background image

Iris diaphragm should not be used to control the brightness of illumination. Iris diaphragms are designed to 
help achieve high resolution of specimen and provide contrast in the image.  Smaller apertures will deliver 
higher contrast to image.  However, closing aperture too much will reduce resolution.  Experimentation is 
the best method of determining the correct opening of  diaphragm.  Some suggested openings for iris 
diaphragm are: 

 

OBJECTIVE

 

 

 

DIAPHRAGM OPENING

 

4x 

 

 

From fully closed to 1/8 open 

10x 

 

 

1/8 to 1/4 open 

40x 

 

 

1/4 to 1/2 open 

100x 

 

 

1/2 to 3/4 open 

 

G.  Usage of blue filter (one 32mm O.D. transparent blue filter has been provided with your microscope) 

 

a)  Placing a filter into the optical path will absorb some of the light from the illuminator base, limiting the 

light output.  Filters should only be used when they help enhance the image. 

 

b)  The fluorescent bulb in your microscope produces daylight type of illumination. Use of the transparent 

blue filter will produce a slightly blue light, and blue filter does not need to be used with this microscope 
under normal circumstances. 

 

c)  To insert filter, grasp filter holder knob and swing out filter holder, insert filter into slot provided and 

swing filter into optical path. 

 

d)  When 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 objective lens, care must be exercised when positioning these 

lenses into the optical path, in order to prevent damaging the front lens element and specimen slide. 

 

d)  In order to obtain maximum resolution of the 100x oil immersion lens,  it is necessary to apply 

immersion oil between the coverglass of slide and front lens of the objective. 

 

(1)  Use of a very small amount of immersion oil is required. 

 

(2)  All air bubbles must be removed from between lens and slide by gently rotating nosepiece back and 

forth. 

 

Objective Specification Chart

 

 

Objective 

N.A. 

Color Code 

Ring 

Field of 

View 

Working 

Distance 

Magnification with 

WF10X eyepiece 

Din 4X 

0.10 

Red 

4.5mm 

26.4mm 

40X 

Din 10X 

0.25 

Yellow 

1.8mm 

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 

 

I. 

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.  Use Windex to clean immersion oil off lens 
surfaces is recommended. 

 

Содержание 156

Страница 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 ...

Страница 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...

Страница 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...

Страница 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...

Страница 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...

Страница 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...

Страница 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...

Отзывы: