Development and qualification of a VH-TDMA for the study of pure aerosols
Development and qualification of a VH-TDMA for the study of pure aerosols
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DOI：
10.1080/02786826.2018.1547358
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发表时间：
2019-01
影响因子：
5.2
通讯作者：
Christopher R. Oxford;Charles M. Rapp;Yang Wang-;Purushottam Kumar;Daniel Watson;J. Portelli;Eric A. Sussman;Steven Dhawan;Jingkun Jiang;B. Williams
中科院分区：
文献类型：
--
作者：
Christopher R. Oxford;Charles M. Rapp;Yang Wang-;Purushottam Kumar;Daniel Watson;J. Portelli;Eric A. Sussman;Steven Dhawan;Jingkun Jiang;B. Williams
摘要我们研制了一种挥发性和吸湿性串联微分迁移率分析仪（VH-TDMA），用于气溶胶的研究。这种VH-TDMA测量尺寸分布、挥发性和吸湿性，并包括一个辅助调节器，允许快速连接到其他外部气溶胶调节器。差示迁移率分析仪不受温度控制，因此周围环境会影响测量条件，在测量气溶胶挥发性和吸湿性时，这一点得到了充分考虑。对于挥发性调节器，VH-TDMA使用烘箱中的15 m盘管在高温下蒸发气溶胶样品。我们测量了几种单组分模型气溶胶，以鉴定微分迁移率粒度仪（DMPS）通道和每个调节器：吸湿性和挥发性。由于本研究中的电源校准不足，TDMA通道仅限于粒径大于70 nm的颗粒。DMPS通道是能够重现硫酸铵粒度分布相比，常见的扫描迁移率粒度仪。对于吸湿性，在4小时的实验中，测量的硫酸铵生长因子的标准偏差为0.03。根据该数据，TDMA观察到的相对湿度误差为±0.6%，制造商报告的相对湿度误差为±1.2%。挥发性通道再现了先前发表的锯齿形图案的室温饱和蒸气压从雾化的C3-C9二酸。室温饱和蒸气压的最大百分比差异约为80%。升华的焓来自二酸单调增加（除了辛二酸）和类似的测量质量渗出技术。版权所有© 2019美国气溶胶研究协会
Abstract We create and qualify a Volatility and Hygroscopicity Tandem Differential Mobility Analyzer (VH-TDMA) for the study of aerosols. This VH-TDMA measures size distributions, volatility, and hygroscopicity and includes an auxiliary conditioner that allows quick connection to other external aerosol conditioners. The differential mobility analyzers are not temperature controlled, allowing the surrounding environment to influence the measurement conditions, and this is fully accounted for when measuring aerosol volatility and hygroscopicity. For the volatility conditioner, the VH-TDMA uses a 15 m coil of tubing in an oven to evaporate aerosol samples at elevated temperatures. We measured several single component model aerosols to qualify the differential mobility particle sizer (DMPS) channel and each of the conditioners: hygroscopicity and volatility. Due to insufficient power supply calibration in this study, the TDMA channel is limited to particle sizes greater than 70 nm. The DMPS channel was able to reproduce ammonium sulfate size distributions when compared to common scanning mobility particle sizers. For hygroscopicity, the standard deviation in the measured ammonium sulfate growth factors was 0.03 over a 4-h experiment. From this data, the TDMA has an observed relative humidity error of ±0.6% with manufacturer reported error of ±1.2% relative humidity. The volatility channel reproduced the previously published saw tooth pattern of room temperature saturation vapor pressures from atomized C3-C9 diacids. The maximum percent difference in room temperature saturation vapor pressure was approximately 80%. The enthalpy of sublimation derived from the diacids increased monotonically (except for suberic acid) and resembled measurements from mass effusion techniques. Copyright © 2019 American Association for Aerosol Research