spectrophotometry
physics
spectrophotometry, branch of spectroscopy that deals with measurement of the radiant energy transmitted or reflected by a body as a function of the wavelength. Ordinarily the intensity of the energy transmitted is compared to that transmitted by some other system that serves as a standard. Different types of modern spectrophotometers cover wide ranges of the electromagnetic spectrum: X-ray, ultraviolet, visible, infrared, or microwave. Two laws express the relationship between the absorption of radiant energy and...