Hamburg University of Technology
Abwasserwirtschaft und Gewässerschutz
Eißendorfer Straße 42 (M)
Tel: +49 40 42878 2419
Fax: +49 40 42878 2684
Water and wastewater analyses for environmental control require considerable expenses, especially with respect to instrumentation. The importance of purchase of low-cost laboratory equipment has been recognised by environmental initiatives which are active in poor regions. Photometers are versatile instruments in water and wastewater analysis. Unfortunately, they are expensive. This site provides a manual for the construction of a low-cost photometer operated with a tricolor LED. The following are examples of nutrient analyses which can be performed with the low-cost LED photometer with the wavelengths 430, 565, and 627 nm, resp.: ammonia, ortho-phosphate, nitrate and nitrite. However, any photometric methodology applying absorption maxima close to one of the three mentioned wavelengths can be realized with this low-cost photometer.