1.1 本规程涵盖了对气体和蒸汽扩散采样器性能的评估，该采样器在4到12小时的采样周期内以及风速小于0.5 m/s的情况下使用。此类采样周期和风速在室内工作场所环境中最常见。当扩散时，本规程不适用于风速小于0.1 m/s的静态或区域采样 外部 取样器可能控制从环境空气到取样器附近所需的对流。如果有一个合适的暴露室，该实践可以扩展到涵盖取样器在其他采样周期和条件下的使用。目的是提供一组简明的实验，主要根据单个采样器精度图对采样器进行分类。 定义了精度( 3.2.2 )在本标准中，考虑了不精确性和未修正的偏差。准确度估计是指在工作场所环境中通常预期的采样器使用条件。这些条件可以通过温度、大气压力、湿度和环境风速来表征，当在现场使用取样器时，这些条件都可能是恒定的或准确的。此外，准确度考虑了分析物扩散损失对浓度时间加权平均值估计的影响，该平均值在时间上可能不恒定。除准确度外，还测试取样器是否符合制造商规定的容量限制，可能是在存在干扰化合物的情况下。 1.2 本实践是之前扩散采样器研究的延伸 ( 1- 14 ) 2. 以及实践 D4597 , D4598 , D4599 和MDHS 27。这里的一个重要进展是在实际使用条件下估计采样器的精度。此外，降低了采样器评估的成本。 1.3 从类似分析物中获得的知识加速了采样器评估。例如，建议对表征同源化合物系列分离点处分析物取样的数据进行插值。目前 ( 9 ) 建议。根据目前的实践，在对单个同源序列成员使用的取样器进行评估后，考虑到采样率、容量、分析回收率和干扰，高分子量成员将接受部分验证。 如果发现对给定取样器或分析物系列的影响可以忽略不计，则可以省略扩散分析物损失测试。 1.4 以国际单位制表示的数值应视为标准值。本标准不包括其他计量单位。 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。 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 气体或蒸汽取样通常通过活性炭等收集介质主动泵送空气来完成。与泵相关的问题——不便、不准确和费用——无法从这种类型的采样中解决。本实践涵盖的替代方法是使用扩散将利息化合物移动到收集介质上。由于使用方便和总监测成本低，这种采样方法具有吸引力。 5.2 然而，以前的研究发现，一些采样器的准确性存在重大问题。因此，尽管扩散采样器可能提供过多的数据，但扩散采样器的不准确和误用仍可能影响研究。 此外，工人保护可能基于错误的假设。本规程的目的是通过实现一套广泛接受的性能测试和验收标准，以证明任何给定的预期使用的扩散采样器的有效性，来应对扩散采样中的不确定性。

1.1 This practice covers the evaluation of the performance of diffusive samplers of gases and vapors for use over sampling periods from 4 to 12 h and for wind speeds less than 0.5 m/s. Such sampling periods and wind speeds are the most common in the indoor workplace setting. This practice does not apply to static or area sampling in wind speeds less than 0.1 m/s, when diffusion outside the sampler may dominate needed convection from the ambient air to the vicinity of the sampler. Given a suitable exposure chamber, the practice can be extended to cover sampler use for other sampling periods and conditions. The aim is to provide a concise set of experiments for classifying samplers primarily in accordance with a single sampler accuracy figure. Accuracy is defined ( 3.2.2 ) in this standard so as to take into account both imprecision and uncorrected bias. Accuracy estimates refer to conditions of sampler use which are normally expected in a workplace setting. These conditions may be characterized by the temperature, atmospheric pressure, humidity, and ambient wind speed, none of which may be constant or accurately known when the sampler is used in the field. Furthermore, the accuracy accounts for the effects of diffusive loss of analyte on the estimation of time-weighted averages of concentrations which may not be constant in time. Aside from accuracy, the samplers are tested for compliance with the manufacturer’s stated limits on capacity, possibly in the presence of interfering compounds. 1.2 This practice is an extension of previous research on diffusive samplers ( 1- 14 ) 2 as well as Practices D4597 , D4598 , D4599 , and MDHS 27. An essential advance here is the estimation of sampler accuracy under actual conditions of use. Furthermore, the costs of sampler evaluation are reduced. 1.3 Knowledge gained from similar analytes expedites sampler evaluation. For example, interpolation of data characterizing the sampling of analytes at separated points of a homologous series of compounds is recommended. At present the procedure of ( 9 ) is suggested. Following evaluation of a sampler in use at a single homologous series member according to the present practice, higher molecular weight members would receive partial validations considering sampling rate, capacity, analytical recovery, and interferences. The test for diffusive analyte loss can be omitted if the effect is found negligible for a given sampler or analyte series. 1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 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. 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 Gas or vapor sampling is often accomplished by actively pumping air through a collection medium such as activated charcoal. Problems associated with a pump – inconvenience, inaccuracy, and expense – are inextricable from this type of sampling. The alternative covered by this practice is to use diffusion for moving the compound of interest onto the collection medium. This approach to sampling is attractive because of the convenience of use and low total monitoring cost. 5.2 However, previous studies have found significant problems with the accuracy of some samplers. Therefore, although diffusive samplers may provide a plethora of data, inaccuracies and misuse of diffusive samplers may yet affect research studies. Furthermore, worker protections may be based on faulty assumptions. The aim of this practice is to counter the uncertainties in diffusive sampling through achieving a broadly accepted set of performance tests and acceptance criteria for proving the efficacy of any given diffusive sampler intended for use.