Reasons for phase drift

[GMarsh]

Hi,

I am noticing phase drift in the FRF acquired on a cylindrical thin shell. When I acquire a vibration signal during machining of that structure, the time domain signal also shows a phase drift.

Please find attached snapshot of the FRF and vibration time domain signal.

Can someone suggest what might be possible causes for such phase drift and if possible how to avoid them. I made a survey on this in Google but found no useful info w.r.t my problem.

Thank you.

Regards
Geoff

P.S: Greg had a look at this FRF some weeks back and electricpete recently commented in another thread on phase drift on vibration signal. I am trying to correlate both, if possible.

 

[GregLocock]

"if that data is correct."

so got it in the first answer.

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

http://eng-tips.com/market.cfm?