Abstract
It is presented a new instrument specially developed to measure sunlight extinction in water bodies. It uses commercial photodiodes with no monochromatic sensitive band and it is based on the use of absorbance data for each wavelength at different depths. With this instrument we can perform "in situ" measurements for sunlight extinction coefficient. Then, the effect that the absorption due to the water itself has on this coefficient can be established, differentiating it from absorption by other components, dissolved or dispersed, in the water column. The amount of these water components, such as suspended solids, dissolved chemical products or phytoplankton, can be established in water bodies by their specific sunlight absorption spectra. © 2011 Elsevier B.V. All rights reserved.
