Patent ID: 7010991

Claim:
A device for counting particles on a sample surface, comprising: a scanner having at least one opening for receiving particles from a sample surface; a particle counter for counting particles passed therethrough; a conduit having a first end connected to the scanner and a second end connected to the particle counter, wherein the conduit includes first and second tubes; the particle counter includes: a pump for producing an airstream flowing from the scanner opening, through the first tube, through the particle counter, and back to the scanner via the second tube, for carrying the particles to the particle counter for quantitation; a heat-sink for dissipating heat generated by the pump; and a circulating fan for normalizing air temperature inside the particle counter; a sensor for measuring a rate of flow of the airstream; and a controller for controlling a speed of the pump in response to the measured rate of flow of the airstream to maintain the airstream at a constant flow rate while the particle counter quantitates the particles in the airstream.