Colour Standard Reagent 500 Hazen

Colour Standard (500 Hazen) is a calibration standard. The Hazen colour test uses a Pt/Co solution and was developed for water treatment facilities where the colour of water could be used as a measure of concentration of dissolved and particulate material. Slight discolouration is measured in Hazen units (HU). Impurities can be deeply colored as well, for instance dissolved organic compounds called tannins can result in dark brown colors.