Determining Sample Frequency
Determining Sample Frequency
(OP)
I need to determine the sample frequency for measuring pressure pulsations. I have a V6 running at 3300 RPM (maximum). If this produces 165 exhaust events every revolution, how do you calculate the resolution necessary to capture all the significant data?





RE: Determining Sample Frequency
I suggest ou look at www.tti4edu.com and sign up for some of their courses.
Regards
Dave
RE: Determining Sample Frequency
p.s. thanks for the info on the TTI......
Steve
RE: Determining Sample Frequency
Regards
Dave
RE: Determining Sample Frequency
You can always throw out extra data. Trying to infer missing data is always significantly harder.
TTFN
RE: Determining Sample Frequency
Should I re-think this?
Regards,
Steve
RE: Determining Sample Frequency
You will very likely however have things you're interested in occurring at several multiples of the firing frequency.
I would suggest looking up to the 9th order, at least: i.e., 3 x 165 = 495 Hz.
This is not of course the resolution.
But if you are as you say interested in the backpressure, not acoustics, you could get the information you need with a far lower sampling rate; just a few times per second would suffice.
BTW, it's not the transducer that determines the sampling rate, in general, but the data acquisition system itself.
When I do this type testing, I use a pressure transducer from PCB Piezotronics 1501A01FJ15 which nominally is a 0-15 psi static pressure sensor but appears to have a -15 - +15 psi range, and has good dynamic response.
RE: Determining Sample Frequency