An improved model of the condensation nucleus counter with stereo-photomicrographic recording

A new model of the condensation nucleus counter with stereo-photomicrographic recording is described which is distinguished by perfect symmetry in its construction, reduced turbulence, two separate microscopes with photographic attachments and a novel dark-field illumination which eliminates completely fogging of the graticule even after prolonged use of the instrument. A view-finder microscope permits observations of the graticule so that the instrument can also be used for counting nuclei by eye. When the graticule is removed the droplets can be photographed in space stereoscopically.