Specifications

Precautions for open and short measurements
Open measurement must be performed so that it accurately measures the stray capacitance. To do
this, keep the distance between the test fixture terminals the same as when they are holding the
DUT. In addition, set the integration time, averaging, and test signal level so that the instrument
measures with maximum accuracy. If an open measurement is performed under improper condi-
tions, stray admittance (Yo) is not correctly measured, resulting in an open compensation error.
Short measurement is performed by connecting the test fixture terminals directly together or by
connecting a shorting device to the terminals. The residual impedance of the shorting device should
be much lower than the DUT’s impedance, otherwise it will directly affect the measurement results.
Figure 4-5 shows an example of a shorting device that is applicable to the Agilent 16047A, and
16047D test fixtures. This shorting bar (Agilent part number 5000-4226) typically has residuals of 20
nH and 1 mΩ. Hence, the shorting bar is not suitable for low impedance measurement. For very low
impedance measurement, you should use a test fixture in which the fixture terminals can be con-
nected directly together.
together.
Figure 4-5. Example of shorting device (Agilent part number 5000-4226)
4-5
Material: Brass (Ni-dipped)
Thickness: 1.0 mm
Residual impedance: 20 nH, 1 mΩ