Keithley 6514 - Figure 4-5 Source Resistance and Capacitance; Table 4-2 Minimum Recommended Source Resistance Values

Amps Measurements 4-11
source resistance values for various measurement ranges. Note that the recommended source
resistance varies by measurement range because the R
F
value also depends on the measurement
range.
Table 4-2
Minimum recommended source resistance values
Range
Minimum Recommended
Source Resistance
pA 1GΩ to 100GΩ
nA 1MΩ to 100MΩ
µA 1kΩ to 100kΩ
mA 1Ω to 100Ω
Current Source
R
F
C
F
-
+
V
noise
R
S
C
S
V
S
V
O
Z
F
Z
S
Model 6514 Ammeter
Figure 4-5
Source resistance
and capacitance