Hioki IM9202, Instruction Manual

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16
Making Measurements
Short Correction
Short correction is performed to eliminate the device’s residual short impedance. The short plate is
used.
CAUTION
To prevent damage to the screw in the center of the short plate, orient the screw
perpendicularly before insertion and tighten with an appropriate amount of force.
About short impedance
At high frequencies, a DUT’s structure and dimensions exert a significant effect on impedance
values.
DUTs have a variety of shapes and dimensions, and it is not possible to precisely define a short
impedance that will accommodate all of those possibilities. Although short correction is performed
to correct for the residual impedance of the test fixture, the fact that short impedance is undefined
means measured values will incorporate an error component.
There are two methods for performing short correction of the test fixture.
• Using a short device with the same shape as the DUT
The value after short correction is the difference in impedance between the DUT and the short
device. The short device’s impedance will affect measured values.
• Using a fixed reference without regard to the size of the DUT
The value after short correction is the sum of the DUT’s impedance and the impedance caused by
the effects of the fixture’s electrodes. The impedance of the fixture’s electrodes affects measured
values.
The device use a fixed reference to perform short correction without regard to the size of the DUT.
Consequently, measured values include the impedance of part of the fixture’s base plate and of
the L-side electrode. Since a deterioration in the fixture’s residual impedance will affect measured
values, it is recommended to check the residual impedance on a daily basis.
You can also prepare your own short device with the same shape as the DUT you plan to measure
and use it to perform short compensation.
However, be sure to use the same correction method when comparing measured values.
IMPORTANT
Do not scratch the electrode and short plate of the device or touch them directly with your hand.
It may affect the measurement accuracy and reproducibility.
HIOKI IM9202A961-00