Olympus U-CBE User manual

A X 5 8 9 4
INSTRUCTIONS
COMPENSATORS
This instruction manual is for the Olympus Compensators. As this manual pertains only to the compensators,
also refer to the instruction manual for your polarizing microscope (BX53/BX53M-P or CX31-P) so that you
understand the operating procedures of the entire system.
To ensure the safety, obtain optimum performance and familiarize yourself fully with the use of these units,
we recommend that you study this manual thoroughly before using them.
Retain this instruction manual in an easily accessible place near the work desk for future reference.
Optical Microscope Accessory

IMPORTANT
These units employ a UIS2/UIS (Universal Infinity System) optical design, and should be used only
with a microscope, eyepieces, objectives and condenser matching the UIS/UIS2 optics.
Less than optimum performance may result if inappropriate accessories are used.
1Getting Ready
1. A compensator is a precision instrument. Handle it with care and avoid subjecting it to sudden or severe
impact.
2. Do not use the compensator where it is subjected to direct sunlight, high temperature and humidity,
dust or vibrations.
(Working environment ambient temperature and humidity should be in the range of 0-40 °C and 30-
90%, respectively. Temperature at storage location should never be allowed to get below -10 °C).
1. To clean the lenses and other glass components, simply blow dirty away using a commercially
available blower and wipe gently using a piece of cleaning paper (or clean gauze). If a lens is stained
with fingerprints or oil smudges, wipe it gauze slightly moistened with commercially available absolute
alcohol.
!Since the absolute alcohol is highly flammable, it must be handled carefully.
Be sure to keep it away from open flames or potential sources of electrical sparks --- for
example, electrical equipment that is being switched on or off.
Also remember to always use it only in a well-ventilated room.
2. Do not disassemble any part of the compensator.
If the equipment is used in a manner not specified by this manual, the safety of the user may be imperiled.
In addition, the equipment may also be damaged. Always use the quipment as outlined in this instruction
manual.
2Care and Storage
3Caution

1 OUTLINE 1
2 NOMENCLATURE 2
3 ASSEMBLY 5
4 PREPARATION AND MEASUREMENT 7
4-1
Berek Compensator (U-CBE), .............................................................................................................................................................................7
Thick Berek Compensator (U-CTB)................................................................................................................................................................7
4-2 Brace-Köhler Compensator (U-CBR1, U-CBR2)............................................................................................................11
4-3 Quarts Wedge (U-CWE2)....................................................................................................................................................................14
4-4 Senarmont Compensator (U-CSE).............................................................................................................................................16
CONTENTS

1
1OUTLINE
Compensators are used for measuring the retardation in specimens with double refraction. Some
compensators* may also be used to enhance image contrast in polarized light observation. The following
table shows the retardation measuring range of the various compensators.
Measuring Range of Compensators
Compensator Name Measuring Range
Thick Berek (U-CTB) 0 -- 20 λ
Berek (U-CBE) 0 -- 3 λ
Quartz Wedge (U-CWE2) 1 -- 4 λ
* Senarmont Compensator (U-CSE) 0 -- 1 λ
* Brace-Köhler Compensator 1/10 λ(U-CBR1) 0 -- 1/10 λ
* Brace-Köhler Compensator 1/30 λ(U-CBR2) 0 -- 1/30 λ
λ= 546.1 nm (e-line)

2
U-CBE, U-CTB
2NOMENCLATURE
Berek Compensator (U-CBE)
Thick Berek Compensator (U-CTB)
Compensator
Scale 2
One turn equals 10°
(minimum reading 0.05°)
Compensator knob
Scale 1
0-60°
(minimum reading 10°)
* The illustration shows the U-CTB. The U-CBE’s γaxis direction is different.

3
U-CBR1, U-CBR2
Brace-Köhler Compensator
(U-CBR1, U-CBR2)
Compensator Scale 2
One turn equals 20°
(minimum reading 0.1°)
Compensator knob
Scale 1
40-0-40°
(minimum reading 20°)
* The illustration shows the U-CBR2. The U-CBR1 is the model with the same design
as the U-CBR2 but only the product name is different.

4
U-CWE2, U-CSE
Quartz Wedge
(U-CWE2)
Senarmont Compensator
(U-CSE)
Compensator
Compensator
Retardation indication

5
} The assembly method is the same for all the compensators.
The compensator is designed to be inserted in the test plate
adapter (U-TAD) or polarization attachment (U-PA).
With U-TAD
1. Loosen the clamping knob @ at the front of the revolving
nosepiece and remove the dummy slider.
2. Insert the test plate adapter (U-TAD) ² and tighten the
clamping knob @.
3. Loosen the test plate adapter clamping knob ³ and insert
the compensator | as far as the click-stop position (where
the compensator is not engaged into the light path), then
tighten the clamping knob ³.
With U-PA
1. Disengage the Bertrand lens from the light axis.
2. Engage the analyzer in the light path and set the rotary scale
to position “0”.
3. Push in the compensator as far as it will go, and then pull it
slightly out until it stops in the click position.
# If the compensator is inserted at a tilted position, it
may impinge against the insertion slot. Always set to
position 30°.
} When measuring, insert the compensator one step further
to position it in the light path.
Preparation for Measuring
} Preparation for measuring is the same for all compensators.
Fig. 1
3ASSEMBLY
@
²
³
|

6
Perform the cross-Nikol adjustment and the eyepiece cross
line alignment as described in the instruction manual for the
polarizing microscope (BX53/BX53M-P or CX31-P).
Note on Measuring:
} Measuring is usually performed with the condenser’s top-lens swung out and the aperture iris
diaphragm stopped down. If it is required to maintain brightness and resolution, the top-lens should
be left engaged although measuring accuracy will decrease.
} When measuring retardation, backlash error may occur when the compensator knob is rotated (U-CBE,
U-CTB, U-CBR1, U-CBR2). Accordingly, keep the rotation direction always uniform. If the knob is rotated
too far, turn it fully back and restart rotation by keeping the direction uniform till the measured portion.
1Adjusting the Extinction

7
U-CBE, U-CTB
4PREPARATION AND MEASUREMENT
1. Position the specimen on the rotatable stage (U-SRP) and
focus on the specimen.
} Do not use the interference filter in this adjustment.
1. Rotate the stage until it attains the position of extinction
(position where the observed portion of the specimen looks
darkest).
2. Rotate the stage further by +45° and then clamp it.
3. Rotate the compensator knob and set the U-CBE or U-CTB
scale to position 30°.
4. Insert the U-CBE or U-CTB into the test plate adapter (U-TAD)
or polarization attachment (U-PA) as far as it will go.
Measuring
} If an interference filter (IF 546 or IF 550) is available, use of
this filter will improve measurement accuracy.
1Adjusting the Extinction
4-1 Berek Compensator (U-CBE), Thick Berek Compensator (U-CTB)
2Adjusting the Rotation Position
Fig. 2-1
Fig. 2-2
Interference
fringe

8
U-CBE, U-CTB
4-1 Berek Compensator (U-CBE), Thick Berek Compensator (U-CTB)
5. Rotate the compensator knob and confirm that the measured portion on the center of the specimen is
dark as shown in Fig. 2-1 (Note). If it is not dark, rotate the stage by -90° and clamp.
(Note) Instead, a black interference may be observed with certain specimens (Fig. 2-2).
If the black fringe does not intersect the center of the field of view even after rotating
the stage 90°, the retardation of the specimen is outside the measurable range, and
measuring with the U-CBE or U-CTB is not possible. (See page 1)

9
U-CBE, U-CTB
} If an interference filter (IF 546 or IF 550) is available, use it
in this measurement.
1. Place an interference filter in the filter holder of the microscope
frame.
# If an interference filter is used, multiple black dots or
fringes will be visible. Use the black dot or fringe that
is visible when the interference filter is not used.
To identify this dot or fringe, check the position of
the black dot or fringe without using the filter before
engaging it, then engage the interference filter and
confirm the same black dot.
2. Rotate the compensator knob to the position where the
measured portion on the center of the field of view is darkest
(Fig. 3) Find the angle at this position by totaling the readings
of scales 1 and 2. →θ1
3. Rotate the compensator knob in the opposite direction and
read the angle of the position with which the measured
portion on the center of the field of view is darkest in the
same manner as in step 2 above. →θ2
4. Repeat steps 2 and 3 several times, obtain the mean value
of θ1, θ1, and that of θ2, θ2, and finally find the overall mean
value θusing the following formula:
θ = 2
│θ1– θ2│
3Measuring Retardation
Fig. 3

10
U-CBE, U-CTB
5. After finding the mean value θ, use the conversion table provided with the compensator to find the
retardation. The formula on the next page may also be used to find the retardation.
# If on interference filter is used, use the data on the e-line of the conversion table.
Retardattion (nm) = C · │1 / ε2 –1 / ω2│
2│1–sin2 θ/ ω2 – 1–sin2 θ/ ε2│
C = Invariables of compensator =
ω, ε: Ordinary ray, extraordinary ray refraction
d : Prism thickness of compensator
Shown in
the attached
conversion table.
d · ω1 1
2ε2ω2
F – line
λ= 486.1 nm
e – line
λ= 546.1 nm
d – line
λ= 587.6 nm
C – line
λ= 656.3 nm
U-CBE ω=
ε=
1.38020
1.39211
1.37859
1.39043
1.37774
1.38954
1.37662
1.38838
U-CTB ω=
ε=
1.66820
1.49092
1.66158
1.48762
1.65836
1.48633
1.65437
1.48459

11
U-CBR1, U-CBR2
4-2 Brace-Köhler Compensator (U-CBR1, U-CBR2)
Measuring the Fiducial Point
1. Insert the U-CBR1 or U-CBR2 into the test plate adapter (U-TAD) or polarization attachment (U-PA) as
far as it will go.
2. Rotate the compensator knob to obtain extinction. At this point, find the angle by totaling the readings
of Scales 1 and 2. →θ0
3. Pull out the U-CBR1 or U-CBR2 to remove the compensator from the light path again.
Measuring
} If an interference filter (IF 546 or IF 550) is available, use of this filter will improve measurement accuracy.
1Specimen Placement
1. Position the specimen on the rotatable stage (U-SRP), in such a manner that the specimen center portion
coincides with the intersection of the eyepiece cross lines, and focus on the specimen.
2Measuring Retardation
1. Place an interference filter (IF 546) in the filter holder on the light exit of the microscope.
2. Rotate the stage until it attains the extinction position (where the observed portion of the specimen
becomes dark).
3. Rotate the stage by +45° and then clamp it.
4. Loosen the test plate adapter (U-TAD) clamping knob, and insert the U-CBR1 or U-CBR2 as far as it will
go. Then tighten the clamping knob.

12
U-CBR1, U-CBR2
5. Rotate the compensator knob to adjust in such a manner that
the point to be measured on the specimen attains extinction.
At this point, read the angle. →θ
· If the reading on Scale 1 is indicated by black digits
Read the white digits on Scale 2.
· If the reading on Scale 1 is indicated by green digits
Read the green digits on Scale 2.
} Find the angle by totaling the readings of Scales 1 and 2.
(Tip)
γaxis direction (vibration direction in which the
speed of the light becomes slower) when the
specimen became dark when the digits on
Scale1 were rotated towards the black digits.
γaxis direction when the specimen became
dark when rotating in direction of the green
digits.
Insertion
direction
of slider
Insertion
direction
of slider

13
U-CBR1, U-CBR2
If the specimen does not become dark even after rotating the stage, the retardation of the
specimen is outside the measurable range, and measuring with the U-CBR1 or U-CBR2
is not possible. (See page 1)
6. To find the retardation, insert the read angles into the following formula:
Retardation (nm) = R0· sin (2 ·│θ– θ0│)
R0= Compensator constant (This can be found in the attached data sheet.)
θ = Angle at the extinction position of the measuring point when the specimen is placed on
the stage.
θ0= Angle when the field of view becomes dark when the specimen is not placed on the stage
(fiducial point)
│θ– θ0│
When the values of both θand θ0are indicated by digits of the same color →θ– θ0
When the values of θand θ0are indicated by digits of ditterent colors →θ + θ0
Example:
·θ = 25.4° (black), θ0= 0.5° (black)
│θ– θ0│= 25.4° – 0.5° = 24.9°
·θ = 22.3° (green), θ0= 0.2° (black)
│θ– θ0│= 22.3° + 0.2° = 22.5°

14
U-CWE2
4-3 Quarts Wedge (U-CWE2)
Measuring (Note) Do not use the interference filter (IF 546 or IF 550) in the following measurement.
Otherwise, the measurement will not be possible.
1Specimen Placement
2Adjusting the Rotation Position
1. Position the specimen on the rotatable stage (U-SRP) and focus on the specimen.
1. Rotate the stage until it attains the extinction position (where the observed portion of the specimen be-
comes dark).
2. Rotate the stage further by +45° and then clamp it.
3. Insert the U-CWE2 into the test plate adapter (U-TAD) or polarization attachment (U-PA). Slide the U-CWE2
and check whether there is a position where the specimen becomes dark. Note that, when the 4X or 10X
objective is used, the specimen does not become dark even in the right position unless the aperture iris
is stopped down. If the specimen cannot be made darker by stopping down the aperture iris, rotate the
stage by -90° and clamp it.
If the specimen does not become dark even after rotating the stage 90°, the retardation
of the specimen is outside the measurable 1-4 λrange, and measuring with the U-CWE2
is not possible. (See page 1)

15
U-CWE2
} The U-CWE2 indicates retardation values (1 to 4 λ) using
two scales on the side. Read the reading of the scale for
the module used (U-TAD or U-PA).
1. Slide the U-CWE2 and adjust so that the measuring point
on the specimen becomes dark.
2. At this point, note the value indication on the side of the
U-CWE2 seen at the edge of the adapter. This reading shows
the approximate range of the retardation at the measuring
point. (Arrow indicated position Fig. 4)
3. Based on this estimate and using the interference color chart
(*), find the retardation by comparing the background color
outside the measuring point and the color at the measuring
point when the U-CWE2 is removed from the optical path.
(*) Download the file of interference color chart from OLYMPUS
webside (below mentioned URL).
http://www.olympus-ims.com/microscope/bx-pol-chart
The downloaded file includes multiple interference color
charts which differ depending on the type of light source
unit. Select the interference color chart applicable to your
light source unit.
3Measuring Retardation
Fig. 4

16
U-CSE
4-4 Senarmont Compensator (U-CSE)
Measuring } Always use interference filter (IF 546 or IF 550). If interference filter is not used,
measurement will not be possible.
# Due to its high detection sensitivity, use of the IF546 interference filter is recommended.
1Adjusting of Analyzer Angle
# Perform the following adjustment with no specimen positioned on the stage.
1. Insert the U-CSE into the test plate adapter (U-TAD) or polarization attachment (U-PA) as far as it will go.
2. Fine adjust the polarizer of the condenser (U-POC) to obtain complete extinction.
3. Then fine adjust the rotatable analyzer (U-AN360P) to obtain complete extinction.
4. Repeat the steps 2 and 3 about 3 to 5 times.
5. At this point, read the analyzer’s final angle. →θ0

17
U-CSE
2Specimen Placement
1. Position the specimen on the rotatable stage (U-SRP), in such a manner that the specimen center portion
coincides with the intersection of the eyepiece cross lines, and focus on the specimen.
3Adjusting the Fiducial Point
4Adjusting the Fiducial Point
1. Rotate the stage and adjust so that the measured portion on the specimen becomes dark.
2. Rotate the stage by +45° and then clamp it.
3. Pull out the U-CSE from the test plate adapter (U-TAD) or polarization attachment (U-PA), push the test
plate (U-TP530) into the U-TAD or U-PA and confirm that the interference color of the measured portion
changes from the sensitive color to blue. If the color changes to red-orange-yellow instead of blue, rotate
the stage by -90° and then clamp it. Now pull out the test plate from the U-TAD or U-PA.
1. Place an interference filter in the filter holder on the light exit of the microscope.
2. Rotate the analyzer dial and adjust so that the measuring point on the specimen becomes dark.
3. At this point, read the analyzer’s angle. →θ
4. Find the retardation by using the following formula:
Retardation (nm) = 180°
546 X │θ– θ0│