The measurement of Chemical Oxygen Demand of waste water or other chemical effluents involves the treatment of the water sample with chemicals like potassium dichromate, mercuric sulphate, silver sulphate and sulphuric acid. The chemical reaction in this mixture is accelerated by heating the mixture at 150 C in a suitable chemical digester.

The Uniphos COD digester is designed to carry out the above mentioned operation. It consists of an electrically heated block with thermostatic control which can set any operating temperature between 70 C to 350 C