1.1 本试验方法涵盖土壤中痕量铀和钍的能量色散X射线荧光光谱化学分析。与用于校准的一般地面土壤成分不同的任何样品基质（即肥料或主要是岩石的样品）必须单独校准，以确定不同基质成分的影响。 1.2 在样品初始干燥和研磨后进行分析，并在干燥的基础上报告结果。所用的样品制备技术将土壤中存在的任何岩石和有机物质纳入样品中。这种样品制备的试验方法不同于涉及翻转和筛选样品的其他技术。 1.3 对铀和钍在每克20至1000μg的浓度范围内进行线性校准。 1.4 以国际单位制表示的数值应视为标准。括号中的英寸-磅单位仅供参考。 1.5 本标准并非旨在解决与其使用相关的所有安全问题（如有）。本标准的用户有责任在使用前制定适当的安全、健康和环境实践，并确定监管限制的适用性。 1.6 本国际标准是根据世界贸易组织技术性贸易壁垒（TBT）委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认标准化原则制定的。 ====意义和用途====== 5.1 该试验方法是使用核材料厂现场的土壤进行开发和校准的。本试验方法可用于测量土壤中铀和钍的污染程度。由于该技术的检测限（名义上为每克20μg）接近这些污染物的典型背景水平，因此该方法可用于现场区域的快速表征，以指示污染点。然后在清理后，可以使用EDXRF验证污染的消除，或者如果需要将清理测试降至所需的背景水平，可以使用其他分析方法（如比色法、荧光法、磷光法等）。该试验方法也可用于根据确定的污染水平对土壤进行离析- 现场施工和开挖。

1.1 This test method covers the energy dispersive X-ray fluorescence (EDXRF) spectrochemical analysis of trace levels of uranium and thorium in soils. Any sample matrix that differs from the general ground soil composition used for calibration (that is, fertilizer or a sample of mostly rock) would have to be calibrated separately to determine the effect of the different matrix composition. 1.2 The analysis is performed after an initial drying and grinding of the sample, and the results are reported on a dry basis. The sample preparation technique used incorporates into the sample any rocks and organic material present in the soil. This test method of sample preparation differs from other techniques that involve tumbling and sieving the sample. 1.3 Linear calibration is performed over a concentration range from 20 to 1000 μg per gram for uranium and thorium. 1.4 The values stated in SI units are to be regarded as the standard. The inch-pound units in parentheses are for information only. 1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee. ====== Significance And Use ====== 5.1 This test method was developed and the instrument calibrated using ground soils from the site of a nuclear materials plant. This test method can be used to measure the extent of contamination from uranium and thorium in ground soils. Since the detection limit of this technique (nominally 20 μg per gram) approaches typical background levels for these contaminants, the method can be used as a quick characterization of an on-site area to indicate points of contamination. Then after cleanup, EDXRF may be used to verify the elimination of contamination or other analysis methods (such as colorimetry, fluoremetry, phosphorescence, etc.) can be used if it is necessary to test for cleanup down to a required background level. This test method can also be used for the segregation of soil lots by established contamination levels during on-site construction and excavation.