查看“︁輻透”︁的源代码

'''輻透'''（英文''phot''，符號''ph''）是[[光度學]]所用的[[照度]]單位，也就是單位面積內通過的[[光通量]]。

輻透並不是國際單位制的標準單位，而是舊式[[CGS單位制]]的單位。名詞''phot''是André Blondel在1921年創造的<ref>Parry Moon. "System of photometer concepts", in the ''Journal of the Optical Society of America'', volume 32, number 6 (June 1942). – Page 355: "The lumen was proposed by Blondel in 1894 and is now universally accepted. The names, phot and stilb were likewise coined by Blondel (1921) and are in general use on the Continent."</ref>。

在[[公制]]單位中：

:<math>1\ \mathrm{phot} = 1\ \frac{\mathrm{lumen}}{\mathrm{centimeter}^2} = 10,000\ \frac{\mathrm{lumens}}{\mathrm{meter}^2} = 10,000\ \mathrm{lux} = 10\ \mathrm{kilolux}</math>

公制量綱：

:照度 = [[發光強度]] × [[立體角]] / 長度<sup>2</sup>

==另見==
*[[照度]]
*[[流明]]
*[[勒克斯]]
*[[光度學]]
*[[光]]

==參考資料==
<references/>
[[Category:厘米-克-秒制]]
[[Category:光度学单位]]