Do Dissolved Oxygen Sensors need Cleaning?
The re-emergence of Optical Dissolved Oxygen Sensors around 6-7 years ago generated a lively and interesting discussion which revolved around the relative merits of Optical and Galvanic Dissolved Oxygen sensors. We understand that opinions will differ, so in order to accommodate our customers preferences we are pleased to offer our OxyTechw² sensor in both ‘Galvanic’ and ‘Optical’ versions.
One of the outcomes from the debate appears to be an understanding within the market recognising that the measurement principle is not the only important element of the sensor selection process. Indeed it can be argued that proper installation and an appropriate cleaning regime for the sensor are of equal importance. Accordingly, each variant of the OxyTechw² is available with a mounting option that is inherently self-cleaning mechanism and we recommend this for use particularly in activated sludge applications. When designed correctly a self cleaning mechanism provides extended periods between maintenance thereby reducing running costs. It is important however that the cleaning system doesn’t create a maintenance problem of it’s own.
The design has no moving parts and removes the requirement for a compressor thereby saving energy and removing the need for costly maintenance. The FlexTech mounting bracket range has a flexible coupling and can be used in conjunction with our Dissolved Oxygen, pH, Redox and Conductivity sensors. The shaft assembly places the sensor below the surface of the water, away from the worst of the fouling and any surface effects that can create a false high reading. As a result the sensor moves continuously preventing a build up of biofouling on the surface of the sensor, additionally any ragging that occurs causes increased movement allowing the rags to be swept off the shaft by the flow in the tank. This inexpensive option has been used with great success by our customers for many years, saving money on maintenance and and energy and provides an highly effective monitoring system when combined with our 7300w² Monitor and the choice of optical and galvanic sensors for Dissolved Oxygen measurement.