I am looking to acquire data from several sensors on a machine, each of which are part of a control system featuring several grounds linked at a single central point. I need each sensor's signal at the point of measurement compared to its own ground at that point, while avoiding ground loop issues caused by the common ground in the DAQ.
The sensors operate on a 5 V supply and generate an analog output between 0-5 V, with an output from DC to 20 kHz. I would like the DAQ to log the sensor signals, while isolating grounds, with an accuracy of 0.2 %.
What component or circuit exists that performs this function?
Best Answer
Given that the OP has revealed that the DAQ is the DT9816-S, in order to get the most from converting its very good single ended input to a differential input, I would suggest using the AD8221 instrumentation amplifier as a decent choice. I've used them myself when designing DAQs for test beds and found them to be pretty good: -
Because of the need to protect sensitive inputs I would use series resistors with each input. They will also allow for a little RFI filtering: -
The gain set resistor can be left open circuit for G = 1 operation.