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Coarse focus knob Iris diaphragm lever Knobs controlling X and Y Swing-out filter holder movement of mechanical stage Fine focus knob Illuminator condenser Power on/off switch and fuse holder on back of base Base Models 156 & 156-S Monocular Head...
INTRODUCTION Thank you for your purchase of a National microscope. It is a well built, precision instrument carefully checked to assure that it reaches you in good condition. It is designed for ease of operation and years of carefree use. The information in this manual probably far exceeds what you will need to know in order to operate and maintain your microscope.
8. SAFETY RACK STOP: When properly adjusted, controls maximum upward travel of stage. Prevents higher power objectives from breaking specimen slides, prevents damage to objective lenses. This stop has been pre- adjusted at the factory. 9. FOCUSING KNOBS: Coarse focusing knobs (larger knobs) located on each side of arm, raise or lower stage to bring specimen image into focus.
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5.5mm 100X Din 40X 0.65 Blue 0.45mm 0.48mm 400X Models 156-S and 157 only Din 100X 1.25 White 0.18mm 0.06mm 1000X When finished viewing, all parts that come in contact with oil must be cleaned. Failure to do so could permanently damage the 100x oil immersion objective lens.
Before having costly servicing done, or before returning to National for “warranty repair”, make certain to examine the front lens element with a magnifying glass or eye loupe for the presence of such contaminants. If a microscope is returned to National for warranty repair, and it is determined that such contaminants are the problem, this is not covered under warranty and National will submit a cost estimate for cleaning.
CERTAIN TO TURN SWITCHES OFF AND REMOVE PLUG FROM POWER SOURCE OUTLET BEFORE CHANGING BULBS. B. To replace bulb (National #800-138) ..gently lay microscope on side. Using a Phillips (cross-head) type screwdriver, remove 5 each 3mm Phillips (cross-head) screws from bottom of base. Remove base plate to expose bulb.