Demonstration of a Transportable Fabry-Pérot Refractometer by a Ring-Type Comparison of Dead-Weight Pressure Balances at Four European National Metrology Institutes. - Clayton Forssén; Isak Silander; Johan Zakrisson; Eynas Amer; Dávid Szabó; Thomas Bock; André Kussike; Tom Rubin; Domenico Mari; Stefano Pasqualin; Zaccaria Silvestri; Djilali Bentouati; et al. (Sensors, 2024)