HP 3468A - Current Measurement Guide

Your
3468A
has
the
capability
of
measuring
DC
or
True
RMS
AC
Currents
up
to
3
amps.
The
current
function
is
protected
by
a
3
Amp,
250V
fuse.
If
the
fuse
opens,
refer
to
Chapter
V
before
replacing.
The
illustration
below
shows
the
inter-
nal
current
shunt
and
fuse
used
in
the
3468A.
The
unknown
current
flowing
through
the
current
shunt
produces
a
voltage
which
can
then
be
measured.
Current
inputs
of
greater
than
1
amp
may
cause
the
current
shunt
to
change
value
slightly
due
to
self
heating
(somewhat
like
a
thermistor).
Sufficient
time
should
be
allowed
for
the
circuitry
to
settle
after
the
measurement
is
complete,
before
other
critical
current
measurements
are
made.
DC Current
The
DC
Amps
key
puts
the
3468A
into
the
de
current
measuring
mode.
When
measuring
currents,
remove
all
other
tests
leads
from
the
3468A
front
panel.
There is one range available for dc current measurements:
3 amp range.
AC Current
Measuring
ac
current
is
identical
to
de
current,
except
that
the
AC
Amps
key
is
used
to
select
the
measurement
function.
Also,
two
ranges
are
available
for
the
measurement.
A Commands
F5 Selects DC Current mode
F6 Selects AC Current mode
SENSE
(4 wine? (2 wire?
ALL TERM
£500VpK
MAX
7 3A/250V
FUSE
“intemal
to
the
3468A
DC OR
AC
CURRENT
SOURCE
Figure 2-1. Current Measurements
11