OPTO-EDU A15.2604, Manual

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b. Put the up analyzer in good position and rotate to 0°,then analyzer and polarizer should in
orthogonal position, field will become more darker from objective, otherwise should adjust the
analyzer.
You can determine mineral slice sample’s interference colors order, birefringence ,extinction
type , extinction angle, elongation sign etc through orthogonal polarizing angle , Also can
judge whether it’s crystal twin mineral.
c. Switch analyzer to 90°, the analyzer and polarizer in same direction, the polarizing light can
transmit completely if no sample on stage and can observe in bright field. If sample slice has
anisotropic material
(besides vertical optical axis ) also can observe interference color for complementary color, it is
different from orthogonal interference color.
d. Putting the polarizer out of optical path can achieve single polarizing observation.
Single polarizing light can observe and determine mineral’s outside characteristic(shape,
cleavage), optical properties of light absorption(color,diversity),optical properties related with
refractive index(processus, exasperate, edge, baker red
、
dispersion etc.)
e. Angular deflection of analyzer can enhance contrast when in
bright field.
f. According to sample’s interference pattern to choose suitable compensation slip(λ , λ/4,
quartz wedge) ,then insert the midbody slot, mark side is upward ,location notch is
backward(left is λ, right is λ/4,middle for normal observation). quartz wedge also in the same
notch.
λ( gypsum
、
first class red)slip can show first class purplish red in orthogonal polarizing light,
inserting optical path will higher or lower
the interference color lever, is appropriate for mineral with more lower interference color(below
second yellow).
λ/4(mica) can show first class grey interference color
，
inserting optical path will rise , drop
one interference color lever according to color spectrum
，
is appropriate for mine with more
higher interference color .
Insert quartz wedge in the optical path will appear interference color from one class to four
class from thin to thick in orthogonal interference condition.
g. Putting Bertrand lens shift slip in the optical path can make conoscopic observation.