Photometric Analysis

the set of methods of quantitative chemical analysis based on the relationship between the concentration of a substance in a solution or gas and the absorption of radiation. For monochromatic radiation, this relationship is expressed (within a specific range of concentrations) by the Bouguer-Lambert-Beer law. Photometric analysis includes measurements in the visible, ultraviolet, and infrared regions of the spectrum. It generally involves comparison of the intensity of radiation passing through a sample of the material being analyzed with the initial intensity or the intensity of a reference sample. The method of photometric analysis that uses visible light is called colorimetry. Photometric analysis in which the intensities of the monochromatic components of transmitted radiation are scanned is called spectrophotometry. Methods similar to photometric analysis include atomic absorption analysis, turbidimetric analysis, and nephelometric analysis.