photometer n. Quick reference
A Dictionary of Psychology (4 ed.)
... n . An instrument for measuring luminous intensity , older types usually involving visual comparisons of the illumination from a specified light source with that from a standard comparison source, and more modern types using photoelectric cells that generate electrical signals in response to light. photometry n . The measurement of luminous intensity , luminous flux , and related phenomena, or the branch of physics concerned with these phenomena. [From Greek phos , photos light + metron a...
Instruments of Science Reference library
Deborah J. Warner
The Oxford Encyclopedia of the History of American Science, Medicine, and Technology
...and Space Administration (NASA) with help from the European Space Agency and operated by the Space Telescope Science Institute, was placed in a low earth orbit in 1990 ; it was built with a primary mirror of 2.4-meter aperture, as well as cameras, spectrographs, and photometers. Americans have been involved with astronomical photography since the 1840s and with astronomical spectroscopy since the 1860s. Notable here were the diffraction gratings produced on engines designed and constructed by Lewis Rutherfurd of New York and Henry Rowland of...
