Merged optical methods. There are many proprietary optical smoke measurement products like the 'nephelometer' or the 'aethalometer' which use several different optical procedures, which include more than one wavelength of light, within just one instrument and apply an algorithm to offer a superb estimate of smoke. 1970 – Tobacco https://broadfar.com/the-benefits-of-switching-to-nusos-heated-tobacco-solutions/