NI 9219: 4-wire configuration, resistance, voltage and current measurements

[kosist90]

Dear LabVIEW community!

Please, help me with advise regarding the following.

I use NI 9219 module, for measuring of resistance in 4-wire configuration. Is it possible with such physical connection to setup first task to measure resistance, and then reconfigure task to measure voltage and current? Will it give proper values for voltage and current? Or physical connection should also be changed?

Thanks in advance!

[kosist90]

Update: according to wiring from the specifications, we can measure voltage, in differential mode. But current, seems, no...
Is it correct?

[Call.Me.Wilbur]

Hi,

That is not necessarily correct. In order to measure voltage differentially you would also need to connect bias resistors. Unless you had those present in your 4-wire resistance configuration you may not be able to accurately measure voltage that way.

If your signal source is not grounded you may be able to use a RSE configuration.

If you haven’t already seen the following document I recommend taking a look at it.

http://www.ni.com/white-paper/3394/en/