Geo,

The Rb you’re looking at , sorry, the computer is looking at is U Ka at 13.6, ?Rb has a Ka of 13.4 they can get confused if the ROI is not selected correctly. However in this case the Amptek Ka library doesn’t have a listing for U Ka so it’s never reported.? We need to check and fix these libraries.

Here’s some sage advice; The computer is not your friend, it hates you and everything you stand for because you’re smarter than it is. Its crafty – It has a Critical Need Detector and it’ll wait for the best possible moment to get its revenge. To avoid this DO EVERTHING YOURSELF.

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To interpret spectra? first look at it. Good well defined peaks or Noisy? Rerun it for a longer count

Then start at the low energy side and manually set ROI’s for each peak. For each peak find its peak energy and the look up in the x-ray table to determine what are the possible elements. Then look the for the Kb or Lb and confirm what you are looking at. Ka to Kb ratio is abt 5:1 La to ?Lb ?is 1:1 or so. If it doesn’t have a brother then it’s not a positive ID just unconfirmed.? Low Z elements won’t have any L peaks only K. Middle Z will have both and High Z will have L and possibly K depending on excitation energy. ?Some peaks are going to be good peaks others will be unknowns. The unknowns are artifacts and will include the sum, escape, ?backscatter, Compton, Rayleigh and merged peaks that are there just to harass and humble you.

In each case it’s up to you to interpret the data, the computer picks will 100% get you into trouble without verification .

Do not preconceive anything. For the Theromino and PXRF ?crowd - Don’t set any element lines on the screen. YOU set them as you ID an element. Don’t bias yourself. Believe nothing verify everything.? Just because you always had a Pb line set up doesn’t mean this time it’s not an As.? If you can’t figure it out without help lines you’re using a faulty interpretation model that will surely get you in trouble.? BTW ?the Garbage-In-Garbage- Out phrase was actually based on computer XFR interpretations ?not on the computer models it is usually attributed to.

XRF interpretation is not quick or easy but It’s very satisfying…when it works

Dud

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I’m not sure what the Amptek look up library can handle. It seems it only is set up for a Ka Kb or La Lb can ?we mix K’s and L’s ?in there as well and have it report correctly?? Inquiring minds want to know.

Dud

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