COD Test Tube for Water Analysis
Open COD test tube, hold it at an angle and slowly add
2.0 mL of the pretreated sample solution from the reaction tube without mixing so that two separate layers
Screw cap securely on to test tube, hold tube by the cap, place tube into the safety bottle and shake
(Caution, test tube becomes hot). Place tube into the heating block. Start heating programme.
After 2 h remove test tube from heating block, allow to cool down to room temperature and shake gently
Clean outside of test tube and measure.
Adjust photometer to zero by using blank value “NULL”