Development of underwater fluorimeters for assessing biochemical constituents of coastal seawater

We developed two underwater fluorimeters (VIS&UV) for in-situ assessments of aquatic fluorescence constituents. Two prototypes had been developed to assess chlorophyll a and BOD5, respectively, and were deployed under a buoy platform for long-term field tests. Design considerations include exciting light use efficiency, weak fluorescence signal detection, ambient light suppression, corrosion resistance and anti-biofouling. The prototypes demonstrated excellent linearity in response to fluorescence emissions in laboratory calibrations and good environment suitability during the field tests. We had obtained a large amount of observational data and maintenance experience.