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Related to colorimetry: spectrophotometry, Beer's law


Any technique by which an unknown color is evaluated in terms of standard colors; the technique may be visual, photoelectric, or indirect by means of spectrophotometry; used in chemistry and physics.



(1) In analytical chemistry, colorimetry is a group of photometric methods of quantitative analysis based on the determination of the concentration of substances in a colored solution by measuring the amount of light absorbed by the solution. The amount of light absorbed, the thickness of the layer of solution, and the concentration of the solution are related by a formula that obeys the Bouguer-Lambert-Beer law:

(1) I = Io · e-kcl

where I is the intensity of light after passing through the absorbing medium, Io is the intensity of the incident light, l is the thickness of the layer of solution (in cm), c is the concentration of the absorbing substance (in moles per liter), and K is a constant for light of a particular wavelength. After the logarithm is taken, equation (1) takes the form

(2) In (Io/I) = Kcl = D

where D is the optical density of the solution. It follows from equation (2) that D is directly proportional to the concentration of the substance in the solution.

A distinction is made between subjective (visual) and objective (photocolorimetric) methods of colorimetry. In visual methods, the optical density is determined by comparing the color of the solution being studied with the colors of a series of standard solutions, as well as by using visual colorimeters. In objective methods, photoelectric colorimeters are used.

(2) In physics, colorimetry is the methodology of measuring and expressing color in quantitative terms, and also the set of such methods.


The science of measuring color. The International Commission on Illumination (Commission Internationale de l'Eclairage) governs this subject along with all aspects of lighting and illumination. See CIE Lab and colorimeter.
References in periodicals archive ?
Both of the above concepts depend upon using more sophisticated color models, color appearance models, for metrics of illumination quality rather than the fundamental models of colorimetry (CIE XYZ tristimulus values and chromaticity coordinates) and color difference metrics (CIELAB).
The initial proposal of this research was to compare the two analytical methodologies (colorimetry and HPLC-IR) only at the extraction ratio of 1:20 (mass of sample in g:volume of extractor solvent in mL), as Brito (2008) had already managed to quantify phytate in diets and excreta from broilers by colorimetry at this extraction ratio.
Metamerism usually refers to the phenomenon in which sources that are spectrally different appear the same; in this case, it refers to stimuli that are numerically the same according to the CIE system of colorimetry despite being spectrally different.
Digital photos, colorimetry, attenuated total refection-Fourier transform infrared spectra (ATR-FTIR), thermogravimetric (TG) analysis and mechanical tests were used to characterize the plasticized PVC sheets exposed to artificial UV weathering.
It also offers superior image reproduction, colorimetry and video processing, and perfectly matches with the regular LDK HD cameras in a multi-camera production.
Key words: black printer, achromatic reproduction, colorimetry
To further characterize the structural color it produced, the colorimetry principle is introduced.
Given that it is easy to see when the material stops flowing and turns into a gel, the new approach of nitric oxide detection is simpler and less subject to interpretation than other detection methods, such as colorimetry and spectroscopy.
Table 1: Time and temperature program of heat treatment Sample M* M1 M2 M3 M4 M5 M6 M7 Temperature ([degrees]C) - 1150 850 950 1000 1050 1100 1150 Time (h) - 1 2 2 2 2 2 2 Table 2: Results of colorimetry for initial mica and heat-treated samples L* Sample 20[degrees]* 45[degrees] 75[degrees] 110[degrees] M 15.
This edition includes translations of the first resolutions on colorimetry and a paper on Wright's work on the 1931 system as well as articles on basic CIE colorimetry, color difference metrics, spectral color measurement, tristimulus color measurement of self-luminous sources, color management, and color rendering of light sources.
Meanwhile, standards regarding test methods for paint and varnishes cover issues such as procedures for exposing specimens in condensation-water atmospheres, colorimetry, (NOTE: CORRECT SPELLING) bend tests and pull-off tests for adhesion, amongst other procedures.
UV-visible light spectrophotometer Cary 100 was used for the analysis of formaldehyde by using colorimetry.