What is the maximum dissolved oxygen concentration that can be accurately measured by the SBE 43 DO sensor?
The measurement range and accuracy of the SBE43 are not defined in discrete units (mL/L, mg/L, µMol/L, etc.) Rather, the range and accuracy specification are expressed as a ratio of the calculated oxygen saturation point. This saturation value depends on the temperature and salinity of the water, decreasing in higher temperatures and higher salinities.
The more detailed answer is a theoretical maximum value can be calculated. While the absolute maximum value would need to be calculated using the highest value one could select as a reference saturation point in natural waters, this theoretical maximum value’s calculation is demonstrated below:
10.84 ml/l (15.49 mg/l) the oxygen saturation point for
In the coldest (-2°C) and least saline (0 PSU) water, the oxygen saturation point is 10.84 ml/l (15.49 mg/l. Using this as a reference saturation point, 10.84 ml/l is multiplied by 1.2 to make 13.01 ml/l (18.59 mg/l), or 120% of the oxygen saturation; this represents the upper end of the measurement range in the given water and can be called the theoretical maximum value for the sensor.