Difference between revisions of "Aitken dust counter"

From Glossary of Meteorology
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<div class="definition"><div class="short_definition">(''Or'' Aitken nucleus counter.) An instrument developed by John Aitken for  determining the [[dust]] content of the [[atmosphere]].</div><br/> <div class="paragraph">A sample of air is mixed in an expandable chamber with a larger volume of dust-free air containing  [[water vapor]]. Upon sudden expansion, the air in the chamber cools [[adiabatically]] below its [[dewpoint]],  and [[droplets]] form with the dust particles as nuclei. A portion of these droplets settle on  a ruled plate in the instrument and are counted with the aid of a microscope. <br/>''See'' [[dust counter]].</div><br/> </div><div class="reference">Aitken, J. 1923. Collected Scientific Papers.  236&ndash;246. </div><br/>  
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<div class="definition"><div class="short_definition">(''Or'' Aitken nucleus counter.) An instrument developed by John Aitken for  determining the [[dust]] content of the [[atmosphere]].</div><br/> <div class="paragraph">A sample of air is mixed in an expandable chamber with a larger volume of dust-free air containing  [[water vapor]]. Upon sudden expansion, the air in the chamber cools [[adiabatic process|adiabatically]] below its [[dewpoint]],  and [[droplets]] form with the dust particles as nuclei. A portion of these droplets settle on  a ruled plate in the instrument and are counted with the aid of a microscope. <br/>''See'' [[dust counter]].</div><br/> </div><div class="reference">Aitken, J. 1923. Collected Scientific Papers.  236&ndash;246. </div><br/>  
 
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Latest revision as of 15:22, 25 April 2012



Aitken dust counter

(Or Aitken nucleus counter.) An instrument developed by John Aitken for determining the dust content of the atmosphere.

A sample of air is mixed in an expandable chamber with a larger volume of dust-free air containing water vapor. Upon sudden expansion, the air in the chamber cools adiabatically below its dewpoint, and droplets form with the dust particles as nuclei. A portion of these droplets settle on a ruled plate in the instrument and are counted with the aid of a microscope.
See dust counter.

Aitken, J. 1923. Collected Scientific Papers. 236–246.