Metrolab Blog

BOD test with Control Test Tablets

BOD (Biochemical Oxygen Demand) is an analytical procedure for determining the amount of dissolved oxygen consumed by aerobic biological microorganisms in water. The analysis occurs in a given water sample at a certain temperature over a specific period. It is most commonly expressed in milligrams of oxygen consumed per liter of sample at the constant temperature of 20 °C during 5 days of incubation (BOD5) or monitoring the complete oxidation value after a maximum period of 30 days (BODultimate). BOD determination is widely used as an indication of the organic quality of water and the degree of organic pollution of water.
BOD Test using Control Test Tablets
In order to check the complete RESPIROMETRIC Sensor System, it is possible to use the Control Test Tablets, performing an oxygen demand experiment analogous to the BOD method.
Introducing a tablet, a certain amount of oxygen in the test is chemically absorbed. Thus, inside the bottles a reproducible negative pressure increases which can be used for a system check. Thanks to the software RespiroSoftTM it’s possible to read the test value after 24-48 hours and this value should remain constant for 5 days. In this way, the whole BOD System can be tested, including the stirring system, the incubator, the correct sealing and calibration of the complete pressure measurement system sensor.

Download the full application note here.