Handheld hydrogen leak detector (RD-3) adopts dual sensor detection mode, both "small range high sensitivity" and "large range high precision" dual range leak detection function, and has real-time display of measurement results and parameter storage functions. When the gas concentration in the measured environment reaches or exceeds the preset alarm limit, it will alarm immediately. The instrument can be used in hydrogen production station, hydrogenation station, fuel cell system production workshop, hydrogen energy bus company, hydrogen testing laboratory and other occasions.