HI97708 / HI 97708 Nitrite High-Range Portable Photometer

Photometer

Nitrites can be harmful to aquatic organisms even in low concentrations and for this reason, they are closely monitored in aquaculture facilities. In cooling towers, however, an adequate amount of nitrites is necessary to prevent corrosion. In high concentrations, they can be harmful to the environment and to humans. They are, therefore, normally monitored to verify the quality of water for domestic use, as well as lakes and ponds.

Nitrites are an intermediate product in the nitrogen cycle and are produced by ammonia oxidation with water, or even originate in industrial waste directly. They must not be present in drinking water.

The HI97708 uses an adaptation of the ferrous sulfate method to measure nitrate up to 150 mg/L (ppm). When the reagent is added to samples containing nitrite, the sample will turn a pink tint; the greater the concentration, the deeper the color. The associated color change is then colorimetrically analyzed according to the Beer-Lambert Law. This principle states that light is absorbed by a complimentary color, and the emitted radiation is dependent upon concentration. For low levels of nitrite, a narrow band interference filter at 575 nm. As the change in color of the reacted sample increases, absorbance of the specific wavelength of light also increases, while transmittance decreases.