User`s guide

Description
This command disables or enables the automatic input impedance mode for
dc voltage measurements. Normally, the instrument's input resistance is
fixed at 10 MΩ for all dc voltage measurements to minimize noise pickup. In
the automatic input impedance mode ("AUTO ON"), the input impedance is
automatically varied according to range. For the 100 mV, 1 V, and 10 V
ranges the input impedance is automatically set to "HI-Z" (>10 GΩ) to
reduce the effects of measurement loading errors on these lower ranges. For
the 100 V and 1000 V ranges, the input impedance remains at 10 MΩ.