Airborne Ultrasonics
During deterioration and failures, many industrial systems generate characteristic noises. Airborne Ultrasonic Testing helps optimize industrial systems and prolong equipment life by enabling you to detect, characterize, and analyze these noises. In a nutshell, noise is a vibration of molecules through something like air, grease, or metal. We know from vibration analysis that all vibrations can be broken down to energy levels at specific frequencies. The ear translates energy levels into intensities, which we perceive as volume. Noise levels can also be measured by instruments and are usually represented in units of decibels (dB). The ear translates frequencies between 20 Hz and 20,000 Hz (the audible, or sonic, range) into tones. Frequencies above the sonic range (greater than 20 kHz) are referred to as ultrasonic and are beyond our ability to hear without assistance. Many equipment and system faults exhibit characteristic noises in both the sonic and the ultrasonic range: A pressurized gas or steam leak generates a rushing sound in the ultrasonic range. A bearing with a race defect will generate impacting noises in the sonic range, while a bearing that is under-lubricated will generate high noise levels in the ultrasonic range. A steam trap will generate ultrasonic noise both when the trap opens and closes and when the condensate discharges from the trap. Ultrasonic noise is also created downstream of a leaking valve.