actinometry

actino- +‎ -metry

• IPA^(key): /ˌæktɪˈnɒmətɹi/

actinometry (countable and uncountable, plural actinometries)

1. the measurement of the heating power of electromagnetic radiation, especially that of solar radiation
   • 1855, Matthew Fontaine Maury, The Physical Geography of the Sea, and Its Meteorology:

     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. the measurement of the chemical or actinic energy of light
   • 1878, William de Wiveleslie Abney, A treatise on photography:

     ACTINOMETRY (chapter title)

• actinometer
• actinometric