2.2 Magnification and Calibration

Question 1

What is magnification

Answer 1

how many times larger the image is than the actual size of the specimen

Question 2

What is resolution

Answer 2

determines the amount of detail that can be seen (higher resolution=greater detail)
it is the ability to see individual objects as separate entities

Question 3

Explain how resolution is impacted by diffraction

Answer 3

light passes through sample (diffraction of light waves)
light waves spread out when they reach surfaces of the specimen
light waves reflected close together due to tightly packed specimens and so reflected rays overlap leading to a blurry image

individual objects cannot be distinguished as separate entities so detail is lost

Question 4

What is diffraction

Answer 4

the tendency of light waves to spread out as they pass close to physical structures such as those present in specimens

Question 5

How can electron beams alter resolution?

Answer 5

Resolution can be increased using beams of electrons which have a much shorter wavelength than light
diffracted less which allows them to be close together without overlapping which allows for a clearer image

Question 6

Magnification calculation

Answer 6

image size
___________
actual size

Question 7

what is an eyepiece graticule

Answer 7

small glass disc on the eyepiece that has a fine scale of 0-100 with no units but its relative size of divisions changes as magnification does
can be calibrated using a stage micrometer

Question 8

What is a stage micrometer?

Answer 8

microscope slide with a very accurate micrometer scale engraved on it (um)
usually 100 divisions - 1mm=1000um
1 division = 10um

Question 9

Why should all measurements be in the same units?

Answer 9

Reduces error
Simplifies calculation
Reduces confusion