2009 R&D 100 Winner
Environmental studies of virtually every type have been limited simply by the size and power consumption of commercially available differential mobility analyzers (DMAs). Precise data about ultrafine particle concentrations in aerosols is of significant interest to the respiratory health community, and critical relationships between dosimetry and long-term health effects require large data sets from statistically sufficient populations. That objective can now be realized with the NASA Mini-Classifier, a joint effort of NASA Glenn Research Center, Cleveland, Ohio, along with Washington Univ. in St. Louis, Mo. The device is a complete, self-contained DMA that directly measures the particle size distribution of sub-micrometer particles, which includes the ultrafine (<100 nm) regime. The general method of operation is based on the theory of differential mobility separation. This technique requires the incoming particles to be charged to a defined electrical charge state. The device contains an efficient, yet small particle charger based on the theory of unipolar field charging. The complete, integrated package contains all provisions for computer control, data analysis, data logging, and data display via an internal LCD display—neatly arranged in a 3-in.3 package, a fraction of the size of the nearest competitor’s device. The device offers major reductions in power usage and cost as compared to other DMAs.
Technology
Self-contained differential mobility analyzer
Developers
NASA Glenn Research Center
Washington Univ.
