composition — this is called Energy-Dis-
persive X-ray (EDX) or Energy-Dispersive
Spectroscopy (EDS).
During an EDS analysis, the material
of interest is bombarded with electrons. e
incoming electrons knock existing electrons
out of their orbitals and into higher orbitals.
When these electrons fall back to their initial
state, x-ray energy is released. Depending on
the elements that are present, the energy that
is released will have a specific wavelength.
e detector quantifies the amount of energy
released at each wavelength. EDS software
matches the measured energies to specific
elements that are likely to be present within
the material, giving the user a qualitative list
of likely elements and the relative amounts of
those elements within the material. Elemental
identification with EDS can be performed
over the entire area on view in the SEM or on
specific particles or areas within the sample. A
more detailed analysis can identify the loca-
tion of each element within the material.
When performing an EDS analysis, it
is important to select operating parame-
ters compatible with the material. Higher
operating voltages are required for elements
with higher atomic numbers. Because EDS
functions in a similar way to the SEM, the
SEM/EDS in Comparison Against other Common Particle Counters and Elemental Analysis Technologies
FEATURE
AUTOMATIC
PARTICLE COUNTER
ANALYTICAL
FERROGRAPHY
ICP ELEMENTAL
ANALYSIS
RDE ELEMENTAL
ANALYSIS
SEM/EDX
Sample Preparation Requirements Usually Yes Yes No Yes
Particle Detection Range (microns) 2-100 2-500 <3 <7 0.2-2,000
Individual Particle Size and Shape Usually Yes No No Yes
Total Element Chemical
Analyses Range
No No 38 32 98
Particle Classification by Chemistry No Limited No No Yes
Particle Classification by
Morphology and Chemistry
No Yes No No Yes
Analyses Time (minutes) 5 10 3 3 10 to 30
Ease of Use
(1=easy, 5=moderate, 10=difficult)
5 10 5 3 1
Particle Size Distribution Yes No No No Yes
Automated Trending Yes Limited Yes Yes Yes
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