Checking The Extinction Of Light; Use Of Tint Plates - Optika Italy B-380 Serie Manuel D'instructions

10.2 Checking the extinction of light

1. Remove the specimen from the light path and
insert 10x objective.
2. Loosen the locking screw of the polarizer ① and
check that the scale is in the "0" position ②. (Fig.
17)
nsert rotatable analyser in the light path, loosen
3. I
the locking screw ③ and put the vibration scale
on 0° ④, then lock the locking screw ③. (Fig.
18)
4. Loosen the polarizer locking screw ① and rotate
the polarizer scale ② to obtain total extinction
(total dark in the eyepieces or "Crossed Nicol
position"). Tighten the screws ①. (Fig. 17)
• It may happen that the scale of the polarizer
is not perfectly aligned on the reference mark
but is shifted by one or two notches. This
is not a defect but is due to the mechanical
alignment of the polarizers during assembly.

10.3 Use of Tint plates

Three tint plates are supplied with the microscope:
• l plate (1 order Red)
st
• l/4 plate
• "Quartz wedge" plate (Q)
1. Put a specimen on the stage and focus.
2. Insert in the right slot of the Bertrand lens ⑤ one
of the tint plates ⑥. (Fig. 19)
3. In polarized light, inserting one of the plates will
have chromatic effects on the specimen.
• Using the l plate (also called 1
specimen will take a magenta tinge.
• Using the l/4 plate the specimen will take on a
colour tending to pale yellow.
• Using the Q plate the specimen will present a
series of coloured bands that will fade as the
plate is inserted.
order Red) the
st
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②
④
⑤
⑥
①
F ig. 17 F ig. 17
③
F ig. 18 F ig. 18
F ig. 19 F ig. 19