本文件规定了采用低角度X射线法（包括X射线）对纳米多层涂层进行基材条件和调制周期的测试（包括低角度X光方法的原理、涂层的要求、X射线测量仪器的要求、仪器和样品的校准、测试条件和计算过程）反射率（XRR）和掠入射X射线衍射（GIXRD）。

This document specifies the substrate conditions and testing of the modulation period (including the principles for low-angle X-ray methods, the requirements of the coatings, the requirements for X-ray measuring apparatus, the calibration of apparatus and samples, and the testing conditions and calculation process) of nano-multilayer coatings by low-angle X-ray methods including X-ray reflectivity (XRR) and glancing incident X-ray diffraction (GIXRD).