Figure 4.

Comparison of performance properties across different generations of EC including EH (this figure can be seen in color online). Four performance properties are summarized in box-whisker plots for cartridge models (Trtchounian et al., 2010), cartomizer models (Williams & Talbot, 2011), disposable button-activated models, and disposable airflow-activated models (current study). Each box shows the median, 75% percentile (blue box), 25% percentile (red box), and minimum and maximum values. The number of brands in each group was: six cartridge style, two cartomizer style, four button-activated disposable brands, and five airflow-activated disposable brands.