XRF Manual
Contents
1. Highlight the sample you want to analyze you can get older expired data via the advanced search option If there are more than one entry for your file e g after a reevaluation via the touch screen use the top entry original data If you want to copy data to another drive use the windows explorer Go to X SPECPlus Data Files TempSSD Use copy and paste do not drag or delete files Highlight the entry you want to analyze Click evaluation options right upper corner Select a calibration e g elements evm for a chunk of metal and a preparation e g solid or mylar 3 6 Click Apply amp Close to close the evaluation options window Click the Interactive Qualitative Mode button bottom of page A new window opens Braz tulle A periodic system will pop up Click on Select the Elements Toolbar option individual elements to see their XRF lines Decide if an element is present or not by comparison of the spectrum with the XRF lines Take into account that some lines might be escape or sum peaks and that all lines of an element K L and M have to be found in the correct ratios for the element to be present Continue until all lines are accounted for as either an element peak or an escape or sum peak Make a note for elements that might be potentially hidden by e g an escape peak For the later evaluation leave out palladium The machine has a palladium source and Pd lines will always be present whether Pd is2. XRF User Manual 1 X Ray Fluorescence Data Collection and Analysis Matthias Zeller Jerry Hunter Sept 19 2008 A Data Collection Logging In The login and password to log into the program as a normal user are ysul for both the username and password If you need to use any feature only available with an administrator login ask one of the instrumentation scientists for assistance Loading Samples 1 If using powders or liquids the sample should fill the XRF sample cups about half way 2 Place the 3 6 um mylar film in between the two cups and press down fast and hard Try not to touch the mylar film with bare hands 3 If the sample is a solid make sure the sample fits into the 40mm rings inside the machine If it is too small place it in a plastic sample cup with mylar film such as used for powders or liquids 4 Lift the chamber door and place the sample in any empty space 5 Close chamber door 6 For manual loading of samples see Appendix 3 XRF User Manual 2 Calibration 1 2 Press measure It is important to calibrate the machine at the beginning of each day The screen on the XRF machine should be highlighted on Loader If not highlight Loader To calibrate the machine select the space in which the copper disc is located delete any experiment defined for this position Under choose your application press recal Highlight copper disk calibration Press Next On the loader screen hig
3. cape peak or sum peaks as real signals The spectrum needs to be visually inspected and every line needs to be assigned to a certain element Only these lines should then be used in the re evaluation Leaving out elements that exhibit X ray lines that overlap with lines of actually present elements allows these to be calculated with higher accuracy You can do a quick re evaluation via the Touch Screen Interface see chapter B Re evaluation of Data using the Touch Screen Interface A thorough and reliable re evaluation should be done via the program Spectra EDX on the flat screen computer to the left of the instrument see section C Re evaluation of Data using SpectraEDX XRF User Manual 5 B Re evaluation of Data using the Touch Screen Interface l 6 For a quick and non quantitative analysis you can make a re evaluation of the data using the touch screen interface The X ray facility staff HIGHLY recommends to use Spectra EDX as described in section C for sample evaluation If you decide to use the touch screen interface click results to make sure your sample is still highlighted or highlight it Click graph You may need to refresh the screen by pressing E You can identify the peaks on the graph by touching the center of the peak on the screen you may have to zoom in on the peak first and pressing Eos Select and or unselect X ray lines by pressing e this will bring you to the periodic table to select or deselect X ray lines of el
4. ements Change or add elements Energy Information SelectUnselect Element r uo ulen alha eain en Pef aul Ho Cn Pel Tea Kap oll ar m Conca Pm sm Eul sa w by Ho Er Tm vo Lu a ce Pr Na ooo The periodic table is composed of buttons A red or orange button indicates that the X ray lines for this element are selected and a grey button indicates that they are deselected The spectra series K L and M can be switched on or off for all elements The Energy Information area lists available lines and reports their energy in eV Select the elements you are interested in By highlighting the elements in the table you can choose which elements you want to keep or eliminate This might be important as you might have additional information such as those certain elements are for sure absent By leaving these out all elements that exhibit X ray lines XRF User Manual 6 that are close to the ones unselected will be calculated with higher accuracy After changing elements press the re eval button to updated the spectrum This may take a few minutes Press ok An updated graph appears with only the elements you specified 7 To print your results press print in the bottom right hand corner of the screen a WAIT UNTIL YOU HEAR THE CUTTING NOISE TO REMOVE THE PAPER IF YOU TEAR TOO EARLY THE MACHINE WILL JAM Summary of Graph Controls Aut
5. hlight the copper disk space The hourglass shows calibration in progress in the bottom right hand corner It will take about 8min for the calibration to complete While the calibration is running you can start setting up your sample s They will be queued and once the calibration disk is returned to its original spot the next samples will be measured Sample Analysis 1 2 Highlight the spot on the touch screen that corresponds to where you will put your sample Under Choose Application select which application you want to run the application you choose will depend on your sample and what results you are looking for Description of Methods Elements Powder and Solid used to find out what elements are present in the sample XRF User Manual 3 Fluoride Pellet Powder used to find what ratios of fluorides are contained in the sample Use pellet method if sample is in a pressed pellet and powder if the sample is in powder form Oxides Powders Solid used to find what ratios of oxides are contained in the sample Use powder if sample is in powder form and solid if sample is in solid form Water used to find what elements are contained in a liquid sample More methods that are less often used are listed under Other You are not limited to just these methods Methods can be created and adjusted to accommodate different types of analysis Enter the sample ID and press next Under Select the Prepara
6. id state detector e g a SiLi device will inadvertently knock out Si K shell electrons in the detector reducing that X ray s energy measured in the detector by the Si absorption edge energy 1 84 KeV Say you re looking at something will lots of Fe Ka of 6 40 KeV the Si escape peak of Fe Ka will appear at 4 56 KeV You see this escape peak only for the major elements present Sum peaks this phenomenon occurs where the count rates are moderate to high when two X rays impact the detector virtually instantaneously the pulse created and measured is the sum of the two X ray energies Say you have a sample with lots of Si Ka of 1 74 KeV and Al Ka of 1 487 a peak at 3 23 KeV is the sum peak not to be assumed to be a K peak Ka of 3 31 KeV
7. in the sample or not XRF User Manual 8 7 Write down all elements you wish to use for the analysis When done you may want to print out the spectrum including the XRF lines for your records hard copy and or pdf and label individual lines by element on the hard copy 8 Click on the alternative mode window button e In the new window click on initialize me then Show All Elements ale Highlight elements you do not want to have included in the analysis Via a right mouse click select set not present After every change click initialize again When only the elements of interest are left over click on compute ye concentrations _ 9 You may want to write down the RWP and the R RO value bottom bar of window after the refinement is finished Values for R RO should be below a value of 20 to be regarded as reliable 10 Print the results for your records to pdf XRF User Manual 9 D Data analysis pitfalls Artifacts escape peaks and sum peaks peak overlaps and excessive dead time are all phenomena that an EDS user must be aware of Modern analytical software used in processing energy dispersive X ray spectra can generally take them into account but such software is not perfect Also many users will look at the raw spectra where the software may or may not have labeled the artifacts Escape peaks there is a statistical probability that some of the X rays generated in the sample and impacting the sol
8. o Scale w The Auto Scale function scales the data so that the whole spectrum is fits inside the Graph Area Live Mode a When Live Mode is on the Graph Area will display either the current i measurement if a sample is being measured or the last measure ment if no sample is being measured If Live Mode is off the spectra from the selected sample in the Loader screen automatic systems or the selected sample from the Results screen is displayed tion the Cross Hairs near the peak of interest and press this button Add Lines This button will display the periodic table page so that you can select specific element emission lines to be displayed in the Graph Area see section Adding Element Lines SH Guess Line Res This button automatically adds an element emission line Simply posi Zoom IQ This Thumbwheel is used to Zoom in or out of the spectra Position the Cross hairs on the region of interest and do the following Q Move the Thumbwheel up to Zoom out Move the Thumbwheel down to zoom in Press and hold the thumbwheel to centre the region XRF User Manual 7 C Re evaluation of Data using SpectraEDX Measure your sample using the touch screen interface Switch over to the computer on the left small flat screen Open the program SpectraEDX If the path is lost e g after a restart you can define it again by highlighting the instrument and clicking connect Open the Evaluation option in SpectraEDX
9. tion choose Mylar 3 6um for powders or for solid samples Solid SpectroBlend or X ray mix this will depend on the type of solid As a standard choose Solid Press complete and or next If asked enter the estimated weight of the sample Press Complete A picture of your sample will appear on the screen Highlight your sample on screen by touching it Press measure An hourglass appears to show your sample is being analyzed e Starting and finishing time are displayed in the bottom right hand corner of the loader screen A standard sample will take about 8 9min to run e If more than one sample needs to be run you can repeat the above procedure for any number of samples to analyze up to 28 You can abort the procedure at any time by highlighting your sample on the loader screen and pressing abort on the screen The spectrum of your sample can be viewed as it is running by pressing graph XRF User Manual 4 10 Once the sample it returned to its original spot and ok is displayed the results can be 11 viewed at the bottom of the screen It takes about one and half to two minutes for results to appear Press results and press last hour to refresh the screen Touch the screen to highlight your sample The results appear at the bottom of the screen At this point you will have to clean up your results because the default software has a tendency to miss assign lines to wrong elements or to assign es
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