Measurement of dissolved oxygen

• There are mainly two methods of dissolved oxygen measurement:

1. Chemical method:

• Also known as the Winkler method.
• Requires well well-established laboratory facility.

2. Instrumental Method:

• Is based on the use of an oxygen meter, a rather expensive device that can be bought from specialized suppliers.
• A dissolved oxygen meter also allows direct measurement of the d/o concentration at the depth of interest.
• The dissolved oxygen content is read from the display board.
• Care should be taken to calibrate the meter regularly to make sure it remains accurate.
• A typical dissolved oxygen meter consists of a probe with an electrode and a processing and displaying unit.