TSI Integrating Nephelometers are designed specifically for studies of direct radiative forcing of the Earth’s climate by aerosol particles, or studies of ground-based or airborne atmospheric visual air quality in clean areas. They may also be used as an analytical detector for aerosol particles whenever the parameter of interest is the light-scattering coefficient of the particles after a pretreatment step, such as heating, humidification, or segregation by size. The light-scattering coefficient is a highly variable aerosol property. Integrating Nephelometers measure the angular integral of light scattering that yields the quantity called the aerosol scattering coefficient, which is used in the Beer-Lambert Law to calculate total light extinction.
The Ames' Extinction Scattering Optical Property (AESOP) instrument measures aerosol extinction coefficient using cavity ring-down technology and scattering coefficient using reciprocal nephelometry. Measurements are made at two wavelengths (675 nm and 405 nm) with sufficient accuracy to obtain aerosol absorption coefficient, single scattering albedo, and the three Ångström exponents.
