Full definition
Predictive technique that detects high-frequency sound waves (20-100 kHz) emitted by friction, turbulence and electrical arcing. Applications: compressed-air leaks (audible at 3 m), bearing defects (detection up to 6 months before failure), partial discharges in electrical equipment, steam trap failures. Equipment: UE Systems, SDT Ultrasound, Sonaphone. Standard: ISO 29821. Non-invasive, suitable for noisy environments.