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X-MET3000TX Series handheld XRF analyzers X-MET3000TX / TXS / TXR
User Manual ^å~äóíáÅ~ä P.O. Box 85 (Nihtisillankuja 5) FI-02631 ESPOO, Finland Tel: 09 329 411 Fax: 09 3294 1300 Email:
[email protected] www.oxford-instruments.com
X-MET3000TX / TXS / TXR User Manual 5102 037-4VE Edition 1.20 March 2006
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Safety Information •
All users of this equipment must read and understand the Safety Information (Section 6) before using the equipment.
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The X-Met generates X-ray radiation when it is operating. In most countries a license or registration is needed to use it.
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Because of the radiation, the X-Met must only be used by persons who have been trained to operate it safely.
CAUTION: This instrument produces X-rays when energised. The X-MET3000TX generates X-ray radiation when it is operating. A red LED indicates that the X-rays are on. The safety of the X-MET3000TX has been verified by radiation safety authorities. As long as there is no physical damage to the instrument, there is no danger of exposure to radiation above permissible levels when the instrument is used according to the instructions. It is important that the distributor and user of the X-Met understand both the correct operation as well as the safety measures that are engineered into the analyzer to prevent incorrect operation.
CAUTION: Corrosion of Beryllium A beryllium window is used in the radiation detector inside the probe. Corrosion of beryllium may occur if it is exposed to moisture, particularly when ions such as chlorine, sulphates, copper or iron are present. Corrosion may damage the detector component. In case of suspected corrosion, store the instrument in a safe place and contact the nearest OIA representative for further instructions. The instrument should not be used or stored in high humidity areas or in circumstances where atmospheric condensation may occur.
CAUTION: Beryllium toxicity Beryllium and its compounds are considered to be toxic. Overexposure is usually caused by inhalation of a) airborne particulates resulting from grinding beryllium metal or its compounds, or b) welding fumes containing beryllium. Beryllium in its solid form, as it is used in the detector window, poses no health hazard. Note: The beryllium window is very thin and thus mechanically weak. Do not grind or machine beryllium window. Removal of corrosion products from this window should be done only by authorized personnel.
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Contents SAFETY INFORMATION .......................................................................................................................... 3 DESCRIPTION OF THE X-MET3000TX..................................................................................................... 7 PRINCIPAL COMPONENTS OF THE X-MET 3000TX ............................................................................... 9 2.1. PRINCIPAL PARTS...........................................................................................................................................9 2.2. THE ANALYZER ...........................................................................................................................................11 2.3. THE PDA COMPUTER ..................................................................................................................................12 2.4. ENVIRONMENTAL OPERATING CONDITIONS FOR THE X-MET3000TX.........................................................13 2.5. POWER SUPPLY ............................................................................................................................................14 Battery power ................................................................................................................................................14 Line (A/C) power ...........................................................................................................................................14 Charger..........................................................................................................................................................14 2.6. HOT SURFACE ADAPTER .............................................................................................................................15 PRE-OPERATING INSTRUCTIONS.......................................................................................................... 17 3.1. PREPARING THE X-MET FOR USE ................................................................................................................17 3.2. SWITCHING BACKLIGHT ON/OFF................................................................................................................17 3.3. CALENDAR AND CLOCK ADJUSTMENT .........................................................................................................17 3.4. CHARGING THE BATTERIES ..........................................................................................................................18 3.4.1. Charging instrument batteries .............................................................................................................18 3.4.2 Charging the PDA internal battery.......................................................................................................18 3.5. BENCH TOP OPERATION ...............................................................................................................................18 3.6 TO TURN OFF THE INSTRUMENT ....................................................................................................................19 3.7. SAMPLE PREPARATION ................................................................................................................................19 ANALYSIS MEASUREMENTS................................................................................................................. 21 4.1. START UP .....................................................................................................................................................21 4.2. MAKING MEASUREMENTS ............................................................................................................................21 4.2.1. General ................................................................................................................................................21 4.2.2. Name Sample .......................................................................................................................................23 4.2.3. Select Method.......................................................................................................................................24 4.2.4. Display spectra ....................................................................................................................................26 4.2.5. Configuration Backup..........................................................................................................................27 INSTRUMENT SETTINGS........................................................................................................................ 29 5.1 GENERAL ......................................................................................................................................................29 5.2. FP METHOD SETTINGS .................................................................................................................................29 5.2.1. Set Measurement Time.........................................................................................................................29 5.2.2. Output Settings.....................................................................................................................................30 5.2.3 Test Measurement .................................................................................................................................30 5.2.4. Method Type Parameters.....................................................................................................................30 5.2.5. User Setup............................................................................................................................................35 5.2.6. Assay Screen Settings...........................................................................................................................35 5.2.7. Energy Calibration ..............................................................................................................................36 5.3. EMPIRICAL ASSAY METHOD SETTINGS .........................................................................................................37 5.3.1. Set Measurement Time.........................................................................................................................37 5.3.2. Output Settings.....................................................................................................................................37 5.3.3. Test Measurement ................................................................................................................................37 5.3.4. Method Type Parameters.....................................................................................................................38 5.3.5. User Setup, See Section 5.2.5...............................................................................................................39 5.3.6. Screen Settings, See Section 5.2.6........................................................................................................39 5.3.7. Method Parameters..............................................................................................................................40 5.4. IDENTIFICATION METHOD SETTINGS ............................................................................................................43 5.4.1. Set Measurement Time.........................................................................................................................43 5.4.2. Output Settings.....................................................................................................................................43 5.4.3. Test Measurement ................................................................................................................................43 5.4.4. Method Type Parameters.....................................................................................................................43 4
5.4.5. User Setup ........................................................................................................................................... 44 5.4.6. Screen Settings..................................................................................................................................... 44 5.4.7. Method Parameters ............................................................................................................................. 44 INSTRUMENT CALIBRATION ................................................................................................................ 47 6.1. GENERAL .................................................................................................................................................... 47 6.2. CALIBRATING WITH X-MET 3000 CALIBRATION SOFTWARE ..................................................................... 47 6.3. MSG AND FP CALIBRATION ........................................................................................................................ 47 6.4. ADDING A REFERENCE TO AN IDENTIFICATION METHOD ............................................................................. 47 6.4.1. Adding a reference sample to a predetermined identification method ................................................ 47 6.4.2. Setting screening conditions for a reference ....................................................................................... 48 6.4.3. Adding a sample to the identification library when sample type is not known.................................... 49 SAFETY INFORMATION ........................................................................................................................ 49 7.1. RADIATION SAFETY .................................................................................................................................... 49 7.1.1. Customer Responsibilities ................................................................................................................... 49 7.2. DESCRIPTION AND USE OF THE SAFETY INTERLOCKS ................................................................................... 51 7.2.1. Precautions to take when analysing Small samples ............................................................................ 52 7.2.2. Precautions to take when analyzing thin samples ............................................................................... 53 7.3. RADIATION PROTECTION DOS AND DONTS ............................................................................................... 53 7.4. RADIATION DOSE RATES ............................................................................................................................. 54 7.4.1. The intensity of the primary beam ....................................................................................................... 54 7.4.2. Scattered Radiation dose rates ............................................................................................................ 55 7.5. WHAT TO DO IN CASE OF EMERGENCIES ...................................................................................................... 57 7.5.1. Minor damage ..................................................................................................................................... 57 7.5.2. Major damage ..................................................................................................................................... 57 7.5.3. Loss or theft ......................................................................................................................................... 57 7.6. CUSTOMER MAINTENANCE ......................................................................................................................... 57 APPENDIX 1: TROUBLESHOOTING ...................................................................................................... 59 8.1. IF MEASUREMENT WILL NOT START ............................................................................................................. 59 8.2. IF THE X-MET PROGRAM ”LOCKS UP” ........................................................................................................ 59 APPENDIX 2: X-MET3000TXS – SOIL MEASUREMENTS ..................................................................... 61 9.1. DESCRIPTION OF THE X-MET3000TXS ...................................................................................................... 61 9.2 RADIATION SAFETY ...................................................................................................................................... 62 9.3 DETECTING HEAVY ELEMENTS IN SOIL ......................................................................................................... 63 9.3.1 Heavy elements..................................................................................................................................... 63 9.3.2 Typical soil remediation project........................................................................................................... 63 9.3.3 Sampling............................................................................................................................................... 64 9.4 SELECTING OPERATING MODE ...................................................................................................................... 65 9.5 MEASUREMENTS .......................................................................................................................................... 65 9.6 SAMPLE PREPARATION ................................................................................................................................. 65 9.6.1 Sample cups .......................................................................................................................................... 66 9.6.2 Sample Bags ......................................................................................................................................... 68 APPENDIX 3: X-MET3000TXR – MEASUREMENT OF ELECTRONIC COMPONENTS .......................... 69 10.1 DESCRIPTION OF X-MET3000TXR............................................................................................................ 69 10.2 METHODS ................................................................................................................................................... 69 10.2.1 Auto Detect ......................................................................................................................................... 69 10.2.2 Alloy FP.............................................................................................................................................. 71 10.2.3 Plastic FP ........................................................................................................................................... 71 10.3 ANALYZING DIFFERENT MATERIALS ........................................................................................................... 71 10.3.1 Measuring time................................................................................................................................... 71 10.3.2 Non-homogeneous material................................................................................................................ 71 10.3.3 Metals ................................................................................................................................................. 72 10.3.4 Solders ............................................................................................................................................... 72 10.3.5 Plastics ............................................................................................................................................... 73 10.3.6 Printed circuit boards and semiconductor chips ................................................................................ 73 10.3.7 Powders, pellets, etc. .......................................................................................................................... 74 APPENDIX 4: ENERGIES OF K AND L LINES ........................................................................................ 75 5
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Description of the X-MET3000TX The X-MET3000TX series analyzers are portable elemental analyzers intended for various different applications. The X-MET3000TX is primarily intended for metal alloy analysis, the X-MET3000TXS for soil and mining analysis, and the X-MET3000TXR for electronic industry applications. The basic configuration of all these models is the same and this manual covers operation instructions for all these analyzers. Application specific information for use of the TXS and TXR model can be found in the appendices. The X-MET3000TX series analyzers are based on energy dispersive X-ray fluorescence technology and use an X-ray tube as the source of excitation. The X-MET3000TX provides a method for chemical analysis or sample identification (sorting) directly from samples in various forms. The instrument is a fully portable analyzer with an integrated PDA (Personal Digital Assistant) computer. Within the XMET3000TX analysis program, the user may select analytical modes, view spectra and save data.
Figure 1.1. Field portable configuration of X-MET3000TX
The analyzer is battery operated with A/C operation as an option. In some cases, it may be more convenient to use the X-MET3000TX in a stationary bench top configuration. The picture below (Fig 1.2) shows the X-MET in the stand provided. There are grooves in the body and the handle which slide into the stand. Note that for bench top operation, the instrument can be used with battery or A/C (line voltage) power.
Figure 1.2. Bench top installation of X-MET3000TX
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Principal components of the X-MET 3000TX 2.1. Principal parts
Analyzer
Instrument stand for bench top use
Battery charger
Battery (*2)
AC adapter
PDA computer
Included accessories:
PDA AC adapter
PDA AC adapter plug
USB Synchronisation cable
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Standard shipping case
Stylus
Remote extension cable for PDA
PDA display shield set
Safety shield for small samples
Kapton window film kit
Shoulder strap
Protection cover User Manual
Optional accessories: (depending on analyzer type)
Sample bag holder
Background plate
Sample cup holder
Sample bags
Sample pressing tool
Remote trigger cable
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Sample cups
Sample cup film
Pistol holster
Rod adapter
Weld beam adapter
2.2. The Analyzer The excitation source in the X-MET3000TX is an X-ray tube. The standard target material is Silver. The analyzer contains a high resolution Si-PIN diode detector with Peltier cooling. To turn on the instrument, turn the X-MET3000TX interlock key to the “ON” position.
Figure 2.2.1
The second lock is for removing the palmtop computer from the instrument.
Figure 2.2.2 There are two indicator lights on the analyzer: The yellow light is always on when the power is on. The red light is on when X-rays are being generated. Figure 2.2.3 There are two (round) connection ports on the instrument. The one on the front is for connection to the PDA, using the remote PDA extension cable, during bench top operations (see Figure 1.2). (The second port, located on the handle is for connecting the remote trigger cable. Figure 2.2.4
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The infrared safety sensor on the instrument nose operates by detecting IR reflected from the sample surface. It is designed to prevent accidental X-ray activation while no sample is in place in front of the analyzer. Figure 2.2.5
2.3. The PDA computer The removable PDA computer in the X-MET includes the user interface for operating the instrument. The computer is installed in the cradle of the instrument. The display is a 320×240 pixel color touch screen, which can be operated either with a fingertip or the stylus provided. For further information about the computer refer to the HP iPAQ Pocket PC instruction guide. The guide can be found with the CD delivered with the instrument.
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2.4. Environmental operating conditions for the X-MET3000TX Temperature Analyzer
-10 to 50 °C
Charger
-10 to 45 °C, operating -40 to 70 °C, non-operating
Humidity Continuous operation at 20 to 95 % RH, non condensing. The charger is designed for indoor use only.
Shock resistance In transport and operation the instrument must not be dropped or left in exceptional conditions, which might damage its sensitive components. During the measurement, small vibrations may lead to inaccuracies if the vibrations influence the detector. Line voltage Analyzer 90 – 240 V, 50 – 60 Hz. PDA 100 – 240 V, 50 – 60 Hz Charger 85 - 265 V, 47 - 63 Hz
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2.5. Power supply Battery power The X-MET batteries are situated inside the handle. To remove the battery, push the switch and pull to remove the battery. Each fully charged battery will operate the X-MET for approximately 4 hours.
Line (A/C) power Line operation of the X-MET is possible by connecting the AC adapter to the instrument. To do this, remove the battery and connect the AC adapter to the plug in the bottom of the handle.
Charger The battery charger is provided for charging X-MET batteries. To charge a battery, remove it from the X-MET and connect the battery to the charger. Charging the X-MET batteries can take up to 2 hours if they are fully discharged. Note: the PDA has internal batteries. Be sure to fully charge the PDA batteries using the iPAQ AC adapter prior to using the instrument for the first time. The PDA draws power both from the X-MET battery and its own internal battery, but will not charge from the X-MET battery.
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2.6. Hot Surface Adapter
The hot surface adapter is a standard feature of the X-MET3000TX. It is designed for measurement at hot surfaces like hot tubes or plates. The adapter lowers the heat conduction and radiation from the hot sample to the detector. This is necessary because the detector crystal has to be cooled and stabilized to maintain its analytical performance. However, the heat conduction can not be prevented completely, thus there are limitations on the measurement times. Table 1 illustrates the limitations – surface temperatures with measurement and cooling times between measurements.
Table 1 Sample Temperature
Measurement time
Cooling time between measurements
300oC
15 s
10 min
300oC
5s
5 min
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Pre-operating instructions
3.1. Preparing the X-MET for use 1. Insert a fully charged battery into instrument. 2. Remove stylus from the PDA computer. 3. Unlock the PDA computer lock with the key (Figure 2.2.2). Slide the PDA computer snugly into the cradle on the instrument. Take care to seat the PDA on the connector correctly
4. Lock PDA computer into place. 5. Turn the X-MET power key to “ON” position (Figure 2.2.1). The yellow power indicator is switched on. Wait 1-2 minutes for the peltier cooler and X-ray tube to stabilize. 6. Push PDA power switch “ON”.
3.2. Switching backlight ON/OFF From the ”Start” menu on the PDA main screen, tap ”Settings”, then ”System” and then ”Backlight”. Set the parameters according to your need.
3.3. Calendar and clock adjustment The setting of the date and time is done from the main screen of the PDA. To change the settings, tap the date on the screen and perform the adjustments. If the PDA battery power has been completely discharged or the PDA has been reset, it may be necessary to adjust the date and time settings.
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3.4. Charging the batteries 3.4.1. Charging instrument batteries Turn the instrument off (Section 3.7). Remove the battery from the instrument. Connect the charger to the battery. The Power light on the charger is green when it is connected to the power supply. The Status light on the charger is amber when the battery is charging. When charge is complete, the Status light is green.
3.4.2 Charging the PDA internal battery
Turn the instrument off (Section 3.7.). Remove the PDA from the instrument by unlocking the PDA lock with the key. Insert the PDA adapter plug into the charging port on the bottom of the PDA. Plug one end of the PDA AC adapter into an electrical outlet and plug the other end into the PDA adapter plug in the bottom of the PDA. The amber charge light on PDA blinks while the battery is recharging and turns solid amber (nonblinking) when the battery is fully charged.
It is recommended that the PDA battery be completely charged before use if instrument has not been used for several days. Battery low warning messages will be displayed when the PDA battery charge is low.
3.5. Bench top operation To set the instrument for bench top operation, do the following: Place the instrument in the instrument stand provided so that the grooves in the instrument slide into the stand. (See Figure 1.2.). Connect the PDA to the X-MET with the remote extension cable using the port on the front of the X-MET.
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Turn on the instrument.
WARNING: To measure small sized samples, which don’t completely cover the measuring window and /or the infrared sensor, use the safety shield provided.
3.6 To turn off the instrument To turn off the X-MET, exit the analysis program, turn the PDA power off and turn the X-MET 3000TX power key to “OFF” position.
3.7. Sample preparation The sample surface should be clean of dust, corrosion, oil etc. The analysis is done on the surface of the sample, so the surface must be representative of the material. If the sample is smooth and clean (no rust, oil, dirt etc.), no sample preparation is necessary. If the sample surface is dirty it should be cleaned. Contamination on the sample surface will have the greatest effect on light element analysis (Ti, V, Cr). Dirt and oil can be simply cleaned from the surface with a cloth. Rust, paint and coatings should be removed by grinding the sample surface.
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Analysis Measurements 4.1. Start up After powering ON the X-MET (see Section 3.1) the analysis program is started from “Start” menu (Figure 4.1.). Tap “X-MET” to start the program.
Figure 4.1. Start menu The “X-MET3000” screen (Figure 4.2.) appears with “Waiting for Connection” message in the lower left corner (this may take up to 30 sec.).
Figure 4.2. Getting connected
4.2. Making measurements 4.2.1. General The X-MET is usually delivered to the user fully calibrated. Therefore, it can be used for daily work without any preparation other than that described in Section 3. After start up the X-MET will go to the measurement screen (Main menu) (Figure 4.3.).
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Via this menu the user can: 1. Select the mode of operation. 2. Make a measurement. 3. Name the sample to be measured. 4. Display the spectrum of the latest measurement. 5. Access the settings to change, for example, the measurement time. Measurements are made by putting the nose of the analyzer on the sample (or the sample on the nose), and pressing the trigger on the analyzer. Be sure that the infrared sensor on the nose of the instrument is covered or the measurement will not start. The red light indicates that the X-ray tube is generating X-rays. Make sure that you keep the analyzer on the sample during the entire measurement. If the sample does not cover the infrared sensor no data will be acquired. In that case release the trigger immediately and reposition the sample to cover the sensor. The total measurement time and the elapsed measurement time will show at the bottom of the measurement screen (figure 4.4.) After the measurement time has elapsed, release the trigger. The calculation takes a few seconds, depending on the selected method, sample type and grade identification. When the measurement is completed and results are shown (Figure 4.5) a new measurement can be started. To hide the menus in the measurement screen tap once in the white area above the menu boxes. To unhide the menus tap the screen again. Note: The instrument will take 1-2 minutes to stabilize after switching the instrument power on. During this stabilization time it is not possible to perform measurements.
WARNING: When the X-MET3000TX is operating, ensure that the sample completely covers the aperture and IR sensor or use the small parts shield. This prevents stray radiation from exiting the instrument.
WARNING: Never point the instrument at yourself or another person even with a sample in place.
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Figure 4.3. Measurement screen, Main menu.
Figure 4.4. Measurement in progress.
Figure 4.5. Measurement results screen.
4.2.2. Name Sample The user can give a name to the sample to be measured. If the result is saved, the name will be also saved. To name a measurement, tap “Name Sample” on the main menu. This brings you to the screen where you are prompted to input the name using the keyboard (Figure 4.6.). If the name consists of a continuous string, a space and a number (for instance PIPE 5), the number is automatically increased after every measurement (PIPE 6, PIPE 7 etc.). Note: You can only name a sample before it is measured. Entering a sample Name by tapping on the name box in the results screen will name the next sample.
Figure 4.6. Name sample.
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4.2.3. Select Method To select the desired method tap “Select Method” from the main screen. This will activate a screen where you will find all the methods stored in the instrument memory (Figure 4.7). The method name and type are shown. To select a method, highlight the method and tap “Select Method”.
Figure 4.7. Selecting a method. There are three method types available: ‘Empirical Assay’. ‘Identification’. ‘Fundamental Parameters’.
4.2.3.1. ‘Empirical Assay’ method type ‘Empirical Assay’ is an Assay & Grade method for measuring the elemental concentrations of unknown samples. An empirical assay method is a set of calibration curves and other parameters that calculate the concentration of a specific set of elements in an unknown sample. It is the result of a calibration procedure. The calibration procedure assay method is created using a set of standards which have assay values for the elements being analysed in the unknown samples. The standards have concentrations that vary from one another and span the range of concentrations expected in the unknown samples. Analysis of samples outside the calibration range can result in erroneous results.
Figure 4.8. Result of an empirical assay method measurement
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The X-MET software automatically checks to see if the analysis results are outside the calibration range. If this occurs, the results are displayed with an arrow next to the number. If the arrow is pointing to left, the result is below the calibration range. If it is pointing to the right, the result exceeds the range. In either instance, the results should be reviewed before accepting them. If the out of range indicator shows often for an analyte, it may be necessary to recalibrate the method for the new range of concentrations. 4.2.3.2. ‘Identification’ method type Often it is not necessary to find out the actual assay values for an unknown sample, but only necessary to identify or verify the sample grade, or proprietary alloy name. This is done by comparing the X-ray spectrum of the unknown sample to the spectra of known samples, which have been recorded in the memory during the calibration. If a similar sample is stored in the reference library, the X-MET will simply give the name of the sample as it is stored in the memory. The name can be the grade of the alloy e.g. SS 316, or any other name under which that sample was stored. Where a positive identification is made, the identified sample name is shown together with the note Good Match.
Figure 4.9. Result of positive identification of 2 ¼ Cr 1Mo If the measured sample is slightly different from any reference in the memory then Possible Match is displayed, together with the closest reference name(s). Where a Possible Match is identified one or two reference names can be given by the instrument. Note: The first given reference name is a closer match to the measured sample. When the measured sample is not similar to any of the references stored in the memory, the message No match is given.
Figure 4.10. Result of negative identification.
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A test value called Difference shows the closeness of the measured sample to the reference in the memory. The closer the value is to zero the more exact the measured sample and the stored reference signatures are to each other. The threshold values between good, possible and no match can be set during the calibration of the instrument.
4.2.3.3. ‘Fundamental Parameters’ method type ‘Fundamental Parameters’ (FP) is an Assay & Grade method for measuring the elemental concentrations of unknown samples. FP analysis provides assays based on fundamental knowledge of X-ray physics, the detector response, and the basic spectra of a few standards. There are three different FP methods available depending on instrument configuration. Alloy FP provides chemical analysis of elements commonly found in alloys. The concentration range for each element can vary from 0% up to 100%. The program normalises the results to 100%. Soil FP is for analysing heavy element concentrations in soil. Plastic FP is for analysing heavy elements in plastic or other low density material.
Low concentrations of elements are not shown if their value is less than 2 standard deviations (STD). The elements are shown in decreasing order of magnitude, thus making it easier to read the results (Figure 4.5).
4.2.4. Display spectra The user can view the spectrum of the latest measurement by tapping “Display Spectra” (main menu). Figure 4.11 shows the screen used to plot spectral data. The data on the right side of the spectrum shows information relating to the Cursor position in the spectrum. Cursor Energy displays the energy value in keV. Channel is the cursor’s position in channels. Count gives the number of counts at the cursor’s position. Select “Zoom In” to view any part of the spectrum in more detail. Once an area has been enlarged, a new area can be enlarged again. To restore to the previous scale select “Zoom Out”. To restore to original settings select “Fit to Window”. To zoom on the Y-axis enable “Zoom on Y-Axis”.
Figure 4.11. Spectral display.
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Select “XRF Line Display” to place markers on the spectrum identifying the α and β lines for the K and L series of the X-ray lines. To select an element, tap the element symbol (Figure 4.12.) and tap “Ok” to view. The markers for the selected elements will be shown as in example Figure 4.13.
4.12. Selection of element for line identification
4.13. Spectral display XRF line markers
4.2.5. Configuration Backup This feature backs up all files associated with calibrated methods. To start the backup procedure, select Configuration Backup from the Main menu (Figure 4.3.) and then “Store Configuration” in the menu shown in Figure 4.14.
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4.14. Configuration Backup Settings
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Instrument settings 5.1 General A user can select different choices and options related to the instrument operation and data output. To start these functions first tap “Settings” in the main menu. The content of the “Settings” menu is different depending on the selected method type.
5.2. FP method Settings
Figure 5.1. Settings menu of a FP method 5.2.1. Set Measurement Time The measurement time can be changed by selecting “Set Measurement Time:” on the Settings menu. This brings you to the screen where you are prompted to set the time using the keyboard (Figure 5.2). Tapping “Del” deletes the last character entry and tapping “Clear” empties the edit field.
Figure 5.2. Measurement time setting.
If the measurement time is set to 0 (zero), the measurement time elapses until the trigger is released. The result is updated in the screen at intervas of couples of seconds. the final result is calculated after releasing the trigger.
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5.2.2. Output Settings Data produced during analysis can be stored to the PDA. To activate saving of data select “Output Settings” on the Settings menu. There are two different file formats for saving analysis results. The logfile stores the data displayed in routine analysis in text format. The table file uses a worksheet format, and the stored results can be processed further with Excel program. To save results tap either “Write logfile?” or “Write tablefile?”, depending on the desired format. The button changes to YES (results will be saved) if it was earlier NO and vice versa. The selected value (YES/NO) is shown in bold font. To specify the directory path and filename where the analysis results will be stored, select “Log filename:” or “Table filename:” depending on what was selected as an output format. Spectra of the analysis measurements can be saved by tapping the “Write spectra?” button. The directory where the spectra will be stored can be changed by selecting “Set spectra directory:”.
Figure 5.3. Output settings.
5.2.3 Test Measurement The test measurement function provides a means to measure an arbitrary sample and display the recorded X-ray spectrum on the screen. Select the desired current / voltage pair and press the trigger to start the measurement. During the measurement the elapsed and total measurement time is shown, as usual. After the measurement is finished the spectrum is shown (see Section 4.2.4 Display Spectra). 5.2.4. Method Type Parameters This screen allows the changing of various parameters related to the selected measurement method.
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Figure 5.4. Method type parameters of FP method. 5.2.4.1. STD Display Standard deviation (STD) is the precision of the measurement based on the counting statistics. To display the measurement’s statistical error for each analysed quantity select “STD Display” ON. 5.2.4.2. Concentration The measurement unit can be changed either to percent (%) or parts per million (ppm). 5.2.4.3. Invisible Element Correction The X-MET3000 cannot measure the elements with a lower atomic number than Ti (22). Those elements are called “invisible elements”. If their concentrations are significant, the analysis will be distorted because of the normalization to 100%. If the concentrations of invisible elements are known beforehand, the user can input the values manually. If the invisible element correction is not needed, it can be switched off. To enable invisible correction select “Invisible Element Correction” ON from the “Method Parameters” screen (Figure 5.4). 5.2.4.4. Set Invisible Element If the concentrations of invisible elements of the sample are known, select the “Set Invisible Elements” button. The Invisible Element screen is shown, see Figure 5.5. To choose an element select “Add Element”, this will open the screen shown in Figure 5.6. Choose the element you want to add and select “Ok”. To set the known concentration choose “Change Element Value”. Figure 5.8. shows the added element list.
Figure 5.5. Manual input of invisible elements.
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Figure 5.6. Adding elements.
Figure 5.7. Set concentration.
Figure 5.8. Added elements
Individually add all the elements you want to include as invisible elements. An element can be removed by first highlighting the element and then selecting “Delete Element”. When the user has manually input the concentration of invisible elements, they are used until the input is changed. 5.2.4.5. Grade tables On the result screen, the X-MET is able to show the grade name(s), or trade name(s) of the measured sample. The instrument does this by comparing the assays of the measured sample with those in a grade table. A grade table is a list of grade names with associated upper and lower assay limits for the analytes. Grades for the FP methods are automatically inserted in the system. The FP chooses the appropriate grade table according to the matrix element. Matrix elements are the elements which usually form the biggest part of the sample. For instance, low alloy steels contain about 95% iron, the rest (5 %) being alloying elements. Thus Fe is the matrix element of low alloy steels.
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5.2.4.6. Grade Expansion Coefficient: In this screen you may expand the grade identification limits. A value, which expands the lower and upper limit of grades , is calculated from n*STD. N is a discrete value, 0,1,2,3 or 4, and this can be changed by the user.
Figure 5.9. Grade expansion coefficient. 5.2.4.7. Grade Table Editor To create or edit grade files in the X-MET use the built-in grade editor. To access the grade editor, select “Grade Table Editor” from the Method Type Parameters screen (Figure 5.4.) and the ‘Select Matrix Element’ screen, shown in Figure 5.10, is displayed.
Figure 5.10. Select Matrix Element
An FP method chooses the right grade table according to the matrix element. Choose the desired matrix element by tapping the element symbol. The ‘Add/Edit/Remove Grade’ screen will be displayed (Figure 5.11).
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5.11. Grade editor, grade list screen. All the existing grade names for the selected matrix element will be listed. There may not be any grade names if a grade table for the selected matrix element has not yet been created. To add a new grade, tap “Add”. The user is prompted to give a name to the grade (see Figure 5.12). The name can have a maximum of 15 characters. Tapping “Remove” deletes the highlighted grade. The deletion is confirmed before the actual operation.
5.12. Edit New Grade Name screen To edit the grade, highlight the grade name and tap “Edit” (Figure 5.11). A screen (Figure 5.13.), with element list and with lowest and highest allowed concentrations, is shown. To add a new element, tap “New Element”. To remove a highlighted element, tap “Remove Element”. To edit lowest and / or highest allowed concentrations, tap the current value and a screen (Figure 5.14.) is shown where new values can be entered.
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5.13. Grade editor, editing grade
5.14. Editing concentration limits
5.2.5. User Setup Access to the X-MET instrument functions is categorized by three levels. Access to a level may be protected with a password. The user mode that is currently in use is highlighted. Normal User – Lowest level where functions related to making measurements and data storing are available. Supervisor – Medium level which allows calibration of the instrument. This level is protected by a password. Service – Highest level which is used only by service personnel. This level is protected by a password. In supervisor mode, the password of this level can be changed by tapping “Change password”.
Figure 5.15. User setup.
5.2.6. Assay Screen Settings To change the font size and the scrollbar size, go to “Assay Screen Settings”.
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Figure 5.16. Screen settings.
5.2.7. Energy Calibration In this screen the user can perform an energy calibration measurement. This is done by measuring the DUPLEX 2205 sample supplied with the instrument. To do the energy calibration measurement, place the sample in front of the analyzer and press the trigger. After the measurement is finished, release the trigger. If you do not wish to perform this measurement you may exit this screen by tapping “Skip Measurement”.
Figure 5.17. Energy calibration Note: The instrument needs about a 2 minutes warming up period after switching the instrument power on before it is ready for making measurements.
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5.3. Empirical assay method Settings
Figure 5.18. Settings menu of empirical assay method
5.3.1. Set Measurement Time The measurement time can be changed by selecting “Set Measurement Time:” on the Settings menu. This brings you to the screen where you are prompted to set the time using the keyboard (Figure 5.2). Tapping “Del” deletes the last character entry and tapping “Clear” empties the edit field. If the measurement time is set to 0 (zero), the measurement time elapses until the trigger is released. The result is updated in the screen at approximately two (2) second intervals (Figure 5.19). The final result is calculated after releasing the trigger.
Figure 5.19. Updating screen during measurement
5.3.2. Output Settings See Section 5.2.2. 5.3.3. Test Measurement See Section 5.2.3.
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5.3.4. Method Type Parameters This screen allows the changing of various parameters related to the selected measurement method.
Figure 5.20. Method type parameters of empirical assay method
5.3.4.1. Standard Deviation See Section 5.2.4.1.
5.3.4.2. Distance Scaling If distance scaling is enabled, the analysis is automatically corrected for irregular shape of the sample and for distance changes between the sample and the analyzer. The distance scaling works by identifying the sample and scaling the measured spectrum to a similar spectrum in the memory. If the sample is not identified, a warning is shown (Figure 5.21).
Figure 5.21. Distance scaling failed In this case, there is no matching reference in the spectrum library of the method. However, the user can add typical samples to the identification library for distance scaling. The sample to be used for scaling must be even and cover the whole measurement window of the instrument. Adding samples to a method is described in the Section 6.4.
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5.3.4.3. Edit Grades On the result screen, the X-MET is able to show the grade name(s), or trade name(s) of the measured sample. The instrument does this by comparing the assays of the measured sample with those in a grade table. A grade table is a list of grade names with associated upper and lower assay limits for the analytes. Grades for empirical assay methods are always associated with predefined assay methods. Thus the X-MET automatically uses a correct table to look for grades. To create or edit grade files in the X-MET use the built-in grade editor. To access the grade editor, select “Edit Grades” from the Method Type Parameters screen (Figure 5.20.) and a screen, as shown in Figure 5.11, is displayed. All the existing grade names for the selected matrix element will be listed. There may not be any grade names if a grade table for the selected matrix element has not been yet created. To add a new grade, tap “Add”. The user is prompted to give a name to the grade (Figure 5.12). The name can have a maximum of 15 characters. Tapping “Remove” deletes the highlighted grade. The deletion is confirmed before the actual operation. To edit the grade, highlight the grade name and tap “Edit” (Figure 5.11). A screen (Figure 5.13) with element list and with lowest and highest allowed concentrations is shown. To add a new element, tap “New Element”. To remove a highlighted element, tap “Remove Element”. To edit lowest and / or highest allowed concentrations, tap the current value and a screen (Figure 5.14.) is shown where new values can be entered.
5.3.4.4. Display spectral ID To display the method and reference used in the distance scaling, change Display spectral ID to “YES”.
Figure 5.22. Displaying method and reference used for distance scaling
5.3.5. User Setup, See Section 5.2.5. 5.3.6. Screen Settings, See Section 5.2.6.
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5.3.7. Method Parameters
Figure 5.23. Method parameters menu of an empirical assay method The Method parameters menu offers three functions for the maintenance of calibrated empirical assay methods. These features help to insure accurate method analysis over time while minimising the need for frequent recalibration. This chapter describes the features and their use.
5.3.7.1. Single Point Recalibration Single point recalibration is a method to correct the results for a selected material type only. It is useful when the user has to make an accurate analysis within narrow concentration ranges. Be careful when using this feature, because the correction is only valid for samples close in concentrations to the specific (reference) sample. To perform a single point recalibration, go to “Single point recalibration”. A screen similar to that shown in Figure 5.24 will be displayed. Highlight the analyte you want to correct and press “Set concentration”. Enter the concentration. Then place the reference sample against the measurement window of the instrument and pull the trigger to start the measurement. If the single point calibration is no longer needed, you can reset the single point recalibration by pressing “Reset”.
Figure 5.24. Single Point Recalibration
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5.3.7.2. Check Sample Measurement The function of the check sample is to provide a reference point during calibration that can be used later for updating calibration equations. This applies to empirical assay methods only. During calibration, a sample is measured and stored as a check sample. This sample is representative of the standards used in the calibration. When the sample is measured, the assay values and standard deviations are stored along with the calibrated method. This sets a reference point for the performance of the calibration equation. At any time, the same sample can be measured using the Check sample option. This displays the screen shown in Figure 5.25.
Figure 5.25. Measurement of check sample. Place the check sample against the measurement window and pull the trigger to start the measurement. After the measurement is completed the analysis results are displayed (Figure 5.25.). The first column shows the analyte. Original assay values from the analysis during calibration are shown in the second column. The third column is the assay value from the present analysis. Column four shows the difference between the two values.
Figure 5.26. Results of check sample analysis. If the difference is less than three standard deviations, it is assumed that there is no statistical difference between the measurements. Thus no update is recommended. In this instance, the “Cancel” button should be pressed.
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If the difference between the two measurements of an analyte is more than three standard deviations, the deviating analyte is marked with yellow colour. In this instance, using the check sample results to update the calibration curve is recommended. To update the calibration simply press the “Save” button. The intercept of the calibration equation will be adjusted so the new analysis will correspond with the original. If the difference between the two values is more than ten standard deviations, the following warning is displayed “Check to see if sample is correct”. Press the “Cancel” button and check the following before updating the calibration: 1) Check that the sample currently being analysed is the sample used for the original check sample measurement. 2) Make sure that the sample is stable over time and has not changed in composition since the original analysis. 3) Insure that the sample has been properly placed against the measurement window.
If all these conditions have been met, then re-measure the sample and update the calibration if necessary.
5.3.7.3. Analyte Correction Correction of the calibration equation (of an empirical assay method) with the check sample creates a coefficient that is applied to the calibration´s curve intercept value. The “Analyte correction” option shows the correction coefficient and allows for it to be manually changed. Figure 5.27 shows the correction coefficients. To enter a manual correction coefficient, highlight the element to be changed then press the “Change Offset” button. A dialogue box opens and the new value can be entered. When the “Ok” button is pressed, the new value will be used to update the calibration equation.
Figure 5.27. Analyte Correction
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5.4. Identification method Settings
Figure 5.28. 5.4.1. Set Measurement Time The measurement time can be changed by activating “Set Measurement Time” on the Settings menu. This brings you to the screen where you are prompted to set the time using the keyboard (Figure 5.2). Tapping “Del” deletes the last character entry and tapping “Clear” empties the edit field. If the measurement time is set to 0 (zero), the measurement time elapses until the trigger is released. The result is updated in the screen at approximately 2 second intervals (see Figure 5.19.) The final result is calculated after releasing the trigger.
5.4.2. Output Settings See Section 5.2.2.
5.4.3. Test Measurement See Section 5.2.3.
5.4.4. Method Type Parameters This screen allows the changing of various parameters related to the selected measurement method.
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Figure 5.29. Method type parameters of an identification method 5.4.4.1. Difference Display A test value called Difference shows the closeness of the measured sample to the reference in the memory. The closer the value is to zero the more exact the measured sample and the stored reference signatures are to each other. The threshold values between good, possible and no match can be set during the calibration of the instrument. To display the measurement’s difference value, change “Difference Display” to YES. 5.4.4.2. Confirm Possible Match / Confirm No Match A user may be prompted to confirm a ‘Possible Match’ or ‘No Match’ by selecting ‘Yes’ for the corresponding option. A pop-up message box is displayed (see example Figure 5.30).
Figure 5.30. Confirmation box of No Match 5.4.4.3. Display Screening Path Change the “Display Screening Path” to YES, to display the intermediate results of the screening chain, not only the final result.
5.4.5. User Setup See Section 5.2.5.
5.4.6. Screen Settings See Section 5.2.6. 5.4.7. Method Parameters
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Figure 5.31. Identification method parameters The thresholds options define the limits for Good, Possible or No Match. If the difference between the measured sample and the reference sample, that best matches the measured sample, is below the fine threshold value, it is considered to be a good match. If the difference is between the fine and coarse threshold values, it is a possible match. If the difference is greater than the coarse threshold value, there is no match. To change the threshold value, select the button and enter a new value. If ‘No Match’ is reported for a measurement, the result may be recalculated using a different method. Select “Recalculation Method” and select the method you wish to use for recalculation, from the list.
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Instrument calibration 6.1. General In order to give accurate results the X-MET needs to be carefully calibrated for all the sample types to be measured. Although the instrument is often delivered fully calibrated, complete software tools for user calibration are available.
6.2. Calibrating with X-MET 3000 Calibration Software
The empirical assay methods and the identification method are created with X-MET 3000 Calibration Software, which runs on an external PC. For further information about this software refer to the X-MET 3000 Calibration Manual.
6.3. MSG and FP calibration Both MSG (Metal Standard Generation) and FP calibration software can be accessed from the “Calibration” button on the Main Menu (Figure 4.3). These calibrations are usually provided when the instrument is delivered and in general the user does not need to create these. For further information about this software refer to X-MET 3000 Calibration Manual.
6.4. Adding a reference to an Identification method A user can perform the most commonly used operations for the identifications, directly in the PDA program. The user can add a new reference for an Identification method simply by making a sample measurement, and instructing the X-MET to store the measured spectrum. 6.4.1. Adding a reference sample to a predetermined identification method The user can add samples to any identification method calibrated into the X-MET by proceeding as follows: Select the method by tapping “Select Method” in the Main Menu (Figure 4.3). Choose the identification method according to the sample type you are about to add. For example if you have a Stainless steel sample, then highlight the SS ID method and tap “Select Method”. Choose Settings in the Main Menu and then Method Parameters. Select “Reference Maintenance” at the bottom of the screen (Figure 5.31). This will bring a new menu onto the screen (Figure 6.1), with a list of all the references stored in the selected method. A date next to the sample name indicates that the reference is measured and has a spectrum in the identification library.
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Figure 6.1. Adding a reference into memory Tap the “Add Sample” button and type in the desired sample name for the sample to be added (Figure 6.2) Tap the “OK” button. Make sure that the new sample name is highlighted on the sample list. Place the sample on the analyzer and pull the trigger to start the measurement. Keep the analyzer on the sample during the entire measurement time. After the measurement is complete the sample name and its spectrum are stored in the memory.
Figure 6.2. Defining standard name Note: When storing references you should use a measurement time long enough to collect a well-defined spectrum (60 – 120 seconds). The sample is now added to the selected X-MET identification library.
6.4.2. Setting screening conditions for a reference Screening means instruction to the X-MET to use another method to re-calculate the result, if the reference in question has been identified. The reason for this may be that more accurate identification or concentration analysis is needed. Note: Screening happens only if the result from the identification is Good match. To define the screening method for a reference, press the “Set Screening Method” in the “Reference Maintenance” menu (Figure 6.1.). This will bring a menu on the screen, which shows all the calibrations in the X-MET memory. Scroll to move the cursor to the method you wish to use. Tap the “Select” button to select the method.
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6.4.3. Adding a sample to the identification library when sample type is not known If the exact type of a sample is not known, it is not possible to allocate it to a predetermined identification method. However, the user may allow the X-MET to deduce the general sample type and target method. First select the general identification calibration from the “Select Method” menu. Then make a measurement as usual. The X-MET will now first try to identify the sample type and will switch directly into the most likely calibration method. Select this as the target method on the “Select Method” screen, and add the reference into the target method as described in Section 6.4.1.
Safety Information You MUST: Read and understand this entire safety section. Contact the appropriate regulatory authority to determine what is needed (see Customer Responsibilities 7.1.1)
Have received training in the safe operation of the X-Met (see Customer Responsibilities 7.1.1).
Complete a risk assessment for the safe operation of the X-Met (Refer to 7.4 for dose rates).
Maintain a list of authorized users. Check correct functioning of analyzer once a month. See Customer Responsibilities 7.1.1 and Customer Maintenance 7.6).
7.1. Radiation Safety
The X-Met3000TX series must only be used by persons who have been trained to operate the probe safely. Do not point the instrument at any person when it is in operation. Users must not try to gain access to the radiation enclosure. Servicing must only be carried out by engineers trained by Oxford Instruments.
7.1.1. Customer Responsibilities
Contact the appropriate regulatory authority to determine if registration or licensing requirements apply: For example, in the United Kingdom, equipment of this type is defined as a radiation generator, and its use is governed by the ‘Ionising Radiation Regulations 1999’ (IRR99); the ‘Health and Safety at Work etc. Act 1974’ (HSAW); the ‘Management of Health and Safety at work Regulations 1999’ and the ‘Provision and Use of Work Equipment Regulations 1998’. Users must notify the Health and Safety Executive (HSE) of their intention to work with ionising radiation. (Notification is only done once, or when an employer makes a material change to their work that would affect the particulars of the original notification. If the employer has already notified the HSE, further notification following the purchase of a 3000TX is not required). Help and advice is available from the HSE infoline on telephone number 0845 345 0055. The HSE require 28 days notice. There is a requirement to appoint a Radiation Protection Advisor (RPA). The RPA will help specify work procedures to be followed including training requirements for the correct use of the equipment.
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Test the device for correct operation of the ON/OFF mechanism every six months and keep a record of the test results. If the instrument fails the test, contact an OIA representative immediately for instructions and return the instrument for repair. Maintain a record of the instrument use and any service to shielding and/or containment mechanisms for two years or until the ownership of the instrument is transferred or the instrument is decommissioned. Report to appropriate authority any possible damage to shielding and any loss or theft of the instrument. Transfer or loan the instrument only to persons specifically authorized to receive it, and report any transfer to the appropriate regulatory authority, normally 15 to 30 days following the purchase, if required. Report the transfer of the instrument to an appropriate OIA representative. Comply with all instructions and labels provided with the instrument and do not remove labels. Removal of labels will void the warranty. Do not abandon the instrument.
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7.2. Description and use of the safety interlocks The X-MET3000TX has been designed with a failsafe safety circuit to prevent inadvertent exposure of the operator to the X-ray beam. The safety system for the instrument consists of three failsafe lights, a key lock, a trigger to activate X-rays, and an infrared sensor. The function of each safety feature is described below: Primary power safety keylock –
A key lock is employed to control power to all components. The key lock must be turned on before any actions can be initiated. NOTE: Remove the key from the analyzer when not in operation to prevent unauthorised use.
Yellow, High voltage on, failsafe warning light –
When the key lock is turned on, the yellow light will be activated to indicate there is voltage to the power supply. If the bulb has failed or has been removed, the safety circuit will not permit application voltage.
Operator trigger interlock – When the trigger is pulled, X-rays are generated if the following conditions are met:
Infrared beam safety sensor –
The infrared beam safety sensor, located at the nose of the instrument, will not permit X-rays to be generated unless a solid object covers the infrared beam.
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Dual red X-ray on failsafe warning light –
When the trigger is pulled and the infrared sensor is engaged, the red lights will be activated indicating the generation of Xrays. If one or both of the red LED’s are burned out, X-rays will not be generated.
Do not point the instrument at any person when the probe is activated. Note that the form of the primary beam is a narrow cone that points obliquely to the left, not directly forwards. The radiation intensity is high in the primary beam and therefore no part of the body should be exposed to that radiation. While measuring, make sure that the instrument is in contact with the sample and that the whole measurement window and infrared sensor are covered by the sample. In cases where the sample doesn’t cover the whole measurement window use the safety shield for small samples. Thin samples may allow higher exposure; see 7.2.1.
7.2.1. Precautions to take when analysing Small samples Small samples that do not cover the measurement window entirely are quite obviously potentially risky to measure because part of the primary radiation may go through the sample un-attenuated. To eliminate the risk the protective safety shield for small samples is provided to cover the sample entirely.
Protective safety shield for small sample measurement.
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7.2.2. Precautions to take when analyzing thin samples A less obvious risk to radiation exposure is caused by the measurement of thin samples. Part of the radiation coming from the X-ray tube is so high energy that it penetrates thin samples, especially if they are of low atomic number material. The following table gives the relative intensities after the radiation has gone through aluminum / iron sheets of various thicknesses. (The tube is run at 40 kV, 2µA). Aluminium sheet
Relative intensity
Iron sheet
Relative intensity
0 mm 1 mm 2 mm 3 mm 4 mm 5 mm 10 mm
100 55 36 26 19 15 5
0.0 mm 0.1 mm 0.2 mm 0.3 mm 0.4 mm 0.5 mm 1.0 mm
100 31 15 8 5 3 0,4
NOTE: If the sample is unable to stop the primary radiation the dose rate may be high behind the sample. An aluminum sample must be quite thick before it absorbs most of the radiation whereas iron provides much better shielding. In practice the difference is important and means that it is wise to measure aluminum samples at arms length.
7.3. Radiation Protection DOs and DONTs DO Read and understand the safety information (Section 7)
DONT Override the safety features
Follow any instructions given Store the key away from the analyzer when not in operation to prevent unauthorized use.
Point the analyzer at any person or animal Leave the key with the analyzer when not in use
Store the analyzer in a safe location when not in use. Keep control over who is authorized to use the device.
Leave the analyzer unattended if not safely stored away. Allow people into the beam path and train users in managing this risk.
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7.4. Radiation Dose Rates 7.4.1. The intensity of the primary beam The following table reveals the intensity of the primary beam when the infrared sensor is intentionally bypassed and no sample is placed in front of the probe. It gives the time that hands may be kept in the beam at different distances from the probe window without exceeding the limit given by the law. The limit for a radiation worker is 500 mSv per year and if we assume that the person works for a 50 weeks a year the weekly dose is 10 mSv /a. The distance is calculated from the window, but the tube is actually about 3 cm from the window. Reduce exposure by maintaining the maximum possible distance from the radiation source to the operator or member of the public. Exposure rate is reduced as the distance from the source is increased. The greater the distance, the less amount of radiation received. Doubling the distance from a point source reduces the dose rate (intensity) to 1/4 of the original. Tripling the distance reduces the dose rate to 1/9 of its original value. Distance (cm)
Time per year
Time per week
100 50 25 10 5 0
1300 h 344 h 96 h 20 h 7h 1h
26 h 6 h 53 min 1 h 55 min 25 min 9 min 1 min
Although occasional ”accidental” bypassing remains within permissible levels careless handling of the instrument may cause overdoses. Looking at the distances the doses in this case are most likely obtained by the user himself.
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Primary beam direction if the safety logic circuit is bypassed
7.4.2. Scattered Radiation dose rates Measurements taken at 10cm from analyzer with analyzer pressed against a sample. Operating current 3.1µA. (1µSv = 100µrem).
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Position
µSv/hr
Position
µSv/hr
1
0.07
8
0.07
2
0.07
9
0.06
3
0.04
10
0.05
4
0.05
11
0.05
5
0.05
12
0.06
6
0.06
13
0.05
7
0.07
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7.5. What to do In case of emergencies The X-ray emission from the instrument could be harmful to a person if they operate the analyzer without the appropriate training. If the instrument is lost or stolen, notify the local and/or state regulatory agency as soon as possible.
The first action to take in the event of an accident with instrument is to turn off the device and remove the battery pack.
7.5.1. Minor damage If any hardware item appears to be damaged, even if the system remains operable, contact your nearest OIA representative immediately. Use of a damaged analyzer may lead to unnecessary radiation exposure and/or inaccurate measurements. 7.5.2. Major damage If the analyzer is severely damaged, contact an OIA representative immediately and the appropriate regulatory agency in your state or country. Care must be taken to ensure that personnel near the device are not exposed to unshielded X-rays that may be generated. Removal of battery pack will stop all X-ray production. 7.5.3. Loss or theft Notify the appropriate regulatory agency in the country or state in which the device is being utilized. In addition, contact your nearest OIA representative immediately in case of a stolen device. Take the following precautions to minimize the chance of loss or theft: Never leave the analyzer unattended when in use. When not in use, always keep the device in its shipping container and store it in a locked vehicle or in a secured area. Keep the key separate from the analyzer. Maintain records to keep track of all instruments, and the operators assigned to use them and where they were used.
7.6. Customer Maintenance Establish a routine for checking the correct functioning of the infrared beam safety sensor, located at the nose of the analyzer: Measure a sample in the normal way but pull away from the sample during the measurement. The measurement will immediately cease as the safety beam is uncovered. Do this once a month to check that x-ray emission does indeed cease unless a solid object covers the infrared beam. Similar rules apply in other countries. Users should contact their local Oxford Instruments representative for specific advice.
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Appendix 1: Troubleshooting
8.1. If measurement will not start A1. If the X-MET program is started before the instrument power is turned on the program cannot communicate with the instrument. ⇒ 1. Exit the X-MET program and turn off the instrument power. 2. Take the PDA out of the instrument and press the reset button at the back of the PDA. 3. Remount the PDA onto the instrument. 4. Make sure the instrument power is switched “ON” before starting the X-MET program.
A2. If the infrared sensor is not covered the measurement will not start. ⇒
Make sure that the infrared sensor is covered completely.
A3. The sample surface may be too darkly coloured to reflect light to activate the infrared sensor. ⇒
Insert a piece of white paper between the sample and the infrared sensor.
A4. The battery is discharged and yellow light is not on or yellow light is blinking. ⇒
Is the yellow light on? If it isn’t or it is blinking change the battery or connect the instrument to the AC adaptor. Note! Yellow light will become dim when battery is low.
A5. There is no communication between the PDA and the instrument. ⇒ PDA not seated properly. Exit the analysis program, remove the PDA and re-seat it on the connector assuring that it is firmly seated. Restart the program and try again.
8.2. If the X-MET program ”locks up” If other programs are running the X-MET program may ”lock up”. Closing other programs frees system memory for other tasks. 1. Go to the ”Start” menu and tap ”Settings”. 2. Tap the ”System” tab. 3. Tap the ”Memory” icon and tap ”Running Programs” and then tap “Stop All”.
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Appendix 2: X-MET3000TXS – Soil measurements 9.1. Description of the X-MET3000TXS The X-MET3000TXS is a portable, elemental analyzer with an integrated PDA (Personal Digital Assistant) computer. It is based on energy dispersive X-ray fluorescence technology. It uses an X-ray tube as the source of excitation and a Peltier cooled Si-PIN detector. The X-MET3000TXS provides a method for the chemical analysis of soil. Besides heavy elements measurements in soil X-MET3000TXS can also be used for mining applications where applicable. Field portable x-ray fluorescence is an exemplary field method offering rapid, cost-effective screening of heavy metals in soil. Measurements can be done either in the field (direct measurements from the soil or bagged soil measurements) or in the laboratory (prepared samples in the sample cups). Even in instances where laboratory analysis is required, field XRF can be used to rapidly pre-screen samples to obtain the optimum efficiency from the laboratory sampling effort. Since XRF analysis does not destroy the sample, any sample collected and measured in the field can be retained for verification by a laboratory. The instrument is delivered to the customer with a Fundamental Parameter analysis program for soils. An Empirical soil calibration, with a factory soil sample set, is available as an option. By aid of a special calibration program, customized empirical calibration models can be created for an analyzer. The analyzer is battery operated with A/C operation as an option. In some instances, it may be more convenient to use the X-MET3000TXS in a stationary bench top configuration. The picture below shows the X-MET in the stand provided. There are grooves in the body and the handle, which slide into the stand. Note that for bench top operation, the instrument can be used with battery or A/C (line voltage) power.
Figure 9.1 Bench top installation of X-MET3000TXS with safety shield for sample bag measurements.
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9.2 Radiation safety Please read thoroughly the “radiation safety” section in the XMET3000TX User’s Manual. In addition, the following safety measures should be taken into consideration when analyzing soil type samples: Note: When measuring light matrix samples (for example, soil or sediment) they must not be held on the analyzer measurement nose by hand. A Radiation safety shield, either for plastic bag measurements (see Figure 9.2) or for sample cup measurements (see Figure 9.3) or the background plate (see Figure 9.4) should always be used, not only to avoid radiation health risks but also to make a measurement background constant.
9.2 Safety shield for sample bag measurements
9.3 Safety shield for sample cup measurements (option)
9.4 Background plate
It should be noted also that the analyzer must be kept at right angles against the sample to minimize the scattering radiation (see Figures 9.5 and 9.6).
9.5 Correct analyzer position
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9.6 Incorrect analyzer position
9.3 Detecting heavy elements in soil 9.3.1 Heavy elements Heavy elements are normally considered as an element with density 4 – 5 g/cm3 and higher. Based on this definition all elements heavier than titanium (Ti) are heavy elements. However, normally only poisonous heavy elements are considered: arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), mercury (Hg), vanadinium (V), nickel (Ni), lead (Pb) and zinc (Zn). Some of the metals like Cu and Zn are poisonous only in high concentrations and they exist in normal, not contaminated soil as well. Most often the heavy elements originate from industry, for instance from waste burning plants (Cd, Hg), shooting tracks (Pb), mining (Cd, Cu, Ni, Zn), traffic (Pb) and fertilizers (Pc, Cd, Hg). Heavy elements cause harm both to human health and to the environment. Humans can be exposed to heavy elements by food plants, water and air. In the human body they concentrate into the liver and kidneys. In nature, heavy elements may cause harm to soil microbes and bacteria and they also can damage the vegetation. In different countries there are determined accepted concentration levels (reference value, target value, guideline value, soil quality criteria…) for heavy elements. Levels are determined based on use of the land. Typical classification is for example: 1) play grounds, 2) residential areas, 3) parks, 4) industrial areas. Concentration levels and their classification may vary significantly from one country to another. 9.3.2 Typical soil remediation project Depending on the goals of a remediation project an exact research plan needs to be done by the project management. At the very beginning of the project polluting elements need to be identified so that the actions of the project can be defined. Also, as soon as possible, a pollution degree needs to be defined on the contaminated area. It is very expensive to move contaminated soil from one place to another. Because of that sometimes soil removing can be avoided by more profitable but slower actions: for example, trees can be planted on a contaminated area to take care of remediation –they can absorb the polluting elements from the soil through their roots. A Research plan includes as a minimum the following issues: -
all participants involved
-
the target of the research plan: are we doing preliminary study just to check if the site is probably polluted or probably clean or are we finding hot spots of the area or are we checking the border outlines for polluted area?
-
background information of an area i.e. all available history information
-
estimation for occupational health risks
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-
what is the geochemistry of the site and what kind of soil properties will be examined
-
analysis requirements: what kind of analysis methods are used at the site and how much analysis work need to be done in the laboratories
-
what kind of analysis is done: qualitative, quantitative, maximum concentrations, average concentrations, concentration ranges
-
sampling method
-
sampling tools and sample preparation techniques
-
sampling plan
-
documentation
-
conclusion
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actions based on the project
After the project research plan has been made it is very important that it will be followed during the project so that all the reseach results can be interpreted. X-MET3000TXS can be used for example for profiling the polluted site in order to determine a sampling plan. Heavy element hot spots can be found quickly. Also remediation processes (excavations, load of trucks) can be controlled as well as the soil cleaning processes by the XMEt3000TXS analyzer. 9.3.3 Sampling Like in all XRF analysis sample itself plays an important role in the quality of analysis. Especially in soil analysis due to nature of soil itself the sampling and sample preparation are major important. Typically soil mixture to be analyzed with FPXRF (Field Portable X-Ray Fluorescense analyzer) is collected from five different points in the area of size 10m x 10m. There are various subjects related to sampling at the contaminated soil site. At least following questions need to be answered: -
Are we doing random or systematic sampling?
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Do we have only horizontal coordinates in our sampling map or are we taking samples also vertically?
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What is the sample amount? What is the sample bag material?
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How do we name the samples? How do we store the samples and how do we transfer them? Are we taking single samples, collection samples or do we do parallel sampling?
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How many samples are taken and how many of them will be analyzed at site?
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What kind of sampling diary is kept?
An example: Person who takes care of the sampling has enormous responsibility in the successful research and therefore he should have both experience and education. If the examined soil amount is 20 000kg and from that 10 kg collection sample of is taken and 1kg of collection samples is given to the laboratory where analysis is done from amount of 0.5g. In this instance the laboratory analysis is done from 0.025ppm sample amount of original soil amount and of course that 0.025 ppm should represent the whole 20 000kg. Quite often soil contains particles with vast range: Particle size may vary from fine clay powder ( 2 mm. Again, measure the sample from 3 different points by a measuremet time of 180 s. If the average result of this sample differ less than 20% with the average results of original sample containing all particles with diameter > 2 mm it means that the measured sample from sampling points is reasonably homogeneous and can be interpret as semi-quantitave results. If the results between non-sieved sample and sample sieved with > 2mm sieve differ more than 20% it indicates that the soil is not homogeneous and particle size is affecting to the results. If so, then sample should be sieved by using 250 µm sieve. If results from this sample sieved with 250 µm sieve differ less than 20% from the previous (> 2mm) then it indicates that minimum 2 mm sieving should to be done before measurements. If the results differs more than 20% from the sample sieved through 2 mm then particle size is still affecting the result. In this instance 125 µm sieve should be used to aduquate to assure the quantitative data quality level. Etc. 9.6.1 Sample cups XMET3000TXS measurements can be done either through the plastic bag or in the sample cups. Always better repeatability and accuracy is obtained when careful sample preparation, sample cups and safety shield for the sample cups are used. This is not only because of the sample homogenity but also because of the constant measurement geometry.
Inconsistent positioning of samples in front of the analyzer window is a potential source of error because the X-Ray signal decreases as the distance from the X-Ray tube increases. Maintaining a consistent distance between the window and the sample minimizes the problem. For the best results, the window of the analyzer should be in direct contact with the sample.
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When preparing the sample the penetration depth of the radiation should be taken account. When measuring soil for example Cr analysis is done from about 100 µm sample layer and Cd analysis is done from about 6 mm sample layer. For example in Cd case if the sample layer is thinner than 6mm then mass of the sample must be standardized i.e. sample cup weight should be equal from one sample to another although the sample volume would be different. For good results, soil samples should be dried and then ground fine enough to be essentially homogeneous. For Cu and Fe analysis this means grain size about 50 - 80 µm. For lighter elements the grain size should be even smaller, about 20 µm. However, acceptable results may be obtained in practice with coarser materials. Dry and ground soil sample should fullfill the sample cup. Sample should be pressed by a sample pressing tool to get air out of the sample material.
The sample cup consist of a plastic cell and a snap-on ring with a piece of plastic foil clamped between them. Pressing tool is used to remove an extra air from the sample.
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9.6.2 Sample Bags When making the analysis through the plastic bags, a flat, smooth and clean powder surface should be made for measurements. Before using any commercial sample bags it should be checked that the plastic does not contain any elements (for example such as Zn or Ti) which may disturb XRF analysis. It is recommended that sample bags provided by OIA Oy are used for the measurements.
At least particles with diameter > 2 mm should be removed from the sample. In some instances also the fine part with diameter > 0.5 mm of the sample is sieved out of the sample to avoid the classification in a sample cup or in the plastic bag. If the sample amount in the sample bag is too small i.e. the thickness of the sample under the analyzer is less than about 1cm then background plate should be used not only for the radiation safety issues but also to keep the measurement background constant.
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Appendix 3: X-MET3000TXR – Measurement of electronic components 10.1 Description of X-MET3000TXR X-MET3000TXR is a handheld EDXRF analyzer designed for quality control and RoHS compliance screening of plastics, metals and electronic components. X-MET provides quick quantitative analysis of all restricted elements; Pb, Cd, Hg, Cr and Br. Various different materials can be measured with the instrument; cables, PCB’s, components, plastic housings, solder material, fasteners etc. In addition to RoHS screening application X-MET3000TXR can be used also for many different sorting and quality assurance applications like measuring solder composition (Sn, Ag, Cu, Bi, Pb etc) and plastics (Cl, Ti, Fe, Sb, Sr, Ca, Zn etc). Basic configuration of TXR model is same as TX and all general information applies also to TXR model. PDA user interface is also similar than in TX model.
10.2 Methods Standard methods in X-MET3000TXR are Alloy FP and Plastic FP. Both are standardless fundamental parameter calibrations. Depending on instrument set-up it is possible also that there is empirical assay and/or ID models in method list for instance for solder alloys. Generally, ID method detects measured material based on spectral “fingerprint” and goes automatically to proper method, which can be either empirical or FP assay method or additional ID method.
Figure 10.1. Selecting a method. 10.2.1 Auto Detect Auto detect mode is Empirical Identification method which is used to detect material type. Depending on detected material type system will automatically use proper calibration method. Typical calibration methods in X-MET3000TXR analyzer are Alloy FP for metals and Plastic
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FP for low-density materials. Operation of Auto Detect method can be fine-tuned by adding own reference samples to the database in following way:
Figure 10.2. Reference maintenance
When Auto Detect mode is active press Reference Maintenance button in bottom of Main Screen. From Reference maintenance menu choose Add Sample and give name to the reference Measure sample by using at least 60s measuring time. Set screening Method, which method should be used with this type of the sample, for instance with plastic sample this would be Plastic FP. Notice: When measuring first time after addition of new reference result, result update will take long time as database is re-built.
Analysis method Sample name
Screening method
Measurement time Results Standard deviation
Detected grade
Add Reference to modify auto detect ID
Figure 10.3. Typical result screen, Auto Detect mode
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10.2.2 Alloy FP Alloy FP is general calibration for all metals types and allows measurement of wide concentration range (0-100%) of all typical metals. It is possible to measure wide range of alloys used in electronic industry including, Nickel, Iron, Cobalt, Copper, Lead, Titanium, Zinc, Silver, Gold alloys etc. Important feature of Alloy FP calibration is that result is always normalized to 100%. This means that if material contains light elements, which wont be detected by X-MET3000TXR Alloy FP (e.g. C, H, O, Si, Na, Mg, Al, P, Cl, S, Ca) analyzer reports higher concentration than true value as result of detected elements is normalized to 100%. All materials, which contains these elements should be measured with Plastic FP which takes into account amount of light elements in calculation. Following 29 elements are measured with alloy FP: Ag , As, Au, Bi, Cd, Co, Cr, Cu, Fe, Hg, Ir, Mn, Nb, Ni, Pb, Pt, Sb, Se, Sn, Sr, Ta, Ti, V, W, Cd, Zn, Zr, Br, Re
10.2.3 Plastic FP Plastic FP is general calibration for all “light matrix” material, even that it is specifically optimized for plastics. Plastic FP is recommended method for all materials, which contains light elements such as : C, H, O, Si, Na, Mg, Al, P, Cl, S, Ca etc. Typical light matrix materials include: Plastic, rubber, soil, ceramics, wood, paper, cardboard, soil, fiberglass, liquids, fabric, paint etc. Plastic FP, takes into account amount of light elements and gives correct result even that some of these elements cant be detected by X-MET3000TXR. However, pure metals cant be measured (excluding Al & Mg alloys) with Plastic FP as it is optimized for “light matrix” materials. Following 22 elements are measured with Plastic FP: Cl, Br, Sn, Sb, Ti, Cr, Mn, Fe, Ni, Cu, Zn, As, Pb, Bi, Se, Cd, Hg, Sr, Ag, Au, Mo, Ta. Plastic FP is designed to work in “light matrix” materials, thus maximum concentration of heavy element it can measure is about 20%.
10.3 Analyzing different materials 10.3.1 Measuring time Recommended measuring time for RoHS screening is dependent on target precision that is required for results by user. Generally recommended measuring time for measuring trace amount of heavy metals in homogeneous material is 120s, which enables detection of all RoHS elements which exceeds restricted limit (Cd 100ppm, Pb 1000ppm, Hg 1000ppm, Cr 1000ppm, Br 300ppm) in most materials. However if target is just to sort SnPb solder from lead-free solder or detect if Br fire retardant is used in plastic, required measuring time can be less than 10s. When measuring time is extended detection limit will be lower and repeatability of measurement result improves. As an example, when measuring time is doubled, detection limit lowers about 40%. 10.3.2 Non-homogeneous material When analyzing material, which is not uniform, i.e. it includes many different material like printed circuit board or semiconductor chip, measuring result will be average of measuring spot area. Measuring spot size is about 5 x 6 mm in X-MET3000TXR analyzer. When measuring small components weld beam adapter (p/n4103407P) can be used to restrict measurement area.
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Figure 10.4. weld beam adapter ED-XRF is generally surface measurement method and most of the signal is received from surface of the sample. This applies particularly to metal alloys. However, when measuring light metal alloys like aluminum and magnesium alloys or other “low density” materials like paper, ceramic or plastic measuring depth can be several millimetres. As an example when measuring semiconductor chip, not only plastic cover is analyzed, but also some of the internal layers, thus measurement result will represent about average within penetration depth. If accurate results are required it is advisable to separate all the different materials from each other and measure them separately.
10.3.3 Metals Metals generally are homogeneous in nature and analysis result will represent real metal composition. However, if there is coating in metal its good idea to scrape the coating off and measure separately coating material and base metal to ensure correct results. Alloy FP is correct method for metals and metallic coatings and Plastic FP for paints etc.
10.3.4 Solders In order to comply with the various directives, i.e. ensure electronic components are Pb-free and conform to the RoHS requirements, electronic manufactures have in many cases eliminated the traditional tin-lead solder and replaced it with non-lead containing solders. The most common replacement for tin-lead (Sn-Pb) solder is tin-silver-copper (Sn/Ag/Cu or SAC) solder. One of the most important characteristics of this solder is that the Pb level is less than 1000 ppm. In addition also total solder composition is very important to maintain characteristics of the solder and prevent defects like tin whiskering. To be able to get correct measurement result, only solder material should be in measuring spot area. If for instance solder is measured directly from PCB, result will be average of whole area, which means that solder composition result is not correct. All correct elements will be reported but their concentration is much lower than real solder composition itself. Best method for measuring solder composition from homogeneous material like PCB is alloy FP. It is important to notice, that empirical calibrations like solder empirical works only for similar materials that calibration set (pure solder) for other type of materials result will be completely wrong.
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10.3.5 Plastics Many metals such as titanium, lead, cadmium, zinc, iron, bromine have been used for years in the manufacture of plastic products. Content of metals in plastic material can be measured using X-MET3000TXR with plastic FP method. Plastic FP can be used also to separate PVC (poly vinylchloride) plastic from other plastic types based on Chlorine (Cl) content. Plastics as such can be treated as uniform material, if they are not coated or painted. If plastic part is coated or if it contains many different materials, these materials should be measured separately if accurate quantitative results are required. Plastic thickness should be minimum 1mm to ensure accurate results.
Figure 10.5. Analysis of plastic material When measuring plastics, it should be taken into account that penetration depth to plastic material is maximum 10mm, which means that when measuring for instance cable insulation or monitor housing analyzer “sees” matrial also under the plastic material. In this instance analysis result represents average of measuring depth not only plastic material. Also, when measuring thin plastic materials (
