Spectrophone measurements of the absorption of visible light by aerosols in the atmosphere

Simultaneous in situ measurements of the absorption and scattering by aerosols were made in ambient room air and in air with large amounts of added aerosols, such as cigarette smoke. For room aerosols, the extinction contribution due to absorption was typically one half that from scattering. The absorption measurements were made with an acoustically resonant spectrophone powered with a 0.5-W argon laser.