Specifications

5-4
5.1.2 Measurement techniques for high/low capacitance
Depending on the capacitance value of the DUT and the measurement frequency, you need to
employ suitable measurement techniques, as well as take necessary precautions against different
measurement error sources.
High-value capacitance measurement
The high-value capacitance measurement is categorized in the low impedance measurement.
Therefore, contact resistance and residual impedance in the test fixture and cables must be mini-
mized. Use a 4T, 5T, or 4TP configuration to interconnect the DUT with the measurement instru-
ment. When the 4T or 5T configuration is used, the effects of electromagnetic field coupling due to a
high test signal current flow through the current leads should be taken into considerations. To mini-
mize the coupling, twist the current leads together and the potential leads together, as shown in
Figure 5-6. Form a right angle (90°) between the current leads and potential leads connected to DUT
terminals.
Figure 5-6. High-value capacitor measurement
Also, for an accurate measurement, open/short compensation should be properly performed. During
the open/short measurements (in the 4T or 5T configuration), maintain the same distance between
the test cables as when the DUT will be measured. For electrolytic capacitors, which require a DC
bias voltage to be applied, the open/short compensation should be performed with the DC bias func-
tion set to ON (0 V bias output.)
The component dependency factors discussed in Section 1 should be taken into account, especially
when measuring high-value ceramic capacitors. The high-value ceramic capacitors exhibit a large
dependence on frequency, test signal voltage (AC), DC bias, temperature, and time.
Magnetic fields generated around
the test cables are canceled by
twisting the cables.