Hertz

Hertz, pronounced hurts, is the unit used to measure the frequency (rate of occurrence) of periodic waves and vibrations. Its symbol is Hz. Periodic waves are made by objects whose vibrations repeat at regular intervals. Such objects include tuning forks, human vocal cords, and radio transmitters. A wave's frequency is the number of complete cycles (vibrations) that occur each second. One hertz equals one cycle per second. The musical note "A" has a frequency of 440 Hz or 440 cycles per second. Radio waves may have frequencies of many million hertz.

The hertz was adopted in 1960 by an international group of scientists at the General Conference of Weights and Measures. It was named for Heinrich R. Hertz, a German physicist.

Contributor: Bruce F. Field, Ph.D., Senior Electronics Engineer, National Institute of Standards and Technology.

Hertz

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