Despite intensive research work during the last decades, the interruption process in high-voltage circuit breakers is still not fully understood. Especially with regard to the adaption of today's switching technologies for SF6-substitutes as e.g. CO2 (carbon dioxide) an improved understanding of the physical processes during current interruption is required. Here optical emission spectroscopy (OES) offers time-resolved access to physical properties, e.g. temperature and pressure, in the nozzle system. Thus OES measurements are performed by means of a circuit breaker model in this contribution. The obtained arc temperature profiles and temperature characteristics are in good agreement with the results of CFD simulations (computational fluid dynamics).