Filter/dilution tunnel. A smoke sample is drawn by way of a tube where it is diluted with air, the ensuing smoke/air mixture is then pulled through a filter and weighed. This is the internationally identified approach to measuring smoke from combustion.[sixty six] 1600 – Tobacco utilized as cash-crop – https://broadfar.com/non-combusted-cigarettes-a-safer-alternative-or-just-a-myth/