CHARMEX VHTMA quick look Operational from: 5th July to 12th of July Selected sizes: 40 nm, 80 nm Oven temperature: 120 o C Problems Charging in DMA at larger sizes and highest humidities. Material used in oven needs to be changed (strong odeur + temperature limit = 200 o C).

GF40 – Slight diurnal variation – Little spread in GF AVG values. – GF AVG ranged from 1.4 to 1.6 GF80 – More spread in data – Less diurnal variation – GF AVG ranged from 1.6 to 2.0 CHARMEX VHTMA quick look

Effects of volatile material D 0 = 40 nm (Oven = 120 o C) Growth factor measured by HTDMA Growth factor measured by VHTDMA (after aerosol passed through oven) Shrink factor of aerosol after passing through oven (no humidification) Large red circle indicates regions where there are differences between the GF AVG measured by the HTDMA and VHTDMA

Effects of volatile material D 0 = 80 nm (Oven = 120 o C) Growth factor measured by HTDMA Growth factor measured by VHTDMA (after aerosol passed through oven) Shrink factor of aerosol after passing through oven (no humidification) Large red circle indicates regions where there are differences between the GF AVG measured by the HTDMA and VHTDMA

Effects of volatile material D 0 = 40 nm (Oven = 120 o C) Growth factor measured by HTDMA Growth factor measured by VHTDMA (after aerosol passed through oven) Shrink factor of aerosol after passing through oven (no humidification) Large red circle indicates regions where there are differences between the GF AVG measured by the HTDMA and VHTDMA

Effects of volatile material D 0 = 80 nm (Oven = 120 o C) Growth factor measured by HTDMA Growth factor measured by VHTDMA (after aerosol passed through oven) Shrink factor of aerosol after passing through oven (no humidification) Large red circle indicates regions where there are differences between the GF AVG measured by the HTDMA and VHTDMA

HTDMA RH=90% HTDMA > VHTDMA VHTDMA > HTDMA Individual GF spectrums as a function of time (corrected for DMA transfer function)

VHTDMA RH = 90% HTDMA > VHTDMA VHTDMA > HTDMA Individual GF spectrums as a function of time (corrected for DMA transfer function)

HTDMA>VHTDMA Juillet 6, 0934 SF = 0.9 Very little volume is volatilised Big difference in GF -scan time = 30 minutes 80 nm 40 nm Selected periods

80 nm 40 nm SF = 0.9 Very low volatile and hygroscopic Material -scan time = 30 minutes HTDMA>VHTDMA Juillet 6, 1034 Selected periods

VHTDMA>HTDMA Juillet 10, nm 40 nm SF = 0.8 to 0.9 more volume is volatilised ->More volatile ->More hydrophobic coating Semi-volaile organic coating? Selected periods

New hygroscopic modes after volatilisation?? HTDMA VHTDMA

Next steps… Examine data on 9th where more hygroscopic modes appear after the aerosol is volatilised. Comparison with meteo data Comparison with PILS (cutoff 200 nm)

DMA1(Dry) DMA2(Wet) Humidifier Drier CPC Aerosol Inlet Oven Direction of flow Switching valve

DMA1 # of particles Diameter (nm) DMA2 after oven+humidity DMA2 after humidity