Field case · Condition monitoring
Blower fan 1X rising and falling every 3 seconds: a nearby machine at 49.84 Hz
Quick answer
A 1X reading that swelled and faded on a roughly 3 second cycle. In the spectrum a nearby machine ran at 49.84 Hz against 50.15 Hz. The difference, 0.31 Hz, gives a beat period of 3.2 seconds, which matched the field observation.
What the case covers
- What the analyst saw
- The check
- What beating is
- What to take from it
Takeaway. A level that swells and fades every few seconds is a prompt to look for a second source a fraction of a hertz away.
Read the full case, with the data and the numbers