2.2- magnification and calibration

What is diffraction?

Diffraction is when light spreads out when it gets closer to the structures

What’s the objective lense?

Objective lens is the part of microscope that is closest to the specimen

What does resolution allow for?

Resolution allows us to see individual objects as separate things

How can resolution be increased?

Resolution can be increased by using electron beams that have wavelength shorter than light

Equation to calculate magnification

Magnification = image size/ actual image

What does 1 micrometre( $\mu m$) equal too in nanonmetre (nm)

1 $\mu m$ = 1000 nm

Unit conversion

What’s a scale bar?

A scale bar is a line on a micrograph or image that represents a specific length.

How to calculate magnification using a scale bar

Magnification = scale bar image / actual scale bar length

What is calibration?

Calibration correlates the reading of a microscope lens with those of a standard in order to check the microscopes accuracy

What is an eyepiece graticule?

An eyepiece graticule is a glass disc placed inside a microscope’s eyepiece, used to calibrate a microscope when measuring specimens

What is a slide micrometre?

A slide micrometre is a scale made on a microscope slide with lines ruled in divisions, usually of 0.01 mm, typically used to calibrate an eyepiece graticule

What does an eyepiece graticule have on it?

A scale ruled on if

What does an eyepiece graticule look like?

What does a stage micrometre look like?

What are the steps to calibrate a microscope?

1. Place a stage micrometre on the stage of the microscope

2. Line up one of the divisions on the eyepiece graticule with a fixed point on the stage micrometre

3. Count the number of divisions on the eyepiece that match up with the measurement on the stage micrometre

4. Calculate the distance in micrometres of one division on the eyepiece graticule