For the municipality of the same name in Gloucester County, see Monroe Township, Gloucester County, New Jersey.
How to measure dissolved oxygen. Dissolved oxygen is measured using a dissolved oxygen meter. The best method is to take the measurement in the field at the same time each day because DO concentrations can vary throughout a 24 hour period.issolved oxygen (DO) is a measure of the quantity of free oxygen molecules in water.
Why Dissolved Oxygen is Important. Dissolved oxygen analysis measures the amount of gaseous oxygen (O2) dissolved in an aqueous solution. Oxygen gets into water by diffusion from the surrounding air, by aeration (rapid movement), and as a waste product of photosynthesis.s dissolved oxygen levels in water drop below 5.0 mg/l, aquatic life is put under stress. The lower the concentration, the greater the stress. Oxygen levels that remain below 1-2 mg/l for a few hours can result in large fish kills. 1  Back to Parameters List. 2  Chemical Testing Main Page. 3  Water Watch Home Page.