Getting More Mileage out of Dissolved Oxygen Sensors in Long-term Moored Applications

The SBE 43 dissolved oxygen (DO) sensor is a complete redesign of the Clark electrode oxygen sensor and is engineered to provide stable, rapid-response dissolved oxygen measurements for profiling and long-term mooring applications. Customers as well as scientists at Sea-Bird are demonstrating that the SBE 43 DO sensor provides high quality moored DO data within 5 % accuracy for five or more months, even in high biological fouling coastal environments. As with all instruments, including optical DO sensors, biofouling ultimately interferes with the quality of moored measurements. When the SBE 43 DO sensor experiences a shift in calibration, it is primarily due to fouling of the membrane, which affects the slope of the sensor´s response. The stable zero offset and the fact that the drift is confined to a linear slope means the calibration is easily corrected with a single reference point taken either in the field while the instrument remains moored, or during post processing of data after the sensor is recovered and validated in the lab.