Filter/dilution tunnel. A smoke sample is drawn via a tube in which it can be diluted with air, the resulting smoke/air combination is then pulled by way of a filter and weighed. This is the internationally acknowledged means of measuring smoke from combustion.[66] 1970 – Tobacco suppliers lawfully obliged https://broadfar.com/non-combusted-cigarettes-a-safer-alternative-or-just-a-myth/