The chemical oxygen demand, ST-COD value
(ST = small scale sealed tube), of a sample is
determined by a dichromate method. The result can be considered as an indicator of the theoretical oxygen demand, i.e. the amount of oxygen
required for the total chemical oxidation of the
organic matter present in the water.
The Lovibond® COD VARIO from Tintometer (Germany) Set-Up allows
precise water testing with minimized effort.
The ST-COD concentration in mg/l O2 is measured by photometric detection.
After adding 2 ml of the sample to a Lovibond® COD VARIO tube test (LR, MR according to ISO 15705:2002), the tube is heated in the reactor
for 2 hours at 150 °C, cooled down and then
analysed in CheckitDirect COD VARIO photometer.
The COD Set-Up is a "ready to use" unit with a CheckitDirect COD VARIO photometer, 25 tube tests for LR and MR (each), the RD 125 thermoreactor for sample digestion and a tube stand.