One of the more common discussions that the service team of Eastern Applied Research has with users of XRF analyzers is the difference between the terms ‘calibration’ and ‘certification’. These terms are often used in place of each other but have very different meanings that require different tasks be performed.
Does your XRF need to be calibrated or certified?
The following is an overview of the terms as they apply to x-ray fluorescence services that Eastern Applied Research offers. More often than desktop XRF users, we have noticed that handheld XRF users tend to request ‘calibration’ when what they actually need is a ‘certification’…but the ideas below apply to each style of XRF.
The majority of desktop XRF analyzers that Eastern Applied works on are involved in quality control of coating thickness measurements, so what follows is geared more towards systems used for that purpose. Slight variations may be applicable depending on the use of a system and style/model (ie Handheld XRF for alloy verification or desktop XRF for RoHS testing…note, we are now Accredited to ISO/IEC 17034 for compositional applications). Please contact Eastern Applied XRF service technicians if you have any questions about the difference in the services or would like to discuss what your XRF analyzer requires.
XRF Certification Service:
The goal of this service is to verify that an XRF analyzer is measuring correctly based on a given tolerance for the application involved. During an XRF certification service, technicians will use their own set of certified reference materials (NIST traceable when applicable) to confirm an x-ray fluorescence analyzer is measuring accurately.
The technician will take a set of measurements when they first begin working on an analyzer, noting mean and variations. They will then clean the system and make any adjustments after reviewing the first set of results. After cleaning/adjustments, they will take a second set of measurements on the same reference materials as before. As long as the analyzer reads within the specified tolerance then system can be certified. Adjustments may include re-adjusting peak channels, alignment of cameras, or reinstalling infinites. If a system can’t be certified after adjustments, then it may be an indication of an XRF analyzer issue requiring repair or the need for a full calibration service. The XRF technician will explain the ‘why’ and any next steps in getting the system within spec (and certifiable).
Certification services are typically performed every six or twelve months, much more routinely than full calibrations. Certifications of performance by an Accredited organization should be important to XRF owners for a few reasons:
As detailed in the links below, the routine XRF certification services also include the safety radiation survey (most often required by the state an analyzer is kept) and a general cleaning of the system to set it up for the best performance moving forward.
Learn More: overview of the XRF certification services for bench-top systems
Learn More: additional handheld XRF analyzer services offered
Learn More: state regulations of x-ray fluorescence analyzers
A calibration service (or recalibration) deals with the software algorithm that is critical in determining accurate measurements. Analyzers may see a drift in results over time for various reasons, perhaps a result of component age, environmental conditions, or just a brand that isn’t as stable as others. Slight drift is common over time but should not be frequent.
Whether noticed by outside service technicians or the day-to-day operators, when results are outside of the acceptable tolerance then a re-calibration is needed. An XRF Service Technician, or sometimes the operator, will re-calibrate the system against reference standards that have been certified for a specific use. This is similar to when a calibration is initially added to the system and, again, should not occur frequently. Some XRF users that we work with handle these types of re-calibrations on their own while others prefer to have our technical staff perform them – that is based on comfort level and how quality manuals detail the maintenance.
The process varies depending on the application and system involved. For coating thickness applications, some newer systems may just require a single piece of certified reference material be used to recalibrate because it may have a fundamental parameters software package. Other models may require full sets be used under empirical calibrations for traceability requirements or it may just be a limitation of an older system.
When looking for routine services an XRF user will want to ask for certification services. An accredited XRF service organization (like Eastern Applied Research) will certify the performance of the analyzer, perform a safety radiation survey, and provide documentation of each.
When an XRF analyzer is not reading accurately (inconsistent results, reading out of tolerance, etc) then the resolve may be a simple calibration service – but it may also be an indication that more is wrong with the analyzer. It’s always best to contact a trusted, and experienced, service provider.
Have questions on what your XRF Analyzer needs? Please contact the Eastern Applied Research service team for a discussion and we’ll help however needed.