2.2 Magnification and calibration Flashcards
why is resolution limited
due to wavelength and diffraction of light (structures are close so light overlaps and detail is lost)
why is resolution limited
due to wavelength and diffraction of light (structures are close so light overlaps and detail is lost)
define magnification
how many times larger the image is than the actual size of the object
how do you adjust magnification
using the objective lens
define resolution
ability to differentiate between 2 points on an image
how do you increase resolution
use beams of electrons as they have a shorter wavelength
how do you calculate magnification
AIM
magnification = image size / actual size
nm —> um —> mm —> m
1000 nm = 1um
1000um = 1mm
1000mm = 1m
what is an eyepiece graticule
glass disc (fitted onto the eyepiece) marked with a fine scale of 1-100
what is the stage micrometer
slide with an accurate um scale engraved in it
how do you calculate 1 graticule division
1 graticule division = no. of um / no. of graticule divisions
how do you calculate measurement
measurement (um) = graticule division x magnification factor
