Current Measurements; Precautions - Keithley 6485 User Manual

Model 6485 and 6487 User's Manual

Current measurements

Precautions

Model 6485 precautions
WARNING
CAUTION
Model 6487 precautions
WARNING
CAUTION
The maximum safe voltage between picoammeter LO and chassis
ground (common mode voltage) is 42V. The Model 6485 does not
internally limit the LO to chassis voltage. Exceeding 42V can create a
shock hazard.
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.
The LO to chassis breakdown voltage is 500V. Exceeding this voltage
may cause damage to the instrument.
The maximum input voltage and current to Model 6485 is 220V peak
and 21mA. Exceeding either of these values may cause damage to the
instrument that is not covered by the warranty.
The maximum safe voltage between picoammeter LO and chassis
ground (common mode voltage) is 505V. The Model 6487 does not
internally limit the LO to chassis voltage. Exceeding 505V can create a
shock hazard.
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 imped-
ance and capable of carrying the short-circuit current of the source, in
order that the LO not exceed 505V.
The maximum input voltage and current to Model 6487 is 505V peak
and 21mA. Exceeding either of these values may cause damage to the
instrument that is not covered by the warranty.
Measurements and Sourcing Voltage 3-5