1.1 本试验方法包括通过快中子热化或减速测量每单位体积土壤和岩石的水质量，其中中子源和热中子探测器放置在由接入管内衬的钻孔中的所需深度。 1.1.1 有关限制，请参阅第节 6. 关于干扰。 1.2 通过将热中子计数率与先前建立的校准数据进行比较，确定单位体积的水质量，表示为受试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确定的有效数字和舍入准则 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。 具体危害见第节 8. . 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 该试验方法是一种快速、无损的技术，用于测量地表以下所需深度处每单位体积土壤和岩石的原地水团。 5.2 该测试方法可用于信息和研究目的。 当使用中描述的程序和方法与每单位体积的实际水质量相关时，从本试验方法中获得的信息最好用于质量控制和验收试验 A1.2.3 . 5.3 该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，受试材料是均匀的，并且氢以试验方法定义的水的形式存在 D2216 . 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。本标准的用户应注意遵守惯例 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 measurement of the water mass per unit volume of soil and rock by thermalization or slowing of fast neutrons, where the neutron source and the thermal neutron detector are placed at the desired depth in the bored hole lined by an access tube. 1.1.1 For limitations see Section 6 on Interferences. 1.2 The water mass per unit volume, expressed as mass per unit volume of the material under test, is determined by comparing the thermal neutron count rate 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 of 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 guidelines 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 hazards are given in Section 8 . 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 measurement of the in-place water mass per unit volume of soil and rock at desired depths below the surface. 5.2 This test method is useful for informational and research purposes. The information acquired from this test method is best used for quality control and acceptance testing when correlated to actual water mass per unit volume using procedures and methods described in A1.2.3 . 5.3 The non-destructive nature of this 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 the material under test is homogeneous and hydrogen present is in the form of water as defined by Test Method D2216 . 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 standard 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.