Abstract: Introducing the theoretical  basis of helium mass spectrometer to leaking detection technology,the automatic control technology is used here , which improves intelligent level and reduces the range switching time and expands the measuring range with the helps of  both  180° non-uniform magnetic field for ion focus and electronic range switching . The paper gives the studied practices to high precision sealed intelligent detection system in detail.

Key words: Vacuum test, Helium mass spectrometer, Leaking detection