Keithley 1801, Инструкция по эксплуатации, Страница: 46 / 93

Operation
3-23
Figure 3-10
Power line ground loops
Experiment
(source)
E
S
R
E
IN
HI
Preamplifier
LO
I
Ground 2
Ground bus
V
G
Input voltage to the preamplifier is:
E
IN
= E
S
+ I R
Resistance of input LO connection
(typically around 100m
Ω
)
Current passing through input LO
connection due to ground voltages
(V
G
) in the ground bus (magnitude
may be amperes).
Source voltage (desired signal)
I R may exceed E
S
by orders of magnitude.
E
IN
≈
I R.
Ground 1