Measure Voltage without Differential Measurement

[tlantz]

Can I accurately Measure the voltage across a resistor without setting up my input channels in Differential Mode. I would ideally like to not have to do this, because using differential mode my DAQ only has 8 input channels, and that would mean that I would need to purchase another one.

Thanks

[markwysong]

Yes, you can, providing that all of your input signals can share a common (-) signal.

Where this won't work is if you're reading voltage across a resistor to measure current. Usually, neither side is ground. If you put your DAQ card in single-ended mode, then connect another channel to an input, some bad things could happen. Your current could go through your other channel, which would give you bad readings, etc.

Just make sure that sharing a common (-) for all your inputs would not cause any problems. If all signals are referenced to the same point, then you can do this.

Mark