noun. An instrument for measuring a property of light, especially luminous intensity or flux.

noun. In photography, a device for determining the proper length of time for exposure. See actinometer.

noun. An instrument for determining the length of time proper for photographic exposures.

noun. An instrument used to measure the intensity of light, specifically to compare the relative ! intensities of the light emitted from different sources.

noun. An instrument for measuring the intensity of light, or, more especially, for comparing the relative intensities of different lights, or their relative illuminating power.

noun. Any of several instruments used to measure various aspects of the intensity of light.

verb. To measure some aspect of light (from a star) using a photometer.

noun. photographic equipment that measures the intensity of light

noun. measuring instrument for measuring the luminous intensity of a source by comparing it (visually or photoelectrically) with a standard source

"To accomplish this mission, a space-based photometer is being developed that employs a 0. 95m aperture Schmidt telescope coupled to a very large focal plane array (FPA) measuring 14” (L) x 14” (W) x 10” (D)."

actinic photometer  arago-davy photometer  becquerel's electrochemical photometer  blondel's photometer  bouguer photometer  

photometric  photometry  

Joly photometer  Kepler photometer  colorimetric photometer  distribution photometer  electronic photometer  

barometer  tensiometer  

1-to-5  10-point  100-point  7-point  calorimeter