In this study, we present a traceable method for determining the counting efficiency of optical particle size spectrometers (OPSS), also known as aerosol spectrometers. The primary standard consists of an aerosol generation setup, a vertical flow tube for particle homogenization and a reference optical particle counter. The OPSS under testing and the reference optical particle counter sample aerosol simultaneously through specially designed isokinetic sampling probes at number concentrations ranging from 0.5 cm⁻³ up to several hundred particles per cm³ (depending on the particle size). Calibration in terms of particle size relies by convention on the use of certified PS (polystyrene) spheres in the size range 100 nm - 10 μm. Here, the counting efficiency profiles of two commonly used OPSS, namely the Model 3330 OPS (TSI Inc., USA) and the 11-D monitor (Grimm GmbH, Germany) are presented for the first time and discussed within the context of the ISO 21501–1:2009 and 21501–4:2018 standards on the calibration of OPSS for indoor/outdoor measurements and optical particle counters (OPC) for clean rooms applications, respectively. We believe that this study can help manufacturers improve the design of their instruments, contribute to the further development of relevant national and international standards and pave the way for a standardised and traceable calibration of OPSS units installed at air quality monitoring stations and industrial/workplace environments.

在这项研究中，我们提出了一种可追溯的方法来确定光学粒度光谱仪 (OPSS)（也称为气溶胶光谱仪）的计数效率。主要标准由气溶胶生成装置、用于粒子均质化的垂直流管和参考光学粒子计数器组成。被测 OPSS 和参考光学粒子计数器样品气溶胶同时通过专门设计的等速采样探头，数量浓度范围从 0.5 cm ^-3到数百个粒子/cm ³（取决于颗粒大小）。按照惯例，粒径校准依赖于使用尺寸范围为 100 nm - 10 μm 的经过认证的 PS（聚苯乙烯）球。在这里，首次介绍了两种常用 OPSS 的计数效率曲线，即 Model 3330 OPS（TSI Inc.，美国）和 11-D 监视器（Grimm GmbH，德国），并在 ISO 的背景下进行了讨论21501–1:2009 和 21501–4:2018 分别用于室内/室外测量的 OPSS 校准和洁净室应用的光学粒子计数器 (OPC) 校准标准。我们相信这项研究可以帮助制造商改进他们的仪器设计，