The standard leak element is the essential calibration device for the helium mass spectrometry leak detector.To improve the sensitivity of the helium mass spectrometry leak detector,the lower leak limit of the standard leak element should he reduced.In view of the problem that it is difficult to reduce the lower leak limit of the standard leak element made of traditional materials by improving the processing technology.A new type of standard leak element based on subnanoporous graphene composite membranes was prepared using CVD method,and the helium permeation performance and preparation process stability were studied.The results show that the leak rate per unit area of single-layer graphene/PMMA composite membranes is 4.17 × 10-12～1.09 × 10-11 Pa·m3/(cm2·s·Pa),and the leak element with a lower limit leak rate of 10-12 Pa·m3/s can be made by adjusting the penetration area of the composite membranes.
维普
万方数据