1.1 这些试验方法包括通过 3. / 8. -中。（9.5毫米）或更小的筛网。当总样本包含较大的颗粒时，使用 3. / 8. -中。（9.5毫米）或4号（4.75毫米）或更细的筛网。在4号筛上分离是判定方法。试验方法 C127 应用于获得较粗部分的比重。这个 D854 应使用试验方法来获得较细部分的比重。总样品比重由中所述的两部分计算得出 12.5 。 1.1.1 这些试验方法不适用于可通过这些方法改变的固体、被禁止使用这些方法的物质污染的固体或高度有机的固体，如漂浮在水中的纤维状物质（见 注1 )。 注1: 试验方法 D5550 可以用于确定具有固体的土壤固体的比重，这些固体容易溶解在水中或漂浮在水中，或者在不能用水的情况下。 1.2 本标准提供了两种进行比重试验的方法。所使用的方法应由请求当局规定，但在测试中列出的土壤类型时除外 1.2.1 。 1.2.1 方法A——潮湿试样的程序， 描述于 11.1 。此程序是首选方法。有机土壤应采用方法A；高塑性细粒土；热带土壤；以及含有halloysite的土壤。 1.2.2 方法B——烘干试样的程序， 描述于 11.2 该程序所需时间较少，可用于清洁沙子。 1.3 单位-- 以国际单位制表示的数值应视为标准，但筛网名称除外。根据实践，使用“替代”系统识别筛网名称 E11 ，例如3英寸。和编号200，而不是分别为75 mm和75µm的“标准”名称。以SI以外的单位报告试验结果不应视为非- 符合此测试方法。使用记录质量磅（lbm）的天平或天平不应被视为不符合本标准。 1.4 所有观测值和计算值应符合实践中制定的有效数字和四舍五入指南 D6026 ，除非被本试验方法取代。 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。所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；并且通常的做法是增加或减少报告数据的有效数字以与这些考虑相称。考虑工程设计分析方法中使用的有效数字超出了这些测试方法的范围。 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）。本标准的使用者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。 真空下的玻璃器皿有可能内爆。应始终使用适当的个人防护设备。参见第节 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》中确立的国际公认的标准化原则制定的。 ===意义和用途====== 5.1 土壤固体的比重用于计算土壤的相关系，如孔隙比和饱和度。 5.1.1 土壤固体的比重用于计算土壤固体的密度。这是通过将比重乘以20°C下的水密度来实现的。土壤固体密度几乎与温度无关。 5.2 土壤固体一词通常被认为是指天然存在的矿物颗粒或不易溶于水的类土壤颗粒。因此，含有外来物质（如水泥、石灰等）的土壤固体、水溶性物质（如氯化钠）和含有比重小于1的物质的土壤的比重通常需要特殊处理（见 注2 )或其比重的限定定义。 注2: 对于一些含有大量有机物的土壤，煤油是比水更好的润湿剂，可以用来代替烘干试样的试验用水。煤油是一种易燃液体，必须极其小心地使用。 当使用煤油作为试验流体时，不应使用本标准。 5.3 天平、比重瓶尺寸和样品质量的规定是为了获得可报告到四位有效数字的测试结果。 注3: 这些测试方法产生的结果的质量取决于执行测试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 通常被认为能够胜任和客观的测试/取样/检查等。这些试验方法的使用者应注意遵守规程 D3740 其本身不能保证可靠的结果。可靠的结果取决于许多因素；实践 D3740 提供了评估其中一些因素的方法。

1.1 These test methods cover the determination of the specific gravity of soil solids that pass the 3 / 8 -in. (9.5-mm) or smaller sieve by means of the water displacement method. When the total sample contains larger particles, it is separated into a coarser and finer portion using a 3 / 8 -in. (9.5-mm) or No. 4 (4.75-mm) or finer sieve. Separation on the No. 4 sieve is the referee method. Test Method C127 shall be used to obtain the specific gravity of the coarser portion. The D854 test methods shall be used to obtain the specific gravity of the finer portion. The total sample specific gravity is computed from the two portions as described in 12.5 . 1.1.1 These test methods do not apply to solids which can be altered by these methods, contaminated with a substance that prohibits the use of these methods, or are highly organic, such as fibrous matter which floats in water (see Note 1 ). Note 1: Test Method D5550 may be used to determine the specific gravity of soil solids having solids, which readily dissolve in water or float in water, or where it is impracticable to use water. 1.2 This standard provides two methods for performing the specific gravity test. The method to be used shall be specified by the requesting authority, except when testing the types of soils listed in 1.2.1 . 1.2.1 Method A—Procedure for Moist Specimens, described in 11.1 . This procedure is the preferred method. Method A shall be used for organic soils; highly plastic, fine-grained soils; tropical soils; and soils containing halloysite. 1.2.2 Method B—Procedure for Oven-Dry Specimens, described in 11.2 . This procedure requires less time and may be used for clean sands. 1.3 Units— The values stated in SI units are to be regarded as standard, except the sieve designations. The sieve designations are identified using the “alternative” system in accordance with Practice E11 , such as 3-in. and No. 200, instead of the “standard” designation of 75-mm and 75-µm, respectively. Reporting of test results in units other than SI shall not be regarded as non-conformance with this test method. The use of balances or scales recording pounds of mass (lbm) 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 , unless superseded by this test method. 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 generally should 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 these test methods 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. Glassware under vacuum has the potential for implosion. Proper personal protective equipment shall be used at all times. See 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 The specific gravity of soil solids is used in calculating the phase relationships of soils, such as void ratio and degree of saturation. 5.1.1 The specific gravity of soil solids is used to calculate the density of the soil solids. This is done by multiplying the specific gravity by the density of water at 20°C. The soil solids density is nearly independent of temperature. 5.2 The term soil solids is typically assumed to mean naturally occurring mineral particles or soil like particles that are not readily soluble in water. Therefore, the specific gravity of soil solids containing extraneous matter, such as cement, lime, and the like, water-soluble matter, such as sodium chloride, and soils containing matter with a specific gravity less than one, typically require special treatment (see Note 2 ) or a qualified definition of their specific gravity. Note 2: For some soils containing a significant fraction of organic matter, kerosene is a better wetting agent than water and may be used in place of test water for oven-dried specimens. Kerosene is a flammable liquid that must be used with extreme caution. This standard should not be used when using kerosene as the test fluid. 5.3 The balances, pycnometer sizes, and specimen masses are specified to obtain test results reportable to four significant digits. Note 3: The quality of the result produced by these test methods 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/etc. Users of these test methods 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.