Engine Vibration Monitoring (EVM): Accelerometers, Filtering, and Alerts

Gas turbine (jet) engines operate very smoothly. Therefore, any detectable vibration is a critical warning sign of potential mechanical failure, such as rotor imbalance or bearing wear.

Monitoring System

An Engine Vibration Monitoring (EVM) system is installed to detect and quantify these vibrations before damage occurs.

• Sensors: Uses accelerometers (often piezo-electric) to measure radial and transverse vibrations.
• Signal Processing: The raw signal is filtered to remove normal engine operational frequencies/noise, isolating only those frequencies indicative of malfunction.
• Indication: The filtered signal is amplified and displayed in the cockpit. The display typically shows a unit-less value (relative scale) rather than a specific physical unit.