Keysight U2741A Guide D'utilisation page 51

V
test
Figure 3-2
The best way to eliminate ground loops is to isolate the digital multimeter from
earth by not grounding the input terminals. If the digital multimeter must be
earth-referenced, connect it and the device under test to the same common
ground point. Also connect the digital multimeter and device under test to the
same electrical outlet whenever possible.
Keysight U2741A User's Guide
R
L
HI
R
L
LO
V
ground
Ground loop induced error
Measurement Tutorial
R = Lead Resistance
L
R = digital multimeter Isolation
i
Resistance
Ideal
V = Voltage Drop or Ground Bus
ground
Meter
R > 10 GΩ
i
3
51