1.1 该试验方法包括地表水中浊度的现场测量。测量范围大于1 TU，小于10 000 TU或浊度计制造商规定的最大可测量TU值。 1.1.1 对高达约1000 TU的真实世界和替代浊度样品进行了精度数据。该测试方法中列出的许多技术都能够测量出高于精度部分中提供的技术（见第 16 )。 1.2 在本试验方法中，“原位测量”指的是浊度计传感器直接放置在现场地表水中，不需要将样品运输到传感器或从传感器运输样品的应用。 地表水是指泉水、湖泊、水库、沉淀池、溪流和河流、河口和海洋。 1.3 本试验方法中涵盖的许多浊度单位和仪器设计在校准中是数值等效的，当通用校准标准适用于 表1 .对定义值的通用校准标准的测量也将在这些技术中产生等效的结果。该试验方法规定了将确定的浊度值分配给用于确定这些值的技术。在不同的技术之间可以观察到浊度标准的数值等效性，但在普通样品中预计不会。 可以实践超出该测试方法范围的改进可追溯性，包括列出用于确定浊度值的仪器的品牌和型号。 1.4 在这种测试方法中，校准标准通常以NTU值定义，但其他指定的浊度单位，如 表1 是等效的。例如，1 NTU形式津标准也是1 FNU、1 FAU、1 BU等等。 1.5 该测试方法在不同的天然水中进行了测试，并使用了作为样品替代品的标准品。建议验证未经测试的基质水的方法响应。 1.6 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。 1.7 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 监测浊度有助于控制过程，监测水生环境的健康和生物学，并确定风暴、洪水、径流等环境事件的影响。 浊度在饮用水、工厂废水、食品和饮料生产用水以及许多其他依赖水的制造过程中是不可取的。浊度通常通过混凝、沉淀和水过滤来降低。浊度的测量可以指示颗粒结合污染物的存在，并且对于监测颗粒废物沉淀过程的完成至关重要。浊度测量的重要用途包括: 5.1.1 遵守许可证、水质指南和法规； 5.1.2 确定水系统中颗粒和相关污染物的运输和归宿； 5.1.3 地表水的养护、保护和恢复； 5.1.4 衡量水和土地使用管理的绩效； 5.1.5 监测水边施工、采矿和疏浚作业； 5.1.6 废水和能源生产废水的特性； 5.1.7 跟踪水井完工情况，包括开发和使用情况；和 5.1.8 作为水中其他成分的替代品，包括沉积物和沉积物相关成分。 5.2 浊度计的校准范围应超过应用TU值的预期范围，但不得超过制造商规定的测量范围。 5.3 本标准中描述的设计检测并响应相对吸收、光散射强度和透射率的组合。 但是，它们并不测量中定义的这些绝对物理单位 3.2.15 和 3.2.19 。 5.4 几种不同的浊度计设计可用于该测试方法，并且一种设计可能比另一种设计更适合特定类型的样品或监测应用。中的选择流程图 附件A1 为特定应用选择合适的浊度计设计提供了指导。 5.5 以反映中建议使用的浊度计设计的单位报告浊度 4.3 看见 表1 和截面 7. 用于讨论报告单元的设计标准和推导。 5.6 表1 和截面 7. 列出了目前在中使用的浊度计设计- 现场测量。该方法的未来修订可能包括额外的设计。

1.1 This test method covers the in-situ field measurements of turbidity in surface water. The measurement range is greater than 1 TU and the lesser of 10 000 TU or the maximum measurable TU value specified by the turbidimeter manufacturer. 1.1.1 Precision data was conducted on both real world and surrogate turbidity samples up to about 1000 TU. Many of the technologies listed in this test method are capable of measuring above that provided in the precision section (see Section 16 ). 1.2 “In-situ measurement” refers in this test method to applications where the turbidimeter sensor is placed directly in the surface water in the field and does not require transport of a sample to or from the sensor. Surface water refers to springs, lakes, reservoirs, settling ponds, streams and rivers, estuaries, and the ocean. 1.3 Many of the turbidity units and instrument designs covered in this test method are numerically equivalent in calibration when a common calibration standard is applied across those designs listed in Table 1 . Measurement of a common calibration standard of a defined value will also produce equivalent results across these technologies. This test method prescribes the assignment of a determined turbidity values to the technology used to determine those values. Numerical equivalence to turbidity standards is observed between different technologies but is not expected across a common sample. Improved traceability beyond the scope of this test method may be practiced and would include the listing of the make and model number of the instrument used to determine the turbidity values. 1.4 In this test method, calibration standards are often defined in NTU values, but the other assigned turbidity units, such as those in Table 1 are equivalent. For example, a 1 NTU formazin standard is also a 1 FNU, a 1 FAU, a 1 BU, and so forth. 1.5 This test method was tested on different natural waters and with standards that served as surrogates for samples. It is recommended to validate the method response for waters of untested matrices. 1.6 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. 1.7 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 Turbidity is monitored to help control processes, monitor the health and biology of aquatic environments and to determine the impact of environmental events such as storms, floods, runoff, etc. Turbidity is undesirable in drinking water, plant-effluent waters, water for food and beverage production, and for a large number of other water-dependent manufacturing processes. Turbidity is often reduced by coagulation, sedimentation and water filtration. The measurement of turbidity may indicate the presence of particle-bound contaminants and is vital for monitoring the completion of a particle-waste settling process. Significant uses of turbidity measurements include: 5.1.1 Compliance with permits, water-quality guidelines, and regulations; 5.1.2 Determination of transport and fate of particles and associated contaminants in aquatic systems; 5.1.3 Conservation, protection and restoration of surface waters; 5.1.4 Measure performance of water and land-use management; 5.1.5 Monitor waterside construction, mining, and dredging operations; 5.1.6 Characterization of wastewater and energy-production effluents; 5.1.7 Tracking water-well completion including development and use; and 5.1.8 As a surrogate for other constituents in water including sediment and sediment-associated constituents. 5.2 The calibration range of a turbidimeter shall exceed the expected range of TU values for an application but shall not exceed the measurement range specified by the manufacturer. 5.3 Designs described in this standard detect and respond to a combination of relative absorption, intensity of light scattering, and transmittance. However, they do not measure these absolute physical units as defined in 3.2.15 and 3.2.19 . 5.4 Several different turbidimeter designs may be used for this test method and one design may be better suited for a specific type of sample or monitoring application than another. The selection flowchart in Annex A1 provides guidance for the selection of an appropriate turbidimeter design for a specific application. 5.5 Report turbidity in units that reflect the design of the turbidimeter used as recommended in 4.3 . See Table 1 and Section 7 for a discussion of the design criteria and derivation of reporting units. 5.6 Table 1 and Section 7 lists the turbidimeter designs currently used for in-situ measurements. Future revisions of the method may include additional designs.