Revolving Nosepiece Or Turret.docx 4r16k

a) Revolving Nosepiece or Turret: This is the part that holds two or more objective lenses and can be rotated to easily change power. b) Coarse adjustment knob: Also referred to as rough focus, this knob raises and lowers the microscope stage quickly. It should only be used in connection with the low magnification lenses. c) Condenser: to focus the light onto the specimen. d) Stage: This is the flat surface on which the slides are placed on. It can be moved up and down for focusing. e) Iris diaphragm: Adjusts the amount of light that reaches the specimen. f) Mirror - reflects light upward through the diaphragm g) Eyepiece: The lens the viewer looks through to see the specimen. The eyepiece usually contains a 10X or 15X power lens. h) High Power Objective: For detailed viewing or small specimens i) Low Power Objective: For large specimens or overview j) Fine adjustment Knob: tunes the focus and increases the detail of the specimen. k) Glass slide: used to hold objects for examination under a microscope SYTEMATIC MANNER ON USING THE MICROSCOPE 1. When moving your microscope, always carry it with both hands. Grasp the arm with one hand and place the other hand under the base for . 2. Turn the revolving nosepiece so that the lowest power objective lens is "clicked" into position. 3. Place the microscope slide on the stage and fasten it with the stage clips. You can push down on the back end of the stage clip to open it. 4. Using the coarse adjustment, lower the objective lens down as far as it will go without touching the slide! Note: Look at the slide and lens from the side when doing this. 5. Look through the eyepiece and adjust the illuminator (or mirror) and diaphragm for the greatest amount of light. 6. Slowly turn the coarse adjustment so that the objective lens goes up (away from the slide). Continue until the image comes into focus. Use the fine adjustment, if available, for fine focusing. 7. Move the microscope slide around so that the image is in the center of the field of view and readjust the mirror, illuminator or diaphragm for the clearest image. 8. You should be able to change to the next objective lenses with only slight focusing adjustment. Use the fine adjustment, if available. If you cannot focus on your specimen, repeat steps 4 through 7 with the higher power objective lens in place. DO NOT ALLOW THE LENS TO TOUCH THE SLIDE! 9. The proper way to use a monocular microscope is to look through the eyepiece with one eye and keep the other eye open (this helps avoid eye strain). If you have to close one eye when looking into the microscope, it's ok. , everything is upside down and backwards. When you move the slide to the right, the image goes to the left! 10. Do not touch the glass part of the lenses with your fingers. Use only special lens paper to clean the lenses. 11. When finished, raise the tube, click the low power lens into position and remove the slide. PRECAUTIONARY MEASURES 1. Always carry the microscope with two hands - one on the arm and one underneath the base of the microscope. Hold it up so that it does not hit tables or chairs. Never swing the microscope. 2. When using the microscope start with the low power lens and work up to the desired magnification. These microscopes are parfocal, which means that all powers should be in focus when the turret is rotated.

3. Check out the microscope to make sure all the lenses are clean and the mechanical parts are in working order. Report any malfunction to the instructor so that it may be remedied. 4. Keep the microscope clean. When anything is spilled or otherwise gets on the microscope, clean it up immediately. 5. Never move the stage upwards with the coarse adjustment while viewing through the eyepieces. Get the lens close to the slide while viewing from the side to make sure that they never touch. Then move the

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stage downward with the coarse adjustment while viewing through the lens. This will prevent the possibility of ramming the lens into the slide, thereby ruining a slide you have just made and, quite possibly, damaging the lens. Moist, living or preserved materials must be observed through a coverslip. This protects the lens as well as tends to make the object under view optically flat. Be sure to maintain a safe distance between the coverslip and the objective lenses. Clean the lenses with lens paper only. DO NOT CLEAN THE LENSES WITH HANDKERCHIEFS, FACIAL TISSUES, PAPER TOWELS, ETC.--they will scratch the lenses. If your lenses are very dirty, obtain some lens cleaning solvent from the instructor. If you cannot obtain clear focus or good lighting, or if your microscope seems not to be working properly, IMMEDIATELY CALL YOUR INSTRUCTOR. He/she can either assist you or see that the microscope is repaired. Return your scope to the cabinet with light cord wrapped around its base and with the lowest power objective lens in position.

GENERALIZATION In order to perform an experiment well, there is a need to familiarize one’s self with the different apparatuses used in the laboratory. In order also to have accurate results, we need to know how an apparatus, like the microscope, is operated and how to handle them.