Applications of non evaporable getter pump in vacuum metrology

► The ultimate pressure of 7.9 × 10-10 Pa was generated by the combination of turbomolecular pump and NEG pump. ► The lower limit of the static expansion vacuum standard can be extended to 10−7 Pa by using the NEG pump when an inert gas is used as the test gas. ► The lower limit of the constant conductance method vacuum leak standard is hopeful to be extended to less than 10−10 Pa m3/s in the same way.