What specific property of hydrogen necessitates the use of specialized leak detection equipment?

The specific property of hydrogen that necessitates the use of specialized leak detection equipment is its small molecular size. Hydrogen molecules are exceptionally small, much smaller than the molecules of most other gases. This small size allows hydrogen to leak through very tiny openings and imperfections in seals, fittings, and materials that would be impermeable to larger molecules. Conventional leak detection methods, such as soap bubble tests or pressure drop measurements, may not be sensitive enough to detect these small hydrogen leaks. Specialized hydrogen leak detectors use various technologies, such as electrochemical sensors, thermal conductivity sensors, or ultrasonic sensors, to detect even trace amounts of hydrogen in the atmosphere. These detectors are designed to be highly sensitive to hydrogen and to minimize interference from other gases. The small molecular size of hydrogen, therefore, makes specialized leak detection equipment essential for ensuring the safety and integrity of hydrogen systems.