photometer

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photometer

 [fo-tom´ĕ-ter]
1. a device for measuring the intensity of infrared, ultraviolet, or visible light.
2. a device for testing the sensitivity of the eye to light by determining the light minimum.

pho·tom·e·ter

(fō-tom'ĕ-tĕr),
An instrument designed to measure the intensity of light or to determine the light threshold.
[photo- + G. metron, measure]

photometer

[fōtom′ətər]
Etymology: Gk, phos + metron, measure
an instrument that measures light intensity. It usually is composed of a source of radiant energy, a filter for wavelength selection, a cuvette holder, a detector, and a readout device.

photometer 

An instrument for measuring the luminous intensity of a light source or a surface, by comparing it with a standard source. The comparison can be done either with the human eye (as in the Lummer-Brodhun or SEI exposure photometers) or with a photoelectric cell (as in the Pritchard photometer). Syn. illuminometer; luxometer. See illuminance; luminance.
flicker photometer Visual photometer in which the observer sees a field illuminated alternately by two sources to be compared. When the sensation of flicker disappears, the intensity of the test source can be deduced by reading that of the reference standard source to which it is compared. For luminance difference, the frequency of alternation is chosen to be below the critical fusion frequency but for colour difference it is chosen above it. See critical fusion frequency.
Lummer-Brodhun photometer A cube in which two adjacent or concentric portions of a comparison viewing screen are separately illuminated by the test source and a standard source. The instrument gives quite accurate readings when the two sources are of identical colour.
Macbeth photometer Photometer using the Lummer-Brodhun cube, an eyepiece and a movable standard source illuminating a diffusing surface seen as an annulus by reflection within the cube. The portion of the source to be measured is seen through the cube as a spot within the annulus. The brightness of the annulus is adjusted until it matches that of the spot.
objective photometer See physical photometer.
physical photometer A photometer employing a radiant energy sensitive element (e.g. a photoelectric cell, a thermopile) and an intensity indicator. Example: Pritchard photometer. Syn. objective photometer.
Pritchard photometer See physical photometer.
SEI exposure photometer; subjective photometer See visual photometer.
visual photometer A photometer in which the equality of brightness of a light source or a surface with a comparison standard source is made by visual observation. Examples: flicker photometer; Lummer-Brodhun photometer; Macbeth photometer; SEI photometer. Syn. subjective photometer.

photometer

a device for measuring the intensity of light.
References in periodicals archive ?
These goniometers are lower cost, require less space and can produce the same level of accuracy as a true Type C goniometer, especially when an auxiliary photometer is used to correct for variations in output at different physical orientations of the lamp.
The market segmentation includes different types of photometer such as microscope, multi-wave, fiber optic, infrared, ultraviolet, micro-plate, flame, and portable photometer.
The combined use of sun photometers and LIDAR technology boosts data collection.
Abstract: Complex photometer described in the paper is a portable device with which it is possible to determine simultaneously both the concentration of certain chemical species in water as well as its electrolytic conductivity.
Juno's Diameter "Last December, six pairs of astronomers emerged from Lowell Observatory in Flagstaff, Arizona, and drove off across the deserts of southern California in trucks loaded with telescopes and photometers.
No other sources of reagents are tested and verified by Palintest to give the correct results with Palintest photometers.
The program has been used with a set of absorbance data for wavelengths from 480 to 650 nm with intervals of 2 nm (general model) and specific sets of absorbance data for wavelengths as applied in the various types of multiwavelength hemoglobin photometers (specific models).
The TIP photometers are among the highest sensitivity FUV airglow sensors ever flown.
Tenders are invited for "Supply of test kits for chemical analysis photometers Spectroquant," Pharo "100 and" NOVA "60; general chemicals for physico-chemical tests and supplies for testing drinking water for microbiological indicators for the needs of "Water Supply" Ltd - Gabrovo eight lots.
Sherwood Scientific's Model 420 and Model 425 Flame Photometers come with 420 BlueNotes software.
The portable photometers have been developed by Alexander Smirnov, an AERONET (Aerosol Robotic Network) project scientist at NASA's Goddard Space Flight Center, Greenbelt, Maryland, and his team.