Chapter 4: Introduction to the Light Microscope PDF

MICROSCOPY Zacharias Janssen A glassmaker that invented the first optical telescope.  MICROSCOPE is an instrument used to see objects that are too small to be seen by the naked eye.  The Compound Light Microscope PARTS OF A COMPOUND MICROSCOPE MECHANICAL PARTS ...

MICROSCOPY Zacharias Janssen A glassmaker that invented the first optical telescope.  MICROSCOPE is an instrument used to see objects that are too small to be seen by the naked eye.  The Compound Light Microscope PARTS OF A COMPOUND MICROSCOPE MECHANICAL PARTS  1. arm Supports the tube and connects it to the base  2. base Provides support and serve as a stand 3. body tube holds the eyepiece where the specimen is viewed  4. stage holds the slide containing the specimen to be viewed  5. Stage clips Holds the slide in place  6. Course adjustment knob Moves the tube and the low power objective lens closer or farther away from the stage. 7. Fine adjustment knob Moves up and down; shows more clear and detailed parts of the specimen  8. Revolving nosepiece Revolves to properly position the desired lens. MAGNIFYING PARTS  9. Ocular lens/eyepiece Allows the viewer to look through and see the magnified image of the specimen  10. Objective lens Magnifies the image of the specimen a. Power scanner objective Provides the smallest image Has 4x magnifying power b. Low Power Objective (LPO) Provides a small image Has 10x magnifying power c. High Power Objective (HPO) Gives a large image Has 40x magnifying power  d. Oil Immersion Objective (OIO) Gives the largest image Has 100x magnifying power ILLUMINATING PARTS  11. mirror focuses the light  12. Diaphragm lever/iris diaphragm Controls the amount of light that reaches the specimen  13. Condenser focuses the light on the specimen  14. Light source A small electric light beneath the stage.  USING THE MICROSCOPE  1. Handle the microscope using the curved arm with one hand supporting its base with the other hand.  2. Use the revolving nosepiece to switch from one objective to the other. 3. Look through the eyepiece with both eyes open to avoid eyestrain.  4. While looking through the eyepiece, adjust the concave mirror until you see a circle of light.  5. You can slowly rotate the coarse adjustment knob for a clearer image of an object through LPO.  Use fine adjustment knob for the HPO.  6. You can move the slide over the opening to focus certain parts of your specimen.  7. Use soft cloth or tissue paper to clean outside surfaces of the microscope.  Use lens paper in cleaning lenses of the eyepiece COMPUTING FOR THE TOTAL MAGNIFICATION  Eyepiece Objective Total magnification X magnification = magnification