On Fri, Nov 13, 2015 at 12:27:28PM -0500, Todd Micallef wrote: > Do you have a high Z input dmm on the 10V range? Perhaps you can characterize > its impedance with another high value resistor of known value and then > connect the UUT to the meter and measure its drop across the input with a > test voltage.
Good idea. Yes, I can use a 34401A, whose input could be set for >10GR on 100mV, 1V and 10V ranges. However I can let it be 10MR that need not to be characterized and just measure the voltage from the divider DUT/10M. With 50V and 5GR will be just about 100mV. I can think that the 100mV range is already in effect a 10nA range. It's a high impedance ammeter, but taking in accunt that the source will be 50V the error fall under the precision of the 10MR input impedance, that's only 1%. Or, set the multimeter to >10GR and use a shunt resistor of, say, 1MR .1% (still cheap). Taking in account the multimeter (6.5 digits) in this case will measure only to 10% of the 100mV range, the fact that the >10GR input is not better characterized, the overall accuracy should be anyway the one of my resistor. Thank you! Best regards, Andrea Baldoni _______________________________________________ volt-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.
