Handheld XRF (pXRF) User Guide
V374 | March 2018
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Manual Information
Author(s): | A. Armstrong & N. Lawler | ||
Supervisor Approval: | D. Houpt | ||
Origination date: | 2017 372 | ||
Original version: | V371T | July 2017 | ||
Revised: | V374 March 2018 | ||
Domain: | X-Ray | _GoBack | |
System: | XRF | ||
Keywords: | Elemental analysis |
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Contents
Manual Information
Contents
Introduction
Theory of Operation
Apparatus, Reagents, & Materials
Apparatus Preparation & Set up
Sample Preparation
Starting the Software
Preparing the Sample for Measurement
Starting a Measurement
Processing Sample Results
Uploading Files to LIMS
Quality Assurance/Quality Control
Maintenance and Troubleshooting
Health, Safety, and Environment
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Introduction
When X-ray radiation from the handheld XRF instruments' X-ray tube (source) excites the atoms in the sample, the atoms release fluorescent X-rays. The energy level of each fluorescent X-ray is characteristic of the element excited. As a result, one can tell what elements are present based on the energies of the X-ray emitted. The Olympus DELTA Premium handheld XRF (pXRF) detects and determines the fluorescent X-ray energies, produced. These energy patterns are characteristic to specific elements and allows for elemental measurements on section halves and discrete samples.
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Theory of Operation
X-ray fluorescence is the production of X-rays in the electron orbits. The handheld XRF functions by bombarding the atoms of the target sample with x-rays. Some of the photons collide with K (and L) shell electrons of the sample, dislodging them from their orbits. This leaves a vacant space in the K (L) shell, which is immediately filled by an electron from the L, M, or N (M or N) shell. This is accompanied by a decrease in the atom's energy, and an X-ray photon is emitted with energy equal to this decrease.
Since the energy change is uniquely defined for atoms of a given element, it is possible to predict definite frequencies for the emitted X-rays. This means that when electrons are dislodged from atoms, the emitted X-rays are always identical. These X-rays are analyzed with an X-ray detector and the quantity of K shell and/or L shell X-rays detected will be proportional to the number of atoms of the particular element or elements present in the sample.
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Apparatus, Reagents, & Materials
Laboratory Apparatus
Discrete Samples
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- XRF Laptop & power bar
- Section half & discrete barcode scanner
- Innov-x Delta advanced PC Software
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Apparatus Preparation & Set up
General Precaution: Isolate the Instrument
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Inside the pXRF case are: the pXRF, docking station, micro-USB cable, docking station power supply, pXRF AC power supply, and pXRF batteries.
The pXRF can be operated through the User Interface on the analyzer or through a dedicated pXRF laptop. Be consistent with the chosen method.
First take the docking station and place in in your dedicated area (Figure 1). The pXRF will rest in the docking station when not in use. Connect the docking station to power through the labeled power supply.
Figure 1. Docking Station
Figure 2. pXRF in Docking Station 
Then take out the pXRF and rest it in the docking station (Figure 2).
Figure 2. pXRF in Docking Station
The pXRF has two options for receiving power: an AC power supply inserted into the gun and connected to a wall socket or batteries inserted into the gun. For measurements taking place over a small amount of time the batteries are fine, however for longer periods the AC Power Supply is preferred. If using the batteries understand that if the pXRF powers off before data has been 'exported' from the software, all measurements will be deleted. The Olympus DELTA Premium pXRF has a small internal battery which allows the lithium battery packs to be "hot-swapped" without losing power to the pXRF. The internal battery will keep the pXRF running for approximately thirty seconds, so work quickly to slot the new battery into place.
Pull the rubber latch at the bottom of the handle open (Figure 3).
Figure 3. pXRF handle open
Insert the preferred method of power supply into the handle (Figure 4). The battery and AC Power Supply are keyed and only fit into the analyzer one way
Figure 3. pXRF handle openFigure 4. AC battery source inserted into pXRF
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You can now turn on the gun. Press the power button on the top of the analyzer for a couple of seconds (Figure 5). The button will illuminate green when on, as shown below in Figure 6.
Figure 5. pXRF power button outlined in red. pXRF is off.
Figure 6. pXRF turned on
The following step is only applicable at this stage if controlling the pXRF through the computer. If choosing to use the pXRF alone move on to 'Discrete Samples'. The pXRF interface users will use the laptop during the 'Export Files' Section later on.
Open the dedicated pXRF laptop and login to the computer with the following: user: XRFHost Password: B113@iodp.
To operate the gun and have it correctly write files administrator privileges are needed. If you login with something different, such as 'daq' 'daq', there are no administrator privileges and the gun will not work properly.
Connect the pXRF to the computer via the micro USB cord (Figure 7). Micro USB ports are very fragile so take care when plugging in or removing.
Figure 7. pXRF connected to laptop via micro USB cable. A. micro USB port. B. Laptop usb port
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Note: The Olympus DELTA Flex Stand can be set up in a second orientation, with the instrument standing upright. This is not recommended on board, because the samples are more likely to rock with ship's motion and give inconsistent results.
When it is time to remove the sample chamber pull the release handle and while holding the handle, lift off the sample chamber (Figure 12)
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Figure 13. pXRF being lowered into section half shielding. pXRF oriented with indents facing set screws. Again, please note that it will be necessary to cover the core surface with Ultralene film and GLAD® Plastic Wrap in order to protect the nose of the instrument and the underside of the shield from contamination. See Preparing Section Halves, below.
Important! Do not measure the core section half without covering it with film!
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Figure 14. Mortar and pestle along with scoopula. XRF Sample Cup components denoted with red arrows A. Open-end Ring B. Cup C. Cap D. Ultralene® film box E. Whatman Filter Paper F. Foam plug inserts
- Figure 15. Ultralene® covering of one side of cup
A XRF Sample cup has three components: cup, ring, and cap. Take a piece of Ultralene® film and stretch it over one end of the cup. Place the open ring over the film and cup and snap it firmly onto the cup. This will create a tight window on one end of the sample cup (Figure 15). Ultralene® is very thin and prone to ripping. Check for rips before and after sample powder is added.
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Important! Even a small amount of sediment on top of the thin film will be transferred to the pXRF, and will affect the measurement of the next core section half.
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The main measurement window then pops up.
Performing a Cal Check
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Before any measurements are taken, a *Cal Check* needs to be performed. A Cal Check is an internal calibration check in which the analyzer measures a particular stainless steel alloy to ensure the unit is measuring properly. A calibration check is required when the gun is turned on and every 10 hours thereafter. The information bar indicates when a Cal Check is needed by displaying "Perform a Cal Check" as shown in Figure 22, arrow B, below. It is not possible to proceed until the check is done. Place the gun in its docking station.
Figure 20. Performing a Calibration Check. A. CalCheck Button B. Indicator Bar C. Disabled 'Start' button
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!worddavee4ea07e7d0c243fb55f9ffc909b9e6a.png|height=137,width=551! *Note{*}: When using the *Flex Stand{*}, it is possible to perform the *Cal Check* by simply placing a stainless steel disk on the instrument nose and closing the lid of the *Flex Stand{*}. An extra stainless steel disk can be found in the pXRF supplies.
Click the *Cal Check* button located on the bottom left as shown in Figure 20, arrow A. The instrument will measure the stainless steel disk and check the peaks and their ratios to ensure that it's getting the expected results. The *Start* \[analytical measurement\] button will remain grayed-out and disabled until the pXRF passes the CalCheck. If the analyzer fails a Cal Check please refer to the '{*}CalCheck Fails{*}' Section in Troubleshooting.
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Setting Parameters
Parameters that require setting or editing include: mode and measuring time.
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Figure 22. Innov-X Set Up Screen. A. Set Up tab B. Test Condition button C. Test Time area D. Save button
Establish the measuring time for each beam. To access this, click the Set Up button at the top of the screen as shown in Figure 22, arrow A, below. On the left hand panel, click Test Condition. This will show the minimum (Beam # Min) and maximum (Beam # Max) time currently set for each beam. Adjust the settings as desired in seconds and click Save.
The behavior of the Test Time settings is as follows. If the minimum time is set to 1 s and the maximum time is set to 30 s (as shown in Fig. 22), the pXRF will scan until it determines that it has a good profile (via manufacturer-defined quality conditions) and stop measuring before it gets to 30 s. However, even if the pXRF has not reached a "good profile," it will stop at the maximum time.
If the user wants to ensure the pXRF measures for the same time on each measurement, set the minimum and maximum time to the same number (e.g., Beam 1 Min = 30, Beam 1 Max = 30). We do not recommend measurement times below 30 seconds, and longer times may be necessary to get good resolution of weak lines.
Naming the Sample for Measurement
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Tap the Home button 
. You are now in the main measurement window. First set the Mode in which you'd like to measure in. The gun has a Geochemical and Soil Mode. Each one has different scanning parameters which preferentially pick up some elements better than others. The gun will remember the chosen mode and does not have to be chosen each time a new measurement is taken or the Gun is turned off/on.
To access the Modes click on 'Mode' button 
. This directs you to the 'Mode' Screen where you can choose between the Geochemistry and Soil modes (Figure 27). Click on each to see it's corresponding features and select the one best for your analysis.
Figure 27. Mode Screen.
Now that the Mode is set, establish the measuring time for each beam. Each Mode has preset measuring times but these are changeable. To access the Measurement Time, in the Mode Setup screen click on 'Test Condition.'
Figure 28. Test Setup screen. 
In the Test Conditions screen, tap the Test/Tools button 
. This brings you to the Test Setup screen (Fig. 28). Enter the Minimum and Maximum time currently set for each beam (Fig. 8). Adjust the settings to your liking and click 'Save'.
Note: If the minimum time is set to 1 and the maximum to 30, if the gun determines it has a good profile in less than 30 seconds it will stop actively measuring. If you want to ensure it measures for the full time, set the minimum and maximum time to the same number. Ex: Minimum 30s and Maximum 30s
Naming a Measurement
Staying in the Test Setup screen, tap the Label Defaults button located in the bottom left corner. 
This is where you can manually input sample information. Editable fields are as follows: Run Number, Sample Name, Text ID, SHLF Offset, and Comment (optional field).
Run Number: A sequential number increased by +1 with every measurement, ex: 1, 2, 3… This number will start at 1 for the measurement of the expedition.
Sample Name: Sample Name according to the sample or section half label. Ex: 366-U1234A-20F1-W
Text ID: Unique 11 digit ID for each sample or section half located under the barcode on the label.
Offset for SHLF: The point where a measurement is made on a section half, measured as distance from the top of the section. This field will only have a value for section half measurements.
Comment: A brief description of the measurement. An optional field.
Click 'Save' in the lower right portion of the screen. If you do not click save the information will revert back to the prior run and there will be two measurements with the same name. The measurements are parsed by time so measurements will not overwrite one another there will just be multiple measurements with the same information.
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Warning! NEVER activate the X-ray source when the Flex Stand door is open! The Sample Chamber door does not have a safety trigger and the pXRF will continue to emit X-Rays if door is open.
Section Half Measurement
- Locate the area on the section half to be measured. Make sure that portion has a layer of Ultralene on it. Put a layer of glad wrap on the rest of the core that the lead shield might touch. We do not want to contaminate the core or pXRF.
- Place the shield over the core so the point of measurement is centered. Use the plexiglass view-finder to help find this spot.
- Take note of the measurement position on the core using the ruler. Lower the pXRF into the shielding oriented so the two indents on the analyzer are on the same side as the tightening screws.
- Tighten the screws until it feels firm. This locks the pXRF into place and helps stabilize it. Keep a hand on the handle while measuring to ensure it does not fall.
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If the minimum time has been set to the same number as the maximum time for each beam setting (see Setting Parameters, above), the run time will be exactly what was set. If the minimum time is smaller than the maximum time, the pXRF may stop the measurement early, if the quality of the measurement satisfies its internal quality criteria. (These criteria cannot be adjusted by the end user.)
Important! Record each measurement taken on the paper log sheets provided by the technician. The log sheet will be a life-saver later in the expedition.
PC Interface
Figure 29. Innov-X Start Button
Press the green Start button located on the bottom left of the screen as shown in Figure 29, below. The measurement can be started in either the Test Information or Analysis window.
The spectral graph and elemental concentrations will populate after each beam has completed measuring.
pXRF Interface
Navigate to the Test screen (Figure 30). Start the test by pulling the trigger or tapping the Start Test button.
Figure 30. Start and mid-way through an active test. 
The results are displayed immediately upon test completion. Tap the Spectral Plot button to view the spectrum results (Figure 31).
Figure 31. Completed test and results. Results shown as both a list and as a spectrum. 
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This step is done by the technician.
Open MegaUploadaTron (MUT). If the file(s) are not yet in the DATA > IN; transfer them now. MUT requires two file types per uploaded file: '.csv' and '.spm'. The filenames must be identical for MUT to recognize the two as linked and MUT will not allow an upload unless both files are present.
Check the boxes for the files to be uploaded. The Misc column identifies files that have not been uploaded as shown in Figure 34.
Figure 34. MUT XRF Uploader.
Figure 35. MUT pXRF Pre-Upload Form. A indicates the selection boxes. B. Editable fields
B highlights the editable fields.
Click Upload in the bottom right of the window. This brings up the pXRF Pre-upload Form as shown below in Figure 35. This form lists all measurements and allows files to be edited. The fields in white are editable: Run Number, Sample Name, TextID, Offset for SHLF, and Comment. Measurements can also be checked or unchecked to upload or not upload to LIMS. Cross check measurements with the log sheets and make edits as necessary.
Keep a close eye out for duplicate lines. It is easy to inadvertently create multiple measurements with the same name, if the Save button isn't pressed when identifying the sample (see Naming the Sample for Measurement, above).
If any changes need to be made to the editable fields or if scientists require a different file type, from the MUT main screen, click Options > Set active analyses… to open the Configure Acitve Analyses window as shown in Figure 36. Follow the prompts in the window and select Handheld X-Ray Fluorescence Analysis to see the configurable options. The option wheel icon will only appear when the analysis type is on the Active uploaders side and is highlighted.
Figure 36. Configure Active Analyses screen (pXRF shown active).
Figure 37. MUT Settings for pXRF Analysis.
Once the wheel is clicked, the window in Figure 37 appears.
These settings determine what MUT is searching for to validate the data before upload. These values are editable, but it is strongly recommended to have a developer assist you with this. If other labels (see Naming the Sample for Measurement, above) are enabled in the Olympus Innov-X software, those columns can be added here. Add the column name to the EditableColumns value exactly as it appears in the Innov-X menu.
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It is important to keep the pXRF clean and if the Prolene® window becomes dirty (or breaks), it should be replaced immediately. For instructions on how to replace the Prolene® Window please refer to the Olympus 'DELTA_Family--User—International' User Manual.
Keep the batteries away from extreme temperatures, and talk to the ET's about the best way to promote long battery life.
One of the things I worry about the most is the mini-USB connector on the side of the instrument to connect to the PC. The cables are somewhat easy to damage, but the biggest concern is the port itself. Mini-USB ports are very easy to damage, so take care to protect it against force from the side (i.e., pulling the cable sideways).
Delete Files from Software
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The pXRF has a feature to apply linear regressions for elements, quantifying data as it is measured. It is NOT recommended for use. Data Quantification should be done outside of the software by the scientists. Please note that this feature can provide erratic results and not detect elements that are present.
Troubleshooting
Indicator Bar shows a 'CommError'
This indicates a Communication Error between the pXRF and the computer. If this error shows up at the initial startup window, close and restart the software. The gun must be connected via the micro-USB cable before turning on the software. If this error shows up while the software is already open, close and restart the software. In this instance the connection between the analyzer and computer was broken, either through the cable being unplugged or the Gun turned off. If that happens.
Files are missing from the Data Management Panel
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Within two seconds of starting a test, the analyzer attempts to detect backscatter radiation from the sample. If it fails to detect this backscatter radiation (i.e., no sample is detected), the test aborts to prevent accidental exposure. Upon an abort action, the filter wheel returns to the 0 position, the X-rays shut off (the tube current decreases to 0.0 µA), and the red light stops blinking. If the probe is pulled away from the sample while a test is in progress, testing will stop and X-rays will shut off.
This safety works slightly differently inside the sample chamber. If the pXRF starts measuring inside of the sample chamber without a sample inside the X-rays will continue emitting until it switches to Beam 2. At the start of the second beam the analyzer will abort the measurement. Beam 1 is a higher voltage and the analyzer detects the x-rays bouncing off the walls in there. If a run was started but a sample was not put in the chamber it is NOT SAFE to open the sample chamber door.
Software trigger lock
After a five-minute lapse between tests (default time), the trigger automatically locks. The pXRF analyzer also has a dead man trigger protocol, in which the user is required to pull and hold the trigger for the duration of the test. When the dead man trigger is enabled, releasing the trigger prematurely will abort the test. However, it is not recommended to use the trigger—instead, trigger the measurements from the PC, and thus further away from the instrument.
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