Patent ID: 9459194
Filing Date: 2016-10-04
CPC Classification: G01N

Claim Text:
1. An apparatus for measuring size and concentration of particles, the apparatus, comprising: a body having proximal and distal end portions, said body defining a chamber through which charged particles may flow, said body being configured to operate at a pressure below an atmospheric pressure; an end cap disposed on the proximal end portion of the body, the end cap having an orifice; an exhaust port disposed on the distal end portion of the body; a particle detector disposed inside of the chamber adjacent to the exhaust port; a particle source disposed outside of the chamber adjacent to the orifice, said particle source being configured to generate the charged particles at atmospheric pressure; a focusing electrode disposed inside of the chamber, said focusing electrode being configured to minimize lateral dispersion of the charged particles inside of the chamber; an electronic gate disposed downstream of the focusing electrode, said electronic gate being configured to trap and release the charged particles as they flow inside of the chamber, said focusing electrode and said electronic gate further dividing the chamber into a jet relaxation region between the end cap and the focusing electrode and a drift region between the electronic gate and the particle detector; a plurality of electrodes disposed on the body in the drift region downstream of the electronic gate, said plurality of electrodes being configured to generate an electric field inside the chamber so as to control drift velocities of the charged particles released from the electronic gate towards the particle detector; and a timing device configured to measure a time taken by the charged particles to travel from the electronic gate to the particle detector, wherein a measurement of the size and concentration of the charged particles is based on an output signal from the particle detector and the time measured by the timing device.