Dissolved oxygen (DO) us a measurement of the total amount of gaseous oxygen that is dissolved in water. The measurement is typically expressed as milligrams of dissolved oxygen per litre of water (mg/L) or parts per million (ppm).
DISSOLVED OXYGEN (DO)
WHY IS IT IMPORTANT?
Most living organisms depend on oxygen in one for or another to maintain the metabolic processes that produce energy for growth and reproduction. Although present in large amounts in the atmosphere, water solubility of oxygen is quite low and heavily depends on temperature varying from 14.6 mg/L at 0 °C to 7 mg/L at 35 °C at 1 atm pressure. The low solubility of oxygen is the primary reason why the purification capacity of natural waters is limited, and it is necessary to treat wastes to remove pollutional matter before discharge to receiving bodies of water. The concentration of dissolved oxygen in water is the determining factor as to whether the biological processes are carried out aerobically or anaerobically. As all aerobic treatment processes depend on the presence of dissolved oxygen, monitoring DO is indispensable for controlling the rate of aeration. Dissolved oxygen based control enables operators to ensure that sufficient oxygen is supplied to maintain aerobic conditions as well as preventing excessive use of air and energy.
HOW WE MEASURE
Real Tech’s DO probe uses a luminescent optical technology approved by the ASTM International Method D888-05. The compact and robust sensor requires no calibration and very minimal power. Without oxygen consumption, the sensor allows for accurate measurement in many applications, especially those with very low oxygen concentrations.