Calculating Magnification and Size
D. Faure February 21, 2012
Scanning electron microscope image of a snout beetle
http://remf.dartmouth.edu/images/insectPart2SEM/source/20.html Image: public domain. Feb. 2012
Calculating Linear Magnification
of an Electron‐Micrograph using it's scale bar
There are three steps:
Measure the length of the scale bar ‐ in mm.
32mm
Convert your measurement into µm.
32 x 1000 = 32000µm
Calculate the magnification.
(Magnification = measured length /the number written.
As long as you have the SAME UNITS)
32000µm / 100 µm = 320x
magnification
Magnifiation = the number of times bigger the scale bar actually
is, compared to the measurement written on it?
Scanning electron microscope image of a snout beetle
http://remf.dartmouth.edu/images/insectPart2SEM/source/20.html Image: public domain. Feb. 2012
Calculating Specimen Size
using a scale bar
There are four steps:
Measure the length of the Specimen in mm.
(show working)
83mm
Measure the length of the scale bar in mm.
32mm
Calculate how many scale bar lengths make the specimen.
(Divide length of specimen by length of scale bar)
83mm / 32mm = 2.6
Calculate the size. Multiply the scale bar label by the last answer.
(UNITS are the same as the scale bar)
2.6 x 100 µm = 260µm
1
Calculating Magnification and Size
D. Faure February 21, 2012
Scanning electron microscope image of a snout beetle
http://remf.dartmouth.edu/images/insectPart2SEM/source/20.html Image: public domain. Feb. 2012
Calculating Specimen Size
using magnification
There are three steps:
Measure the length of the Image of the Specimen in mm.
(show working)
Magnifiation = x 320
Convert the length of the Specimen image to µm.
(x 1000)
Calculate the actual size.
Divide the length of the specimen image by the magnification
(UNITS are µm)
Electron microscope image of pollen grains from oriental lily.
http://remf.dartmouth.edu/images/botanicalPollenSEM/source/3.html Image: public domain. Feb. 2012
Calculating Linear Magnification
of an Electron‐Micrograph using it's scale bar
There are three steps:
Measure the length of the scale bar ‐ in mm.
Convert your measurement into µm.
Calculate the magnification.
(Magnification = measured length /the number written.
As long as you have the SAME UNITS)
magnification
Magnifiation = the number of times bigger the scale bar actually
is, compared to the measurement written on it?
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Calculating Magnification and Size
D. Faure February 21, 2012
Electron microscope image of pollen grains from oriental lily.
http://remf.dartmouth.edu/images/botanicalPollenSEM/source/3.html Image: public domain. Feb. 2012
Calculating Specimen Size
using a scale bar
There are four steps:
Measure the length of the Specimen in mm.
(show working)
Measure the length of the scale bar in mm.
Calculate how many scale bar lengths make the specimen.
(Divide length of specimen by length of scale bar)
Calculate the size. Multiply the scale bar label by the last answer.
(UNITS are the same as the scale bar)
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Electron microscope image of pollen grains from oriental lily.
http://remf.dartmouth.edu/images/botanicalPollenSEM/source/3.html Image: public domain. Feb. 2012
Calculating Specimen Size
using magnification
There are three steps:
Measure the length of the Image of the Specimen in mm.
(show working)
Convert the length of the Specimen image to µm.
(x 1000)
Calculate the actual size.
Divide the length of the specimen image by the magnification
(UNITS are µm)
Magnification = x 2500
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Calculating Magnification and Size
Human leukocyte ­ showing golgi apparatus
http://remf.dartmouth.edu/images/humanBloodCellsTEM/source/3.html Image: public domain. Feb. 2012
D. Faure February 21, 2012
Calculating Linear Magnification
of an Electron‐Micrograph using it's scale bar
There are three steps:
Measure the length of the scale bar ‐ in mm.
Convert your measurement into nm this time.
Calculate the magnification.
(Magnification = measured length /the number written.
As long as you have the SAME UNITS)
magnification
Magnifiation = the number of times bigger the scale bar actually is,
compared to the measurement written on it?
Calculating Specimen Size
using a scale bar
There are four steps:
Measure the length of the Specimen in mm.
(show working)
Measure the length of the scale bar in mm.
Calculate how many scale bar lengths make the specimen.
(Divide length of specimen by length of scale bar)
Calculate the size. Multiply the scale bar label by the last answer.
(UNITS are the same as the scale bar)
4