In situ measurements using hand-held XRF spectrometers: a tutorial review

Hand-held X-ray fluorescence (XRF) instrumentation has become widely used in a broad range of applications for problem solving. When used for in situ measurements (that is, instrumentation placed in contact with the surface of the sampling target), results can be acquired in a cheap and rapid manner, encouraging rapid resolution of the problem being investigated. However, the interpretation of such results should be undertaken with care to avoid misleading outcomes. In particular, an understanding of the depth of the XRF excited volume, the interpretation of data near detection limit levels and the contributions that can affect the uncertainty budget are important in avoiding errors in the use of XRF data. This tutorial review is designed for hand-held XRF users who do not necessarily have extensive training in XRF methodology. It provides a brief overview of the technique and its development together with a simple and pragmatic approach to understanding issues that affect the interpretation of hand-held XRF measurement results.