Resumen de Building, tune-up and first measurements of aerosol hygroscopicity with an HTDMA

Elisabeth Alonso Blanco, Francisco Javier Gómez Moreno, S. Sjogren, Begoña Artiñano Rodríguez de Torres

• Aiming at measuring hygroscopicity, a Hygroscopic Tandem Differential Mobility Analyzer (HTDMA) has been built and tuned up to allow us to know the size changes of the submicrometer aerosol in relation to the relative humidity (RH). This instrument consists of two custom-made Vienna-type Differential Mobility Analyzers (DMAs) connected in tandem with a humidification system in between (Nilsson et al., 2009). It allows measuring the growth factor between 10-98% RH. In the first DMA, a single aerosol size is selected, while the second DMA, connected to a Condensation Particle Counter (CPC) works as a traditional Scanning Mobility Particle Size (SMPS). In this way the growth factor distribution can be measured once the monodisperse aerosol has passed through the humidifier. This instrument has a temporal resolution of about 3 min for each measure. Both the instrument regulation and the data acquisition software were developed in LabVIEW code.