HP 3457A - SECTION IV PERFORMANCE TESTS; 4-1. INTRODUCTION; 4-3. EQUIPMENT REQUIRED

SECTION IV
PERFORMANCE TESTS
4-1. INTRODUCTION
4-2, Section IV contains Performance Tests designed to verify the accuracy of the HP 3457A Multimeter.
Accuracy specifications are listed in Table 1-1 of this manual. This section also contains Operational
Verification Tests which provide a more rapid method of testing the operation and accuracy of the unit.
The Operational Verification Tests are designed to provide a 90% confidence that the HP 3457A is opera-
tional and meets specifications. Both the Performance Tests and Operational Verification Tests can be per-
formed without access to the interior of the instrument.
4-3. EQUIPMENT REQUIRED
4-4, Equipment required for the performance tests and operational verification tests are listed in the
Recommend Test Equipment table in Section I of this manual. Equipment other than that recommended
may be used as long as the critical specifications are met
4-5. TEST RECORD
4-6, Results of the performance or operational verification tests may be tabulated on the Test Record lo-
cated
at
the
end
of
the
respective
procedures.
The
Test
Record
lists
all
of
the
tested
specifications
and
their
acceptable
limits.
It
is
suggested
that
the
performance
tests
or
operational
verification
tests
be
performed
and
the
results
tabulated
when
the
instrument
is
received.
These
results
can
be
used
for
comparison
with
periodic calibration results.
4-7. CALIBRATION CYCLE
4-8.
This
instrument
requires
periodic
performance
verification.
The
frequency
at
which
the
instrument
should
be
tested
is
dependent
upon
its
usage
and
the
environmental
operating
conditions.
To
maintain
24
hour
specifications,
the
instrument
should
be
checked
daily;
to
maintain
90
day
specifications,
the
instru-
ment
should
be
checked
at
90
day
intervals.
It
is
suggested
that
the
performance
test
be
performed
at
90
day
intervals
for
normal
operation.
4-9. TEST CONSIDERATIONS
4-10. General
4-11,
Because
the
HP
3457A
is
capable
of
making
high
accuracy
measurements,
certain
requirements
need
to
be
made.
For
example,
standards
being
used
to
test
accuracy
should
not
introduce
any
significant
uncer-
tainties
in
the
performance
tests.
A
standard
which
is
ten
times
more
accurate
than
the
HP
3457A
nearly
eliminates
uncertainties.
In
most
cases,
standards
with
these
accuracies
are
not
readily
available,
therefore,
a
compromise
is
necessary.
A
primary
in
house
standard,
one
which
has
been
certified
by
the
National
Bureau
of
Standards
(NBS)
and
can
supply
the
necessary
outputs,
is
recommended.
If
a
primary
standard
is
not
available,
one
of
the
following
may
be
appropriate:
a.
Use
a
standard
which
is
three
or
four
times
more
accurate
than
the
HP
3457A
specifications
to
be
tested.
Keep
in
mind,
however,
the
potential
uncertainties
these
standards
may
introduce.
b,
Use
a
highly
stable
calibrated
standard
and add
the
correction
factors
(usually
supplied
on
the
calibration
charts)
to
the
test reading.
c.
Send
the
HP
3457A
to
an
HP
Service
Center
or
other
NBS-certified
standards
facility
for
calibration.
4-1