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ML7000 Series Metallurgical Microscope Instruction Manual
[12] Now adjust the aperture iris (using lever (c) on the incident illuminator), closing it down slowly while observ-
ing the field of view. A point will be reached where there is a sudden distinct drop in brightness of field of view.
When this occurs, open up the iris slightly, just until the brightness condition reverses, but no more.
[13] This procedure should be followed each time objectives are changed.
[14] The tension control knob is provided to allow the individial user to adjust the focus tension to his/her own
preference. Tension may be increased by turning the knob with a counterclockwise motion. A lighter tension
may be set by turning clockwise.
POLARIZING FACILITY
Polarizer
The Polarizing filter with mount
⑪
is used by inserting in one of the filter
⑫
slots on the vertical illuminator
when polarizing microscopy is required.
Slide-in Analyzer
The Analyzer
⑬
is mounted in an in-tube slider which moves the analyzer in and out of the optical path and
rotates between 0° and 90° by the lever
⑭
. When “in” and at 45 ° position, and with the polarizing filter in
the filter slot, these elements are said to be “crossed” and the field of view is said to be “extinguished”. In this
condition the field of view is dark - except for optically active elements in the field, which rotate the angle of
polarization and thus become visible against a dark background
