1 March 1992 Lens-type refractometer for on-line chemical analysis
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On-line monitoring of the relative chemical content of fluid mixture is needed for a number of industrial applications. This paper describes a lens type refractometer which may be inserted on-line without affecting fluid flow and responds to changes in the refractive index of the fluid and, therefore, to fluid composition. The refractometer includes an optical fiber that delivers light to an optical clear cylindrical fixture through which the chemical mixture flows. The cylindrical fixture/liquid combination acts as a lens whose focal length depends on the refractive index of the medium. Light delivered by the optical fiber is focused on the other side of the lends, at a position that depends on the focal length. Two optical fibers collect the focused light at positions that are selected such as to maximize the sensitivity of the refractometer over the range of interest. For example, for a binary mixture, the tip of one fiber may be positioned at the focal point of the lends when it contains 100% of one chemical species, while the tip of the second fiber may be positioned at the focal point corresponding to the second species.
© (1992) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Michel F. Sultan, Michel F. Sultan, Michael J. O'Rourke, Michael J. O'Rourke, } "Lens-type refractometer for on-line chemical analysis", Proc. SPIE 1587, Chemical, Biochemical, and Environmental Fiber Sensors III, (1 March 1992); doi: 10.1117/12.56547; https://doi.org/10.1117/12.56547

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