Agilent Technologies U1251A Measuring Capacitance, Means the capacitor is charging Discharging

Making Measurements 2

Measuring Capacitance

C A U T I O N

Disconnect the circuit power and discharge all the high-voltage capacitors before measuring the capacitance to prevent any possible damage to the meter or the device under test. To confirm that the capacitors have discharged, use the DC voltage function.

The meter measures capacitance by charging the capacitor with a known current for a period of time, measuring the voltage and then calculating the capacitance. The larger the capacitor, the longer the charge time. Below are some tips for measuring capacitance:

•For measuring capacitance greater than 10,000 µF, discharge the capacitor first, then select a suitable range for the measurement. This will speed up measuring time in order to obtain the correct capacitance value.

•For measuring smaller capacitance ranges, press with the test leads open to subtract any residual

capacitance from the meter or the leads.

N O T E	means the capacitor is charging.	means the capacitor is
	discharging.

Set up the multimeter as shown in Figure 2- 12. Use the red probe lead on the positive terminal of the capacitor and the black probe lead on the negative terminal and read the display.

Agilent U1251A/U1252A User’s and Service Guide 41