Calibration Procedure of a Combined Fluorescence-Backscattering Sensor: The RBRtridente

Fluorometers and backscatter sensors are essential tools in oceanography, used to measure various biogeochemical parameters, and are key components of the BGC-Argo program. The RBRtridente integrates these two sensors into a single device. In this study, we detail the calibration procedure for the RBRtridente, a combined fluorescence-backscattering sensor developed by RBR. The calibration process involves three key steps: gain calibration, temperature compensation, and optical calibration. We describe each step in detail including the methodology for generating primary standards for calibration, as well as the primary and secondary reference instruments used for calibration. The calibration procedure is validated in the field by comparing the measurements of the RBRtridente to other fluorometers and backscatter sensors commonly used as part of the BGC-Argo program.