Photometric determination of the COD. • Photometric determination of decrease in chromate concentration after two hours and oxidation with potassium dichromate/sulphuric acid/silver sulphate at 148 °C. • This test is in accordance to the DIN ISO 15705:2003. • The chemical oxygen demand of a water is determined by silver-catalysed oxidation with potassium dichromate/sulphuric acid at 148 °C during a two hour period. • Type: tube test 0-27. • Range: 2 - 40 mg/l O2. • Sufficient for: 20 determinations. • Sea water suitability: no.