Embed Size (px)
Citation preview
THE COMPONENTS OF A MICROSCOPE
Saleha MurtazaMLT-2nd Year
The microscope have two types of components
Optical Components Non-optical components
OPTICAL COMPONENTS Are the components through
which light can pass through.
Light sourceCondensersObjectivesEye PieceBody Tube
Non-optical Components : Are the components through which light
can not pass through.
StageBaseCoarse and Fine adjustmentsRevolving Nose
LIGHT SOURCE: Two types of lenses are used: Oil Lamps Low Voltage Electric Lamps In ancient times sun light was the basic
light source These lamps operate via transformer and can be adjusted to
the intensity required.
CONDENSER: As light from the lamp is stray out and is
in horizontal path so Main purpose of condenser is to focus or
concentrate the light into the plan of the object
With in the limits the more the light at the specimen the more will be the resolution power.
Condensers are provided with adjusting screws for centering the light path.
APERTURE DIAPHRAGM a part of condenser which control the
diameter of light beam.
<aperture______increse contrast >aperture______decrease contrast
CONDENSER
OBJECT STAGE:
Above the condenser is the object stage which is a rigid platform with an aperture through which the light cam pass.
It supports the glass slide and grip it with clips.
It can be moved vertically and hrizontally to view the slide from each n every side.
STAGE
OBJECTIVES: 9 to 15 pieces of elements are present in
OL. Forms real image
Types:
Four types of objective lenses are used
A-chromates Apo-chromates
Plane chromates Fluorites
A-chromates
Most commonly used Chromatic aberrations are corrected. Focuses blue and red light on the point of
focus.
Apo-chromates: Highly corrected and the most expensive
lenses. No spherical and chromatic aberrations. Made up of a variety of elements and
minerals.
Plane chromates:
No spherical aberrations. Plane of view field is perfectly flat from
edges. Suitable for photomicrography.
Fluorites:
No spherical aberrations. Subtle differences in specimen colour are
present.
Numerical Aperture: NA=n*sin u
n----> refractive index of medium between OL and Ray R
Sin u----> angle between principle axis and outer most ray.
Un-obtainable condition is when Sin 90 when refractive index will be 1.
NOSEPIECE:
Objectives are screwed in a revolving nosepiece through which they are changeable .
Body tube:
Three types are available
Mononuclear Binocular Combined photo binocular
MONONOCULER BINOCULER CMBINED PHOTOBINOCULER
Eyepiece:
Magnifies the image formed by the OL within the body tube.
Present eye with Virtual image. Eyepiece with high focal lengths are
formed for the people using spectacles.
