User Manual SM6026
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short correction, the short plate of low impedance should be connected between test terminals. Another
way is to directly connect Hc with Lc or Hp with Lp, then connect both.
Note:
When the DUT is a polarity component, before testing, the high potential terminal should be
connected to the terminal with mark “+”, “Hc” or “Hp” and the low terminal should be connected to the
terminal with mark “-”, “Lc” or “Lp”.
Warning
: Before testing, please discharge the tested polarity component so as to avoid the damage to
the instrument.
5.3 Eliminate the influence of stray impedance
Figure 5-1 Influence of stray capacitance
Figure 5-2 Eliminate the influence of stray capacitance
When the DUT has high impedance(such as small capacitance), the influence of stray capacitance
cannot be ignored. Figure 5-1 is an example of the use of 4 terminal pair measurement. In this figure, Cd
is connected with Cx in a parallel way and when a conductance plate is positioned under DUT,
capacitance Ch will connect with Cx in parallel after connecting with Cl in series and by this way the
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
