“…This result may appear to contradict the results shown in Figure 2 of the preceding paper. 1 In practice, the lifetime of the droplet, which is dictated by the ambient conditions of temperature and RH, overwhelms the effect of RH alone on particle control efficiency, providing the observed results. These test observations are thus consistent with the assertion that the droplets should be small enough to provide high particle collection efficiency, yet large enough not to evaporate too quickly.…”