18 GMC-I
Messtechnik
GmbH
4.6
Resistance Measurement
For resistance measurement, the
resistance R
x
to be measured is
switched in parallel to the internal
resistance. That is why with open
input terminals (R
x
=
) the scale
value
(full scale deflection) is indi-
cated. The polarity of the voltage to
be measured corresponds to the
markings on the connection sock-
ets „A|
“ and „
“. The resistance
measuring ranges are protected by
a superquick-action melting fuse
FF 1.6A/600V AC in conjunction
with power diodes. The overload
limit of the protective means is 200 A at a maximum (one half wave)
on 600 V
eff
.
Attention!
!
Upon cut-out of the protective means:
Check the measuring electric circuit and eliminate the cause
of overload prior to putting the instrument back to serviceable
condition.
On the ranges
x 1,
x 10 and
x 100 the open-circuit voltage at
the sockets is approximately 100 mV. The voltage across the device
under test can be read on the 0 ... 100 graduation, whereby 100 scale
parts correspond to 100 mV.
On the ranges k
x 1 and k
x 10 the open-circuit voltage at the
sockets is approximately 1 V. The voltage across the device under test
can be read on the 0 ... 100 graduation, whereby 100 scale parts cor-
respond to 1 V. Because the open-circuit voltage is approximately 100
mV on the ranges
x 1,
x 10 and
x 100, resistance measure-
ments are possible on circuit boards that are also equtpped with
semi-conductors.
R
x
V
oltag
e Dr
op
