Optical gas monitoring in sea water: Robust reliable and highly flexible

Abstract

This paper describes our progress towards the development of field deployable pCO2 and NH3 in water measurement technologies. The fluorescence lifetime based pCO2 technology described here has a wide dynamic range of 102-5 × 104 microatmospheres and has undergone numerous field trials that indicate suitability to a wide range of short and long term monitoring applications. The spectrophotometric NH3 technology described is in an earlier stage of development, and the characterization experiments performed to date show that the technology responds reversibly to ammonia concentrations at the low ppb level and could therefore be applicable to a wide range of applications within aquaculture and oceanography. The pCO2 and NH3 sensor prototypes used in these investigations are based on the same mechanical platform, that in future could also form the basis for other water quality monitoring technologies.