Microscopes w1

    Cards (17)

    • what is magnification determined by
      lens ability to bend light
    • what happens when light ray passes through mediums
      ray bends at interface, causing refraction
    • what is the reflective index
      measure of how great a substance slows light
    • what is the objective lens and its role
      collects light passing through specimen and focuses light beam for magnified image
    • why do we use oil for x100 oil immersion lens
      refractive index of air and glass are slightly different, so the oil bridges the gap
    • what is the equation for magnification
      magnification= magnification eyepiece x objective lens
    • what is the nose piece also known as
      revolving turret
    • the stage has a hold called the aperture for the illuminating beam to pass
    • what is the role of the coarse knob
      bring specimen near to focus
    • what is the role of the fine knob
      focus quality sharpened
    • what is the illuminator
      the light source at the base of the microscope. halogen bulbs are often used
    • what is the condenser
      lens used to collect and focus light from the illuminator to the specimen, found under the stage
    • what is the iris diaphragm
      below the condenser, above the light source. used to change intensity and size of light
    • what is the purpose of kohler illumination
      provides optimum contrast and resolution by focusing object, spreading evenly
    • steps for Kohler illumination
      1. place slide on stage and focus at 4x
      2. focus specimen
      3. close down condenser diaphragm
      4. close illuminator so you should see 20p
      5. focus with condenser knobs so 20p edges become sharp
      6. move 20p to centre using screws
      7. open diaphragm
      8. open illuminator iris until full view
      9. adjust condenser iris for better contrast
    • how to use the vernier scale
      1. look where the 0 is
      2. if it is between 10 and 10.1, its 10
      3. then when scale marries up, chose that. meaning if its at 3 it is 10.3
    • what technique can be used to view full slide
      battlement
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