DESIGN AND APPLICATIONS OF THE INTEGRATING NEPHELOMETER - A REVIEW

The purpose of this paper is to document the key literature references and to describe the design philosophy, the principles of the instrume nt, the various possible designs, calibration, systematic errors, appl ications to scientific problems and inherent limitations. According to the design philosophy established in the original publication, instru ments are devised to directly measure the relevant integral aerosol pa rameters, thus eliminating the need for assumptions about particle siz e distribution, particle shape and composition, complex Mie calculatio ns, and the unknown uncertainties associated with them. The key parame ter measured by the integrating nephelometer is the scattering compone nt of extinction as a function of wavelength. This philosophy subseque ntly allows two approaches to the determination of several parameters- direct measurement with the aid of the integrating nephelometer and ca lculation via the Mie formalism. Comparison of calculated and measured values for a parameter allows closure studies; that is, the differenc e between them is an objective measure of the uncertainty that is inhe rent in the combined set of measured and calculated parameter values.