GEMSCOPE
UNITRON
®
73 Mall Drive, Commack, NY 11725 • 631-543-2000 • www.unitronusa.com
11
ADJUSTMENT & OPERATION
(continued)
Adjusting the Iris Diaphragm (Fig. 9)
The iris diaphragm restricts the diameter of the
beam of light entering the objective and
therefore excludes extraneous light to improve
image contrast. It can be adjusted by moving
the diaphragm control lever
.
Brightfield Illumination
Open the baffle by rotating the baffle control
knob
counterclockwise. Inclusions should
stand out as dark objects against a bright
background.
Darkfield Illumination
Close the baffle by rotating the baffle control
knob
clockwise. The stone is illuminated with
diffused light from the sides. View the stone
against the baffle’s black, non-reflective
background. Inclusions stand out as bright
objects.
Adjusting the Top Fluorescent Illuminator
(Fig. 10)
By turning the main switch
to “I” (on) and the
fluorescent lamp switch
to “I” (on), the top
illuminator will provide the equivalent of a
northern daylight overhead light source.
Fig. 9
Fig. 10
