Checking The Extinction Of Light; Use Of Tint Plates - Optika Italy B-380 Serie Manual De Instrucciones

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