2.7. Particle measurements
Number size distribution measurements were conducted using the
TSI Model 3091 Fast Mobility Particle Sizer (TSI, Shoreview, NM). The
instrument was operated at 1 second time resolution in the measurement
range: 5.6–560 nm; the sampling rate was 10 L/min and with exhaust
outside the chamber. Total number concentration was integrated
from the number size distribution. Spherical SOA particles with a mean
density of 1.2 were assumed for the mass calculations (Bahreini et al.,
2005; Saathoff et al., 2009; Turpin and Lim, 2001).