1.1 本试验方法提供了一种监测涉及腐蚀性气体暴露的环境试验的腐蚀性的方法。 1.2 本试验方法使用由所选金属导体制成的电阻监测器（RM）探头，其中一个导体段未覆盖，以允许所选金属导体暴露于腐蚀性气体混合物中，第二个导体段覆盖，以保护该段的金属导体免受腐蚀性气体混合物的直接攻击。覆盖导线段为评估未覆盖段的变化提供了参考。暴露段的电阻与覆盖段的电阻之比提供了与腐蚀性气体试验环境反应形成不良导电腐蚀产物的金属导体量的测量值，从而提供了测试腐蚀性的测量值。 1.3 通过选择合适的金属导体和初始金属厚度，电阻监测适用于广泛的测试条件。 1.4 该方法与试验方法的意图类似 B808 . 1.5 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。 1.6 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。 1.7 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 测试环境的腐蚀性监测提供了一种监测测试腐蚀性综合值的方法，该值无法从测试参数本身进行评估，例如温度、湿度和气体浓度。因此，监控值可用于规范目的，如测试验证。对暴露在腐蚀介质中的导体进行电阻监测是一种公认的做法。 3. , 4. , 5. , 6. 4.2 电阻法假设裸露金属导体段的整个表面上存在均匀腐蚀。局部腐蚀，如点蚀、裂缝或晶界腐蚀，可能会提供无效的测试腐蚀性估计。电阻比随时间变化曲线斜率的显著变化可能表明不希望出现的过程，这可能是由于测试大气或监测器本身的缺陷造成的。 4.3 由于在形成钝化腐蚀膜时，在RM探针的金属导体段上形成的腐蚀产物内的扩散过程受到限制，电阻监测可能无法用于长时间试验暴露的试验箱监测目的。腔室监测取决于检测RM腐蚀速率的变化，作为必须重新验证指定气体浓度的指示信号。然而，低腐蚀速率限制了腐蚀速率随试验条件变化的绝对值；对于抛物线薄膜生长过程，在延长的测试时间内，生长速率随着限制RM灵敏度的时间而降低。 4.4 由于腐蚀速率可能是MFG测试中测试参数的复杂函数，任何给定金属主要对MFG环境中的气体子集作出响应，因此需要多个类型的金属电阻探头，以帮助维持相对气体浓度。 对于此类测试规范，电阻比值必须参考在测试规范提供的已知测试条件下获得的比率。有关各种金属对各种腐蚀剂的敏感性的信息已经发布。 7. , 8. 4.5 RM探针可以从1开始使用 % 厚度消耗高达50 % 腐蚀膜生长消耗的厚度。据报道，导体厚度在25 nm和0.2 mm之间，常见尺寸可在市场上买到。

1.1 This test method provides a means for monitoring corrosivity of environmental tests that involve exposure to corrosive gases. 1.2 This test method uses a resistance monitor (RM) probe fabricated from a chosen metal conductor, with one conductor segment uncovered to permit exposure of the chosen metal conductor to the corrosive gas mixture and the second conductor segment covered to protect the metal conductor of this segment from direct attack by the corrosive gas mixture. The covered conductor segment provides a reference for evaluating changes in the uncovered segment. The ratio of the resistance of the exposed segment to that of the covered segment provides a measure of the amount of metal conductor that has reacted with the corrosive gas test environment to form poorly conducting corrosion product, thus providing a measure of test corrosivity. 1.3 Resistance monitoring is applicable to a broad range of test conditions by selection of the appropriate metal conductor and initial metal thickness. 1.4 This method is similar in intent to Test Methods B808 . 1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 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 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. 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 ====== 4.1 Corrosivity monitoring of test environments provides a means to monitor an integrated value of test corrosivity which cannot be evaluated from test parameters themselves, such as temperature, humidity, and gas concentration. As such the monitor value can be used for specification purposes such as test validation. Electrical resistance monitoring of conductors exposed to corrosive media is a well-established practice. 3 , 4 , 5 , 6 4.2 The resistance method assumes uniform corrosion over the entire surface of the exposed metal conductor segment. Local corrosion such as pitting, crevice, or grain boundary corrosion may provide invalid estimates of test corrosivity. Marked changes in slope of the curve of electrical resistance ratio versus time may indicate undesired processes which can be due to deficiencies in the test atmosphere or in the monitor itself. 4.3 Because of limitations of the diffusion process within the corrosion product formed on the metal conductor segment of the RM probe when passivating corrosion films are formed, resistance monitoring may not be useful for test chamber monitoring purposes for very long test exposures. Chamber monitoring is dependent on detecting changes in the rate of corrosion of the RM as an indicator signal that specified gas concentrations must be reverified. However, low corrosion rates limit the absolute value of the rate of change of corrosion rate with change of test conditions; for parabolic film growth processes, the growth rate decreases with time limiting the sensitivity of the RM at extended test times. 4.4 Since corrosion rate can be a complex function of test parameters in MFG tests with any given metal primarily responsive to a subset of the gases in the MFG environment, more than one type metal resistance probe is required in order to assist in maintenance of relative gas concentrations. For such test specifications, values of resistance ratios must be referred to ratios obtained under known test conditions as supplied by the test specifier. Information relating to the sensitivity of various metals to various corrodants has been published. 7 , 8 4.5 RM probes can be useful from 1 % of thickness consumed upward to 50 % of thickness consumed by the corrosion film growth. Conductor thicknesses between 25 nm and 0.2 mm have been reported and common sizes are available commercially.