Are there troubleshooting tips if a BOD sample is supersaturated with oxygen?
Oxygen concentration of BOD sample is supersaturated
The reason for dissolved oxygen supersaturation is that the sample is colder than what the BOD method requires. Warm the sample in another bottle with headspace to about 20 °C and shake it for 5-10 minutes after warming. Shaking speeds the transfer of dissolved oxygen from the sample into the headspace of the bottle. Transfer the sample into a BOD bottle with dilution (as necessary) after this and analyze the dissolved oxygen.