The HI97727 portable photometer is specially designed for measurement of color of water in natural water based applications such as drinking water and munciple water. Color of water indicates the presence of both unwanted inorganic and organic material, removal of these contents are more important in terms of to make the water more suitable for general use and industrial applications. The HI97727 uses an adaptation of the Standard Method for the Examination of Water and Wastewater, colorimetric platinum cobalt method to measure color of water at levels less than 500 PCU (Platinum Cobalt Units).