Can I Use the NI-9203 in the Same Way I Use an Ammeter?

Updated Jun 4, 2024

Reported In

Hardware

  • NI-9203
  • C Series Current Input Module

Issue Details

I have a NI 9203 module, and I want to use it to measure current into my system, just like I would with an ammeter. Can I do this, or does the COM terminal of the 9203 always need to be connected to ground?

Solution

The NI 9203 can be used to measure the current into your system. In fact, the NI 9203 can be used to measure current at any point in your system, just like an ammeter. The COM terminal of the NI 9203 does not always have to be connected to ground. The figure below shows a setup where the NI 9203 is being used to measure the current into a system. In this case, the COM terminal is connected to the positive input to your instrument.

Additional Information

It is also important to note that using the NI 9203 in this configuration will change the voltage seen across instrument due to the relative weighting of the NI 9203's input impedance to the instruments input impedance.