U2836 Operation Manual Chapter 5 Execute LCR operation and some examples
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measurement result will have errors. If a ground conductor is installed between
high and low terminals, Cd can be reduced to Min. Meanwhile if the ground
terminal is connected to the conductance plate, the influence of Ch and Cl will be
eliminated.
When the DUT is low impedance (such as small inductance, large capacitance), a
large current will flow through test leads Hc and Lc. In this case,
electromagnetic coupling between test leads becomes the main source
of test errors except the influence of the contact resistance on test terminals. If
this coupling cannot be eliminated, it will bring unexpected influence on test
results. Generally, contact resistance affects the resistance of impedance and
electromagnetic affects the reactance of impedance. Test terminals can adopt
4TP connection method. For 4TP connection, the currents flow though Hc and Lc
are equal in value and opposite in direction with those flowing through each
shielding terminals. By this way, the magnetic fields produced by these currents
can be mutually offset and further eliminate the influence of mutual inductance
coupling on test results.
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