Archive for November, 2010

XRF Technology: Detection Systems; a major component

A question that Quickshot XRF associates are often asked is “What is the difference between the QSX-79T and QSX-295T?”  These popular analyzers are very similar, following standard x-ray fluorescence technology, but the major difference is in the detection system each unit utilizes.  You can request overview literature that details how the detection systems affect those two analyzers (request here), but below is a brief overview of the detection systems used in Quickshot XRF analyzers.

A quick overview of the component: The detection system of an x-ray fluorescence instrument collects the energy that results from displaced electrons in the form of an x-ray.  The peak intensities of emitted x-rays are characteristic of the elements contained in the sample and provide information about the elements concentrations that is processed by the software of an XRF analyzer.  Detection systems are selected for an instrument based on their resolution, count rates, ability to filter out background and the testing need the analyzer is being developed to solve.

Proportional Counter Detector Tube:
One of the earliest detection systems, this style does provide an excellent solution for coating thickness measurements when combined with the proper software.  Because of its low cost it has been adapted in gold testing equipment (like the QSX-79T) in recent years, but while it provides reasonable results on gold, it is fairly limited compared to the other analyzers available for gold and precious metals analysis.

Si-PIN Detection System:
While previous detection systems that reached the resolutions that Si-PIN detectors reach required Liquid Nitrogen (LN2) to cool the detector, Si-PIN technology does not require LN2.  The resolution allows an analyzer using Si-PIN to separate elemental peaks with greater definition and the instrument will offer greater accuracy over a broader range of elements.  It is much more economical than the next detection system developed (SDD, see below) and Si-PIN provides excellent results for precious metals identification; so it is featured in the QSX-295T.

Silicon Drift Detector (SDD):
One of the newer options in the Quickshot XRF line-up of instruments, this technology was developed in the early 2000’s and provides the benefit of detecting lighter elements than Si-PIN systems.  For most applications this is not important (and can not justify the cost increase) but the technology has its place in laboratory settings and will be featured in a new handheld analyzer from QSX.

Quickshot XRF appreciates the questions about XRF technology and hopes to highlight a few more answers in future blog entries.  Feel free to leave a comment/question about an aspect of the technology or contact us to discuss – and, if you are considering the QSX-79T and QSX-295T, be sure to request an overview of their differences (request here).