| AVS 60th International Symposium and Exhibition | |
| Vacuum Technology | Monday Sessions |
| Session VT-MoM |
| Session: | Vacuum Measurement and Metrology |
| Presenter: | J.H. Hendricks, NIST |
| Authors: | J.H. Hendricks, NIST J.A. Stone, NIST G.F. Strouse, NIST D.A. Olson, NIST J.E. Ricker, NIST P. Egan, NIST G. Scace, NIST D. Gerty, Sandia National Laboratories |
| Correspondent: | Click to Email |
We have now concluded the first year of a five year program that aims to fundamentally change the method for realizing and disseminating the SI unit for pressure. The innovative technique represents a paradigm shift in the way the unit for pressure and vacuum is realized, creates new measurement infrastructure for NIST, and has the potential to create exciting spin-off technology that will have large impacts for US manufacturing and world metrology. We will move from primary standards based on artifacts for pressure and temperature and move to standards based on quantum-chemistry calculations of helium's refractive index. The underlying metrology behind this advance is the ultra-accurate determination of the refractive index of gases by picometer optical interferometry. The optical-based primary pressure standard will improve accuracy and allow the complete replacement of all mercury-based pressure standards which are expensive to operate and have environmental and health hazards. We describe our progress in designing and building our fixed length and variable length optical cavities and will discuss the uncertainty budget and technical challenges associated with this project to build an optical primary pressure standard.