Patents Assigned to Dryden Engineering Co., Inc.
  • Patent number: 5253538
    Abstract: A device and method for counting particles on a sample surface. The device includes a scanner having a surface for interfacing with the sample surface. The scanner is connected to one end of a tube which has two canals. The other end of the tube is connected to the particle counter. One of the tube canals supplies air from the particle counter through holes in the scanner surface for dislodging and fluidizing particles on the sample surface. The other tube canal returns air with the sample surface particles to the particle counter. After the particles are counted they are removed from the air stream by a filter. The air is then recycled back through the supply canal of the tube to facilitate additional particle counting. The method for using the device involves passing the scanner over the sample surface for predetermined periods, and collecting, counting and computing the average relative number of particles per unit area.
    Type: Grant
    Filed: April 26, 1991
    Date of Patent: October 19, 1993
    Assignee: Dryden Engineering Co., Inc.
    Inventors: Robert H. Swick, Gene J. Sullivan, Donald G. Lutz, Richard S. Dryden