The langley (Ly) is a unit of heat transmission, especially used to express the rate of
solar radiation
Sunlight is the portion of the electromagnetic radiation which is emitted by the Sun (i.e. solar radiation) and received by the Earth, in particular the visible light perceptible to the human eye as well as invisible infrared (typically p ...
(or
insolation) received by the earth. The unit was proposed by
Franz Linke in 1942 and named after
Samuel Langley (1834–1906) in 1947.
Definition
One langley is
*1
thermochemical calorie per
square centimetre,
*41 840 J/m
2 (
joule
The joule ( , or ; symbol: J) is the unit of energy in the International System of Units (SI). In terms of SI base units, one joule corresponds to one kilogram- metre squared per second squared One joule is equal to the amount of work d ...
s per
square metre
The square metre ( international spelling as used by the International Bureau of Weights and Measures) or square meter ( American spelling) is the unit of area in the International System of Units (SI) with symbol m2. It is the area of a square ...
)
See also
*
Solar constant
*
Radiant exposure
References
Units of measurement
Non-SI metric units
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