is required.

대표청구항 ▼

[ What is claimed is:] [1.]1. A system for the detection and localization of gas emitted from a container, the system comprising:a light source for producing non-pulsing light;means for scanning said non-pulsing light across a surface of the container;a light source for producing visible light colin

[ What is claimed is:] [1.]1. A system for the detection and localization of gas emitted from a container, the system comprising:a light source for producing non-pulsing light;means for scanning said non-pulsing light across a surface of the container;a light source for producing visible light colinear with the non-pulsing light for visualizing the non-pulsing light;a photoactive tracer gas pressurized within said container;means for detecting photoacoustic sound; andmeans for processing said photoacoustic sound, said means for processing said photoacoustic sound being non-synchronous with said means for scanning said non-pulsing light, wherein said non-pulsing light excites said gas leaking from said container creating a photacoustic sound with said means for detecting the photoacoustic sound, and said means for processing said photoacoustic sound non-synchronously with said means for scanning said non-pulsing light.