Water Colors

Colorimeters are devices for determining the concentration of a substance in solution. A colorimeter uses the absorbance of light by the substance to determine the concentration. Filters or light emitting diodes are used to produce the desired light wavelength. Usually colorimeters are part of a test system for specific determinations such as Fluoride, Nitrates, Chlorine concentration etc. in water. These test systems are in wide use in analysis of waste water and drinking water. Orion AQUAfast and Hach water analysis portable colorimeters are examples of water quality test systems. In these test systems a reagent is dissolved in the water sample and reacts specifically with the substance to be determined, such as Chlorine, and the sample changes color. The absorbance is measured and compared to the absorbance of a standard solution for which the level of Chlorine is known. The absorbance is directly proportional to the concentration of Chlorine in the sample.