Comparison between EDS and WDS
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Table 3110. Comparison between EDS and WDS techniques.

EDS
WDS
Full name
Eenergy dispersive X-ray spectroscopy Wavelength dispersive X-ray spectroscopy
Principle

Measures the energy of X-ray photon

Determine the wavelength of X-ray

Spectrum range

Measures across a broad range of energies in the spectrum Measures specific regions within the spectrum
Efficiency

More efficient for an unknown specimen

More efficient for the concentration of specific, known element
Speed
Quicker for large energy ranges Slower for large energy ranges

Throughput of X-rays

Lower Higher
Spatial resolution
The same  
Energy resolution
Lower: ~ 125 eV Higher: ~5-10 eV

EDS and WDS profiles of BaTiO3

EDS and WDS profiles of BaTiO3. The green spectrum presents a standard EDS of of BaTiO3, while the red one presents a standard WDS. EDS shows the overlapped Ba Lα-Ti Kα and Ba Lβ1-Ti Kβ peaks.

Sensitivity

OK Better due to separation of overlapping peaks
Peak-to-background ratio
Lower Higher
Specimen limitation
Gases cannot be analyzed and liquids are limited to those that have very limited volatility and will not contaminate the column and specimen chamber because specimens must be exposed to vacuum conditions.
Hardware
Attached to electron microscopes

 

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