Standard Guide for the Appropriate Uses of Hand Held XRF Devices to Evaluate and Classify Copper-Bearing Scrap Materials

Importancia y uso:

5.1 This guide is intended for the identification and classification of copper-bearing scrap materials. Such identification and classification may include grading for commercial purposes, determining compliance (within the limits of the technology) with compositional specification requirements, determining fitness for use, or determining compliance with other acceptance or rejection criteria.

5.2 The composition and quality of scrap materials may vary. Such variations may be of importance for commercial value, fitness for use, or compliance with acceptance criteria. Such variation may be substantial and significant even though undetectable by visual inspection or other traditional means. Although stationary or laboratory equipment (such as ICPs or spark AES) may provide accurate and useful reports; in many cases the pace of operations, volume, location of the materials, the time available to make decisions, or the level of accuracy required makes the use of stationary or laboratory equipment impractical. By no means does this guide recommend discontinuance or avoidance of stationary laboratory equipment. Superior accuracy of such equipment is still a valuable resource for finer detection limits, detection of materials not readily observed by current handheld technology, validation of results obtained from handheld devices, and (where required) mill certifications.

5.3 Portable hand held XRF devices with suitable analytical capability bridge the gap between identification needs and the potential impracticality of non-portable equipment and devices. Hand held XRF devices might not meet or exceed the precision of stationary or laboratory equipment, but their suitability and precision may be situationally adequate for the user to make decisions where and when needed. “Suitability” in this case may be defined by the user if inspecting their own material, or by mutual agreement between buyer and seller. In any event, users are encouraged to consult Appendix X1 herein as well as the equipment manufacturer to understand the capabilities and limitations of the technology and their particular device.

5.4 The technologies discussed herein are evolving. As such, they are as of this writing not yet capable of accurately identifying and quantifying certain elements on the Periodic Table. Current limitations are enumerated and discussed in Appendix X2.

5.5 The technology and methods covered in this guide are related to hand held X-Ray fluorescence spectrometry (hand held XRF).

5.6 XRF analyzers are typically programmed to respond to a specific set of alloys selected as representative of the composition of the materials examined. The displays are numeric and show the percent concentration of each measured element. Depending on the manufacturer and the equipment design, up to 25 elements may be displayed, but a smaller number is likely sufficient for identification of an alloy.

5.7 Hand held XRF technology is limited in its ability to detect and quantify lighter elements. Depending on the technology and version, these limits may begin with sulphur and lighter. Hand held XRF technology is not considered quantitatively accurate for aluminum at low levels of concentration or independent of its concentration in copper alloy. Users are advised not to rely on hand held XRF technology to identify the presence of beryllium, which cannot be measured directly by hand held XRF.

5.8 Even for detection limits or certain elements at the borderline range of an instrument’s or a technology’s capabilities, hand held XRF devices are still useful as an inspection and detection device to identify material or pieces as candidates for more precise analysis with laboratory equipment. In such cases, the hand held XRF device readings may not be direct acceptance criteria, but can be criteria (at the user’s discretion) as an intermediate step in a more detailed inspection practice.

5.9 Users are cautioned of the limitations of hand held XRF technology, particularly in the case of dispute resolution where the parties to a disagreement each have hand held XRF devices with differing Limits of Detection or where the contaminant at issue is at the borderline of instrument capability, or both.

Subcomité:

B05.08

Volúmen:

02.01

Palabras clave:

alloys; copper; hand held; spectroscopic devices; XRF;