Omicron Lab CT Analyzer, User Manual

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CT Analyzer User Manual
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2.7 Improving the Quality of Measurement Results
2.7.1 4-Wire Measurement vs. 2-Wire Measurement
If the secondary side of the test object does not provide screw terminals for
connecting the delivered terminal adapters or banana sockets to insert the
measurement leads directly, and it is therefore necessary to use clamps (e.g.
crocodile clamps or Kelvin clamps) for the connection of the measurement
leads, always use the 4-wire connection technique as described below.
Otherwise, the possibly existing contact resistance of the clamps could
affect the measurement results, i.e., the
CT Analyzer possibly delivers
incorrect measurement results.
Both connection techniques are shown in the following figure.
Figure 2-19 Demonstration of 2-wire and 4-wire connection technique
The measurement leads from the
"Output" sockets and input "Sec" of
the
CT Analyzer are connected to the
test object via separate clamps.
One clamp is used for each
measurement lead!
Correct!
Separate measurement leads are
used for the "Output" sockets and
input "Sec" of the
CT Analyzer , but
the measurement leads are
connected to the test object via a
common clamp.
Two measurement leads use one
single clamp!
Do not use!
Do not use!
OK
4-wire connection 2-wire connection