Ma'anar ƙamus na kalmar "radiant flux" yana nufin jimlar adadin kuzarin da ake fitarwa ta hanyar tushe kowace raka'a na lokaci. Yawancin lokaci ana auna shi da watts kuma ana amfani da shi don kwatanta adadin ƙarfin da wata tushe ke haskakawa a cikin nau'in igiyoyin lantarki, kamar haske. Yawancin lokaci ana amfani da kalmar a fagen ilimin kimiyyar lissafi da injiniyanci don bayyana adadin kuzarin da ake fitarwa ko turawa ta hanyar haske, kamar kwan fitila ko rana.