You should include the effects of input bias current - the maximum
should be specified, and likely in the pA range at room temperature.
Just put a very high resistance from input to common, and read the
voltage to calculate the current at zero input. Likewise, you can
connect the resistor to va
Recently, I was curious about the HP 3456A input impedance. The manual
states >1E10 ohms. But, what is my 40+ year-old meter today? Using a 10 V
source and a switchable 1x/10x scope probe I did a quick check. When the
scope probe is switched to 10x a 9 meg series resistor is inserted between
th
