![background image](http://html.mh-extra.com/html/national/167-series/167-series_instructions-for_708338005.webp)
5
E.
Eyepieces: Remove the dust caps from eyepiece tubes. Avoid touching any lens surface and Insert
eyepieces into the eyepiece tubes.
F.
Filter: Swing out filter holder has built in frosted filter
– must be in place when using the 4x and 10x
objectives.
OPERATION
G. Illumination.
1.
Before operating microscope,
adjust intensity control located on side of base to the minimum
position.
This should be done prior to each time light is turned on or off. This will extend bulb life.
2.
Insert power plug into 12VDC switching power converter, then insert plug on other end of converter into
power jack on back of microscope base. Note that the 12VDC converter will operate on either 120v or
240v current, 50 hertz or 60 hertz, eliminating the need for any other transformer.
3.
Push rocker switch at rear of base to ON position.
4.
Rotate intensity dial on illuminator base until image is illuminated.
5.
Adjust intensity of light to match requirements of objective and specimen slide.
6.
In case of equipment malfunction, see “Trouble Shooting” procedures.
H. Interpupillary adjustment of viewing head (Models 168 and 169 only)
1.
Look through microscope and adjust distance between the two eyepiece tubes by grasping the sliding
mounts to left and right of eyepieces and sliding together or apart.
2.
When a full field of view is observed through both tubes, and images blend into one, interpupillary
distance is corrected for your eyes. Check the interpupillary scale and note index reading for future
reference, in case other users will be changing this adjustment from time to time.
3.
Adjust the diopter scales, located on each eyepiece tube, to the same numerical value as indicated on
the interpupillary scale. This must be done in order to maintain parfocality of objective lenses. If
interpupillary distance is changed, adjust eyepiece diopters accordingly.
I.
Focusing the microscope.
1.
Position the 4x objective lens into the optical path, making sure that lens is properly indexed in its click-
stop position.
2.
Place standard specimen slide (cover slip up) on top of stage surface.Swing moveable finger on slide
holder outward. Place specimen slide against fixed side of slide holder. Slowly release moveable finger
until it makes contact with specimen slide.
3.
Rotate coarse focusing controls until specimen comes into focus.