Chapter 16: Uncertainty and pXRF Measurements

Uncertainty for laboratory instrumentation adheres to the general guide for uncertainty in measurement (GUM). However, portable X-ray fluorescence technology does not lend itself comfortably to the GUM framework for two reasons: calibration models are often kept proprietary by manufacturers and uncertainty is needed on single observation measurements. The present chapter outlines an approach that is feasible across instrumentation, regardless of whether calibration methods are disclosed. In addition, a review of quantitative and qualitative uncertainty is provided for reference.