1.1 本规程提供了进行环境试验的程序，涉及暴露在受控数量的腐蚀性气体混合物中。 1.2 本实施规程规定了气体、温度和湿度控制所需的设备和方法，使试验能够以可重复的方式进行。通过使用对照试样测量再现性，对照试样的腐蚀膜通过质量增益、库仑法或各种电子和X射线束分析技术进行评估。再现性也可以通过使用电阻或质量/频率变化方法的现场腐蚀速率监测器来测量。 1.3 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。 1.4 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熟悉所有危险，包括制造商提供的本产品/材料的适当材料安全数据表（MSDS）中确定的危险，建立适当的安全、健康和环境实践，并在使用前确定监管限制的适用性。 看见 5.1. 2.4 . 1.5 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====== 4.1 混合流动气体（MFG）测试用于模拟或放大在各种应用环境中电触点或连接器可能经历的环境条件下的暴露 ( 1. , 2. ) . 4. 4.2 暴露于制造试验的试样范围从裸露的金属表面到电气连接器，再到完整的组件。 4.3 通常选择特定的测试条件，以便在测试实验室中模拟某些代表性现场环境或环境严重程度对标准金属表面（例如铜和银试样或多孔镀金层）的影响 ( 1. , 2. ) . 4.4 由于制造试验是模拟试验，因此试验条件和降解反应（化学反应速率、反应产物的组成等）可能并不总是与制造试验中所测试产品的使用环境中发现的相似。指南中提供了适用于各种环境的模拟条件选择指南 B845 . 4.5 制造暴露通常与评估触点或连接器电气性能的程序结合使用，例如在制造暴露前后测量电接触电阻。 4.6 制造测试对于接触表面镀有或覆有金或其他贵金属表面的连接器系统非常有用。对于此类表面，环境产生的故障通常是由于高电阻或接触区域中形成绝缘污染引起的间歇性故障。这种以薄膜和硬颗粒形式存在的污染通常是由于孔隙腐蚀和腐蚀产物从贵金属涂层中的孔隙和未电镀的贱金属边界（如果存在）迁移或变色蠕变造成的。 4.7 制造商暴露可用于评估新型电接触金属化由于环境暴露于试验腐蚀性气体而导致的劣化敏感性。 4.8 制造商暴露可用于评估连接器外壳的屏蔽能力，该外壳可作为腐蚀性气体进入的屏障。 4.9 制造商暴露可用于评估其他连接器材料（如塑料外壳）对测试腐蚀性气体降解的敏感性。 4.10 制造试验通常不用作孔隙度试验。有关孔隙度测试的指南，请参阅指南 B765 . 4.11 如果失效机制不是污染气体腐蚀，例如在镀锡可分离触点中，制造试验通常不适用。

1.1 This practice provides procedures for conducting environmental tests involving exposures to controlled quantities of corrosive gas mixtures. 1.2 This practice provides for the required equipment and methods for gas, temperature, and humidity control which enable tests to be conducted in a reproducible manner. Reproducibility is measured through the use of control coupons whose corrosion films are evaluated by mass gain, coulometry, or by various electron and X-ray beam analysis techniques. Reproducibility can also be measured by in situ corrosion rate monitors using electrical resistance or mass/frequency change methods. 1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.4 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 Material Safety Data Sheet (MSDS) 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. See 5.1.2.4 . 1.5 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 Mixed flowing gas (MFG) tests are used to simulate or amplify exposure to environmental conditions which electrical contacts or connectors can be expected to experience in various application environments ( 1 , 2 ) . 4 4.2 Test samples which have been exposed to MFG tests have ranged from bare metal surfaces, to electrical connectors, and to complete assemblies. 4.3 The specific test conditions are usually chosen so as to simulate, in the test laboratory, the effects of certain representative field environments or environmental severity levels on standard metallic surfaces, such as copper and silver coupons or porous gold platings ( 1 , 2 ) . 4.4 Because MFG tests are simulations, both the test conditions and the degradation reactions (chemical reaction rate, composition of reaction products, etc.) may not always resemble those found in the service environment of the product being tested in the MFG test. A guide to the selection of simulation conditions suitable for a variety of environments is found in Guide B845 . 4.5 The MFG exposures are generally used in conjunction with procedures which evaluate contact or connector electrical performance such as measurement of electrical contact resistance before and after MFG exposure. 4.6 The MFG tests are useful for connector systems whose contact surfaces are plated or clad with gold or other precious metal finishes. For such surfaces, environmentally produced failures are often due to high resistance or intermittences caused by the formation of insulating contamination in the contact region. This contamination, in the form of films and hard particles, is generally the result of pore corrosion and corrosion product migration or tarnish creepage from pores in the precious metal coating and from unplated base metal boundaries, if present. 4.7 The MFG exposures can be used to evaluate novel electrical contact metallization for susceptibility to degradation due to environmental exposure to the test corrosive gases. 4.8 The MFG exposures can be used to evaluate the shielding capability of connector housings which may act as a barrier to the ingress of corrosive gases. 4.9 The MFG exposures can be used to evaluate the susceptibility of other connector materials such as plastic housings to degradation from the test corrosive gases. 4.10 The MFG tests are not normally used as porosity tests. For a guide to porosity testing, see Guide B765 . 4.11 The MFG tests are generally not applicable where the failure mechanism is other than pollutant gas corrosion such as in tin-coated separable contacts.