actinometry

noun

1. (countable, uncountable)the measurement of the heating power of electromagnetic radiation, especially that of solar radiation

   “the air with its actinometry presents itself in the light of a thermal adjustment , by which the land and sea are prevented from becoming seething hot”

2. (countable, uncountable)the measurement of the chemical or actinic energy of light

   “ACTINOMETRY (chapter title)”