an instrument for measuring the capacitance of electrical equipment—such as capacitors and cables—that runs on commercial-frequency alternating current. In direct-acting faradmeters, the measuring mechanism is an electromagnetic, electrodynamic, or ferrodynamic quotient meter; the scales of such faradmeters are marked in microfarads and picofarads. Rectifier faradmeters have an electromagnetic measuring mechanism.
The readings of a faradmeter depend on the voltage supplied to the instrument. For this reason, a faradmeter must be adjusted, by moving the pointer of the instrument to the zero point of the scale, before a measurement is made. The measurement error is 1–4 percent.