Good evening!
I am attempting to measure the frequency of voltage for a flowmeter using an NI 9205. Knowing the frequency, I can then calculate the flow rate of the fluid. However, I am having a hard time checking to see if my values that labview is reporting for the frequency is accurate. I doubt the values because the frequency reported by labview is the same, regardless of flow (unless there is no flow, then the value is quite different). However, I also doubt the flowmeter since it was purchased for under $10...I have a tone measurement vi to report the frequency.
One reason why the frequency may be wrong is the voltage isn't changing from 5, to 0. It may go from 5.0, to 5.1, then 0.0, 0.1? So is the tone measurement accounting for the period from 5.0-0.1? Or from 5.0 to 5.1 etc. Below is my block diagram. We are doing continuous sampling at 2k Hz and n=500. Any suggestions/comments are greatly appreciated!
Thank you!