Despite minimal improvements in performance over decades, industrial and scientific measurements of gas pressure are still made with manometers containing toxic mercury. Piston gauges are more accurate but require exchange of weights during calibration and can be slow, bulky, complex, and require additional methods below 3 kilopascals. In theory, the drawbacks could be fixed using photon-based devices that use helium or other gases as the calculable reference substance. Miniaturisation could also enable faster, cheaper, calibration-free measurements.
The project will develop photon-based standards, applying quantum methods showing potential as a replacement primary standard of the SI unit of pressure, the pascal. Various methods will be tried, some pioneering, combined with new calculations of thermodynamic and electromagnetic gas properties. Performance will then be compared with current primary pressure standards. Technologies developed will be promoted to end users and standards bodies: as quantum-based realisations of the pascal could enable more accurate and versatile pressure measurement methods, to benefit other fields of metrology, wider science, industry and manufacturing.