How do envelope readings correlate with normal vibration measurements?
Because they have different goals, they measure different things. You should use both techniques in your predictive maintenance program to maximise your ability to predict problems and to maximise your cost savings. If your normal vibration measurements correlate very strongly all the time with your enveloping readings, you should be suspicious of your envelope filter setting. The low-end filter setting should be above10X rotational speed. The high-end filter setting should be 6 orders of the outer race frequency (about 200X rotational speed).
