1.1 目的和应用- 本试验方法描述了使用复阻抗测量仪（CIMI）估算现场土壤干密度和含水量的程序、设备和解释方法。 1.1.1 本试验方法的目的和应用是测试多孔材料，如道路基层或建筑地基中使用的多孔材料，这些材料可能在不同的试验现场部署。测试设备包括与被测多孔材料接触的电极和向多孔材料提供电磁信号的传感器单元。 响应信号揭示了电参数，如复阻抗，可等同于材料特性，如密度和含水量。 1.1.2 本试验方法中所述的CIMI测量适用于道路和基础用压实土壤的测量。 1.1.3 本试验方法描述了使用CIMI估算土壤和土壤团聚体就地密度和含水量的程序。使用射频（RF）电压源测量土壤的电特性，该电压源连接至打入土壤和土壤的土壤电探针- 按规定的模式和深度测试骨料。这些特性的某些算法与湿密度和含水量有关。电测量值与密度和含水量之间的这种相关性是使用校准方法实现的。在校准方法中，密度和含水量由测量土壤密度和含水量的其他ASTM测试标准确定，然后将相应测量的电特性与土壤物理特性相关联。 1.2 单位- 以国际单位制表示的数值应视为标准值。括号中给出的英寸-磅单位是数学转换，仅供参考，不被视为标准。 1.2.1 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 除非被本标准取代。 1.3 广义理论: 1.3.1 土壤的两个关键电学性质是电导率和相对介电常数，表现为复数值- 可以确定的阻抗。 1.3.2 土壤电导率主要影响复阻抗的实部，土壤相对介电常数主要影响复阻抗的虚部。 1.3.3 土壤的复阻抗可以通过将两个电极放置在待测土壤中的已知距离和已知深度来确定。在电极上施加已知频率的交流电，可以测量通过土壤的电流、电极上的电压以及电压和电流之间的电相位差。 根据这些已知和测量参数计算复阻抗。 1.3.4 根据确定的复阻抗，使用由并联的电阻器（R）和电容器（C）组成的电网来表示被测土壤的模型。 1.3.5 使用土壤模型过程，可以在土壤湿密度和复阻抗幅值之间，以及在每单位测量的土壤水质量和C和R值的商之间建立关系。 1.3.6 土壤模型过程导致用于土壤的土壤的物理和电气特性之间的数学关系- CIMI的具体校准。 1.3.7 提到 附录X1 更详细地解释原地土壤的复阻抗测量及其在现场测量中用于估计干密度和含水量。 1.4 注意事项: 1.4.1 CIMI方法的低电平射频输出功率水平是无害的。 1.4.2 为仪器提供的国际单位制是英寸-磅单位的替代品，如果其他类似的国际单位制满足英寸制定的技术要求，则可以接受- 磅仪器。 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）。没有与本标准相关的已知危险。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 本标准试验方法中所述的CIMI测量适用于道路和基础用压实土壤的测量。 5.2 该试验方法用于根据电测量估算土壤和土壤团聚体的密度和含水量的现场值。 5.3 该测试方法可用于施工中使用的压实土壤和土壤骨料混合物的质量控制和验收测试，也可用于研究和开发。 该方法的最小干扰特性允许在单个测试位置进行重复测量，并对结果进行统计分析。 5.4 限制: 5.4.1 本试验方法概述了CIMI测量程序，使用连接到土壤传感器单元的控制台，通过金属探针将3.0 MHz射频电压施加到原位土壤中，金属探针以规定的距离打入土壤中。本测试方法不讨论使用的CIMI电子、计算机或软件的细节- 估算土壤密度和含水量的board算法 5.4.2 在本标准中，很难处理各种各样的土壤。然而，数据显示在 X3.1 提供适用于CIMI使用的土壤类型列表。 5.4.3 本标准中用于规定如何收集、记录或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。本标准中规定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。 注1: 尽管本试验方法中包含精度和偏差声明，但本试验方法的精度取决于执行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测试。本试验方法的使用者应注意遵守规程 D3740 本身不能确保可靠的结果。可靠的测试取决于许多因素；实践 D3740 提供了一种评估其中一些因素的方法。 5.5 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 ，除非被本试验方法取代。

1.1 Purpose and Application— This test method describes the procedure, equipment, and interpretation methods for estimating in-place soil dry density and water content using a Complex-Impedance Measuring Instrument (CIMI). 1.1.1 The purpose and application of this test method is for testing porous material such as used in roadway base or building foundations that may be deployed in the field at various test sites. The test apparatus includes electrodes that contact the porous material under test and a sensor unit that supplies electromagnetic signals to the porous material. Response signals reveal electrical parameters such as complex impedance which can be equated to material properties such as density and moisture content. 1.1.2 CIMI measurements as described in this test method are applicable to measurements of compacted soils intended for roads and foundations. 1.1.3 This test method describes the procedure for estimating in-place density and water content of soils and soil-aggregates by use of a CIMI. The electrical properties of the soil are measured using a radio frequency (RF) voltage source connected to soil electrical probes driven into the soils and soil-aggregates to be tested, in a prescribed pattern and depth. Certain algorithms of these properties are related to wet density and water content. This correlation between electrical measurements, and density and water content is accomplished using a calibration methodology. In the calibration methodology, density and water content are determined by other ASTM Test Standards that measure soil density and water content, thereafter correlating the corresponding measured electrical properties to the soil physical properties. 1.2 Units— The values stated in SI units are to be regarded as standard. The inch-pound units given in parentheses are mathematical conversions which are provided for information purposes only and are not considered standard. 1.2.1 All observed and calculated values shall conform to the guidelines for significant digits and rounding established in Practice D6026 unless superseded by this standard. 1.3 Generalized Theory: 1.3.1 Two key electrical properties of soil are conductivity and relative dielectric permittivity which are manifested as a value of complex-impedance that can be determined. 1.3.2 The soil conductivity contributes primarily to the real component of the complex-impedance, and the soil relative dielectric permittivity contributes primarily to the imaginary component of the complex-impedance. 1.3.3 The complex-impedance of soil can be determined by placing two electrodes in the soil to be tested at a known distance apart and a known depth. The application of a known frequency of alternating current to the electrodes enables a measurement of current through the soil, voltage across the electrodes, and the electrical phase difference between the voltage and current. Complex-impedance is calculated from these known and measured parameters. 1.3.4 From the determined complex-impedance, an electrical network consisting of a resistor (R) and capacitor (C) connected in parallel are used to represent a model of the soil being tested. 1.3.5 Relationships can be made between the soil wet density and the magnitude of the complex-impedance, and also between the soil water mass per unit measured, and the quotient of the values of C and R using a Soil Model process. 1.3.6 The Soil Model process results in mathematical relationships between the physical and electrical characteristics of the soil which are used for soil-specific calibration of the CIMI. 1.3.7 Refer to Appendix X1 for a more detailed explanation of complex-impedance measurement of in-place soil, and its use in field measurements for the estimation of dry density and water content. 1.4 Precautions: 1.4.1 The low-level RF output power levels of the CIMI method are harmless. 1.4.2 The SI units presented for apparatus are substitutions of the inch-pound units, other similar SI units should be acceptable providing they meet the technical requirements established by the inch-pound apparatus. 1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. There are no known hazards associated with this standard. 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 CIMI measurements as described in this Standard Test Method are applicable to measurements of compacted soils intended for roads and foundations. 5.2 The test method is used for estimating in-place values of density and water content of soils and soil-aggregates based on electrical measurements. 5.3 The test method may be used for quality control and acceptance testing of compacted soil and soil aggregate mixtures as used in construction and also for research and development. The minimal disturbance nature of the methodology allows repetitive measurements in a single test location and statistical analysis of the results. 5.4 Limitations: 5.4.1 This test method provides an overview of the CIMI measurement procedure using a controlling console connected to a soil sensor unit which applies a 3.0 MHz RF voltage to an in-place soil via metallic probes that are driven into the soil at a prescribed distance apart. This test method does not discuss the details of the CIMI electronics, computer, or software that utilize on-board algorithms for estimating the soil density and water content 5.4.2 It is difficult to address an infinite variety of soils in this standard. However, data presented in X3.1 provides a list of soil types that are applicable for the CIMI use. 5.4.3 The procedures used to specify how data are collected, recorded, or 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 prescribed in this standard do not consider material variation, purpose for obtaining the data, special purpose studies, or any considerations for the user’s objectives; 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 analytical methods for engineering design. Note 1: Notwithstanding the statements on precision and bias contained in this test method, the precision of this 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. Users of this test method are cautioned that compliance with Practice D3740 does not in itself ensure reliable results. Reliable testing depends on many factors; Practice D3740 provides a means of evaluating some of those factors. 5.5 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.