Filter/dilution tunnel. A smoke sample is drawn through a tube where it is diluted with air, the ensuing smoke/air combination is then pulled through a filter and weighed. This is the internationally regarded means of measuring smoke from combustion.[66] Fire-cured tobacco is hung in huge barns in which fires https://broadfar.com/oraco-pioneering-a-smokeless-future-with-innovative-nicotine-delivery/