Model 499ADO Dissolved Oxygen Sensor

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INSTALLS in aeration basins or pipes. RUGGED CONSTRUCTION. EASILY REPLACEABLE MEMBRANE, no special tools required. AUTOMATIC COMPENSATION for changes in membrane permeability with temperature. AUTOMATIC PRESSURE EQUALIZATION to maintain correct membrane tension. COMPATIBLE with most Delta and Rosemount Analytical Analyzers. VARIOPOL CONNECTOR OPTION allows the sensor to be replaced without running new cable.

FEATURES AND APPLICATIONS The Model 499ADO sensor is designed for the continuous determination of dissolved oxygen in water in the range 0 to 20 ppm. The primary application is aeration basins in municipal and industrial wastewater treatment plants. The sensor can also be used to measure dissolved oxygen in aquaculture ponds. The Model 499ADO is a membrane-covered amperometric sensor. The sensor consists of a gas-permeable membrane stretched tightly over a gold cathode. A silver anode and an electrolyte solution complete the internal circuit. During operation, oxygen diffuses from the sample through the membrane to the cathode. A polarizing voltage applied to the cathode reduces the oxygen to hydroxide. The reaction produces a current between the cathode and the anode which the analyzer measures. The current is directly proportional to the rate at which oxygen reaches the cathode, which is ultimately proportional to the concentration of oxygen in the sample.