Century Dictionary and Cyclopedia
- n. The measurement of the intensity of radiation.
- n. the measurement of the heating power of electromagnetic radiation, especially that of solar radiation
- n. the measurement of the chemical or actinic energy of light
GNU Webster's 1913
- n. The measurement of the force of solar radiation.
- n. The measurement of the chemical or actinic energy of light.
- n. measuring the intensity of electromagnetic radiation (especially of the sun's rays)
- actino- + -metry (Wiktionary)
“These is also a photometric photographic catalogue of the stars nearest to the pole in PARKHURST's “Yerkes actinometry” (1912),  which contains all stars in B.”
“n. - instrument measuring heating power of the sun's rays; Photography, instrument for calculating exposure times. actinometry, adj.”
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