Question about the scanning electron microscope with energy dispersive Spectrometer

[sniper711220]

Hi
I have several copper-tin-lead alloy standards with varying Pb contents(5, 10, 15, 20).
I analyzed them by the SEM-EDS, but it keeps giving me lower Pb concentrations(around 2, 5, 7, 10 individually).
The totals are good around 100 precents, but just inaccurate(tin is the same, bur Pb is lower and Cu is higher than their real values.
I use the default internal calibration (leaded glass) to calibrate Pb element.

Have anyone encountered such a problem and how to solve it ？

Thanks
Gary

 

[mrfailure]

This is why EDS analysis is considered SEMI-quantitative. You will get different results depending on the energy you collect at, but results can easily skew. You should try using different energy levels to see what gets you the closest. DO NOT use this tool for the purpose of accurate quantitative analysis - you should instead actually do quantitative chemistries if that is the goal.