This dissolved oxygen sensor is based on optical measurement
The 2610 Optical Dissolved Oxygen sensor uses optical technology to measure dissolved oxygen, rather than the galvanic or polarimetric measurement technologies that have been used traditionally. The existing technologies require membranes and reference solutions, while the optical technique does not. The 2610 incorporates an optical sensor cap that is factory-calibrated and needs no field calibration. The main advantages are reduced maintenance and energy costs. The 2610 sensor was designed primarily for wastewater-treatment applications, and can handle both freshwater and saltwater environments. — Georg Fischer Piping Systems, Tustin, Calif.