Fluke 1625-2 User Manual page 38

1625-2
Users Manual
3. Press "START TEST"-button and note result of R
4. Connect clip-on transformer. See Figure 9.
5. Turn central rotary switch to position " RE 3pole".
6. Press "START TEST" again.
If the measured value R
transformer by more than 5 %, adjust the clip-on transformation ratio (tr) correspondingly:
Example:
Your clip-on transformer has a transformation ratio of tr = 1000:1. The measurement
without clip-on transformer results in a value R
value of R
The deviation thus reads (1.175 - 0.983) Ω = + 0.192 Ω and referring to R
error evolves as following:
The new transformation ratio to be set calculates:
30
Figure 9. Clip-on Transformer Connection
deviates from the R
E
= ×
trnew trold
= 1.175 Ω is measured.
E
100
trnew
value.
E
value determined without clip-on
E
−
R ( withclip ontransfor
E
−
R ( withoutcli p onTransfor
E
= 0.983 Ω. With a clip-on transformer a
E
Ω
. 0 192
× = +
% 19 5 . %
Ω
. 0 983
. 1 175
= × =
1000 1195
. 0 983
edw018.eps
mer )
mer )
= 0.983 Ω an
E