noun.
the measurement of the heatingpower of electromagnetic radiation, especially that of solar radiation
noun.
the measurement of the chemical or actinic energy of light
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
noun.
measuring the intensity of electromagnetic radiation (especially of the sun's rays)
Word Usage
"These is also a photometric photographic catalogue of the stars nearest to the pole in PARKHURST's “Yerkes actinometry” (1912), [11] which contains all stars in B."