Keithley 6485, Руководство пользователя

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Model 6485 and 6487 User’s Manual Connections 2-5
Basic connections to DUT
Model 6485 DUT connections
Connections
Basic connections are shown in Figure 2-5 , the DUT is the current to be measured. Circuit
high is connected to the center conductor of the input connector and circuit low is con-
nected to the connector’s shell.
Figure 2-5
Basic Model 6485 connections
HI
LO
DUT
INPUT*
* Maximum Continuous Input Signals
220V Peak, DC to 60Hz sine wave
WARNING If it is possible for the DUT or external supply to present more than
42V 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 42V.
CAUTION Current limiting resistors are required for DUTs capable of forcing
voltages 220V or greater. Damage to the instrument may result if volt-
ages greater than 220V are forced on the Model 6485 Input HI.
Noise and safety shields
Figure 2-6 shows typical measurement shielding. A noise shield is used to prevent
unwanted signals from being induced on the picoammeter input. Amps measurements
below 1
μ
A may benefit from effective shielding. Typically, the noise shield is connected
to picoammeter input LO. Additionally, Figure 2-6 shows LO connected to earth ground
via the ground link.