
From the U.S. Code Online via GPO Access
[wais.access.gpo.gov]
[Laws in effect as of January 2, 2001]
[Document not affected by Public Laws enacted between
  January 2, 2001 and January 28, 2002]
[CITE: 15USC223]

 
                      TITLE 15--COMMERCE AND TRADE
 
            CHAPTER 6--WEIGHTS AND MEASURES AND STANDARD TIME
 
                 SUBCHAPTER V--STANDARDS OF ELECTRICITY
 
Sec. 223. Units of electrical measure

    From and after July 21, 1950, the legal units of electrical and 
photometric measurement in the United States of America shall be those 
defined and established as provided in the following paragraphs.

Resistance-ohm

    The unit of electrical resistance shall be the ohm, which is equal 
to one thousand million units of resistance of the centimeter-gram-
second system of electromagnetic units.

Current-ampere

    The unit of electric current shall be the ampere, which is one-tenth 
of the unit of current of the centimeter-gram-second system of 
electromagnetic units.

Electromotive force and electric potential-volt

    The unit of electromotive force and of electric potential shall be 
the volt, which is the electromotive force that, steadily applied to a 
conductor whose resistance is one ohm, will produce a current of one 
ampere.

Quantity-coulomb

    The unit of electric quantity shall be the coulomb, which is the 
quantity of electricity transferred by a current of one ampere in one 
second.

Capacitance-farad

    The unit of electrical capacitance shall be the farad, which is the 
capacitance of a capacitor that is charged to a potential of one volt by 
one coulomb of electricity.

Inductance-henry

    The unit of electrical inductance shall be the henry, which is the 
inductance in a circuit such that an electromotive force of one volt is 
induced in the circuit by variation of an inducing current at the rate 
of one ampere per second.

Power-watt

    The unit of power shall be the watt, which is equal to ten million 
units of power in the centimeter-gram-second system, and which is the 
power required to cause an unvarying current of one ampere to flow 
between points differing in potential by one volt.

Energy--joule; kilowatt--hour

    The units of energy shall be (a) the joule, which is equivalent to 
the energy supplied by a power of one watt operating for one second, and 
(b) the kilowatt-hour, which is equivalent to the energy supplied by a 
power of one thousand watts operating for one hour.

Intensity of light--candela

    The unit of intensity of light shall be the candela, which is one-
sixtieth of the intensity of one square centimeter of a perfect 
radiator, known as a ``black body'', when operated at the temperature of 
freezing platinum.

Flux of light--lumen

    The unit of flux of light shall be the lumen, which is the flux in a 
unit of solid angle from a source of which is the intensity is one 
candela.

(July 21, 1950, ch. 484, Secs. 1-11, 64 Stat. 369; Pub. L. 88-165, Nov. 
4, 1963, 77 Stat. 299.)


                               Amendments

    1963--Pub. L. 88-165 substituted ``candela'' for ``candle'' wherever 
appearing.
