The particle number concentration was positively associated with the puff duration and puff flow rate.
A Single Cigarette Smoking Machine (SCSM-STEP, CH Technologies), was calibrated to a puffing regimen of 60 mL puff volume, 4 s puff duration and a 30 s inter-puff interval.
The peak heating coil temperature and the count median diameter (CMD) of EC aerosols increased with a longer puff duration and a lower puff flow rate.
With continuous puff flow, aerosol is being generated from the first moment the puff activates; by contrast, if the bell curve profile was employed for e-cigarette puffing, insufficient aerosol would be generated across the puff duration.
Puff parameters used were: 35 mL puff volume, 2 s puff duration, one puff every 60 s; this protocol was based on an ISO standard machine-smoking method [41].
There are numerous regimes and voltage setting an electronic device can be puffed at, and we have already talked about how puff duration is more important than volume, and that how higher voltage activation results in greater aerosol delivery.
As we can see here, the puffing parameters (specifically the puff duration and square profile instead of bell) and voltage settings play a significant role in aerosol nicotine delivery.
Mainstream smoke yields were firstly measured (mean values of three replicates of 5 cigarettes) using the standard ISO smoking regime [33] (with a puff volume of 35 cm3, puff duration of 2 sec and puff interval of 60 seconds) and a Filtrona linear smoking machine.
Another smoking regime was used to evaluate the removal efficiency at a higher flow rate often referred to as the Health Canada Intense regime (HCI) [34], i.e. using a puff volume of 55 cm3, puff duration of 2 sec and puff interval of 30 seconds, with any filter tip ventilation holes blocked (note that in the current study no filter tip ventilation was used).
However, no effect of training on smoking topography (e.g. number of puffs taken, puff duration, etc).
Figure 10c illustrates the overall effect of a puff peak, extending far greater than the actual puff duration.
