1.1 本试验方法包括通过伽马辐射衰减计算土壤和岩石的湿密度，其中伽马源和伽马探测器放置在钻孔中的所需深度，通常由接入管衬里。 1.1.1 有关限制，请参阅第节 6. ，“干扰。” 1.2 通过将检测到的伽马辐射率与之前建立的校准数据进行比较，计算湿密度（单位为被测材料的单位体积质量）（见 附件A1 ). 1.3 单位- 以国际单位制或英寸-磅单位表示的数值应单独视为标准值。每个系统中规定的值不一定是精确的等价物；因此，为确保符合本标准，每个系统应独立使用，且两个系统的值不得组合。在本标准文本中，先出现国际单位制，然后是括号中的英寸-磅（或其他非国际单位制）单位。 1.3.1 以国际单位制以外的单位报告试验结果不应视为不符合本标准。 1.4 所有观察值和计算值应符合实践中制定的有效数字和舍入指南 D6026 . 1.4.1 本标准中用于规定如何收集、记录和计算数据的程序被视为行业标准。此外，它们代表了通常应保留的有效数字。使用的程序不考虑材料变化、获取数据的目的、特殊目的研究或用户目标的任何考虑因素； 通常的做法是增加或减少报告数据的有效位数，以与这些考虑因素相称。考虑工程设计分析方法中使用的有效数字超出了本标准的范围。 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。 第节给出了具体的预防说明 8. ，“危险。” 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 该测试方法是一种快速、无损的技术，用于计算in- 根据试验方法，将土壤和岩石的密度放置在表面以下的所需深度，而不是表面测量值 D6938 . 本试验方法中同样描述了替代破坏方法。 5.2 该测试方法用于信息和研究目的，仅在与其他公认方法（如测试方法）相关时用于质量控制和验收测试 D2937 . 5.3 测试方法的无损性允许在单个测试位置进行重复测量，以进行统计分析，并监测随时间的变化。 5.4 本试验方法固有的基本假设是，康普顿散射和光电吸收是γ射线与受试材料的主要相互作用。 5.5 通过将检测到的γ辐射率与先前建立的校准数据进行比较，可以将探头响应（以计数为单位）转换为湿密度（参见 附件A1 ). 5.6 探针计数响应也可直接用于与其他探针读数的无单位相对比较 5.6.1 对于密度高于水密度的材料，同一土壤类型内较高的计数率与较低的密度有关，相反，同一土壤类型内较低的计数率与较高的密度有关。 5.6.2 对于密度低于水密度的材料，同一土壤类型内较高的计数率与较高的密度有关，相反，同一土壤类型内较低的计数率与较低的密度有关。 5.6.3 由于探针响应对水密度附近密度的功能影响，因此在从该密度范围内的探针响应得出结论时应格外小心。 注1: 本标准试验方法产生的结果质量取决于执行该试验的人员的能力以及所用设备和设施的适用性。符合实践标准的机构 D3740 通常认为能够胜任和客观的测试/采样/检查等。本试验方法的使用者应注意遵守规程 D3740 本身并不能保证可靠的结果。可靠的结果取决于许多因素； 实践 D3740 提供了一种评估其中一些因素的方法。

1.1 This test method covers the calculation of the wet density of soil and rock by the attenuation of gamma radiation, where the gamma source and the gamma detector are placed at the desired depth in a bored hole, typically lined by an access tube. 1.1.1 For limitations see Section 6 , “Interference.” 1.2 The wet density, in mass per unit volume of the material under test, is calculated by comparing the detected rate of gamma radiation with previously established calibration data (see Annex A1 ). 1.3 Units— The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined. Within the text of this standard, SI units appear first followed by the inch-pound (or other non-SI) units in brackets. 1.3.1 Reporting the test results in units other than SI shall not be regarded as nonconformance with this standard. 1.4 All observed and calculated values shall conform to the guide for significant digits and rounding established in Practice D6026 . 1.4.1 The procedures used to specify how data are collected, recorded, and calculated in this standard are regarded as the industry standard. In addition, they are representative of the significant digits that should generally be retained. The procedures used do not consider material variation, purpose for obtaining the data, special purpose studies, or any considerations for the user’s objectives; and it is common practice to increase or reduce significant digits of reported data to be commensurate with these considerations. It is beyond the scope of this standard to consider significant digits used in analysis methods for engineering design. 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. Specific precautionary statements are given in Section 8 , “Hazards.” 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 is useful as a rapid, nondestructive technique for the calculation of the in-place density of soil and rock at desired depths below the surface as opposed to surface measurements in accordance with Test Method D6938 . Alternative destructive methods are likewise described in this test method. 5.2 This test method is useful for informational and research purposes, only to be used for quality control and acceptance testing when correlated to other accepted methods such as Test Method D2937 . 5.3 The non-destructive nature of the test method allows repetitive measurements to be made at a single test location for statistical analysis and to monitor changes over time. 5.4 The fundamental assumptions inherent in this test method are that Compton scattering and photoelectric absorption are the dominant interactions of the gamma rays with the material under test. 5.5 The probe response, in counts, may be converted to wet density by comparing the detected rate of gamma radiation with previously established calibration data (see Annex A1 ). 5.6 The probe count response may also be utilized directly for unitless, relative comparison with other probe readings 5.6.1 For materials of densities higher than that of about the density of water, higher count rates within the same soil type relate to lower densities and, conversely, lower count rates within the same soil type relate to higher densities. 5.6.2 For materials of densities lower than the density of water, higher count rates within the same soil type relate to higher densities and, conversely, lower count rates within the same soil type relate to lower densities. 5.6.3 Because of the functional inflection of probe response for densities near the density of water, exercise great care when drawing conclusions from probe response in this density range. Note 1: The quality of the result produced by this standard test method is dependent on the competence of the personnel performing it, and the suitability of the equipment and facilities used. Agencies that meet the criteria of Practice D3740 are generally considered capable of competent and objective testing/sampling/inspection, and the like. Users of this test method are cautioned that compliance with Practice D3740 does not in itself assure reliable results. Reliable results depend on many factors; Practice D3740 provides a means of evaluating some of those factors.