1.1本指南的目的是定义一种测试程序，用于应用激光衍射（LD）方法估计平均液滴尺寸分布，该平均液滴尺寸分布表征了指定喷雾发生装置在指定气体并流条件下使用指定液体产生的液滴流量。预期范围仅限于人工生成的高速合流喷雾。假设液滴直径在1至2000µm的大小范围内，并以喷雾形式出现，喷雾体积小至几立方厘米或大至一立方米。假设液滴尺寸在喷雾体积内分布不均匀。 1.2本指南主要用于指导使用LD仪器测量喷嘴和雾化器的性能。 1.3非均匀喷雾需要测量整个喷雾截面或通过几个弦提供整个喷雾截面的代表性样本。多弦测量的目的是获得表征整个喷雾的单个液滴尺寸分布，而不是单个弦测量值。 1.4本指南的使用要求仪器不会干扰喷雾的产生，也不会显著影响或干扰气体和喷雾的合流。因此，这种技术被认为是非- 侵入的 1.5使用米氏散射理论或夫琅和费衍射近似，根据光散射分布计算液滴尺寸分布。Mie理论的使用说明了通过液滴折射的光，并且对复折射率的实（折射）分量和虚（吸收）分量的知识有特定的要求。Mie理论还依赖于液滴均匀性的假设。夫琅和费衍射近似不考虑通过液滴折射的光，也不需要了解折射率。 1.6仪器应包括数据处理能力，以根据实施规程E799和试验方法E1260将LD散射强度转换为液滴尺寸分布参数。 1.7喷雾对LD仪器发射器光学产生的准直光束可见并可接近。喷雾的形状和尺寸应包含在仪器制造商规定的LD系统光学元件的工作距离内。 1.8 LD光学器件的尺寸范围应适合所研究的喷雾发生装置。例如，仪器报告的最小液滴尺寸等级的上限不得超过 1. / 4. 的大小 D V0.1 . 1.9以国际单位制表示的数值应视为标准值。本标准不包括其他计量单位。 1.10 本标准可能涉及危险材料、操作和设备。 本标准并非旨在解决与其使用相关的所有安全问题。本标准的用户有责任在使用前制定适当的安全和健康实践，并确定监管限制的适用性。 ====意义和用途====== 5.1本指南提供了一种使用LD仪器从近似于通量敏感样品的喷雾式气流中获得液滴尺寸分布的方法。 4. 5.2在许多喷雾中，实验者应按尺寸说明液滴的空间分离。本指南提供了一种对液滴分布进行空间平均的方法。 5.3获得的结果本质上是统计的，是指整个喷雾的液滴尺寸分布的时间平均值。 5.4本指南用于校准喷雾产生装置，以在预先指定的环境和合流条件下产生所需的液滴尺寸分布，或表征未知喷雾，同时将测量中的不确定性降至最低。

1.1 The purpose of this guide is to define a test procedure for applying the laser diffraction (LD) method to estimate an average droplet size distribution that characterizes the flux of liquid droplets produced by a specified spray generation device under specified gas co-flow conditions using a specified liquid. The intended scope is limited to artificially generated sprays with high speed co-flow. The droplets are assumed to be in the size range of 1 to 2000 µm in diameter and occur in sprays that are contained within a volume as small as a few cubic centimetres or as large as a cubic metre. The droplet sizes are assumed to be distributed non-uniformly within the spray volume. 1.2 This guide is intended primarily to guide measurement of performance of nozzles and atomizers using LD instruments. 1.3 Non-uniform sprays require measurements across the entire spray cross section or through several chords providing a representative sample of the overall spray cross section. The aim of multiple-chord measurements is to obtain a single droplet size distribution that characterizes the whole spray rather than values from a single chordal measurement. 1.4 Use of this guide requires that the instrument does not interfere with spray production and does not significantly impinge upon or disturb the co-flow of gas and the spray. This technique is, therefore, considered non-intrusive. 1.5 The computation of droplet size distributions from the light-scattering distributions is done using Mie scattering theory or Fraunhofer diffraction approximation. The use of Mie theory accounts for light refracted through the droplet and there is a specific requirement for knowledge of both real (refractive) and imaginary (absorptive) components of the complex index of refraction. Mie theory also relies on an assumption of droplet homogeneity. The Fraunhofer diffraction approximation does not account for light refracted through the droplet and does not require knowledge of the index of refraction. 1.6 The instruments shall include data-processing capabilities to convert the LD scattering intensities into droplet size distribution parameters in accordance with Practice E799 and Test Method E1260. 1.7 The spray is visible and accessible to the collimated beam produced by the transmitter optics of the LD instrument. The shape and size of the spray shall be contained within the working distance of the LD system optics as specified by the instrument manufacturer. 1.8 The size range of the LD optic should be appropriate to the spray generation device under study. For example, the upper bound of the smallest droplet size class reported by the instrument shall be not more than 1 / 4 the size of D V0.1 . 1.9 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.10 This standard may involve hazardous materials, operations, and equipment. This standard does not purport to address all of the safety problems associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. ====== Significance And Use ====== 5.1 This guide provides a means of using an LD instrument to obtain a droplet size distribution from a spray in gas co-flow that approximates a flux-sensitive sample. 4 5.2 In many sprays, the experimenter shall account for spatial segregation of droplets by size. This guide provides a means of spatial averaging the droplet distribution. 5.3 The results obtained will be statistical in nature and refer to the time average of droplet size distribution of the entire spray. 5.4 This guide is used to calibrate a spray generation device to produce a desired droplet size distribution under prespecified environmental and co-flow conditions or characterize an unknown spray while minimizing the uncertainty in the measurement.