Microscopes Flashcards
How do you carry the microscope?
carry the microscope with both hands; one on the arm and the other under the base. Do not tip the microscope because the eye pieces may fall out. Set it down gently do not bump or drag the microscope
What is used to clean lenses?
- lens paper
* solvents
List what must be done when putting away a microscope:
- Clean every lens with lens paper
- leave the 4x objective lens facing down
- Move the mechanical stage to center, so nothing sticks out at the side
- Open the iris diaphragm all the way (lever all the way to the right)
- Rotate coarse focus adjustment knob so that the stage is ~1 inch from the lamp source
- Set light intensity to the lowest setting and turn the light source switch off
- Set filter to O (bright field)
- Coil and bind cord
- Put microscope in correct slot.
Compound Light microscope
a microscope which uses a light source to illuminate the specimen from below and a series of lenses to enlarge the image of the specimen.
Compound*
2 systems of lenses
Binocular*
2 eye pieces
Parafocal*
A parfocal lens is a lens that stays in focus when magnification/focal length is changed. There is inevitably some amount of focus error, but small enough to be considered insignificant. When stage is set in scanning it is at the appropriate hight for all objectives only fine adjustments should be made.
e- microscope
passes e- beams through specimen, specimen must be covered in metal, allows us to achieve greater magnification than light microscopes
Fixed specimen
a specimen prepared in advanced and used repeatedly
wet-mount/ smear
a specimen that is collected and prepared immediately by the user.
Light passes through the slide into the ___________
objective lens
The longer the objective lens the ___________
the higher the magnification power; smaller the working distance.
Working distance
the space between the slide and the objective lens
The user observes specimens by looking through the ______.
ocular lens
What is the magnification power of the ocular lens?
10x
pointer
a feature of an ocular lens which allows a user to point to a specific area on a slide
One of the ocular lenses will ____ to improve _________.
rotate
resolution
Ocular micrometer
a ruler found in the ocular lens which allows the user to take measurements of a specimen, must be calibrated for each objective lens.
Total magnification
The enlarged size of an object verses its total size when viewed through the objective and ocular lens.
Resolution
How clear the image of the specimen appears
Contrast
How well you are able to determine different parts of the microscope.
Field of view
The area that can be seen with the microscope
image orientation
mirrors are used to observe the specimen so the image will appear backwards and upside-down.
Ocular lens
also called the eye piece, found at the top of the microscope and magnifies the specimen 10x.
Scanning objective lens
has a magnification of 4x. Gives the viewer the largest field of view. ALWAYS START VIEWING AN OBJECT WITH THIS LENS. Ok to use coarse focus
Low power objective lens
has a magnification of 10x. Okay to use coarse focus
Medium power objective lens
magnifies 20x . use fine focus
High Power objective lens
this lens has a magnification of 40x . use FINE FOCUS ONLY.
Oil immersion Objective lens
magnifies 100x , must be used with immersion oil. USE FINE FOCUS ONLY.
Revolving nose piece
or turret; Objective lenses are attached to this, turn to change objective lenses. Turn slowly, you will hear/feel a click when in place.
Arm
the part to hold when carrying a microscope
Base
other hand is placed under the base when carrying, this part rests on the table.
Light source
Comes from the base of the microscope, shines upward to illuminate an object
Stage
The platform where the slide is placed for viewing, there is a hole in the stage where the specimen should be placed over to allow light to shine through specimen. When on scanning bring stage all the way up and focus it from there.
X and Y axis knobs
Allow you to move stage right and left and forwards and backwards
Stage clip
metal clip that holds the slide in place
Coarse adjustment knob
a large knob on ether side of the microscope, used to move the stage up and down to position the object in focus.
Fine adjustment knob
smaller knobs located onto of the coarse adjustment knob. Makes very slight changes used to bring the image of the object into sharp focus
Condenser
The condenser collects light and focuses them into stronger beams, much like an adjustable flashlight changes the intensity of light
Iris Diaphragm lever
located below stage, by moving this lever to the right or left, one can adjust the amount of light that passes through the specimen.
Filter
located below the stage. Rotating the dial will change the filters used to view specimens. O, DF, Ph1, Ph2, Ph3
Main switch
turns on and shuts off power
Light intensity knob/rheastat
controls light intensity
Field iris diaphragm
located on light source
Light source
where light comes from, has a filter holder for additional filters, and field iris diaphragm
“O”
Bright field; good for stains allows color to be seen clearly
“DF”
Darkfeild; provided better contrast than bright field and is best for living specimens.
“Ph1”
Phase contrast 1; Does not work on scanning, helps to improve contrast while using low powered objective lens. Best for viewing live microorganisms
“Ph2”
Phase contrast 2; Does not work on scanning, helps to improve contrast while using medium power objective lens. Best for viewing live microorganisms
“Ph3”
Phase contrast 3; Does not work on scanning, helps to improve contrast while using high powered objective lens. Best for viewing microorganisms. Useful for viewing living cells.
Magnification
a measure of how much larger the image of an object tis compared to the actual size of the object.
Identify 2 ways to adjust the intensity of the light on the microscope.
- manually using the light intensity dial
and iris diaphragm
As the objective lenses get closer to the specimen and the working distance gets shorter what happens to illumination?
it gets dimmer
Formula for times magnified
specimen size um
