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franklin

The unit of electric charge and electric flux in the centimeter-gram-second-franklin system of units. Symbol, Fr.

The franklin was first proposed in 1941¹ as a special name for the unit of electric charge in the cgs electrostatic system. In 1961 the International Union for Pure and Applied Physics’s Symbols, Units and Nomenclature Committee adopted it for use within the cgs-Fr system, and defined it as that charge which exerts a force of one dyne on an equal charge at a distance of 1 centimeter in a vacuum. By this definition, 1 franklin = ¹⁰⁄_c coulombs, where c is the velocity of light in a vacuum in centimeters per second.

A franklin of charge is approximately 3.335 641 × 10⁻¹⁰ coulombs. A franklin of flux is approximately 2.654 × 10⁻¹¹ coulombs.

The unit is named for Benjamin Franklin (1706–1790).

According to the current national standard in the United States², the franklin is not to be used.

1. E. A. Guggenheim.
“Names of Electrical Units” (letter to the editor)
Nature, volume 148, no. 3764, page 751. (Dec. 20, 1941)

2. IEEE/ASTM SI 10™-2002.
American National Standard for Use of the International System of Units (SI): The Modern Metric System.
New York: IEEE, 30 December 2002.

See Section 3.3.3.