Keithley 6487 Reference Manual

Model 6487 Reference Manual Measurement Concepts and Connections 2-5
t^okfkd If it is possible for the DUT or external supply to present more than
505V to the input HI, it is imperative that the connection between
input LO and the external voltage source be sufficiently low impedance
and capable of carrying the short-circuit current of the source, in order
that the LO not exceed 505V.
`^rqflk Current limiting resistors are required for DUTs capable of forcing
voltages 505V or greater. Damage to the instrument may result if volt-
ages greater than 505V are forced on the Model 6487 INPUT HI.
Ohms measurement connections
Basic connections for ohms measurements are shown in Figure 2-4; the DUT is the resis-
tance to be measured. Circuit high is connected to the center conductor of the INPUT con-
nector and circuit low is connected to the V-SOURCE OUTPUT HI terminal. Note that
INPUT LO and V-SOURCE OUTPUT LO are connected together externally.
Figure 2-4
Basic ohms connections
HI
LO
DUT
INPUT*
LO
HI
V-SOURCE OUTPUT
6487
* Maximum Continuous Input: 505V Peak.

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%