30
9. Measurement of solid sample
Note:
Fig. 9-6
Z (thickness direction)
Y
(machining direction)
X
X'
Y'
Z'
sample a
sample b
㸦
right angle to
machining direction
㸧
Double refraction film
(3) Masurement of double refraction samples
(3)-1 Conditions of sample
Referring to Fig. 9-6, make two sample
pieces a and b (different in X and Y axes
from each other as shown in the figure) by
cutting out the material to be measured for
double refraction (Carefully handle the
samples pieces a and b not to mistake
them for each other). Conditions (shape
and size, etc.) of samples should conform
to
the
measurement
conditions
of
glass-plastics and film samples.
Polymer film and so third have different
refractive indices in respective directions
of machining direction of the film (Y
axis), right angle to machining direction
(X axis) and thickness direction (Z axis)
as illustrated by Fig. 9-6.
This phenomenon is called "double
refraction", and Refractive Index must be
measured for each axis.
Measurement of double refraction needs the "Polarizing eyepiece" that is
supplied optionally.
(3)-2 Use of the polarizing eyepiece (optional),
contact liquid, and the test piece.
The samples which have double Refractive
Index can be measured by attaching the
polarizing eyepiece to the NAR-2T. The
polarizing eyepiece can be turned to change
the direction of polarization, which is
indicated by the dot as shown in Fig. 9-13 on
page 32.
Select the appropriate contact liquid and the
test piece depending on the expected
Refractive Index of the film or other solids
sample to be measured.
*Follow the measurement procedure for
glass-plastics and film samples.
