HANNA Instruments HI-96761 [HI96761] Total Chlorine Photometer, Ultra Low Range

The HI-96761 Total Chlorine Low Range Portable Photometer combines accuracy and ease of use in an ergonomic, portable design. A user can accurately determine the concentration of total chlorine in a variety of water samples within a 0.000 to 0.500 mg/L (ppm) range using the HI95761-0 ready made reagents. The HI96761 offers many advanced features including the exclusive CAL Check™ function used for performance verification and calibration of the meter.

As one of the oldest and most common forms of disinfection, chlorine improves water quality by destroying disease-producing microorganisms, and by reacting with other organic and inorganic substances. Chlorine levels must be actively monitored to ensure sufficient chlorine is present for disinfection, as well as to control adverse effects such as taste, odor, and potential reactions with organic matter to form harmful disinfection byproducts.

The HI96761 uses an adaptation of the USEPA method 330.5 to measure total chlorine concentrations of less than 0.500 mg/L (ppm). When the DPD reagent is added to samples containing total chlorine, the sample will turn a pink hue; 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 complementary color, and the emitted radiation is dependent upon concentration. For total chlorine determination, a narrow band interference filter at 525 nm (green) allows only green light to be detected by the silicon photodetector and omits all other visible light emitted from the tungsten lamp. As the change in color of the reacted sample increases, absorbance of the specific wavelength of light also increases, while transmittance decreases.