Olympus U-CBE Instructions Manual page 16

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:
R
0
θ = Angle at the extinction position of the measuring point when the specimen is placed on
θ
0
│ θ – θ
When the values of both θ and θ
When the values of θ and θ
Example:
· θ = 25.4° (black), θ
│ θ – θ
· θ = 22.3° (green), θ
│ θ – θ
13
Retardation (nm) = R
= Compensator constant (This can be found in the attached data sheet.)
the stage.
= Angle when the field of view becomes dark when the specimen is not placed on the stage
(fiducial point)
│
0
= 0.5° (black)
0
│
= 25.4° – 0.5° = 24.9°
0
= 0.2° (black)
0
│
= 22.3° + 0.2° = 22.5°
0
· sin (2 ·
0
are indicated by digits of the same color → θ – θ
0
are indicated by digits of ditterent colors → θ + θ
0
│ θ – θ │
)
0
0
0