Vibration Meter Operating and Analysis Guide
Vibration meters measure machinery vibration for condition monitoring, fault diagnosis, and quality assurance. Understanding vibration analysis helps predict and prevent machinery failures.
I. Measurement Parameters
- Acceleration: Measured in meters per second squared or g. Best for high-frequency vibration analysis.
- Velocity: Measured in millimeters per second or inches per second. Most commonly used for machinery condition assessment as it relates to vibration energy.
- Displacement: Measured in micrometers or mils. Best for low-frequency vibration measurement such as shaft movement.
II. Measurement Procedures
- Sensor Mounting: Attach the accelerometer firmly to the measurement point. Flat magnet mounts provide good high-frequency response. Handheld probes are suitable only for survey measurements.
- Measurement Points: Take measurements at bearing housings in horizontal, vertical, and axial directions. Mark measurement points for repeatability.
- Operating Conditions: Record machine speed, load, and process conditions during measurements for trending comparison.
- Data Collection: Record overall vibration values and, where possible, capture frequency spectra for detailed analysis.
III. Vibration Analysis
- Unbalance: High vibration at one times running speed, predominantly in the radial direction
- Misalignment: High vibration at one or two times running speed, with strong axial vibration component
- Bearing Faults: High-frequency vibration with characteristic bearing defect frequencies
- Looseness: Multiple harmonics of running speed with directional vibration pattern
IV. Maintenance
- Calibrate vibration meters annually using a shaker table with a reference accelerometer
- Inspect cables and connectors for damage; cable noise affects measurements
- Clean sensor mounting surfaces before each measurement
- Replace accelerometers showing sensitivity drift
