Data Sheet

OPERATION
63
Setting the Grounding Mode
Background
When GROUND MODE is set to ON, the GPT-
9500 grounds the return terminal to the ground.
This mode is best for DUTs that are grounded
to an earth ground by their chassis, fixtures or
operation environment. This mode measures
the potential of the HIGH VOLTAGE terminal
with respect to earth ground. This means that
any stray capacitance/resistance that leaks to
earth ground will also be measured. This is the
safest testing mode, though potentially not as
accurate.
When GROUND MODE is set to OFF, the
return terminal is floating with respect to the
earth ground. This mode is for DUTs that are
floating and not directly connected to an earth
ground. This is more accurate than when
GROUND MODE is set to ON as any stray
capacitance/resistance that leaks to the earth
ground from the DUT side of the testing circuit
will not be measured. For this reason, this
testing mode is able to measure to a higher
resolution.
GROUND MODE = ON, DUT grounded
High Voltage terminal
Return terminal
DUT
GPT-9500
stray
resistance,
capacitance