Ultraviolet/Visible Spectroscopy in Process Analyses

Abstract Process analyzers based on selective ultraviolet (UV) and/or visible (VIS) absorption provide highly reliable on‐line composition monitoring and closed‐loop control throughout the process industries. Design criteria for ultraviolet/visible (UV/VIS) analyzers are different to those for laboratory instruments since the process instrument must meet the area electrical classification and often withstand harsh plant environments such as vibration, wide temperature swings, corrosive atmospheres and “dirty” samples. The designs of various types of UV/VIS process analyzers are reviewed, and applications of these analyzers in major process industries are described.