The Petrographic Microscope Flashcards
used to measure
displacement in any direction
Potentiometer:
accommodates the
lamphouse, which contains a 50-
100W high-energy tungsten-halogen
lamp, and sometimes a transformer
and a potentiometer
BASE
trades voltage for
current in a circuit, while not affecting
the total electrical power
Transformer:
used to
dynamically adjust the LED
brightness to suit changing ambient
illumination levels or brightness
changes of the target
Illumination intensity
parts of the
microscope that are located above
the base but below the stage
SUBSTAGE ASSEMBLY
cuts down the
amount of light that reaches the
sample by restricting the area that
light can pass through
Diaphragm / aperture:
consists of two or more
lenses that focus the illuminator light
onto the sample placed on the stage,
and one or more apertures to control
illumination
Condenser
an optical filter
that lets light waves of a specific
direction pass through while blocking
light waves of other directions
(Lower) Polarizer
the platform upon which the
thin section is placed
has degrees marked on it: 360°
around the circular stage, in units of 1
degree (a.k.a., goniometer, and
vernier scale)
STAGE
an accessory
which can be attached to the top of the
rotating stage; allowing an x-axis (leftright)
and y-axis (top-bottom) motion
Mechanical stage
the main (but
usually not the only)
magnification mechanism in the
microscope
OBJECTIVES
where the objectives are
mounted
REVOLVING NOSEPIECE
an optical filter that lets light waves
of a specific direction pass
through while blocking light
waves of other directions
polarizer and analyzer are
oriented at 90° to each other, and
oriented N-S and E-W relative to
the base of the microscope
Analyzer / (Upper) Polarizer
changes the plane of focus so
that the viewer can observe
interference figures
Amici-Bertrand Lens
directs where the
polarized light goes (i.e., to
the eyepieces or the camera
Tubes:
