US Patent 8109129 - Portable nanoparticle size classifier

http://www.freepatentsonline.com/8109129.html

Naneum Limited is a company founded in 2005 with the aim of developing and marketing easy to use instruments for detecting and characterizing airborne nanoparticles. This patent from Naneum teaches handheld instrumentation to classify nanoparticles according to size. Claim 1 reads:

1. A nanoparticle size classifier comprising a variable flow rate system, wherein the variable flow rate system comprises:

a diffusion cell having a single diffusion element disposed therein, the diffusion cell having an inlet and an outlet;

a flow meter;

a pump; and

a pump controller for controlling variable flow rates within the variable flow rate system;

wherein the variable flow rate system is arranged to enable a plurality of particle number concentration measurements to be obtained by passing an aerosol through the diffusion element at various flow rates.