Development and first results of a new fast response microelectrode DO-sensor

A new dissolved oxygen sensor for marine application was developed and first tests in the field were carried out. The sensor uses a micro-electrode as the sensing element that has an inherently fast response and an increased resistance to bio-fouling due to the properties of the electrode material, platinum, and the employed operation regime. Introduction of a cleaning cycle, where the potential applied to the electrode is altered, allows the elimination of material building up at the electrode surface as well as the reconditioning of the electrode-surface, thus minimizing drift and the effect of bio-fouling. Microdisc electrodes ranging between 10 and 50 /spl mu/m diameter have been tested. The sensor has been adapted to operate on a CTD system or on towed instrument platforms. Results of test cruises will be presented.