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In Search of Better Pressure Standards



Jay H. Hendricks, Jacob E. Ricker, Patrick F. Egan, Gregory F. Strouse


Based on highly accurate optical interferometry and fundamental quantum calculations, researchers at the National Institute of Standards and Technology (NIST) in the US are developing an improved definition of the SI unit for pressure that will consign the mercury manometer to history. The five-year project aims to fundamentally change the way the pascal is realized and disseminated, and will raise pressure standards to the level of other SI units based on fundamental constants and also offer a brand new way to redefine the kelvin.
Physics World


pascal, Torr, pressure, vacuum, temperature, kelvin, dimensional, metrology, optical interferometry, Fabry–Pérot, interferometer, refractive index, quantum chemistry, SI, helium, air, mercury manometer
Created August 1, 2014, Updated February 19, 2017