background image

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.  Fine focus knobs (smaller knobs located just below coarse focusing knobs) 
permit more precise image adjustment. 

 
10.  ILLUMINATION:  Built-in substage electric illuminator provides constant, reliable pre-focused illumination. 

 

Observe that the main voltage of your microscope is labeled on the back of the base.  Make certain that 
the main voltage of your microscope corresponds to the voltage of your power outlet, 120v or AC. 

 

OPERATION

 

 
1.  Illumination. 

 
A. 

Insert microscope plug into outlet.

 

 

B.  Push rocker switch at rear of base to ON position. 

 

C.  In case of equipment malfunction, see “Trouble Shooting” procedures. 

 

2.  For model 157 binocular head only, interpupillary adjustment of viewing head  

 
A.  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. 

 

B.  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. 

 

C.  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. 

 

3.  Focusing the microscope. 

 
A.  Position the 4x objective lens into the optical path,  making sure that lens is properly indexed in its click-stop 

position. 

 

B.  Swing moveable finger on slide holder outward.  Place specimen slide (cover slip up) on top of stage 

surface against fixed side of slide holder.  Slowly release moveable finger until it makes contact with 
specimen slide. 

 

C.  Rotate coarse focusing controls until specimen comes into focus. 

 

D.  Adjust fine focus controls until specimen is in sharp focus. 

 

E.  For model 157 binocular head only, adjust diopter for possible difference in eyesight between user’s left and 

right eyes.  If user has 20/20 vision, this adjustment should not be necessary. 
 
a)  Using right eye, peer into the right eyepiece tube.  Adjust sharpness of image by utilizing fine focus 

controls, without touching the diopter ring. 

 

b)  Using left eye, peer into the left eyepiece tube.  Adjust sharpness of image by turning diopter 

adjustment located on left eyepiece tube. 

 

F.  Adjusting the aperture (opening) of iris diaphragm. 

 

Summary of Contents for 156

Page 1: ...c Instruments Inc 6508 Tri County Parkway Schertz Texas 78154 Phone 210 590 9010 Fax 210 590 1104 INSTRUCTIONS FOR MODELS 156 156 S 157 COMPOUND BIOLOGICAL MICROSCOPES Copyright 1 2 01 National Optical Scientific Instrument Inc ...

Page 2: ...iece Knurled diopter ring Sliding interpupillary adjustment grips located on both left and right side of diopter scale Mark on side of eyepiece tube for indexing diopter reading Head locking screw Arm of microscope stand Knobs controlling X and Y movement of mechanical stage Coarse focus knob Fine focus knob Power on off switch and fuse holder on back of base Tension adjustment collar behind focus...

Page 3: ...g to another location or shipped for repairs 156 Monocular Stand with head one eyepiece one rubber eyeshield three objectives condenser specimen holder blue filter dust cover 0 9mm L type key wrench for eyepiece socket set screw and tension adjustment collar and 2mm L type key wrench for rack stop adjustment 156 S Monocular Stand with head one eyepiece one rubber eyeshield four objectives condense...

Page 4: ...o 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 C 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...

Page 5: ...n handling the filter do not touch lens surfaces as fingerprints and smudges will result in poor images H Changing magnification a Rotate revolving nosepiece to position 10x objective into optical path b This microscope has been parfocalized which allows changes from one objective to another while requiring only a slight adjustment of the fine focus controls c When changing to the 40x and 100x obj...

Page 6: ...ye 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 2 MECHANICAL MAINTENANCE A The rack stop screw has been pre adjusted at the factory and should not require re adjustment However if you do attem...

Page 7: ...ages depress fuse cap and rotate turn to lock into fuse holder TROUBLESHOOTING PROBLEM REASON FOR PROBLEM SOLUTION Light fails to operate Outlet inoperative Have qualified service technician repair outlet AC power cord not connected Plug into outlet Lamp burned out Replace lamp Fuse blown Replace fuse 0 5 amp time delay 5mm dia X 20mm long Image does not remain in focus Stage of microscope drops f...

Reviews: