I am passing signals through an organic substrate & recording the response at different locations via differential probes that feed into my DAQ a Pico 24. See diagram below for set up. The sampled signals are in the order of 10s of mV.
I would like to also sample the output from the Op Amp so that I can get accurate time alignment of inputs & outputs. This is now at the limit of my electronics knowledge. Would this just be a matter of putting an appropriate resistor in the red question mark box?