DC voltage measurement of a series coil circuit with NI 9205

[pob@qut]

Hi all,

I need to measure the DC voltage across a circuit comprising 24 coils in series. The voltage across each of the 24 coils ranges from 0 to 10 mV DC (much less than 1 V) . I was looking to use an NI 9205 module (on +/- 200 mV range).

Would the NI 9205 be suitable for this application and what connection arrangement is recommended.

I was thinking that I could not use differential measurement of voltage because of the series coil circuit as I would need to connect say the AI Ch0- of Coil 1 to the AI Ch1+ of Coil 2 etc. Or does the NI 9205 multiplexer negate this concern?

The other option would be to use the nonreferenced single-ended (NRSE), connect a common section within the series coil circuit to AI Sense terminal and then connect AI Ch0+ to Coil 1 and AI Ch1+ to Coil 2 etc. I would then have to calculate the difference in voltage in Labview to determine the individual voltages across the coils.

I would appreciate any comments or advice on the suitablity of the module and recommended wiring connections.

Thanks for your help!

Peter.

[pob@qut]

Series coil circuit for information.Series coil circuit

[Brian.D]

I believe you should be able to use the NRSE configuration, and then just programmatically calculate the individual voltages in LabVIEW. Ensure that you use to th e+/-200mV range so you can detect that the 10 mV.