How to air-calibrate at 20°C.
- Fill a 300 ml BOD bottle with tap water and place in BOD incubator overnight.
- Next morning, turn on your DO meter and allow the system to warm up so that readings stop dropping (5-10 minutes).
- Take the extra BOD bottle out of the BOD incubator. Pour out all but 1" of water and re-stopper. This is your calibration bottle at 20°C.
- Take your DO probe out of the overnight storage bottle and shake off all water droplets. Then place it in the 20°C calibration bottle.
- After readings have stabilized (typically 1-2 minutes), air-calibrate your system.