The most common areas for ultrasonic inspection in the transportation industry are: wind noise, water leaks, air brakes, and emission systems (especially as it relates to IM240). Until the advent of ultrasound, water leak and wind noise detection involved many hours of trial and error with a water hose and flashlight. Often a few trips around the block, listening with a doctor's stethoscope for a wind noise captured two people for many hours. Air brake leaks and emission leaks can take hours to locate using conventional soap and water bubble testing. Not only can service shops benefit from Ultrasonic Inspection, so can Quality Assurance departments by providing accurate, fast and simple testing.How Ultrasonic Detection Works
Compressed gases, when leaking produce a turbulent flow with strong ultrasonic components. By scanning fittings, a leak will be heard as a distinct "hiss". Due to the high frequency, short wave nature of ultrasound, the sound will be loudest at its point of origin. The ULTRAPROBE translates the ultrasonic leak signals into recognizable audible signals where they are heard through headphones and seen as intensity increment on a meter. A unique test called "Ultratone" incorporates a patented ultrasonic transmitter called a Warble Tone Generator. This device is placed in a cabin, tank or container where it floods the area with an intense ultrasonic signal. The generated ultrasound will deflect off solid seals but will flow through a leak path.
Detection Methods
Leaks produce turbulence with high frequency components. To locate compressed gas and air leaks, simply scan the area while listening for a "hissing" sound and follow it to the loudest point. If it is difficult to discriminate location, reduce the sensitivity and continue to follow to the loudest point. Emissions testing can be performed in the same manner. Cabins, fuel tanks, containers, seals and gaskets, wind noise and water leaks may be tested with the unique patented Ultrasonic Warble Tone Generator. Place the generator in the cabin or container and scan the window, door, floor, seals, etc. for sonic penetration which will have a distinct chirping sound and follow to the loudest point. It's that simple.
