pho·to·met·ric \|fōd.ə|me.trik\adjective alsopho·to·metrical\-rə̇kəl\ Etymology:photometric International Scientific Vocabulary photometer + -ic; photometrical from photometer + -ical : of or relating to photometry or the photometer • pho·to·met·ri·cal·ly\-rə̇k(ə)lē\adverb