Ultraviolet/Visible ( UV / VIS ) Absorption Analyzers

During the past half century, photometric analyzers based on ultraviolet/visible (UV/Vis) absorption have found increasingly wide application throughout the process industries. The development of linear photodiode array detectors, holographic gratings, and relatively inexpensive yet powerful industrial computers has resulted in commercially available process photodiode array analyzers with multiwavelength outputs for multicomponent analyses. The light sources used in UV/Vis absorption analyzers can be divided into two broad categories: broadband emission sources and discrete line emission sources. For isolation of spectral lines from a gas discharge lamp or for a relatively broad band of wavelengths, combinations of bandpass and/or blocking filters often provide the least expensive and most stable means of wavelength isolation. There are two basic types of dual-wavelength analyzers: the split beam photometric analyzer and the filter-wheel chopper photometric analyzer.