How is Dissolved Oxygen Monitored?
Because DO is a dissolved gas, it must be measured on site, ideally in the body of water. Drawing a grab sample introduces atmospheric oxygen and temperature changes interfering with the accuracy of the measurement.
Electrodes
Because DO is a dissolved gas, it must be measured on site, ideally in the body of water. Drawing a grab sample introduces atmospheric oxygen and temperature changes interfering with the accuracy of the measurement.
Optical Sensors
This method uses light and luminescent material to measure DO. These electrodes require less maintenance, hold calibration, are not affected by hydrogen sulfide or other dissolved gases. They offer accuracy, stability and reproducibility at fast response times.
Electrochemical Sensors
This method utilizes Galvanic or Clark-type electrodes (anode and cathode in an electrolyte solution) to measure DO. To ensure accuracy the electrodes require frequent calibration and water samples must be gently stirred.
