Insite IG dissolved oxygen measurement

Insite IG has developed a dissolved oxygen measurement system, based on optical fluorescence technology. The system is designed for the harsh environment of wastewater treatment plants, and has also found use in other applications such as environmental monitoring, process waters and aquaculture.

The system measures over a larger range and is also unaffected by ambient light.

Unlike traditional Clarke-type DO sensors, the Insite IG sensor is solid-state, and as such uses no membranes or filling solutions. The system is therefore low maintenance and has demonstrated that it can operate accurately without calibration for six months or even two years.

It also features a wide range (0 to 25 ppm DO), fast response time (90% in less than 60 s) and high accuracy (the greater of 1% of reading or 0.02 ppm). The system operates effectively even at low concentrations of oxygen - there have been tests in which the unit performed well in the 0.03 to 0.08 ppm range.

The sensor works by determining the degree of 'quenching' (dampening) of a fluorescence signal being emitted from the sensor. The degree of quenching correlates to the level of oxygen concentration in contact with the sensing element.

The system is available in fixed and portable (handheld) configurations. The fixed system incorporates signal outputs which can be integrated into existing wastewater control systems.