Abstract
A modern replica of the Aitken counter for detection of aerosol particles smaller in diameter than a half wavelength of visible light has been constructed using modern materials. The instrument employs photographic recording, rather than visual observations, of the cloud drops formed on these particles. This feature eliminates observer bias and provides a permanent record of the observation. Comparison of this instrument with a Pollak photoelectric nucleus counter indicated correspondence in the concentration sensed to well within experimental sampling error.
