Microscopes Flashcards
Formula for TOTAL MAGNIFICATION
TOTAL MAGNIFICATION =
OCULAR LENS MAGNIFICATION
X
OBJECTIVE LENS MAGNIFICATION
WHCI Ocular Lens =
10X
Low Power Objective Lens Magnification =
4X
Medium Power Objective Lens Magnification =
10X
High Power Objective Lens Magnification =
40X
ACTUAL SIZE FORMULA
ACTUAL SIZE =
FIELD OF VIEW (FOV)
DIVIDED BY
# OF TIMES CELL FITS ACROSS FOV
WHCI Microscope FOV Diameters
Low
Low = 4 mm/4000 μm
WHCI Microscope FOV Diameters
Medium
Medium = 1.6 mm/1600 μm
WHCI Microscope FOV Diameters
High
High = 0.4 mm/400 μm
DRAWING MAGNIFICATION FORMULA
DRAWING MAGNIFICATION =
DRAWING SIZE (in mm)
divided by
ACTUAL SIZE (in mm)
What is the function of a BASE on a microscope?
this is the bottom of the microscope, used for support
What is the function of a ARM on a microscope?
supports the tube and connects it to the base
What is the function of a STAGE on a microscope?
supports the microscope slide
has a central opening that allows light to pass through the slide
What is the function of CLIPS on a microscope?
hold the slide in position on the stage
What is the function of DIAPHRAGM on a microscope?
controls the amount of light that reaches the object being viewed
What is the function of a OBJECTIVE LENSE on a microscope?
magnify the object
typically have three possible magnifications: low (4x), medium (10x) and high power (40x)
What is the function of a REVOLVING NOSEPIECE on a microscope?
holds the objective lenses
rotates, allowing the objective lenses to be changed
what is the function of a BODY TUBE on a microscope?
contains the eyepiece (ocular lens)
supports the objective lenses
What is the function of a EYEPIECE (OCULAR LENS) on a microscope?
this is the part that you look through to view the object
magnifies the image of the object, usually by 10x
What is the function of a COARSE ADJUSTMENT KNOB on a microscope?
moves the stage up or down to get the object into focus
is used with the low-power objective lens only
(bigger knob)
What is the function of a FINE ADJUSTMENT KNOB on a microscope?
moves the tube to get the object into sharp focus
is used with medium-power and high-power magnification
is used only after the object has been located, centered and focused under low power magnification using the coarse-adjustment knob
(smaller knob)
What is the function of the LIGHT SOURCE/LAMP on a microscope?
may be an electric light bulb or a mirror that can be angled to direct light through the object being viewed
Precautions NEEDED to know when handling the microscope
Handling the Microscope:
Clean the lens as needed using lens paper ONLY
Carry the microscope by the base and arm – always use 2 hands
When finished with the microscope, always put it away with the stage lowered all the way and the lowest power objective in place
Precautions needed to know when Adjusting the light on a microscope
Adjusting the Light
Use the diaphragm to regulate the amount of light coming through the specimen.
Too much light will not allow the contrast that is often necessary to see the required detail.
