Perform a frequency measurement of an element in an AC circuit to calculate instantaneous power. AC circuits gain their name from the alternating electrical currents that exist in their circuits. These currents change direction a certain number of times per second. The number of times the current changes direction is measured by its frequency in Hertz. The unit Hertz denotes cycles per second. A Fluke multimeter has the ability to measure this frequency after hooking up its leads to the circuit.
Turn on power to the electrical circuit to be tested.
Turn on the Fluke multimeter. Switch the measurement dial to the AC voltage setting. The capital letter "V" with wavy lines above it designates AC voltage.
Connect the red (positive) lead of the multimeter to the positive terminal of the battery that powers the circuit.
Connect the black (negative) lead of the multimeter to the negative terminal of the circuit's battery. The multimeter determines the best range to make the frequency measurement.
Press the "Hz" button on the Fluke multimeter to measure the frequency of the AC circuit in Hertz.