The achievement of this work is that fine tuning of experimental and evaluation parameters can improve the absolute accuracy and reproducibility of selected area electron diffraction (SAED) to 0.1% without using internal standard. Due to the proposed procedure it was possible to reach a reproducibility better than 0.03% for camera length between sessions by careful control of specimen height and illumination conditions by monitoring lens currents. We applied a calibration specimen composed of nanocrystalline grains free of texture and providing narrow diffraction rings. Refinements of the centre of the diffraction pattern and corrections for elliptic ring distortions allowed for determining the ring diameters with an accuracy of 0.1%. We analyze the effect of different error sources and reason the achieved absolute accuracy of the measurement. Application of the proposed evaluation procedure is inevitable in case of multicomponent nanocomposites or textured materials and/or having close diffraction rings where application of automated procedures is limited. The achieved accuracy of 0.1% without internal standard is approaching that of routine laboratory XRD, and reduction of instrumental broadening due to the elaborated evaluation procedure allows for separation of close reflections, provides more reliable ring width and thus improved input parameters for further nanostructure analysis as demonstrated on dental enamel bioapatite.

中文翻译：

---

采集和评估程序以提高 SAED 的准确性

这项工作的成果是微调实验和评估参数可以在不使用内标的情况下将选区电子衍射 (SAED) 的绝对准确度和重现性提高到 0.1%。由于所提出的程序，通过监视镜头电流仔细控制标本高度和照明条件，可以使会话之间的相机长度的再现性优于 0.03%。我们应用了由无纹理的纳米晶粒组成并提供窄衍射环的校准样本。衍射图案中心的改进和椭圆环畸变的校正允许以 0.1% 的精度确定环直径。我们分析了不同误差源的影响，并推断出测量的绝对精度。在多组分纳米复合材料或纹理材料和/或具有紧密衍射环的情况下，应用所提出的评估程序是不可避免的，其中自动化程序的应用受到限制。在没有内部标准的情况下实现的 0.1% 的准确度接近常规实验室 XRD 的准确度，并且由于详细的评估程序而减少了仪器展宽，允许分离近距离反射，提供更可靠的环宽度，从而改进输入参数以进行进一步的纳米结构分析，因为在牙釉质生物磷灰石上得到证明。