Optical DO Process Smart Probe

Suitable for control applications in aeration basins, ponds, and tanks where optimizing oxygen transfer is a key element, the probe can be submersed/immersed in a tank using the 3/4" NPT threads, or installed in a flow cell using the lower sensor threads. Several extension cables can be purchased separately to cover up to 50 meter (164 ft) distance between probe and controller. Principle of Operation The method is based on the principle of fluorescence quenching and features an immobilized Pt- based luminophore that is excited by the light of a blue LED and emits a red light. Dissolved oxygen quenches this excitation. When there is no oxygen present, the lifetime of the signal is the greatest; as oxygen hits the sensing surface, the lifetime becomes shorter. The intensity and lifetime are inversely proportional to the amount of oxygen present; as oxygen interacts with the luminophore it reduces the intensity and lifetime of the luminescence. The lifetime of the luminescence is measured by a photodetector, and is used to calculate the dissolved oxygen concentration. This is, in turn, reported by the controller as % saturation or mg/L of dissolved oxygen. Over time, the sensor's optical components can age but are compensated for by using the reference signal to compensate the measuring path. As a result, the sensor provides accurate dissolved oxygen measurements over long periods of time without the need for frequent calibrations. Factory calibrated Smart Cap that stores data 3/4" NPT external thread at both ends Built-in temperature sensor for measurement Digital probe stores model, firmware, serial number, calibration information and Smart Cap data (serial number, installation date) Minimum maintenance (no electrolyte refill or membrane replacement)