Poor air quality influences the quality of life in the urban environment. The regulatory observation stations provide the backbone for the city administration to monitor urban air quality. Recently a suite of cost-effective air quality sensors has emerged to provide novel insights into the spatio-temporal variability of aerosol particles and trace gases. Particularly in low concentrations these sensors might suffer from issues related e.g., to high detection limits, concentration drifts and interdependency between the observed trace gases and environmental parameters. In this study we characterize the optical particle detector used in AQT530 (Vaisala Ltd.) air quality sensor in the laboratory. We perform a measurement campaign with a network of AQT530 sensors in Helsinki, Finland in 2020-2021 and present a long-term performance evaluation of five sensors for particulate (PM10, PM2.5) and gaseous (NO2, NO, CO, O3) components during a half-year co-location study with reference instruments at an urban traffic site. Furthermore, short-term (3-5 weeks) co-location tests were performed for 25 sensors to provide sensor-specific correction equations for the fine-tuning of selected pollutants in the sensor network. We showcase the added value of the verified network of 25 sensor units to address the spatial variability of trace gases and aerosol mass concentrations in an urban environment. The analysis assesses road and harbor traffic monitoring, local construction dust monitoring, aerosol concentrations from fireworks, impact of sub-urban small scale wood combustion and detection of long-range transport episodes on a city scale. Our analysis illustrates that the calibrated network of Vaisala AQT530 air quality sensors provide new insights into the spatio-temporal variability of air pollution within the city. This information is beneficial to, for example, optimization of road dust and construction dust emission control as well as provides data to tackle air quality problems arising from traffic exhaust and localized wood combustion emissions in the residential areas.

中文翻译：

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维萨拉 AQT530 传感器作为传感器网络的一部分的附加值，用于全面的空气质量监测

空气质量差会影响城市环境中的生活质量。监管观测站是城市管理部门监测城市空气质量的支柱。最近出现了一套具有成本效益的空气质量传感器，为气溶胶颗粒和痕量气体的时空变化提供了新的见解。特别是在低浓度下，这些传感器可能会遇到与高检测限、浓度漂移以及观察到的痕量气体和环境参数之间的相互依赖性相关的问题。在本研究中，我们表征了实验室中 AQT530（维萨拉有限公司）空气质量传感器中使用的光学粒子探测器。我们在赫尔辛基使用 AQT530 传感器网络进行测量活动，芬兰在 2020 年至 2021 年期间使用参考仪器在半年的共址研究中对颗粒物（PM10、PM2.5）和气体（NO2、NO、CO、O3）成分的五个传感器进行了长期性能评估。城市交通站点。此外，对 25 个传感器进行了短期（3-5 周）共置测试，以提供特定于传感器的校正方程，用于微调传感器网络中选定的污染物。我们展示了经验证的 25 个传感器单元网络的附加值，以解决城市环境中痕量气体和气溶胶质量浓度的空间变异性。该分析评估了道路和港口交通监测、当地建筑粉尘监测、烟花气溶胶浓度、郊区小规模木材燃烧的影响和对城市规模的远程运输事件的检测。我们的分析表明，维萨拉 AQT530 空气质量传感器的校准网络为城市内空气污染的时空变化提供了新的见解。这些信息有利于优化道路扬尘和建筑扬尘排放控制等，并为解决居民区交通尾气和局部木材燃烧排放引起的空气质量问题提供数据。