Austin AI systems are based on proved Energy Dispersive X-ray Fluorescence (EDXRF) technology. EDXRF is a favored analysis methodology based on its non-destructive nature, rapid speed, high degree of measurement accuracy, low cost of ownership and having little or no sample preparation.
EDXRF technology is commercially available in many form factors from portable hand-held analyzers to instruments designed for laboratory and R&D facilities. Austin AI specializes in automating EDXRF systems for process control, material sorting & separating. In addition, we've partnered with the NRL to develop a unique, patented cone penetrometer which provides real time, 3 dimensional soil characterization.
Automated on-line EDXRF systems are especially desirable as they are compact, highly durable, and capable of retrofitting into tight areas. They handle mechanical vibrations from surrounding equipment, and extreme temperatures (high & low) conditions. Integrated computers, and in some cases a PLC, interfaces with process control systems to provide data analysis and trending, for process feedback control. The added quality assurance security, increased product throughput and labor savings provide a quick return on investment (ROI).
Basic EDXRF Theory
Austin AI EDXRF instruments are comprised of an X-ray source, detector and electronics. The analysis begins as the X-ray source (high powered X-ray tube) irradiates the sample. X-rays striking the atoms' inner shell (K-shell orbital) electrons impart energy, exciting the electrons and ejecting them from the atom, leaving a vacancy in the inner shell. Electrons from higher-energy orbitals (L and M shell orbitals) transition to fill the vacancy, giving off excess energy as fluorescence (Figure 1).
Figure 1. Theory Illustration
When fluorescence is absorbed by the detector, it changes conductance proportional to the energy of fluorescence (Figure 2).
Figure 2. Fluorescence Collection - Silicon PIN Diode Detector
Detector conductance is processed by the electronics (pre-amplifier, multi-channel analyzer (MCA) board), segregated into a histogram display of intensity (frequency of occurrence as counts per second) vs. energy of fluorescent signal (Figure 3). The fluorescent energy identifies the element, while intensity of fluorescence is proportional to concentration.
Figure 3. Spectrum Sample
EDXRF technique is applied to analysis of materials having major constituents of atomic number greater than 11, sodium (Figure 4). In general practice, EDXRF is used to determine composition of alloys with elements of atomic number 13 (Aluminum) and higher.
Figure 4. Periodic Table of Elements and X-ray Energy Reference