The Collaborative International Dictionary of English v.0.48:
Photometry \Pho*tom"e*try\, n. [Cf. F. photom['e]trie.] That branch of science which treats of the measurement of the intensity of light. [1913 Webster]WordNet (r) 3.0 (2006):
photometry n 1: measurement of the properties of light (especially luminous intensity)