<p><p><strong>References:<br></strong><em>ALLU (2007)</em></p><p>Although x-ray fluorescence is not routinely used on mass mixing projects, a brief description of the method is included here because it could be useful as an investigative tool. At the present state of technology development, it would not be practical to require a certain response from xray fluorescence in specification for mass mixing.</p><p><strong>Method Summary</strong></p><p>X-ray fluorescence analysis can be used to verify correct binder levels in post-treatment soils. The contractor may use x-ray fluorescence as a quality control technique to make changes to mixing parameters. X-ray fluorescence analysis measures the binder content of a sample by measuring the fluorescent x-rays emitted from the sample after exciting it with gamma radiation. To apply the method, a calibration curve is developed using x-ray fluorescence analysis on<br>laboratory-prepared samples of each soil type to be treated. Samples taken from the field are then analyzed and compared to the calibration curves to determine the binder quantity of the post-treatment samples.</p><p><strong>Accuracy and Precision</strong></p><p>Results of the x-ray fluorescence analysis are checked using titration. If considerable differences are found, the calibration curve is adjusted.</p><p><strong>Adequacy of Coverage</strong></p><p>X-ray fluorescence is performed on individual samples, providing local results. Adequacy of coverage depends on the number of samples tested. The number, location, and depths of the tests should be selected based on the judgment of the contractor considering the size of the area to be treated, variability in subsurface conditions, and the type and performance expectations of the proposed facility</p><p><strong>Implementation Requirements</strong></p><p>X-ray fluorescence analysis requires specialized equipment and a trained laboratory staff for calibration. Hand-held point-and-shoot devices are available for use in the field.</p><p><strong>General Comments</strong></p><p>X-ray fluorescence determines the binder amount of small samples. The homogeneity and level of mixing of the entire treated volume should be assessed using previously described observations as well as in situ and laboratory methods.</p></p>