photometer


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Related to photometer: spectrophotometer, flame photometer

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 ?
Because scattered light photometers do not "see" all particle sizes the same, calibration of real-time scattered light photometers to the actual foundry environment being tested is essential for accuracy.
The goniometer can be paired with either a photometer (goniophotometer), for angular luminous intensity measurements only, or with a spectroradiometer (goniospectroradiometer) if angular color information is required.
obtained with ion-selective electrodes in undiluted whole blood or serum should be multiplied by an appropriate factor to have the same values as the substance concentrations tested using the flame photometer (Worth, 1985).
The market segmentation includes different types of photometer such as microscope, multi-wave, fiber optic, infrared, ultraviolet, micro-plate, flame, and portable photometer.
Included within the kit's sturdy IP67 case are cuvettes, sample preparation apparatus and interface cables to allow USB or RS232 connection of the Photometer 8000.
Reference [4] describes principles of recalculation of photometer measured value in amperes into illuminance value in lux, using typical photometer, consisting of a silicon photodiode, a V([lambda])-correction filter, and a precision aperture.
The basic structure of equipment is composed of a photometric clamp, figure 1, which has two semicircular electrodes of stainless steel sheet on each clamping die molded on glass tube, each electrode presenting a hole through which the radiation of a LED, passes on a clamping die of the clip, to a photodiode receiver, located on the other clamping die, monochromatic radiation emitted by the LED having a wavelength corresponding to maximum optical absorbance of the analyzed chemical species, the combined photometer also includes an electrical cable for connection and an electronic part.
It carries three scientific instruments, a very high resolution heterodyne spectrometer, an imaging photometer / medium resolution grating spectrometer and an imaging photometer / imaging Fourier transform spectrometer, designed to take maximum advantage of the characteristics of the Herschel mission.
The photometer is fully integrated with the whole range of Palintest water tests and uses light to measure color changes in water samples treated with a reagent.
The IS-LI system consists of a 20" (550 mm) diameter, hemispherical measurement chamber, mated with a CCD-based imaging photometer or colorimeter.
The only QC is photometer readings that are performed using three photometer cuvettes.