A Joint Research Project within the European Metrology Research Programme EMPIR.
QuantumPascal - Primary Photonic Pressure Measurement - EMPIR 18SIB04
Current realisations of the pascal rely on piston gauges (also known as pressure balances) and liquid manometers containing toxic mercury, both of which measure force per area. Their performance however has remained essentially unchanged over the past few decades and they suffer from practical and environmental limitations.
This project will develop photon based standards, which determine the pressure via gas density using the gas law.
Following the implementation of the redefined SI in May 2019, the uncertainty of the Boltzmann constant has been eliminated, so at a given temperature, photon-based standards promise primary measurements limited only by the accuracy of the quantum calculations.
In the longer term, such primary standards could be miniaturised, providing faster and calibration-free pressure measurements for industry at a fraction of the present cost.