Keithley 261 Instruction Manual page 22

The range switch, OUTPUT jack, and the range resistors are
encased in a floating shield which is normally connected to
resistors, which are mounted on the multiplier switches 5103,
the low side of the output. The shield is connected as a guard
S104, and S105. These resistors (R120 through R1521 are
when the calibration switch SlOl, is in the CAL position.
used to divide the 1lVDC supplied by the voltage supply
down to the selected voltage between 0 and 11V in 0.01 in-
5.3.3 Kelvin-Varley Voltage Divider
crements. The voltage is selected with the three multiplier
switches, S103 through S105.
The Kelvin-Varley voltage divider uses 0.1% precision
5-2