Ultrasonic leak detection has been used for a variety of applications ranging from energy reduction by locating compressed air leaks to quality assurance inspections, such as locating wind noise and water leaks in automobiles. The secret to success is to understand the nature of what type of leak produces a detectible ultrasound and what does not, along with the techniques that can be used for effective leak identification. Once understood, there are instances where the limits of detection can be enhanced to help locate a leak in difficult situations.

Typically, ultrasound leak detection is used to locate leaks where the pressure differential is enough to produce a turbulent flow as the gas moves from the high-pressure to the low-pressure side of a leak. Most often any leak with a rate below 1 × 10^-3 std. cc/sec will not generate a detectable, turbulent flow. For this reason, the majority of leak applications for ultrasound are limited to leaks above this threshold. One of the advantages of ultrasound is that leak detection is not limited to a specific fluid. The technology is open to identifying leaks in all types of gas and even fluid systems.

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