Observation
1. Selecting the objective
Rotate the nosepiece and switch to the objective with the desired magnification.
After changing the objective adjust the condenser aperture and field diaphragm to suit the objective. |
2. Adjusting the aperture
diaphragm
|
Normally, if the aperture diaphragm is closed to 70-80%
of the numerical aperture of the objective then a clear
image with reasonable contrast will be obtained. The scale
on the condenser aperture diaphragm ring shows numerical
aperture (N.A.), so adjust the condenser aperture diaphragm
ring in accordance with the scale.
The numerical aperture of every objective is indicated on
the side of the objective.
40X/0.65X magnification 40X, numerical aperture 0.65 |
3. Adjusting the field diaphragm
The field diaphragm restricts the illumination light to the observation area
of the specimen. If it is opened more than necessary it will
result in reduced contrast due to stray light.
Whenever the objective is changed, rotate the field diaphragm
ring and adjust the field diaphragm image so that it is circumscribed
by the surrounding field of view. |
4. Adjusting the illumination
| If the
magnification of the objective is increased then the field
of view becomes darker. Adjust the illumination with the brightness
adjuster as necessary. Note that when the illumination changes
the color tone also changes at the same time. If the voltage
is turned down, the illumination darkened red tones increase.
If the voltage is turned up and illumination increased, then
blue tones increase. In order to maintain a specific tone
an ND filter is used to adjust the illumination. |
Turning off the lamp
Turn off the power switch and the lamp will be turned off. |