ACTINOMETRY

actinometry

(noun) measuring the intensity of electromagnetic radiation (especially of the sun’s rays)

Source: WordNet® 3.1

Etymology

Noun

actinometry (uncountable)

the measurement of the heating power of electromagnetic radiation, especially that of solar radiation

the measurement of the chemical or actinic energy of light

Source: Wiktionary

Ac`ti*nom"e*try, n.

1. The measurement of the force of solar radiation. Maury.

2. The measurement of the chemical or actinic energy of light. Abney.

Source: Webster’s Unabridged Dictionary 1913 Edition