Instrumentation Aerosol Neutralizer

The steady-state distribution is independent of the ionic concentration. However, the rate of approach to the steady state depends on the ionic concentrations and other properties of the system. The net result can be summarized as follows for the atmosphere. Ions are steadily generated by cosmic rays and radioactive decay processes. These attach to particle surfaces where they are neutralized at a rate equal to their rate of formation. The particle charge distribution is determined by the steady state relationship between particles separated by one charge. In the atmosphere, the equilibration process takes about 30 min. The rate of equilibration can be increased by increasing the ion concentration using a bipolar ion generator. Radioactive ion sources such as are often used in electrical aerosol instrumentation (Chapter 6). 

Additionally, the NOSH Consortium was able to achieve the vast majority of its objectives, including the definition of synthesis methods for stable sources of aerosol nanoparticles of Si02, Ti02, citric acid, silver, and PSL. The PSL particles were particularly important as a calibration standard for several aerosol instruments. The aerosol instrument characterization was successfully completed for numerous aerosol instruments, including the long- and nano-differential mobility analyzers, electrostatic-based impactor, aerosol chargers and neutralizers, and optical and electrostatic detectors. 

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