Hioki BT3554-50, Instruction Manual, Page: 167 / 188

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11
Appendix
11.1 Effects of Extending the Test Lead
and Induced Voltage
Custom-ordering enables the extension of a test lead. Contact your
authorized Hioki distributor or reseller.
Do not attempt to extend a test lead by yourself.
How to reduce induced voltages
The instrument, which uses AC to measure minute resistances,
is susceptible to induced voltages. An induced voltage referred
to here means a voltage that allows the current generated in the
instrument to build an inductive coupling in the test lead and affects
the signaling system.
Since there is a phase difference of 90 degrees from the AC current
(reference signal), the induced voltage, if its level is low, can be
ideally eliminated with synchronous detection. However, if its level
is high, the induced voltage distorts the signals, causing incorrect
synchronous detection. Since the induced voltage increases with
the length of the test lead, the key to reducing the induced voltage
is to shorten the test lead. Reducing the length of the branched
section is particularly effective.
Even when a standard test lead is used, if its arrangement
significantly differs between when zero adjustment was executed
and when measurement was performed using the 3 m
Ω
range, the
effects of the induced voltage can cause measurement values to
vary by approximately 15 digits.
11 Appendix
HIOKI BT3554F961-00 HIOKI BT3554F961-00