Keithley 6487 Reference Manual

G-14 Applications Guide Model 6487 Reference Manual
Up-range input response
Figure G-11 illustrates the type of transient voltage that can be expected when up-ranging
with a full-scale input signal (200μA signal on 200μA range, up-range to 2mA range).
Both the magnitude and duration of this voltage are reduced for lower current ranges. The
current limit imposed by the R
F
is also greatly reduced. The polarity depends on the polar-
ity of the input current. Figure G-11 was measured with a positive input current.
Figure G-11
Transient Voltage
When it is necessary to up-range during auto-ranging operation, multiple ranges may be
crossed to find the correct range. The duration of the transient in Figure G-11 can be
extended in this case, but the magnitude will not increase significantly.

Keithley 6487 Specifications

General

Type	Picoammeter/Voltage Source
Current Measurement Range	20 fA to 20 mA
Interfaces	GPIB, RS-232
Voltage Burden	< 200 µV
Input Impedance	>10^14 Ω
Power	100 V / 120 V / 220 V / 240 V
Basic Current Measurement Accuracy	0.4%