How to measure capacitors/Test a Capacitors (1): How do I correctly measure capacitance and dissipation factor? | FAQ

FAQ

How to measure capacitors/Test a Capacitors (1): How do I correctly measure capacitance and dissipation factor?

Kondensatoren

Bedrahtete Keramik-Vielschichtkondensatoren (MLCC)

Keramik-Vielschichtkondensatoren (MLCC)

A. The key to measure the capacitance and dissipation factor correctly is the meter settings (see Table 1).

Class Type	Capacitance	Frequency	Voltage
Class I	1,000pF and under	1MHz ± 10%	0.5 ～ 5 Vrms
Class I	Over 1,000pF	1kHz ± 10%	0.5 ～ 5 Vrms
Class II	10uF and under	1kHz ± 10%	1.0 ± 0.2 Vrms
Class II	Over 10uF	120Hz ± 20%	0.5 ± 0.2 Vrms

Table 1: Frequency and voltage settings for different capacitance range and class types.

The voltage settings are very critical for high capacitance capacitors. For some cap meters, the applied voltage to the test component is insufficient and thus the capacitance reads low.

The frequency settings are also important. Since capacitance changes with frequency, industry standards specify the test frequency at 1MHz, 1kHz, or 120Hz (see Table 1).

The recognition of the aging phenomenon for EIA class II capacitors is also important. For class II materials, capacitance decreases with Time1. Therefore, an industry convention has been accepted that states the capacitance shall be within tolerance at 1000 hours since the time of the last heat (TOLH)2.