A dissolved oxygen meter measures the amount of oxygen dissolved in an aqueous solution. Oxygen is dissolved in water by the surrounding air, air flow, and photosynthesis. Measurements can be used to monitor processes where oxygen content affects reaction speed, process efficiency or the environment: e.g. aquaculture, biological reactions, environmental testing (lakes, streams, oceans), water/wastewater treatment, wine production.

A dissolved oxygen meter measures the amount of oxygen dissolved in an aqueous solution. Oxygen is dissolved in water by the surrounding air, air flow, and photosynthesis.

Through respiration and decomposition, dissolved oxygen is consumed in water and replenished mainly by air and photosynthesis. The amount of oxygen in water depends mainly on the temperature. Warm water has a lower oxygen concentration than cold water. But high levels of dissolved oxygen can be harmful to plants and animals.

The dissolved oxygen electrode can be used to measure the dissolved oxygen content in the aqueous solution of the tested sample in the field or laboratory. As dissolved oxygen is one of the main indexes of water quality, dissolved oxygen electrode can be widely used to measure dissolved oxygen content in various situations, especially in aquaculture water, photosynthesis, respiration and field measurement. In assessing the ability of streams and lakes to support living organisms, a BOD test is performed to measure the oxygen-consuming aqueous solution of an organic sample as it becomes stale and to determine the relationship between the concentration of dissolved oxygen and the temperature of the sample's aqueous solution.