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The United States of America as Represented by the United States

William Henry Benner

Donald John Holve

Apparatuses, methods, and systems are disclosed for analyzing particles from about 0.001 to about 1 &#x3bc;m in diameter by controlling a gaseous medium through which the particles travel so that properties of the particles, such as diameter, electrical mobility, and charge, are measured. One embodiment of the disclosed apparatuses includes a particle source generator, a nozzle, a chamber, an electronic gate, and a detector. Resolution of the measurements made by the disclosed apparatuses is improved by use of a mathematical deconvolution of a spread in arrival times generated by particles of different sizes and charge levels and non-ideal background flow velocity variations.

Apparatuses, processes, and systems for measuring particle size distribution and concentration

An oxygen analyzer which identifies and classifies microgram quantities of oxygen in ambient particulate matter and for quantitating organic oxygen in solvent extracts of ambient particulate matter. A sample is pyrolyzed in oxygen-free nitrogen gas (N.sub.2), and the resulting oxygen quantitatively converted to carbon monoxide (CO) by contact with hot granular carbon (C). Two analysis modes are made possible: (1) rapid determination of total pyrolyzable oxygen obtained by decomposing the sample at 1135.degree. C., or (2) temperature-programmed oxygen thermal analysis obtained by heating the sample from room temperature to 1135.degree. C. as a function of time. The analyzer basically comprises a pyrolysis tube containing a bed of granular carbon under N.sub.2, ovens used to heat the carbon and/or decompose the sample, and a non-dispersive infrared CO detector coupled to a mini-computer to quantitate oxygen in the decomposition products and control oven heating.

Growing community of inventors

Danville, CA, United States of America

William Henry Benner