Mixed optical techniques. You will discover several proprietary optical smoke measurement gadgets like the 'nephelometer' or even the 'aethalometer' which use several diverse optical procedures, such as more than one wavelength of light, within only one instrument and utilize an algorithm to give an excellent estimate of smoke. )[18] https://broadfar.com/oraco-pioneering-a-smokeless-future-with-innovative-nicotine-delivery/