Techniques Used for Vacuum Standardization

Numerous primary vacuum standards namely Mercury Manometer Standard, Volume Expansion Standard and Orifice Flow Standard of different ranges and designs have been developed by various international vacuum metrology laboratories, for the calibration of vacuum gauges. This paper briefly describes a variety of scientific techniques that had either been used or are employed in different primary vacuum standards of these laboratories. It also describes various approaches by means of which particular scientific techniques employed for vacuum standardization, are theoretically and technically improved. This improvement is essential, to guarantee the accuracy and to make a unique development in vacuum standardization.