Fluke 91 Series II User Manual page 66

4 - 6 91/92/96/99/105 Users Manual
EXTernal milliVolt function. Signals supplied
to the red and black 4-mm banana jack inputs are
measured. The red banana jack is the high input, and the
black banana jack (COM) is the low. The ranges are
300 mV, and 3V. Time base ranges are from 1 µs to
100 ms/div.
Use this mode for low voltages and for the accessories
available for the ScopeMeter test tool.