Rotating machinery analysis - order tracking
Rotating machinery analysis - order tracking
(OP)
People,
How do you do your order analysis? Do you use synchronous sampling (or resampling) using a tach signal? Or do you simply acquire narrow band spectra and then extract the orders by summation across a number of bins?
It's been a while since I last did this sort of thing in the lab and times/practices do change.
How do you do your order analysis? Do you use synchronous sampling (or resampling) using a tach signal? Or do you simply acquire narrow band spectra and then extract the orders by summation across a number of bins?
It's been a while since I last did this sort of thing in the lab and times/practices do change.
- Steve





RE: Rotating machinery analysis - order tracking
I use synchronous sampling. I enter the info of the tach with a NI acquisition card where I also connect the accelerometers.
RE: Rotating machinery analysis - order tracking
We simply get high enough frequency resolution (long enough sample duration) to give us confidence in our frequency estimate of the relevant peaks. Additionally, there are techniques to resolve frequencies to a precision much better than the bin width in most cases as discussed here
thread384-208992: "Interpolating" to estimate exact frequency of peak from FFT results
We use E-monitor software which makes these tasks relatively easy.
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RE: Rotating machinery analysis - order tracking
If so, then .... never mind
(disregard my comments)
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RE: Rotating machinery analysis - order tracking
RE: Rotating machinery analysis - order tracking
For driveline work I could be persuaded either way, but for engine noise I would stick with frequency based analysis. A lot of engine noise work is based on subjective assessments, you can't listen to a synchronous signal (well you can but it would be very odd).
Cheers
Greg Locock
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RE: Rotating machinery analysis - order tracking
From the replies so far, it sounds like there is no clear consensus.
- Steve