X-ray interferometry established a link between atomic and macroscopic realisations of the metre. The possibility of measuring the silicon lattice parameter in terms of optical wavelengths opened the way to count atoms, to determine the Avogadro constant with unprecedented accuracy, and, nowadays, to realise the kilogram from the Planck constant. Also, it is a powerful tool in phase-contrast imaging by X-rays and, combined with optical interferometry, in linear and angular metrology with capabilities at the atomic scale. This review tells the history of the development of this fascinating technology at the Istituto Nazionale di Ricerca Metrologica in the last forty years. Eventually, it highlights its contribution to the redefinition of the International System of Units (SI).

X射线干涉测量法在米的原子实现和宏观实现之间建立了联系。根据光波长测量硅晶格参数的可能性为计数原子，以前所未有的精度确定Avogadro常数以及如今从普朗克常数实现千克的方法开辟了道路。此外，它还是X射线相衬成像中的强大工具，并且与光学干涉术相结合，可在原子级范围内进行线性和角度计量。这篇评论讲述了过去四十年来在Riceca Metrologica的国立Istituto Nazionale di Ricerca地铁上这种令人着迷的技术的发展历史。最终，它突出显示了它对重新定义国际单位制（SI）的贡献。