Vacuum Chuck Holds Filter Pad For Counting Particles

Microscope-stage holder keeps filter pad flat to keep it in focus. Specimen holder is special vacuum chuck that applies suction through flat screen. Suction keeps filter pad flat against specimen holder while microscope stage moving to scan areas denoted by grid. In microscope system equipped with video camera, image-analyzing/particle-counting computer, and automatic focus, use of stage speeds count considerably by eliminating need to stop frequently for manual refocusing. Technician free to perform other tasks while computer controls translation of stage and takes count automatically.