1.1 本规程涵盖了监测大气二氧化硫的两种方法，因此 2. 特定应用于估算或评估大气腐蚀性的沉积速率，因为其适用于建筑物、构筑物、车辆和室外设备中常用的金属。 1.2 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。 1.3 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。 1.4 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 金属材料的大气腐蚀是许多天气和大气变量的函数。二氧化硫等特定腐蚀剂的作用可以显著加速金属的大气腐蚀。重要的是要有可用的大气SO水平信息 2. 当许多金属暴露在大气中，以确定其在大气中的寿命期间对腐蚀损伤的敏感性时。 5.2 大气SO的体积分析 2. 一些研究人员认为，连续进行的浓缩是估计这种气体影响的最可靠方法。然而，这些方法需要复杂的监测设备以及电源和其他设备，使其不适用于许多暴露场所。这些方法超出了本实践的范围。 5.3 硫酸盐化板法提供了一种独立监测SO水平的简单技术 2. 在大气中产生加权平均结果。过氧化铅圆筒是一种类似的技术，可以产生类似的结果，并且结果对低水平的SO更敏感 2. . 5.4 硫酸盐化板或过氧化铅气瓶的结果可用于表征大气腐蚀试验现场的SO有效平均水平 2. 在这些地方的大气中。 5.5 硫酸盐化板或过氧化铅圆筒测试有助于确定SO有效平均水平的小气候、季节和长期变化 2. . 5.6 这些二氧化硫沉积速率测试的结果可用于大气腐蚀速率与大气数据的相关性，以确定腐蚀速率对SO的敏感性 2. 数量 5.7 二氧化硫监测方法也可与其他方法一起使用，如实践 G84 用于测量湿度时间和试验方法 G140型 对于大气氯化物沉积，描述计划建筑或其他施工现场的大气特征，以确定金属材料所需保护措施的范围。

1.1 This practice covers two methods of monitoring atmospheric sulfur dioxide, SO 2 deposition rates with specific application for estimating or evaluating atmospheric corrosivity as it applies to metals commonly used in buildings, structures, vehicles and devices used in outdoor locations. 1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.3 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. 1.4 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 Atmospheric corrosion of metallic materials is a function of many weather and atmospheric variables. The effect of specific corrodants, such as sulfur dioxide, can accelerate the atmospheric corrosion of metals significantly. It is important to have information available for the level of atmospheric SO 2 when many metals are exposed to the atmosphere in order to determine their susceptibility to corrosion damage during their life time in the atmosphere. 5.2 Volumetric analysis of atmospheric SO 2 concentration carried out on a continuous basis is considered by some investigators as the most reliable method of estimating the effects caused by this gas. However, these methods require sophisticated monitoring devices together with power supplies and other equipment that make them unsuitable for many exposure sites. These methods are beyond the scope of this practice. 5.3 The sulfation plate method provides a simple technique to independently monitor the level of SO 2 in the atmosphere to yield a weighted average result. The lead peroxide cylinder is similar technique that produces comparable results, and the results are more sensitive to low levels of SO 2 . 5.4 Sulfation plate or lead peroxide cylinder results may be used to characterize atmospheric corrosion test sites regarding the effective average level of SO 2 in the atmosphere at these locations. 5.5 Either sulfation plate or lead peroxide cylinder testing is useful in determining microclimate, seasonal, and long term variations in the effective average level of SO 2 . 5.6 The results of these sulfur dioxide deposition rate tests may be used in correlations of atmospheric corrosion rates with atmospheric data to determine the sensitivity of the corrosion rate to SO 2 level. 5.7 The sulfur dioxide monitoring methods may also be used with other methods, such as Practice G84 for measuring time of wetness and Test Method G140 for atmospheric chloride deposition, to characterize the atmosphere at sites where buildings or other construction is planned in order to determine the extent of protective measures required for metallic materials.