The ability for the instrument operator to set various conditions (some are detailed below) is of greatest interest to laboratories that have a wide range of material analysis occuring during a day, such as organizational quality control labs, general testing labs, and academic laboratories.  By pre-setting these operating conditions, the user will be able to quickly switch from one condition to another depending on the measurement goal.  This wil save set-up time, increase analyzer accuracy and most likely extend the life of major components.

The first step in method development to ensure good signal is to utilize the minimal voltage required to excite the element of interest.  Increasing the voltage beyond the ionization energy of the target element will increase the baseline noise by producing interfering x-rays from heavier elements.  For example, if measurement of Nickel (Ni) was desired, with an excitation energy of 7.477kV, by only applying 9kV of voltage, the elements beyond Ni in the periodic table are not excited.  This results in less interfering x-rays and an increased signal of the peak of interest.  Understandably, when the measurement of a heavier metal is desired, such as Gold (Au), an increase in baseline is expected due to the higher voltage required.  However, an increase in the signal can be achieved by increasing the amperage.

Filters can also be used to increase the signal of contamination level elements.  Filters essentiallly absorb x-rays in the field of interest that would interfere with the detection of these elements.  For example, light elements such as Phosphorus (P) do not require the use of a filter because of the lower voltages used.  As previously noted, this would produce an increased baseline.  However, it would be advantageous to use a Titanium (Ti) filter if measuring low levels of Mangenese (Mn), to diminish interference from other transition metals that may fluoresce from the matrix.

Secondary targets are also worth mentioning as they can increase the flexibility of the instrument to allow for the detection of a larger array of elements.  For example, Molybdenum (Mo) is a common source in x-ray tubes; however, if the measurement of low level Sulfur (S) in petroleum is desired, the analyst would find that a Molybdenum (Mo) source emits x-rays that interfere with the measurement of Sulfur (S).  By using a secondary target such as Silver (Ag), the interfering x-rays are removed, thereby allowing the sample to be hit with the secondary x-rays that maintain the characteristics of the target and do not interfere with the measurement of low level Sulfur (S).

This is just another benefit that ED-XRF technology offers an end-user.  Contact an Application Specialist to discuss how multiple conditions may benefit your laboratory or review more information on Xenemetrix analyzers that offer the option – The X-Calibur allows the functionality to easily change filters or voltages to obtain an optimal signal in a complex matrix.  Other models, such as the EX-6600 Laboratory Spectrometer, would allow for the use of secondary targets as well.

When organizations take advantage of turret stages they will realize increased efficiencies from the XRF analzyer and the laboratory personnel utilizing it.  Also known as ‘automatic sample changers’, they provide operators with two different approaches to increase measurement efficiency – both are detailed below.

STANDARD BENEFIT: Take Multiple Readings on Multiple Samples
When sample conditions will be the same for all of the samples in a batch, the turret stage provides the operator with time to handle other tasks while measurements are performed.  Simply set the appropriate test parameters and fill the stage with prepared sample materials and begin the measurement.

As an example of the time savings, with a 100 second measurement for each sample in a ten-sample changer, an operator will free up over 16 minutes of time!  This benefit is exponential when taking multiple readings on each sample…take five measurements of each sample at 100 seconds and the operator frees up over one hour of time.

ENHANCED BENEFIT: Set Multiple Conditions
To expand on the benefit noted above, many Xenemetrix analyzers allow users to set multiple measurement conditions and then save them for a quick recall.  This is beneficial because using optimum conditions (ie appropriate filters) for specific elements of interest will enhance the accuracy of the instrument when looking for those target elements.

An operator can prepare five different measurement conditions to focus on five different elements of interest that will be the same for each sample on a ten position sample stage.  The Xenemetrix analyzer can automatically run through the five measurements on the first sample and then automatically move onto the next sample, running through all five conditions before moving onto the next sample.  If a laboratory technician set five conditions and took five measurements of 100-seconds each on ten samples, they would free up over six hours of their time.

Do you feel that this option may help to increase your lab’s throughput?  If so, request a free consultation from an XRF Sales Associate from Eastern Applied to discuss the potential efficiency that it can offer.  The most popular systems with turret stages that vary from 8 to 18 sample spots include the Xenemetrix X-Calibur SDD, X-Cite and the laboratory grade EX-6600 SDD.

Design of a Xenemetrix Turret Stage

Element Xr for Coating Thickness

In March of 2011, Eastern Applied Research was selected as the North American service company for Roentgenanlytik GmbH (Roen).  Soon after, Eastern Applied was able to agree with the manufacturer of XRF for coating thickness applications to release the Element Xr line to the North American market.  Element Xr combines the manufacturing experience of Roen with Eastern Applieds knowledge of coating thickness applications and understanding of the North American market.  Because of this collaboration, the Element Xr line provides top price-to-performance options from basic single layer coatings to complex coating applications, plus thin film and plating bath analysis.

As we look at Element Xr moving into 2012, we are excited to be preparing for the release of the newest system – the Xr 6000.  Among other developments, this versatile unit will feature a streamlined software package that runs on Windows 7 OS and will provide more functionality than in the past.  The Xr-6000 will be available for review at both Pittcon and Sur/Fin events.

Xenemetrix for Material Analysis

After adding the quality line of coating thickness analyzers, Eastern Applied wanted to add a second line for material analysis needs.  Eastern Applied was very excited when associates of Xenemetrix Inc selected our organization as their North American Sales Agent in May of 2011.

Known for producing high quality EDXRF Spectrometers for material analysis, the Xenemetrix line has allowed Eastern Applied to broaden our application reach.  We are now able to focus on petrochemical test solutions (low sulfur verification, lube oil analysis), geological analysis (mining related and soil testing) and forensics related testing.  Additionally, the Xenemetrix product mix focuses on xray fluorescence for general laboratory use, offering highly powerful systems like the EX-6600 series for industrial testing laboratories and cost efficient systems like the X-Cite for academic laboratories.

In addition to these applications, we have also recently announced a collaboration with Xenemetrix to develop the RoHS+SDD unit for detection of hazardous substances in electronics…those of you who now our history know that we were heavily involved in RoHS testing at its early stages.  With the revised RoHS regulations affecting more industries, this new system will provide testing for RoHS plus other quantitative and qualitative analysis.

As Eastern Applied Research moves into 2012, we look forward to launching new systems from both the Element Xr and Xenemetrix line.  Our staff is very excited about the new solutions that can be offered as both have proven to be top analyzers for their target applications…we hope you are excited in our analyzer lines if adding x-ray fluorescence is needed for you in 2012.

Obviously, the more an instrument is used, the faster the x-ray tube will wear – but other factors can affect the tube lifetime and are listed below.  While all of these factors cannot be completely avoided, it can help you understand the expected lifetime of the heart and soul of your XRF analyzer: the x-ray tube.

What Factors Into The X-ray Tubes Life?

• Performing multilayer analysis, such as Au/Ni/Cu
• Using a small collimator, such as 2 mil.  If it is appropriate for your application, use an 8 or 12 mil x-ray beam
• Using a higher voltage than necessary for analysis.  Most instruments automatically set this value in the software based on the known ionization energies of the applicatio; however, a few instruments allow for manual input.
• Inadequate cooling of the x-ray tube related to the air intake fan being plugged with dust and debris or the fan being blocked to receive adequate air intake.  Ensure that the air intake vent is free of dust and has access to ample air intake (environment and location of your XRF is important).
• Smaller sized x-ray tubes generally reach their end of life faster than a larger tube.  The size of the tube is directly related to the type of instrument, but perhaps is something to take into consideration when purchasing a new XRF analyzer.

The Eastern Applied Research support staff is available to discuss any questions regarding the operation of your instrument and adjustments that may extend the life of the x-ray tube and other major components.  Also, try to have a yearly certification/review service performed on your system…these are performed by Eastern Applied technicians, they will provide preventative maintenance and discuss factors like the ones noted above.

When it comes to purchasing XRF calibration standards for thickness analysis you should know what type of format you are seeking as there are two styles to choose from: plated or foil.  Both formats are commonly used throughout industry and provide reliable results.  When determining the best fit for you consideration must be made to the model of XRF analyzer the standards will be used on, constituents of interest and target thicknesses, whether the calibration curve will be created with or without use of fundamental parameters (FP), and how the standards will be used.

Foil Standards: this style is created with the foil of desired material and thickness attached to a stainless steel foil holder.  The foil is then temporarily secured on top of a plastic chip containing the desired base material.  When a range of thicknesses are required, the user will have several foils of difference thicknesses to span the desired range.

Pros of Foil:
-   Versatility: foil standards can be placed over any desired substrate, thereby increasing the range of applications
-   Multi-Layer Flexibility: they are generally stacked on top of one another for a reliable method of multi-layer analysis.  A common question regarding stacking foils is whether or not the air gaps influence results - the answer is no; any air gaps are so small that they are negligible in the thickness reading.
-   Usable Curves: when using stacked foils for multi-layer analysis there are essentially three useful calibration curves, two single layer curves and one multi-layer curve.  By nature, one of the single layers is the first plated layer and can be used to monitor the plating in-process.

Cons to Foil:
-   Fragile: while more versatile, the foils themselves are fragile and must be handled with care to avoid punctures.  Generally speaking, foil standards are not ideal for everyday use or in environments where they might come into contact with a lot of dirt as they cannot be cleaned.

Plated Standards:  these are created by electroplating the desired material of specific thickness onto a permanent base material.  When a range of standards is required, the user will have standard pieces of several different thicknesses to span the desired calibration range (layers and base material in one piece for each thickness).

Plated Standard Pros:
-   Durability: compared with foil pieces, plated standards tend to be more durable and tolerate heavy handling.  However, they are still prone to damage when the measured surface comes into contact with an object that scratches it.  Even the user touching the surface can cause damage due to the dirt from the environment or oils on a user’s hands.
-   Extended Life: fortunately, if scratches or damages do occur on a plated standard, all is not lost.  In most cases, the standard can be polished with a fine grit polish and remarked to reflect the new, lower, value.

Cons to Plated:
-   No Versatility: with the coating permanently fixed onto a base material, a user will need to have a different plated standard for each thickness and base material combination they require.
-   Potential Variation: it is well documented that certain plated metals such as lead, gold, silver and tin (to name a few) will migrate over time; thus potentially changing the thickness of the reference material.  This change takes a long time but can easily be monitored by having reference standards certified yearly by an accredited laboratory.

These are just a few thoughts to help you begin the discussion with Eastern Applied Research’s standards laboratory when it is time to purchase new reference standards.  Request a phone call or email by a lab technician to discuss further.

A few examples of recent major damage issues that we’ve seen…

Hydrochloric Acid Spill – acid was sucked into the XRF analyzers fans, creating corrosion to the internal components and destroying the computer.  Our technical staff was able to clean the system, replacing the corroded boards and components in addition to the computer system (with updated software).

Multiple Units Repaired After Fire Damage – it was like “XRF Backdraft”…smoke, fire and water get on the systems (during the fire and the effort to put it out) and the systems required a thorough cleaning of the ash, completely revamping the interior of the machine and component replacement; but the customers still saved money when compared to investing in multiple new units.

Water Line Over the Analyzer Broke – water everywhere…essentially destroyed the electronics and power supplies.  After an extended dry time then a thorough cleaning and reparing of components/wiring, the analyzer worked well and saved the budget of our customer.

As you can see, in the twenty years that Eastern Applied Research has been providing support of XRF analyzers, our technical staff has seen some very tough spots for our clients and their xray units.  While we can offer the option of new analyzers, not all clients have the budget to consider that – especially after some of the issues that affect much more of a business than just the xray fluorescence unit.

Eastern Applied Research works for the clients and offers all the options possible to solve their problems.  Our in-house staff has worked some ‘miracles’ to limit the out-of-pocket while providing end-users with good working systems.

Hopefully, you don’t run into problems like the above…but, if you do, Eastern Applied will do our best to offer multiple options.  Of course, our technicians can do the minor repairs and adjustments you may require as well so keep us in mind for all questions relating to x-ray fluorescence.  Learn more about our repair and evaluation services or contact us to discuss your interests.

With a reliable XRF based measurement process, companies that provide gold plating services can plate closer to their minimum specification.  If a measurement system can confirm your plating process is controlled properly, then you can save gold (or other metals) – maximizing your profits with the help of XRF technology.  You can lower your target thickness and ensure you are comfortably within your required specification when the XRF analyzer is properly calibrated with the best measurement techniques and standards of low uncertainty.

Without a reliable measurement process, utilizing x-ray fluorescence technology, a plating company will not be able to control excess plating.  You need to define the uncertainty of your measurement process.  Only after it is confirmed that the measurement system is working properly can your plating process be adjusted to near the minimum thickness reliably and consistently.

Reworks from under-plating are expensive, so most plating companies will plate heavy to ensure they meet the minimum.  However, in the long run, this over-plating approach is as expensive as reworks.  As an example, if you are plating 15u” of gold to make sure you meet the clients minimum requirements of 10u”, then you are wasting as much as 50% of your gold.  XRF technology can control your measurement process to target 11u” of gold reaching near a six-sigma confidence level – then you can save 27% on your gold costs.  Again, with increasing gold costs, this savings equation can be substantial (and isn’t just limited to gold, of course).

The first step in maximizing profits is having confidence that you are measuring accurately and with repeatability; then you can adjust the plating line to control your process.  At Eastern Applied Research, we can provide the system, methodology and training to define the measurement uncertainty.  Once we show you that your uncertainty is 2% (this varies per application and system used) you only need to plate 2% higher than the minimum.  Any additional amount of thickness you add is based on your ability to control the plating process itself – but to control that you need the best measurement system and a complete understanding of the measurement uncertainty inherent in any system.

If you are over-plating to avoid out of specification product then you are throwing money away and allowing competitors that use XRF measurement systems to have an advantage that allows them to quote lower than you.  Eastern Applied Research Inc specializes in coating measurement systems, and has for twenty years.  We can help you improve your process and maximize profits – schedule a conversation with an Application Specialist to discuss your process and XRF Technology.

Many states require that an accredited service company is performing the work (Eastern Applied is Accredited to ISO/IEC) and sometimes, as was the case with Oregon, that the service company is registered with the state.  Since Eastern Applied specializes in sales and service of x-ray fluorescence we are licensed with the majority of states to provide instruments and services.

In addition to the vendor or service provider being licensed with a state, the users of X-ray Fluorescence (XRF) should be aware of the individual state laws relating to the systems and what licensing may be required of them as owners.  Many users simply consider the Federal laws that may have to be followed but individual state laws are often more critical in terms of registering a system for use within a state.  Most states require licensing (with a small fee) along with requirements that instrument calibration and safety radiation surveys be performed at designated intervals – with proof of services being appropriately submitted.

Eastern Applied can provide contact information for each state – so contact one of our technical advisors if you are adding a system, have had an XRF Analyzer for a while but don’t know if you are licensed or if you want to make sure you are working with a service provider that is licensed for your state.

OBJECTIVE
To perform a quantitative comarison between the performance of the X-Calibur EDXRF Analyzer with a SDD detector installed or a Si-PIN detector.  The sensitivity and performance of X-Calibur at different energies when equipped with different detectors is expressed in the minimum detection limits (MDL) of the different elements.

SDD versus Si-PIN Diode
Xenemetrix desktop x-ray fluorescence analyzers had traditionally been equipped with Si-PIN detectors that provided outstanding resolution and count rate capacity at the time.  However, Silicon Drift Detectors were introduced and today it has become the ‘detector of choice’ for many material analysis applications.

Si-PIN technology offers an economical detection system which, in turn, allows for a lower priced analyzer.  They also offer a larger active area and thickner depletion depth.  When resolution is critical but high detection efficiency is not important, the Si-PIN system will be suggested.  However, SDD technology offers a much better energy resolution at short peak times; which is helpful at high count rates and can lead to lower limits of detection.

ANALYTICAL CONFIGURATION

Instrument: X-Calibur EDXRF Spectrometer
Anode: Rh-Anode X-ray Tube, 50W
Detector: VARIABLE of SDD or Si-PIN
Analysis Time: 300 seconds per measurement
Goal of Analysis: Determine minimum detection limits (MDL)
Sample Overview: Liquid Samples, no preparation

SAMPLES
A variety of sample solutions were used to determine the MDL; including water, diesel and oil solutions.  The full list can be found in the complete comparison sheet but some include:
-  Certipur Zinc Standard Solution; 1000mg/l, MERK
-  5.6% Na in water (in-house standard)
-  VHG Labs Sulfur in #2 diesel, 1000ppm

Measurement times were set for 300 seconds.  Typical conditions were air but light element information was aquired using a helium purge.  Tube filters varied according to the sample and element of interest.

MINIMUM DETECTION LIMITS
A detailed overview of the MDL determination can be reviewed in the full comparison sheet but a few example results including:
          Element     MDL SDD ppm     MDL Si-PIN ppm
               Na               700                        1,600
               S                 1.3                           3.2
               Zn               0.3                           1.0

Graph of MDL measured with SDD and Si-PIN detectors (S to Ba only)

DISCUSSION
The comparison shows that the main advantage that SDD provides is the ability to acquire spectra at very high count rates without compromising on the resolution.  In this review, it is obvious that the high count rate is key to the low minimum detection limits obtained with the Silicon Drift Detector (SDD).  That being said, the Si-PIN compares favorably with elements that have higher energy and it allows for a lower analyzer cost.

Request the complete comparison (including results, spectrums, etc)
~ or ~
Contact Eastern Applied Research to discuss the available detection systems and elemental analyzers

The National Association of Surface Finishing (NASF) recently held its yearly Sur/Fin conference in Rosemont, IL.  Eastern Applied Research was pleased to be an exhibitor as we had many interesting conversations (face to face ones) throughout the event.

With a large number of our clients being involved in metal finishing, and based in the MidWest, this was an excellent event for catching up with current clients that attended Sur/Fin.  This face-to-face time was beneficial in keeping up to date with current service customers and showing them, many of whom utilize older XRF technologies, the newest x-ray fluorescence for coating thickness measurements – the Element Xr line.

Obviously, the opportunity to speak to potential future clients about all the service, support and solutions that Eastern Applied can offer the metal finishing industry was a great benefit.  Booth personal were able to learn about the concerns of metal finishers and discuss the potential solutions that we can offer.

Demonstrations of the Element Xr line were performed on a prototype of system that will provide another top solution in coating thickness analysis.  In addition, the Eastern Applied associates at the booth were able to discuss our “conti-systems” which allow for faster through-put right on the production floor.

All in all, an excellent exhibition…we look forward to speaking with any attendees again in the near future.