Global rainbow refractometry (GRR) is an important technique for temperature measurements of droplets and has been applied to a wide field of technical sprays. In this work, the application of GRR to sprays with droplets as small as $1-30\text{μ}$m in diameter is investigated by means of Lorenz–Mie theory to evaluate the influence of varying droplet size distributions (DSD) and varying refractive indexes on the global rainbow. DSDs were found by fitting a Rosin–Rammler–Sperling–Bennett distribution to experimental data. Different DSDs, that are typical for flame spray pyrolysis applications were evaluated systematically with varying widths and mean diameters. A study of the angular rainbow maxima position with varying widths of DSDs shows a strong non-linearity. It is concluded that GRR experiments in polydisperse applications should be accompanied with an accurate sizing technique. Furthermore, possible droplet size-dependent distributions of refractive indexes within the samples may influence the results.

全球彩虹折光仪（GRR）是测量液滴温度的重要技术，已被广泛应用于技术喷雾领域。在这项工作中，将GRR应用于雾滴小至$\mathrm{1个}-30\text{μ}$利用Lorenz-Mie理论研究了直径为m的物体，以评估变化的液滴尺寸分布（DSD）和变化的折射率对整体彩虹的影响。通过将Rosin–Rammler–Sperling–Bennett分布拟合到实验数据来发现DSD。系统地评估了具有不同宽度和平均直径的火焰喷雾热解应用中典型的不同DSD。对DSD宽度变化的彩虹角最大值位置的研究显示出很强的非线性。结论是，在多分散应用中的GRR实验应伴有准确的施胶技术。此外，样品中折射率的可能取决于液滴大小的分布可能会影响结果。