By Allan Rienstra
The prevalence of Variable Frequency Driven motors (VFDs) is on the rise and causing quite a concern for condition monitoring technicians. Noise from the whine of the VFD presents challenges for vibration analysts. These challenges can be overcome with ultrasound technology so long as the inspector has a strong level of competency. That includes a better understanding about how to interpret ultrasonic condition indicators.
Ultrasound offers a simple assessment method for determining lubrication replenishment intervals and detection of bearing defects. To overcome the interference from VFD’s, technicians must understand how to interpret the correlation between RMS and Crest Factor data from their ultrasound instrument.