| 摘要 |
A phasing voltmeter having a high impedance AC voltmeter in series with two high impedance probes. Shielding surrounds and electrically isolates the voltmeter and probes. In parallel with the voltmeter and connected electrically with the shielding is an electrical circuit designed to add the capacitive current to a current detected by the probes. The capacitive current is added in such a way that the net effect on the measured current is zero. The electrical circuit comprises two impedance elements, such as resistors, that meet at a junction where they are connected to the shielding. The impedances on either side of the junction are matched either by careful selection of the elements or by selection of adjustable elements so that the junction is a null point.
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