Filter/dilution tunnel. A smoke sample is drawn through a tube in which it is diluted with air, the ensuing smoke/air mixture is then pulled by way of a filter and weighed. This can be the internationally recognized means of measuring smoke from combustion.[66] 1600 – Tobacco utilised as cash-crop https://broadfar.com/non-combusted-cigarettes-a-safer-alternative-or-just-a-myth/