ESR meter with Arduino

What Schottky diode is everyone using that has had success? I am currently using a B340A-E3/61T and the pulse peak at the terminal with no DUT is only around 150mv. I think this is causing my reading to drastically be off. I am trying to wrap my head around how the current voltage divider equations every one is using is working. It doesn't take in account of the clamping voltage and power dissipation of the Schottky diode. Any help would be greatly appreciated!