Based on highly accurate optical interferometry and fundamental quantum calculations, researchers in the US are developing an improved definition of the SI unit for pressure that will consign the ...

Jay Hendricks tells about ongoing work to change the realization and dissemination of the pascal, which will lead to the elimination of mercury-barometer pressure standards. Pressure is one of the ...

The metrology revolution is gathering pace. Hot on the heels of an overhaul of the most fundamental ‘base’ units of measure in the International System of Units (SI) last month, some metrologists are ...