Measure ultra low oxygen concentrations (<10nM)
The STOX microsensor is a specialized oxygen sensor that allows you to measure ultra low oxygen concentrations in the lab or in situ. The STOX sensor has been used to demonstrate that oxygen concentration in the oxygen minimum zone of Peru contains less than 2 nM oxygen.
The STOX microsensor differs from the standard oxygen microsensor in having two sensing cathodes. The primary cathode corresponds to the cathode found in the standard oxygen sensor, the secondary cathode prevents oxygen in entering the sensor when this cathode is polarized. This setup allows for frequent zero calibration in situ and thus enables the sensor to measure extremely low oxygen concentrations.