Abstract: Helium detection is a relatively mature leak detection technology, with ultra-high detection accuracy, and is widely used in the evaporator and condenser of the air conditioning industry. However, limited by helium resources, a low-cost hydrogen-nitrogen mixed gas leak detection technology that can replace helium detection has been applied in a small range in the refrigeration industry. By comparing their respective economic values, describes the overview of the existing hydrogen and nitrogen leak detection equipment, theoretically analyze the relationship between the leakage rates of the two gases, and make leaking test in the vacuum box, integrated analysis the feasibility application, the result is hydrogen and nitrogen detection is feasible in the vacuum box.

Key words: Helium detection, Hydrogen nitrogen leak detection, Leak detection equipment, Vacuum box