Olympus BHT User manual

OLYMPUS SYSTEMMICROSCOPE
Model BHT
OLYMPUS

This instruction manual has been written for the use of the Olympus System Microscope Model
BHT. It is recommendedthat you read the manual carefully inorder to familiarize yourself fully
with the use of the microscope, so that you can obtain optimum performance from it.
IMPORTANT
0 bserve the following points carefully:
Operation
1.
Always handle the microscope with the care it deserves, and avoid abrupt motions.
2.
Avoid the use and maintenance of the microscope in direct sunlight, high temperature and
humidity, dust and vibration.
3. Only use the tension adjustment ring for altering the tension of the coarse adjustment
knobs. (Donot twist the two coarse adjustment knobs in opposite directions simultaneous-
ly, as this will cause damage.)
4. Make sure that the voltage selector switch on the base plate is set to conform with the local
mains voltage.
5.
Make it a point of grounding the microscope to prevent electric accidents.
Maintenance
1. Lenses must always be kept clean. Carefully wlpe off oil or fingerprints deposited on the
lens surfaces with gauze moistened with
a small amount of xylene, alcohol or ether.
2.
Do not use organic solutions to wipe the surfaces of various components. Plastic parts,
especially, should be cleaned with neutral detergent.
3. Never disassemble the microscope for repair. Only authorized Olympus service personnel
should make repairs.
4.
The microscope should be covered with the vinyl dust cover provided and stored in a place
free from humidity and fungi. For extended storage it is recommendedto keep objectives
and eyepieces in desiccators, containing desiccants such as silica gel.

CONTENTS
... STANDARD EQUIPMENT
II. NOMENCLATURE
Ill. ASSEMBLY
...................................
IV. IDENTIFICATION AND FUNCTION OF VARIOUS COMPOhlENTS . .
V. OPERATION ..................................
A. Switching on the Light Source
1 voltage Adjustment and Light Intensity I
B.
Placement of a Specimen Slide
pizGq ...............
kwecimen Slide 1
.............. C. Observation Tube
1. lnterpupillary Distance Adjustment
2. Diopter Adjustment
3. Light Path Selector
D. Condenser Adjustment .
1. Condenser Centration
Field lris Diaphragm
I
Aperture lris Diaphragm I
E. Focusing Adjustment ............................
1. Tension of Coarse Adjustment Knobs and Fine Adjustment
l~seof Rubber Cap for Fine Adjustment Knob
/
2. Pre-Focusing Lever
3. Adjustment of Stage Block Height
F. Use of Immersion Objectives .....
G. Photomicrography
VI. OPTICAL DATA
VII. TROUBLESHOOTING . .

I. STANDARD EQUIPMENT
Component Model
I Line cord UYCP 1 111111
Microscope stand BHT-F
I Quintuple revolving nosepiece BH2-5RE 1 1 1 1 1 1 1
1
Observation tubes
Square mechanical stage with right-hand
low drive coaxial controls BH2-SVR
Abbe condenser BH2-CD 1 1 0
Condensers
--
Swing-out condenser BH2-SC 0 0
Halogen lamp holder LS-20H 1 1
1
Binocular tube BH2-B130
o---
Trinocular tube BH2-TR30
- -
Halogenbulbs 6V20WHAL 2
D Ach. 4X. D Ach. IOX,D Ach. 40X, 1
D Ach. 100X (oil) each
0 bjectives D Plan 4X. D Plan 10X.D Plan 40X
D Plan 100X (oil) 0
1
I Eyepieces WHKIOX 1 2 1 2 1 2 1
1
0
r Filter
1
0
Photo eyepiece
N F K3.3X
I Immersionoil, bottled 11111
0
1
1 VinyTdust cover
0 0
1

II. NOMENCLATURE
The Model BHT consists of various components and interchangeableaccessories as shown in the
photo below.
A wide variety of combinations, standard or optional, is availableaccording toyour
requirements.
Revolving
Objective
"I
Stage
Microscopestand
Observation tube
Halogenlamp
holder
Condenser
Base

- -
Ill. ASSEMBLY
This picture illustrates the sequential procedure of assembly. The numbers indicate the
order of assembly of various components. Remove dust caps before mounting components.
Take care to keep all glass surfaces clean, and avoid scratching the glass surface.
NOTE:
For numbers O @ and 0 please refer toexplanations indetail on the next page.
Eyepiece
Condenser clamping screw
Halogen bulb
Condenser
(The N.A. scale
engraved onthe con-
Microscope stand
denser should face the
microscope front.)
Line cord 0 Outlet

Explanations in detail
@ Mounting the stage
1) Loosen the stage clamping screw @ by
rotating counterclockwise. (Fig.
1)
2) Insert the stage into the mounting dove-
tail of the microscope stand slowly and
lock with clamping screw.
@ Mounting the revolving nosepiece
1) L-oosen the nosepiece clamping screw a.
(Fig. 2)
2) Aligning the nosepiece dovetail slide to
the mounting block
@ , push inthe nose-
piece slowly all the way.
NOTE: Do not tilt or rock the nose-
piece while inserting into the
mounting block.
@ Mounting the observation tube
1) Loosen the clamping knob @ fully. Pull
spring-loaded clamping knob
@ . This
will cause the locating pin
@ towithdraw.
(Fig.
3) If the pin does not, loosen the
screw further until the pin withdraws.
2) With clamping knob @ pulled out, insert
the circular dovetail of the observation
tube into the ring dovetail.
3) Tighten the clamping knob.
Fig.
1
Fig. 3

IV. IDENTIFICATION AND FUNCTION OF VARIOUS COMPONENTS
Light path selector knob
Tension adjustment ring
Clockwise rotation increases
coarseadjustment tension.
Specimenholder
Stage clamprngscrew
Loosen the screw and
the stage can be rotated
Coarse
adjustment knob
/ Coarseadjustment
range 26mm
Aperture ~ris
diaphragm ring
Condenser centering knobs
Y-axis low drive control
knob
Y excursion range 50mm
Voltmeter /
Fineadjustment knob
Graduated in increments
/ Slidinq voltaqe control lever
Voltage lowers as the lever is
pulledtoward the microscope
front.

Photo tube
Condenser height
adjustment knob
Pre-focusinglever
7 Filter mount
L~necord
adjustment
Arrow mark 6 +O indicates
increase
in diaphragm diameter.

Summary of Putting the Microscope into Operation
Model
BHT
Match the voltage selector switch to local mains voltage (page 9).
Switch on the light source (page 9).
Place a specimen slide on the mechanical stage (page 9).
Coarse focus with the 1 OX objective (page 10. 13).
Make interpupillary distance and diopter adjustments (page 11).
Adjust the condenser position (page 12).
Swing in the desired objective.
Adjust light intensity.
Fine focus.
Adjust aperture iris diaphragm and field iris diaphragm (page
12).
Adjustment of Illumination System for Various Objective Powers
I
1 Condenser 1
Compatible Swing intop
lens
Objective
1 magnification
*N.A. is somewhat low, but st111compatible with a 100X objective.
(Cut off this page at dotted line and put iton the wall near the microscope for use as a reminder of micro-
scopic procedure.)
Achromatic-
condenser
BH2-AAC
OLYMPUS
Abbe
condenser
BH2-CD
Swing-out
condenser
BH2-SC
Low power
condenser
BH2-UL-C

V. OPERATION
A. Switching on the Light Source
1) Ascertain that the voltage selector switch @
is set to conform with the local mains volt-
age. (Fig.
4)
If the switch is not correctly set, adjust itby
means of the Allen wrench provided or a
screwdriver.
2) Place the sliding voltage control lever on the
right side of the microscope base to
a posi-
tion closest to you (low voltage position).
Switch on the light source. (Fig. 4)
Voltage Adjustment and Light Intensity
1
As you pushthecontrol leverainthe direc-
tion of the arrow in order to obtain increas-
ing intensity (Fig.
5), the LED readout @
will display the lamp voltage.
B.
Placement of a Specimen Slide
1) Rotate the coarse adjustment knobs in
the direction of the arrow to rack down the
stage so that a specimen slide can be placed
on the stage. (Fig.
6)
NOTE: The rotation of the coarse and fine
adjustment knobs inthe direction of
the arrow will rack down the stage.
2) Opening the spring-loaded finger of the
specimen holder with one hand, place a
specimen slide inside the holder. (Fig. 7)
When the slide comes in contact with the
back of the specimen holder, slowly return
the spring-loadedfinger.
WARNING:
If the spring-loaded finger is
returned quickly, it may cause
damage to the specimen slide.
I -
Fig. 4
Fig. 5
Fig. 6
Fig. 7

I Cover Glass I
An Olympus objective engraved "160/0.17" requires a cover glass of 0.17mm thickness.
If the numerical aperture of the objective is 0.7 or higher (except immersion objectives) and
no correction collar is provided, the resolving power deteriorates to a great extent if cover
glass thickness deviates from the above listed value.
IVOTE: Insome countries a 0.17mm cover glass correspondsto adesignation of #I%.
A cover glass (0.4mm thick) for blood counting, etc. can be used withOlympus objectives
except
D Plan 40X, S Plan Apo 40X and S Plan 100X.
1 Specimen Slide (
Specimen slides 0.8 mm to 1.5 mmthick are
recommended for Olympus objectives.
Specimen slides 0.8 mm to
1.2 mm thick are
recommended for the darkfield condenser
and the differential interference contrast con-
denser.
3) Bring the portion of the specimen for obser-
vation into the light path by means of the
low drive control knobs. (Fig.
8)
* Tighten the stage clamping screw @ in the
microscope front.
1 stage 1
The specimen holder can accommodate two
standard specimen slides simultaneously.
The specimen holder is removable to obtain
a large unobstructed stage surface to hold
specimens up to 55 mm x 85rnm.
To rotate the stage loosen the stage clamping
screw
@ and holding this screw, rotate the
stage into the desired direciton. (Fig.
9)
Q Stage clips for use withimmersion objectives.
(Fig. 10)
A pair of stage clips are optionally available
to hold the specimen on the stage, eliminat-
ing a specimen drag caused by immersion oil
between slide and stage surface. The clips
can be inserted into the holes
@ provided
on the specimen holder.
Fig. 9
Fig. 10

Observation Tube
lnterpupillary Distance Adjustment
1) Click the 10X objective into position.
2) Looking through the eyepieces with both
eyes, adjust the interpupillary distance of
the binocular tube by adjusting the
knurled dovetail slides
@ of the right and
left eyepiece tubes with both handsuntil
perfect binocular vision is obtained. (Fig.
11)
Diopter Adjustment
1) Look at the image through the right eye-
piece with your right eye and focus on
the specimen with the fine adjustment
knobs.
2) Next, look at the image through the left
eyepiece with your left eye and rotate the
diopter adjustment ring
@ to focus on
the specimen without using the coarse
and fine adjustment knobs.
(Fig. 12)
Light Path Selection
1) The trinocular tube is provided with a
light pathselector knob todirect the light
to the observation tube andlor to the
photo tube in 3 positions. (Fig.
13)
Fig. 12
Fig. 13
I
1
/ 100% into binocular tube 20% into binocular tube
1
into photo tube I
80%into ~hototube
Knob Position
Pushed in all the way
(V)
Applica-
tion
@ Observation
@ Dark specimens
Pulledout halfway
(C. V.)
Photomicrography (fo-
Pulledout all the way
(C)
1
The indicator plate is provided at the knob port to summarize the usage of the above
table; it can be consulted before operating the knob.
V: Viewer (whiteletter)
CV: Camera
& viewer (yellow-green letters)
C: Camera (red letter)
The colors of the letters correspond with the color bands on the knob shaft.

D. Condenser Adjustment ,
1. Condenser Centration
1) Stop down the field iris diaphragm with
knurled ring
@ by rotating in the direc-
tion of the arrow. (Fig.
14)
2) Use the condenser height adjustment
knob
@ to move the condenser up and
down until an image of the field dia-
phragm can be seen clearly in the eye-
pieces. The rotation of the knob in the
direction of the arrow lowers the con-
denser.
Field iris
diaphragm image Fieldof view
-7g+('J
Fig. 15
3) Bring the field iris diaphragm image into the center of the field of view with the two con-
denser centering knobs
@. (Fig. 14)
4) Widen the diameter of the iris diaphragm progressively. Ifthe polygonal image of the iris
diaphragm becomes inscribed in the field it means that the field diaphragm
is centered.
(Fig. 15)
Field Iris Diaphragm
The field iris diaphragm controls the diameter of the ray bundle impining on the speci-
men surface and therefore, by stopping down the field diaphragm until it
is slightly
larger than the field of view, it can reduce stray light,which in turn increases image defi-
nition and contrast.
In order to achieve optimum objective performance, the opening of the aperture iris
diaphragm should be matched to the numerical aperture of the objective in use. It is
often preferable, however, to stop down the aperture diaphragm slightly more than in-
dicated by the objective N.A. This will result inbetter image contrast, increaseddepth of
focus and a flatter field.
After completing focus adjustment, re-
move one of the eyepieces from the ob-
servation tube and look into the empty
eyepiece tube. As you stop down the
aperture iris diaphragm, the image of the
iris diaphragm can be seen in the object-
ive pupil. Adjust the opening of the
diaphragm to match the N.A. of the ob-
jective in use. If the specimen is low in
contrast, itis recommended to stop down
to
70% -- 80% of the objective N.A. (Fig.
16)
Opening of the
aperture diaphragm
Objective exit pupil
I
Fig. 16

Focus Adjustment
Tension
of Coarse Adjustment Knobs and
Fine Adjustment.
Although the tension of the coarse adjust-
ment knobs has been already adjusted for
optimum performance by the manufacturer,
'3
'i
it is possible to personally adjust the tension
of the coarse adjustment for either heavy or
light movement depending on the operator's
la
rr
preference by rotating the tension adjust-
ment ring
@. (Fig. 17)
Fig. 17
The ring can be rotated by inserting a screwdriver intoone of the holes on the periphery of
the ring. The clockwise rotation (in the direction of the arrow) tightens the coarse adjust-
ment knobs. Do not loosen the ring too much, because the stage may drop or the fine
adjustment knobs may slip.
NOTE: Do not rotate the right and left coarse adjustment knobs in the opposite directions
simultaneously. If the stage drops and the specimen goes out of focus, the tension
adjustment ring is too loose. Tighten the ring.
I Use of Rubber Cap for Fine Adjustment Knob I
-b
Attaching this cap over the fine adjustment
knob increases the sensitivity of the fine focus-
ing motion. (The rubber cap isoptionally avail-
able.)
2. Pre-Focusing Lever
This lever
@ is provided to prevent possible
contact between specimen and objective as
well as to simplify coarse focusing. (Fig.
18)
The lever is locked after coarse focus has
been accomplished. This prevents further
upward travel of the stage by means of the
coarse adjustment knobs, and automatically
provides a limitingstop if thestageis lowered
and then raisedagain. The pre-focusing lever Fig.
10
does not restrict fine focusing.
3. Adjustment of Stage Block Height
In addition to the vertical movement of the
stage by means of coarse and fine adjust-
ments, the stage block height can be changed
for observation of specimens 'which are
thlcker than standard slides, e.g. chambers,
flasks, etc. with much larger thickness.
The stage block height can be adjusted by
loosening the stage block locking screw
@
Fig. 19
with the Allen wrench provided and retightening itat the upper position.Then, dislocate the
lower limit stop pin beneath the stage block into a lower tapped hole. After lowering the
stage block, reclamp the stage block locking screw
a. (Fig. 19)

F. Use of Immersion Objectives
1) Focus the specimen with a low power objective.
2) Put a drop of immersion oil on the specimen slide and the front lens of the immersion
objective.
3) Turn the revolving nosepiece to bring the immersion objective into the light path, and focus
with the fine adjustment knobs.
NOTE:
@ For immersion condensers such as an achromatic-aplanatic condenser or Abbe
condenser, remove the specimen from the mechanical stage and place a drop of
immersion oil on the front lens of the condenser. Then, place the specimen on
the stage and slowly raise the condenser until firm contact with the undersideof
the specimen slide
is made.
@Care should be taken to prevent oil bubblesfrom forming in the oil
film between
condenser and specimen slide. If any, re-apply immersion oil, for these bubbles
greatly deteriorate the lens performance.
@After use carefully wipe off the immersion oil deposited on the lens surfaces
with gauze moistened with xylene. Never leave oil on the lens surfacesafter use
as oil remnants will seriously impair the performance of the lens system.
G. Photomicrography
The Olympus Photomicrographic Equipment Model PM-IOAD is uniquely qualified to be
used with the BHT microscope for routine and advanced photomicrography. A separate,
detailed instruction manual
is available for the PM-TOAD camera system.
For quick reference, however, you may want to refer to the following pointerswhen using
the PM-IOAD.
1. Photographic Eyepiece
Use
NF K photo eyepieces for photomicro-
graphy.
Insert the eyepiece into the eyepiece tube of
the photo tube. (Fig.
20)
Fig. 20
2. Mounting the Photographic Unit
Slip the body of the photographic unit over the
photo tube. Align the dotson photo tube and
the PM-1OAD body and clamp the camera unit
to the photo tube. (Fig.
21)
3. Setting the Light Path Selector
Refer to section C.3. on page
11.
Fig. 21

4. Focusing Procedure
Use the field of view eyepieces for focusing on the fiIm plane. Each field of view eyepiece
has a focusing front lens and a reticle with
4 frames, each frame indicating thearea covered
by a specific power NFK photo eyepeice. (Fig.
22).
The number at each frame indicates the
magnification of the photo eyepiece. The
,:f;~l
i,mage in the field of view eyepiece and the
i') -- --
image on the film plane are in focus at the
&.' JJLll
same time. Several type field of view eye-
pieces are available, according to the film
size employed. Fig. 22
1) Select the field of view eyepiece matching the camera back in use and insert it into the
right eyepiece tube of the trinocular tube, aligning locating groove and locating pin.
2) While looking through the field of view eyepiece, rotate the eyepiece front lens inscrew
mount to focus on the double cross lines inthe field. For sharp focusing with objectives
4X or lower, the focusing magnifier FT is recommended.
Fieldof view eyepiece
Attachment camera
3) Bring the specimen detail to be photographed within the frame corresponding to the
power of the NFK eyepiece in use and focus on the specimen with the microscope fine
adjustment knobs. Make sure the light path selector knob on the observation tube is
either on the white (V) or yellow-green (CV) band.
PWHKIOX
3%" x 4%"
Polaroid
Back
35WHK10X
35mm Back
4) It is recommended to tighten the tension adjustment ring considerably to prevent the
stage from dropping during long exposures.
4X5WHKlOX
4" x 5"
Sheet Filmor
Polaroid Film
Holder
MHWHKIOX
16mm Bolex
camera
120 Roll Film
Holder

VI. OPTICAL DATA
* Immersion objectives
The resolving power and focal depth are obtained with fully opened aperture diaphragm.
D Achromat
WHKlOX
(Field
number
Technical terms:
D Plan Ach.
Working distance: The distance from the cover glass to the nearest point of the
objective.
lOOX*
1.30
0.20
1.91
0.26
20)
Field of
view
(mm)
2
Total mag. 40X 100X 400X
Numerical aperture: The N.A. represents a performance number which can be com-
pared to the relative aperture (f-number) of a camera lens. The
N.A. values can be used for directly comparing the resolving
powersof all types of objectives. The larger the N.A., the higher
resolving power.
4X
0.10
7.03
34.23
3.36
40X
0.65
0.6
4.58
0.52
Focal
depth
(PI
.
Resolving power:
Focal depth:
40X
0.65
0.27
4.67
0.52
1OX
0.25
7.4
17.5
1.34
10X
0.25
7.2
16.9
1.34
0.10
W.D.
(mm) 18.2
Focal length 30.03
The ability of a lenstoregister small details. Theresolving power
of a lens is measured by its ability to separate two points.
10OX1
1.25
0.17
1.75
0.27
Eyepiece
171.6
The distance between the upper and lower limits of sharpness in
the image formed by an optical system. As you stop down the
aperture iris diaphragm, the focal depth becomes larger. The
larger the N.A. of an objective the shallower the focal depth.
Field number: A number that represents the diameter in mm of the image of
the field diaphragm that is formed by the lens in front of it.
Field of view diameter: The actual size of the field of view in mm on theobject surface.
Resolving
power (fi)
27.45
3.36
3.0 0.7 171.6 27.45 3.0 0.7

VII. TROUBLESHOOTING
If you are unable to obtain full performance from your microscope, please consult withthe
table below as pointers for troubleshooting.
I Phenomenon
Cause
Remedy
I 1. Optical System I
I
a) With illuminator switched I Field iris diaphragm is not I Open diaphragm to proper
on, the field of view is
dark.
b) Fieldof view is cut off or
illuminated irregularly.
1 mounted.
pulled out to C position.
Light path selector lever is
place.
Nosepiece is not correctly
I microscope frame all the way,
position.
Click it into proper position
stopped midway.
Nosepiece is not clicked into itclicks into place.
Insert nosepiece dovetail into
1 I then lock.
according to your purpose.
Slightly rotate nosepiece until
1 Condenser is not centered. ( Center condenser. I
The power of objective used
exceeds the illumination ca-
pacity of condenser.
Field irisdiaphragm isstopped Open diaphragm to proper
down excessively. diameter.
Choose a condenser to meet
your purpose.
c) Dust or dirt is visible in Removedust, etc.
the field of view. 'lean
front lenses.
1 Dirty specimen. I
I ~uston eyepiece. I
d) Excessive image contrast. Condenser is lowered too Adjust condenser height.
much.
1
Aperture iris diaphragm is
stopped down excessively. Open diaphragm to proper
diameter.

lmage is not sharp.
Insufficient contrast. microscopeframe all the way,
lmage details lack defi-
nition.
positioned in the light path.
Phenomenon
e) Resolution problems:
I Objective correction collar is I Rotatecorrection collar, keep-
I not adjusted.
1 ing specimen in fine focus
Cause
Non Olympus objectives are
used.
until optimum resolution is
Remedy
Use Olympus
LB series objec-
tives.
I used with immersion oil.
1
1 Olympus is not used. 1 1
Bubbles in immersion oil.
Immersion oil designated by
Remove bubbles (and reap-
plyoil).
Use Olympus immersion oil.
out of focus, or image is
1 mounted. ( microscopeframe all the way,
f) Field of view is partially
partly out of focus.
1 1 then lock.
Objective is not correctly
positioned in the light path.
Dirty specimens.
Dust on condenser lens.
Nosepiece is not correctly
Slightly rotate nosepiece until
itclicks in place.
Clean.
lnsert nosepiece dovetail into
Specimen is not correctly
positioned on stage. Place specimenslide correctly
on stage, and place stage clips
open it.
lnsert nosepiece dovetail into
microscopeframe all the way,
then lock.
g) Specimen image is partial-
ly out of focus.
Objective is not correctly
positioned in the light path.
Nosepiece is not correctly
mounted.
Slightly rotate nosepiece until
itclicks into place.
h) Field of view becomes
2. Electric System
only slightly brighter by
increasing voltage.
I a) Illuminator is too bright I Line voltage selector switch
Condenser is not centered.
Condenser is not correctly
I
(or too dark) even when I is not matched with local
Center condenser.
Center condenser.
centered.
Condenser is lowered too
mainsvoltage
b) Voltage for illuminator
cannot be raised.
Adjust condenser height.
1
Match selector switch to
mainsvoltage.