Figure 3-2 Noise Caused By Ground Loops - Agilent Technologies 34450A 5½ Digit Multimeter User Manual

34450A Users Guide
R
L
V
test
R
L
V
ground
R = Lead Resistance
L
R = Multimeter Isolation Resistance
i
V
ground

Figure 3-2 Noise caused by ground loops

The best way to eliminate ground loops is to isolate the
multimeter from earth by not grounding the input terminals.
If the multimeter must be earth- referenced, connect it and
the device- under- test to the same common ground point.
Also connect the multimeter and the device- under- test to
the same electrical outlet whenever possible.
HI
LO
= Voltage Drop on Ground Bus
Measurement Tutorial
Ideal
Meter
> 10 G Ω
R
i
3
79