Filter/dilution tunnel. A smoke sample is drawn through a tube exactly where it's diluted with air, the ensuing smoke/air combination is then pulled via a filter and weighed. This is the internationally regarded method of measuring smoke from combustion.[66] 1970 – Tobacco brands lawfully obliged to print a warning https://nuso79022.wikicorrespondence.com/4628093/the_2_minute_rule_for_cigarettes