DC Bias

NI Digital Multimeters Help (NI-DMM 18.1)

Edition Date: March 2018

Part Number: 370384V-01

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To test some polarized components, such as electrolytic and tantalum capacitors, it may be preferable to use only positive voltages. During normal operation, the AC current source swings negative 50% of the time, which results in an inverse polarization of the capacitor under test. To prevent this inverse polarization, you can apply a DC bias to prevent the voltage across the part from becoming negative.

Note  When DC Bias is turned ON, the high potential appears on the HI terminal. Ensure that the component is polarized correctly by connecting the negative terminal of the component to the LO terminal.

The DC bias voltage is a fixed value and can only be turned on and off. The nominal voltage value is 0.45 V and can be used for the 300 pF, 1 nF, 10 nF, 100 nF, 1000 µF and 10,000 µF capacitance ranges. The default setting is OFF.


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