Hey,
I have been doing a current measurement system, which uses one or more DAQs to measure current using shunt resistors.
I wanted to calculate (simplified) the resolution of the system and ran into the following sentence.
Current measurement guide says: "you should use the smallest value resistor possible because this creates the smallest interference with the existing circuit. However, smaller resistances create smaller voltage drops, so you must make a compromise between resolution and circuit interference."
Question is how does resistor size (value) affect resolution?
Because if you have a DAQ e.g. NI 9238 that has 24 bit ADC and +-500 mV range, isn't the resolution always the same: 1/2^24 = ~60nV, as long as the voltage drop doesn't go below 60 nV?