Fluke 8505A - High Speed; Range Command

8500 Series
Tab!©
2A-1. Programming
Instructions
(cont)
Ohms
Fast Ohms
The
Z1 character will place
the instrument
into the
ohms function
and the fast
ohms mode. In
normal
ohms
operation, the unknown
resistor
value Rx
is computed
from
the following
measurements:
VI -V2: the
voltage across
an internal
precision
resistor (Rr)
VO: the voltage across the
unknown
resistor
(Rx).
The value
of
Rx
is then
computed with
Ohm’s Law:
Rx
=
Rr
VO
VI -V2
Fast
Ohms mode differs
in
that the
value of
Rr
(V1-V2)
ls
stored
as a
constant. The
instrument
will the find
Rx by measuring
VO and
multiplying
this constant.
The constant
will change
with
a
function
change,
range change
or overload
condition.
NOTE
Fast
ohms
f'Zr)
differs from
HIGH
SPEED
READING
f'F).
When
using
"!"
for
ohms
measurement,
Rx is
not computed
by
the
DMM.
RANGE
COMMAND
CHARACTERS
The
nine range commands
specify the
following maximum values
by
function.
DC VOLTS
VA or
C
AC
VOLTS
1 Ut
DC or AC
Z or
11
©Hfyis
0
Auto
Auto
CURRENT
Auto
Auto
00
312
mV
Auto
312 pA
31.250
00
2.5V
2.5V
2.5
mA
250Q
00
20V
20V
20 rnA
2 kO
00
160V
160V
160
mA
32 kO
00
1200V
1000V
1.28A
256 kO
00
Auto
Auto
Auto
4.096 MO
00
Auto
Auto
Auto
32.768 MO
00
Auto
Auto
Auto
262.144
MO
2A-9