Published 6 times per year, Metrologia covers the fundamentals of measurements, particularly those dealing with the seven base units of the International System of Units (metre, kilogram, second, ampere, kelvin, candela, mole) or proposals to replace them.The journal also publishes papers that contribute to the solution of difficult measurement problems and improve the accuracy of derived units and constants that are of fundamental importance to physics.In addition to regular papers, the journal publishes review articles, issues devoted to single topics of timely interest and occasional conference proceedings. Letters to the Editor and Short Communications (generally three pages or less) are also considered.