本文件的范围集中于发动机开发和认证环境中固体颗粒数（SPN）计数设备的设置和使用。本文件回顾了从原始和稀释排气流中收集和测量样品的最佳实践，这些样品穿过与安装的后处理装置相关的几个样品探针插入位置。包括适当的稀释技术、样品转移过程和温度管理技术。最后，还包括性能和验证检查，以确保- 可以快速识别术语退化和仪器故障。本文件中的目标粒径范围大于23 nm，符合当前欧盟SPN法规，仅针对固体颗粒。当前常用的测量设备设计用于在23 nm时50%的计数效率和在40 nm时90%的计数效率，因此本文件的内容主要针对这些粒度。预计未来的法规将针对较低的10纳米尺寸切割点。因此，已经添加了一个简短的部分，讨论了在测量该尺寸范围内的粒子时，用户可能需要考虑的最佳实践。

The scope of this document focuses on the setup and use of solid particle number (SPN) counting devices in both engine development and certification environments. The document reviews best practices for collecting and measuring samples from both raw and diluted exhaust gas streams across several sample probe insertion locations relative to installed aftertreatment devices. Appropriate dilution techniques, sample transfer processes, and temperature management techniques are included. Finally, performance and validation checks are covered to ensure that long-term degradation and instrument failures can be identified quickly.The particle size range targeted in this document is >23 nm, which aligns with the present EU SPN regulations and targets only solid particles. Current commonly available measurement devices are designed for counting efficiencies of 50% at 23 nm and 90% counting efficiencies at 40 nm so the contents of this document primarily address these particle sizes. It is expected that future regulations will target a lower 10 nm size cut-point. Consequently, a short section has been added discussing best practices that a user may need to consider when measuring particles in this size range.