**Quantum Standard: Optical Pascal**
Researchers at the National Institute of Standards and Technology (NIST) have made a definitive measurement of the optical pascal, a new method for measuring gas pressure based on thermodynamics and quantum theory. This breakthrough could enable industries to establish their own optical pressure scales directly traceable to fundamental constants, saving time and cost.
**Organizations Developing the Standard:** NIST researchers Patrick Egan, Jack Stone, and Yuanchao Yang from the National Institute of Metrology in Beijing collaborated on this study.
**Current Status:** The new measurement has been published online in Physical Review Applied, with potential applications throughout industry and academia in the U.S.
**Potential Impact:** This development may decrease uncertainties in pressure measurements by relying only on temperature of gases rather than classical mechanics techniques. Industries such as petroleum refining, aircraft manufacturing, internal combustion engines will benefit from more accurate calibrations using this novel method.
The research team overcame challenges by accurately calculating polarizability – how easily gas molecules are influenced by light beams – particularly challenging when dealing with heavier atoms like argon. They achieved precise measurements through an innovative technique called dispersion barometry that measures refraction changes across different wavelengths cancelling out instrument distortions caused due its contraction or expansion under varying pressures
Keywords: polarizability, refractive index, gas
