I would like to monitor relatively higher voltages (up to 160V) using an ADC type DAQ. Most DAQs that I come across can handle around 5-10V of analog input, requiring the voltage to be divided. Here is one I like https://labjack.com/products/t7 . I was planning on running a simple voltage divider to an op-amp buffer (voltage follower) and finally into the input of the DAQ.
My thought is to use something like 3.3 MOhm (R1) and 105 kOhm (R2) to divide the 160V by ~32 (~5V). Then run that output to an op-amp voltage follower and finally into the input of the DAQ. I'm not sure how to size the resistors since the op-amp buffer should be high impedance and limit the current draw. I sized them so big to ensure I'm not drawing much current. Since I am monitoring the voltage, I do not want to load down the source. I want to know if this is a good way to do it, and if there are any better ways.