Research data on pavement particle emissions for D6.5

The levels of particles generated by the circulation of the carousel wheels on the different pavements were evaluated in two complementary ways: through mobile or static measurements. The static measurements correspond to the particles aspirated laterally from the wheels (at a height of 0.15 m and 1.0 ± 0.5 m from the central path of the tread) using an ELPI analyzer. This analyzer provides access to both ultrafine (number-weighted data) and micrometer (volume-weighted data) particle concentrations every second. The ELPI analyzer operates on the principle of electrical impaction. The aspirated particles are electrically charged, separated according to their aerodynamic diameters, and then their impact on the dedicated plates of the analyzer generates an electric current that, after amplification, allows them to be detected and classified by size (between 7 nm and 4 µm). The total volume-weighted concentrations were derived numerically from the number concentrations. Due to the turbulence induced by the passage of the wheels, it was assumed that the samples were relatively homogeneous. The mobile measurements were based on the use of a Promo 2000 particle analyzer (from PALAS). It is a white light optical analyzer that counts particles between 200 nm and 10 µm following light diffraction at 90°. The analyzer was mounted on one of the arms of the carousel in order to measure every second the level of particles generated behind the wheel (at a distance of 0.10 m from it and at a height of 0.10 m) during the passage of different sections. The aspiration speed was of the same order of magnitude as the air flow behind the wheel (< 20% of the rolling speed): about 6 km/h. A custom-made device was added to the system to mark the moment of passage of the instrumented arm at the beginning of the S1 pavement. It was used to locate the periods of circulation of this arm on the different sections (S1, S2, S3 and S4).本研究通过两种互补方法评估了转盘车轮在不同路面循环行驶时产生的颗粒物水平：移动式测量与固定式测量。 固定式测量指使用电气低压冲击分析仪（Electrical Low Pressure Impactor，ELPI）从车轮侧向抽吸颗粒物，采样位置为距胎面中心轨迹0.15m高度、横向偏离1.0±0.5m处。该分析仪可每秒采集超细颗粒物（以数量加权的数据）与微米级颗粒物（以体积加权的数据）的浓度。ELPI分析仪基于电气冲击原理工作：抽吸的颗粒物先被充电，再按空气动力学粒径进行分离，随后撞击分析仪专用极板产生电流，经放大后可被检测并按粒径（7nm至4µm）分类。总体积加权浓度通过数量浓度数值推导得到。由于车轮经过时会诱导湍流，故假定采样样本具有相对均匀性。 移动式测量采用PALAS公司生产的Promo 2000颗粒物分析仪，该设备为白光光学分析仪，通过90°光衍射原理对200nm至10µm范围内的颗粒物进行计数。分析仪被安装在转盘的其中一个臂架上，以便在不同路面区段通行时，每秒采集车轮后方（距车轮0.10m、高度0.10m处）产生的颗粒物水平。抽吸风速与车轮后方的气流速度处于同一数量级，约为6km/h（仅为滚动速度的20%以下）。系统额外加装了定制装置，用于标记带测量臂在S1路面起点处的通过时刻，以此定位该臂在S1、S2、S3、S4各路面区段的循环时段。