Regensburg 2019 – scientific programme

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TUT: Tutorials

TUT 1: Next generation of SI-Units (joint session VA/TUT/TT)

TUT 1.1: Tutorial

Sunday, March 31, 2019, 16:00–16:35, H2

A Quantum-Based Pressure Standard for a New SI Realization of the Pascal — •Jay Hendricks — NIST Thermodynamic Metrology Group, Gaithersburg, MD, US

Moving forward, the next generation of pressure standards will provide a new route of SI traceability for the pascal. By taking advantage of both the properties of light interacting with a gas and that the pressure dependent refractive index of helium can be precisely predicted from fundamental, first-principles quantum-chemistry calculations, a new route of realizing the pascal has been demonstrated. This lecture will briefly cover the classical methods of realizing pressure that have served the metrology community well for the past 375 years. And then will take a deeper dive into the next generation of light-based pressure standards that will enable the elimination of mercury manometers, replacing them with a smaller, lighter, faster, and higher precision standards. From a metrology stand point, the new quantum-based SI pascal will move us from the classical force/area definition, to an energy density (joules per unit volume) definition. Should the technique be further miniaturized, it will lead to a revolution in pressure metrology, enabling a photonics based device that serves both a gas pressure sensor and a portable gas pressure standard all in one.