Lab 1 Microscopes and Measurements Flashcards
What is the function of the Ocular Lens?
The lens located inside the eyepiece that is used to magnify a specimen. On binocular microscopes, thee distance between the two eyepieces containing the ocular lenses should be adjusted by each user/
What is the function of the Objective Lens?
A series of lenses used to magnify a specimen located on the nosepiece just above the stage
What is the function of the arm?
Used for a hand when carrying the instrument; the other hand should be placed under the base
What is the function of the Coarse Focus Knob?
Roughly focuses the specimen by changing the distance between the objective lens and the specimen
What is the function of the Light Source?
Emits light onto the specimen
What is the function of the Blue Filter?
Increases resolution by reducing the wavelength of light
What is the function of the Mechanical Stage? Which microscope is this part of?
Large, flat surface that supports the slide or specimen over the hole that admits light from below. It also allows for the movement of the slide using the mechanical stage knobs. It is part of the compound microscope.
What is the function of the Mechanical Stage Knobs? Which microscope is this part of?
Moves the slide around the stage surface. It is part of the compound microscope.
What does the Fine Focus Knob do?
Sharply focuses the specimen by changing the distance between the objective lens and specimen very precisely.
What does the Condenser do? Which microscope is this part of?
Contains 2 lenses that focus light onto the specimen. It is part of the compound microscope.
What is the function of the Iris Diaphragm? Which microscope is this part of?
Regulates the amount of light passing through the lenses in the condenser. Reducing the amount of light increases the visibility of semi-transparent objects. It is part of the compound microscope. It is part of the compound microscope.
What is the function of the Iris Diaphragm lever? Which microscope is this part of?
Opens and closes the iris diaphragm. It is part of the compound microscope.
What is the function of the Condenser Adjustment Knob? Which microscope is this part of?
Moves the condenser up or down. It is part of the compound microscope.
What is the function of the Lamp Switch? Which microscope is this part of?
Turns the light on and off. It is part of the compound microscope.
What is the function of the Lamp Intensity DIal? Which microscope is this part of?
.Adjusts the brightness of light produced by the light source. It is part of the compound microscope.
What is the function of the Stage? Which microscope is this part of?
Large flat surface that supports the slide or specimen over the hole that admits light from below (T Light). It is part of the dissecting microscope.
What is the function of the Main Switch? Which microscope is this part of?
Controls supply of power to the microscope. Must be in the “on” position for either light to work. It is part of the dissecting microscope.
What is the function of the T Switch? Which microscope is this part of?
Turns the light below a specimen on and off. It is part of the dissecting microscope.
What is the function of the I Switch? Which microscope is this part of?
Turns the light above a specimen on and off. It is part of the dissecting microscope.
What is the function of the Stage Clips? Which microscope is this part of?
Holds a slide in-position over the stage. It is part of the dissecting microscope.
What is the highest power on the TEM?
300 000x
What is the highest power on the SEM?
300 000x
What is the highest power of the Dissecting microscope?
40x
What is the highest power of the Compound microscope?
1000x
What are the two types of electron microscopes?
Transmission Electron Microscope and the Scanning Electron Microscope
What is resolution and how do you improve it?
Resolution refers to the clarity of an image, for a microscope it is the minimum distance that two points of lines can be separated and still be distinguished as separate units.
- Improved by shortening the length of wavelengths (Blue filter)
- Lowering the amount of diffraction (scattering of light) with the help of immersion oil or other forms.
What is contrast and how do you improve it?
Contrast is a quality that makes the image stand out better.
- Adjust the condenser,
- Special light microscope (different types of light/wavelength)
- Staining the specimen with a dye
- Reduce the amount of light passing, either by
–a. Iris diaphragm
–b.Iris diaphragm lever
What is the formula for actual size?
Actual size = fraction of the field occupied / field diameter
Example. Actual size = 1/4 x 2mm
Actual size = 0.5mm
What is the formula for the speed/movement of a specimen?
Distance/time, usually per second
Example: 1.8mm in 20 seconds
1.8mm/20s = 0.09mm/s
What is the formula for the magnification of a drawing?
magnification = size of drawing/actual size of specimen, same units
= 120mm / 0.3mm which is 400x magnification
