1.1 本指南中描述的技术适用于混合流动气体（MFG）测试，该测试包含用于评估包含电触点（如滑环、可分离连接器、机电继电器或开关触点）的设备的物质。这些技术可能与其他设备相关，但用户有责任在测试前确定适用性。 1.2 本指南中描述的MFG测试旨在加速腐蚀降解过程。这些加速度被设计为使得退化发生在比在被测试设备的预期应用环境中的这些过程预期的时间短得多的时间段内。 应用程序环境可以连续变化，从良性到腐蚀性很强。封闭电子机柜内的连接器和触点可能受到与此类机柜外部环境不同严重程度的环境的影响。一般来说，室内环境与室外环境不同。本文所述的MFG测试是特定腐蚀条件的离散实施方案，不能代表所有可能的应用环境。测试说明符有责任确保给定测试条件与说明符的应用条件的相关性。 1.3 本文所述的MFG测试并非旨在复制被测设备的实际预期应用环境。本指南中包含了一个扩展的参考书目，提供了对测试指定人员有用的信息，以帮助他们选择适当的测试方法。参考书目涵盖了从应用条件表征、单一和多种气体效应、材料和产品效应到关键应用和测试变量以及大气腐蚀过程讨论的范围。 1.4 以国际单位制表示的数值应视为标准。 本标准不包括其他计量单位。 1.5 本标准并不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熟悉所有危险，包括制造商提供的本产品/材料的适当安全数据表（SDS）中确定的危险，制定适当的安全、健康和环境实践，并在使用前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====== 4.1 保持电触点上的导电表面对此类触点的持续功能至关重要。表面被腐蚀过程形成的绝缘层污染是一个潜在的危险。MFG测试中触点的实验室测试用于评估设计特征和材料的有效性。 4.2 MFG测试用于触点工艺和材料的开发研究。例如，试样可以暴露于MFG测试，以评估新的接触材料、支撑基底上的新涂层材料层、减少的涂层厚度或保护性表面处理。 4.3 MFG测试也用于测试成品相对于大气腐蚀的耐久性。例如，成品连接器可能会暴露在MFG测试中，并将其性能相互比较或与一组固定要求进行比较。继电器或开关触点可能暴露在操作和非操作条件下，以比较性能。 4.4 MFG测试有助于确定连接器外壳和护罩作为大气腐蚀剂进入接触表面的屏障的有效性。这些测试也可用于评估金属的筛选- 到配合连接器的金属接触区域。 4.5 MFG测试被用作鉴定测试，以确定先前已经建立了测试和应用之间相关性的应用环境中的连接器故障率。 4.6 本指南提供了将与实践一起应用的测试条件 B827 规定了所需的测试操作和认证程序、公差和报告要求。如果测试规范要求的认证或公差不同于实践中提供的认证或容差 B827 ，所需的认证或公差应为测试规范的一部分。 与实践中规范的差异 B827 应在试验操作员向试验指定人员提供的试验报告中报告。本文件中定义的测试条件之一的规范，以声明的形式，如“零件应根据ASTM进行测试 B845 方法Z”，隐含地要求根据实践应用测试条件Z B827 .

1.1 The techniques described in this guide pertain to mixed flowing gas (MFG) tests containing species that are applied to evaluate devices containing electrical contacts such as slip rings, separable connectors, electromechanical relays or switch contacts. These techniques may be relevant to other devices, but it is the responsibility of the user to determine suitability prior to testing. 1.2 The MFG tests described in this guide are designed to accelerate corrosive degradation processes. These accelerations are designed such that the degradation occurs in a much shorter time period than that expected for such processes in the intended application environment of the device being tested. Application environments can vary continuously from benign to aggressively corrosive. Connectors and contacts within closed electronic cabinets may be affected by an environment of different severity than the environment on the outside of such cabinets. In general, indoor environments are different than outdoor environments. The MFG tests described herein, being discrete embodiments of specific corrosive conditions, cannot be representative of all possible application environments. It is the responsibility of the test specifier to assure the pertinence of a given test condition to the specifier's application condition. 1.3 The MFG tests described herein are not designed to duplicate the actual intended application environment of the device under test. An extended bibliography that provides information which is useful to test specifiers to assist them in selecting appropriate test methods is included in this guide. The bibliography covers the scope from application condition characterization, single and multiple gas effects, and material and product effects to key application and test variables as well as discussions of atmospheric corrosion processes. 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 become familiar with all hazards including those identified in the appropriate Safety Data Sheet (SDS) for this product/material as provided by the manufacturer, 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 ====== 4.1 Preservation of a conducting surface on electrical contact is vital to the continued functioning of such contacts. Contamination of the surface with insulating layers formed by corrosion processes is one potential hazard. Laboratory testing of contacts in MFG tests is used to assess the effectiveness of design features and materials. 4.2 MFG tests are used in development studies of processes and materials for contacts. For example, coupon specimens may be exposed to MFG tests to evaluate new contact materials, layers of new coating materials on a supporting substrate, reduced coating thicknesses, or protective surface treatments. 4.3 MFG tests are also employed to test the durability of a finished product with respect to atmospheric corrosion. For example, finished connectors may be exposed to a MFG test and their performances compared against each other or against a set of fixed requirements. Relays or switch contacts may be exposed in the operated and non-operated conditions to compare performance. 4.4 MFG tests are useful for determining the effectiveness of connector housings and shrouds as barriers to ingress of atmospheric corrodants to the contact surfaces. These tests can also be used to assess the screening of the metal-to-metal contact areas of mated connectors. 4.5 MFG tests are employed as qualification tests to determine connector failure rates in application environments for which correlation between test and application has previously been established. 4.6 This guide provides test conditions which are to be applied in conjunction with Practice B827 which defines the required test operation and certification procedures, tolerances, and reporting requirements. Where the test specifier requires certifications or tolerances different than those provided in Practice B827 , the required certifications or tolerances shall be part of the test specification. Differences from the specifications in Practice B827 shall be reported in the test report provided by the test operator to the test specifier. Specification of one of the test conditions defined in this document in the form of a statement such as, “Parts shall be tested in accordance with ASTM B845 Method Z.”, implicitly requires test condition, Z, applied according to Practice B827 .