I am trying to understand the concept of phase measurements better in condition monitoring, as I have read a lot of stuff saying for example 'for unbalance, check if the phase is 180 degrees out of phase between the bearings,' but there is rarely papers telling you how to do it (I have to do this using my own software).
There is also the phase measurement shown on a bode plot during start up and coast down, so I am getting a bit confused.
Is the phase in the first example measured by taking the time waveform from accelerometer vertical data for example, filtering the data to 1X and then comparing the phase from different bearings? or am I on the wrong track?
Can it be done with both proximity probes and accelerometers?
Any help is appreciated.