Agilent Technologies 339B User Manual

7
Measurement
Basics
Introduction
This
chapter provides
information to
help you
work more
eectively
.
Insulation
Resistance
Measurement
Residual
Charge
Eect
Once
a
high
resistance
insulation
material
has
been
charged
with
a
voltage
,
the
material will
continue
to
have
a
residual
voltage
across
it
for
a
while
after
the
charging
voltage is
removed.
So
,
when
you
want
to
measure
high
resistance
materials
after
they
have
been
charged once
,
wait
long
enough
for
the
residual
voltage
to
discharge or
the measurement
value
will
be
incorrect.
How
long
you
must
wait
depends
on
the characteristics
of the
material,
the
charge
voltage
level,
and
the
voltage
level
to
which
the
material
must discharge
to
before
starting
the
measurement.
Absorption
Phenomena
When
a
high
insulation
resistance
material is
charged
with
a
voltage
for
a
long
time
,
the
resistance
value
of
the
material
will
increase
.
So
record
the
time
from
the
start
of
the
pre-charge
to
the
start
of
the
measurement
when
measuring
and
comparing
samples
of
a
material.
The pre-charge
time
should
be
consistent
from
sample
to
sample
.
Voltage
Coecient
and
T
emperature
Coecient
The resistance
value of
an
insulation
material
is
measurement
voltage
dependent:
the
insulation resistance
of most
insulation
materials
increases
,
as
the
measurement
voltage
is
increased.
The resistance value of the insulation material is dependent on the ambient temperature
.F
or
the best measurement accuracy
, measure the DUT while it is in a constant temperature test
chamber.
Record the measurement voltage and the ambient temperature at which the measurement is
made.
Measurement Basics 7-1

Agilent Technologies 339B Specifications

General

Brand	Agilent Technologies
Model	339B
Category	Measuring Instruments
Language	English