How does it work?
Mechanical movements produce a wide spectrum of sound. One of the major contributors to excessive stress in machinery is friction. Ultrasound instruments detect friction. By focusing on a narrow band of high frequencies, an ultrasound instrument detects subtle changes in amplitude and sound quality produced by operating equipment. It then heterodynes these normally undetectable sounds down into the audible range where they can be heard through headphones and observed on a display panel for trending, comparison, and analysis. It has been established that ultrasound monitoring provides early warning of bearing failure. Various stages of bearing failure have been established.
• An 8 dB gain over baseline indicates pre-failure or lack of
lubrication.
• A 12 dB increase establishes the very beginning of the failure
mode.
• A 16 dB gain indicates advanced failure condition
• A 35-50 dB gain warns of catastrophic failure.
