Abstract The micron-sized metallic droplets have been commonly encountered in the utilization of liquid metallic materials. The size of metal droplet is a critical parameter that needs to be determined. This work goes insight into a dual-beam interferometric particle imaging (DIPI) method, which is proposed for the size measurement of opaque micron-sized metallic droplets. Three typical DIPI configurations with signals respectively sampling from the backward scattering, forward scattering, and hybrid-direction scattering regions, are analyzed theoretically, and a generalized model is derived. Proof-of-concept experiments are performed. The DIPI interferograms at the three different scattering regions as well as the digital inline hologram of the same metal droplet are simultaneously recorded. Results demonstrate that the diameters obtained by DIPI of three scattering regions are consistent with each other, and the average deviation values of the three are 1.6%, 2.2%, and 1.7%, comparing to the results of digital inline holography. The DIPI provides an accurate approach for the size measurement of opaque droplets. Besides, it can be carried out over a wide range of angles, breaking the rigorous requirement in the arrangement of apparatus.

中文翻译：

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用于不透明金属液滴尺寸测量的三种双光束干涉粒子成像配置的开发

摘要 在液态金属材料的利用中，经常会遇到微米级金属液滴。金属液滴的大小是需要确定的关键参数。这项工作深入了解了双光束干涉粒子成像 (DIPI) 方法，该方法被提议用于不透明微米级金属液滴的尺寸测量。从理论上分析了三种典型的 DIPI 配置，信号分别从后向散射、前向散射和混合方向散射区域采样，并推导出广义模型。进行概念验证实验。同时记录三个不同散射区域的 DIPI 干涉图以及同一金属液滴的数字在线全息图。结果表明，通过DIPI获得的三个散射区域的直径相互一致，与数字在线全息成像结果相比，三个散射区域的平均偏差值为1.6%、2.2%和1.7%。DIPI 为不透明液滴的尺寸测量提供了一种准确的方法。此外，它可以在很宽的角度范围内进行，打破了对设备布置的严格要求。