Improvement of primary interferometric standard manometer of nrlm

摘要

The interferometric standard mano-barometer (ISB) was developed at NRLM 38 years ago and has been working as the primary pressure standard of atmospheric pressure range and also playing a role as the basis which makes pressure standard of other pressure ranges. The ISB now being used is the third generation ISB manometer (ISB-3)which was facilitates for sixteen years. Because of aging of some parts and possible application of new technologies, the ISB has been improved with restoration and replacements of some parts; mercury U tube, vacuum pumping system, optical chamber for diffraction compensation, pressure controller and so on. This paper describes these improvements and their effects on the pressure measurement.