Leakage Current Errors
The DMM's input capacitance will "charge up" due to input bias currents when the terminals are open–circuited (if the
input resistance is >10 GΩ). The DMM's measuring circuitry exhibits approximately 30pA of input bias current for
ambient temperatures from 0 to 30 °C. Bias current doubles for every 8 °C change in ambient temperature above 30
°C. This current generates small voltage offsets dependent upon the source resistance of the DUT. This effect becomes
evident for a source resistance of greater than 100 kΩ, or when the DMM's operating temperature is significantly
greater than 30 °C.
Agilent Truevolt Series DMM Operating and Service Guide 99
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