1.1 本规程涵盖了样品装置制备和样品处理的各个方面，以防止样品被最初不包含在样品中的微生物污染。 1.2 本规程还涵盖了样品处理注意事项，这些注意事项反映了为微生物测试采集的样品的易腐性。 1.3 本实践是对实践的补充 D4057号 在测试样品是否受微生物污染时，提供燃料手动取样的具体指南。 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 测定燃料和燃料系统中的微生物污染需要燃料产品和相关物质的代表性样品，以便准确评估对燃料、燃料系统部件或两者构成的生物劣化风险。不受控制的微生物污染会对燃料规格特性产生不利影响。 6. 如指南中所述 D6469 微生物会导致各种操作问题，包括过滤器堵塞和微生物影响腐蚀（MIC），后者会导致阀门故障、储罐和管道故障。 5.2 这些微生物采样实践降低了外来微生物污染样品的风险，从而增加了样品中原始微生物种群在采样时间和测试时间之间没有显著变化的可能性。 5.3 微生物检测采样的目的是获得代表性样本，这些样本可能反映采集样本的系统中微生物污染的程度和性质。手册47 7. 阐述了微生物污染计划的原理和设计。认识到微生物污染并非均匀分布在整个燃料系统中，采集的样本数量和类型通常与按照惯例采集的样本不同 D4057号 以确定产品是否符合规范。 5.4 对样品进行的物理、化学和微生物特性测试将规定取样程序、所需的样品数量以及许多样品处理要求。 5.5 燃料系统的设计通常不利于最佳微生物采样。因此，采样设备和样本源的选择反映了可访问性和适合性之间的折衷，以满足样本采集目标。 5.6 实践中提供的指导 D4057号 通常也适用于这种做法。因此，本规程将仅针对那些仅适用于微生物采样的程序。

1.1 This practice covers aspects of sample device preparation and sample handling that prevent samples from becoming contaminated with microorganisms not originally contained within the sample. 1.2 This practice also covers sample handling considerations that reflect the perishability of samples collected for microbiological testing. 1.3 This practice supplements Practice D4057 by providing guidance specific to the manual sampling of fuels when samples are to be tested for microbial contamination. 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 Representative samples of fuel products and associated substances are required for the determination of microbial contamination in fuels and fuel systems in order to accurately assess the biodeterioration risk posed to the fuel, fuel-system components or both. Uncontrolled microbial contamination can affect fuel specification properties adversely. 6 As discussed in Guide D6469 , microbes can cause a variety of operational problems, including filter plugging and microbially influenced corrosion (MIC), the latter of which causes valve failure, tank and pipeline failure. 5.2 These practices for microbiological sampling decrease the risk of contaminating samples with extraneous microbes, thereby increasing the probability that the original microbial population in the sample does not change significantly between the time of sampling and the time of testing. 5.3 The objective of sampling for microbiological testing is to obtain representative samples that are likely to reflect the degree and nature of microbial contamination in the system from which the samples are collected. Manual 47 7 addresses the rationale for and design of microbial contamination programs. Recognizing that microbiological contamination is not distributed uniformly throughout fuel systems, both the number and types of samples collected will normally be different from the samples collected per Practice D4057 in order to determine whether product meets specifications. 5.4 The physical, chemical and microbiological property tests to be performed on a sample will dictate the sampling procedures, the sample quantity required, and many of the sample handling requirements. 5.5 Fuel systems are not normally designed to facilitate optimal microbiological sampling. Consequently, the selection of sampling device and sample source reflect compromises between accessibility and suitability for meeting the sample collection objective. 5.6 The guidance provided in Practice D4057 generally applies to this practice as well. Consequently, this practice will address only those procedures that apply uniquely to microbiological sampling.