Cleaning and Operation of COD Digester SOP

5.1 PRECAUTIONS

Ensure that the instrument is clean and free from dust.
Keep instrument 1 feet away from wall.
Keep instrument away from wash basin or any water source.
Ensure that any solvent/chemical does not fall on the aluminum block, when it is hot.
Use asbestos gloves while handling the hot tubes.
Do not try to remove the tubes from the COD block and keep it in the tube stand.
Do not try to remove the condenser tube when it is hot.
Switch OFF the instrument when not in use.
Calibrate the digital timer controller and heating sensor of COD Digester once in year by the approved outside agency.

5.2 CLEANING:

5.3 OPERATION

Connect the instrument to main supply. Switch on the main supply.
The red coloured bulb will glow indicating the power supply is connected.
The orange coloured bulb will glow indicating heater is on.
The orange coloured bulb remains on till the temperature is attained and will get switched off when the desired temperature is attained.
Adjust the required temperature and time with the help of keys given on the digital controller panel.
Press SET key.
Display will show SP for temperature.
Set 150°C temperature with the help of up and down key.
Again press SET key.
Display will show soak time.
Set 2.0 Hours time with the help of up and down key.
In soak time parameter the digits before decimal are hours & after decimal it is minutes. i.e, (hh:mm)
Fill 30 ml of the content of sample in each tube and tightly close with condenser tube.
Place 30 ml filled tubes in the aluminum COD block of COD Digester for 2 hours.
After completing the cycle, digital alarm for 10 seconds will produce and heating will get automatically stopped.
Allow to cool at room temperature.
Perform further analysis as per Specification of Chemical Oxygen Demand.

Nil

END OF THE SOP