03-21-2012 10:47 PM
I hope I can make this question clear.
If I use signal express to measure an accelerometer, and I view this acceleration on a time graph. Now I add a "Vibration level" block and check the "Export The Integrated Signal" box.
The vibration level in real time looks good. The displacement in mils looks like what it should as far as total displacement.
My question is, how should these too signals line up in time? Would for example the positive side of the acceleration (assuming a sine wave from a calibrator) line up with the positive going displacement "wave"?
Does the "Vibration Level" block take more time to calculate the integral? Would this put a delay between the acceleration and the displacement?
Sorry to make it confusing, in the end I'm trying to verify whether or not, when I measure vibration, my acceleration values in time line up with the double integral (displacement).
I'm using a 9234 with a single channel USB.
Jeff
03-23-2012 04:44 AM
Hi Jeff
I believe that this KnowledgeBase article answers your question:
Comparing Signals from Different Sources in SignalExpress
http://digital.ni.com/public.nsf/allkb/B660452F6A750D7786256FFE004FD7F3?OpenDocument
Timestamps will be retained through the analysis, so as long as you don't choose to ignore them the plots should be synchronized.