The equipment on Richard With (WILL CHANGE).At the coastal steamer Richard With, an automatic CO2 measurement system from General Oceanics was installed in 2023. The main part of the system are equilibrator, CO2 detector and reference gases. Seawater at a flow of 3 L/min is pumped into the equilibrator through a spiral nozzle, which forms a regular spray of seawater. This gives an effective equilibration between the water and the gas phase. The gas phase is then pumped through a Cavity Ringdown detector, where the mole fraction of carbon dioxide is measured. From this, the fugacity of CO2 (fCO2) is calculated by using the respective sea surface temperature and salinity. Four different reference gases are regularly run through the system. Besides the fCO2, also the sea surface temperature and the sea surface salinity are measured by a thermosalinograph (SBE45) (CHECK). The water intake is at 4 m depth.