Fluke 8024B - Page 41

8024B
2-53. Conductance-to-Resistance Conversion
2-54.
The
conductance
measurement
function
of
your
8024B
displays
in
siemens.
To
convert
siemens
to
ohms,
use
either
the
conversion
scale
and
interpolation
table
in
Figure
2-14
or
the
formula:
siemens
=
1/1.
2-55. AC Measurements
2-56.
The
ac
ranges
of
the
8024B
employ
an
average
responding
ac
converter.
This
means
that
the
unit
measures
the
average
value
of
the
input,
and
displays
it
as
an
equivalent
rms
value
for
a
sine
wave.
As
a
result,
measurement
errors
are
introduced
when
the
input
wave
form
is
distorted
(non-sinusoidal).
The
amount
of
error
depends
upon
the
amount
of
distortion.
Figure
2-15
shows
the
relationship
between
sine,
square,
and
triangular
waveforms,
and
the
required
conversion
factors.
2-57. AC/DC Voitage Measurements
2-58.
The
8024B
is
equipped
with
five
ac
and
five
dc
voltage
ranges;
200
mV,
2V,
20V,
200V,
750V
ac/1000V
dc.
All
ranges
present
an
input
impedance
of
10
MQ.
On
the
ac
ranges,
this
is
shunted
by
less
than
100
pF.
When
making
measurements,
be
careful
not
to
exceed
the
overload
limits
given
earlier
in
Table
2-2.
2-59.
Measurement
errors
due
to
circuit
loading
can
result
when
making
either
ac
or
de
voltage
measurements
on
circuits
with
high
source
resistance.
However,
in
most
cases
the
error
is
negligible
(<0.1%)
as
long
as
the
source
resistance
of
the
measurement
circuit
is
10
k©
or
less.
If
the
circuit
does
present
a
problem,
the
percentage
of
error
can
be
calculated
using
the
appropriate
formula
in
Figure
2-16.
2-60. AC/DC Current Measurements
WARNING
INSTRUMENT
DAMAGE
AND
OPERATOR
INJURY
MAY
RESULT
IF
THE
FUSE
BLOWS
WHILE
CURRENT
IS
BEING
MEASURED
IN
A
CIRCUIT
WHICH
EXHIBITS
AN
OPEN
CIRCUIT
VOLTAGE
GREATER
THAN
600V.
DO
NOT
ATTEMPT
IN-CIRCUIT
CURRENT
MEASUREMENT
WHERE
THE
POTENTIAL
IS
GREATER
THAN
600V
DC
OR
AC
RMS.
2-61.
Four
ac
and
four
de
current
ranges
are
included
on
the
8024B;
2
mA,
20
mA,
200
mA,
and
2000
mA.
Each
range
is
diode
protected
to
2
amps
and
fuse
protected
above
2
amps.
If
the
fuse
blows,
refer
to
fuse
replacement
information
given
earlier
in
this
section.
2-62.
In
high
electrical
noise
environments
(near
ignition
switches,
fluorescent
lights,
relay
switches,
etc.)
unstable
or
erroneous
readings
(exceeding
specifications)
may
occur.
The
effect
is
most
obvious
when
measuring
low
level
current
on
the
2
mA
range.
If
an
erratic
or
erroneous
reading
is
suspected,
temporarily
jumper
the
V/Q/S
connector
to
the
mA
connector.
This
will
ensure
an
accurate
measurement.
Remove
this
temporary
jumper
when
the
measurement
has
been
completed.
This
is
recommended
only
for
the
2
mA
and
20
mA
ranges.
CAUTION
To
avoid
possible
instrument
damage
and/or
erroneous
measurements,
remove
the
temporary
V/Q/S-to-mA
jumper
before
attempting
voltage
or
resistance
measurements.
2-24