1.1 这些测试方法包括气泡收集和二氧化硫（SO）的比色测定 2. )在周围或工作场所的气氛中。 1.2 这些试验方法适用于测定SO 2. 超过约25 μ 克/米 3. （0.01 ppm（v））至1000 μ 克/米 3. （0.4 ppm（v）），对应于0.03的溶液浓度 μ g SO 2. /mL至1.3 μ g SO 2. /mL.在0.02的工作分析范围内遵循比尔定律 μ g SO 2. /mL至1.4 μ g SO 2. /mL。 1.3 检测下限为0.075 μ g SO 2. /mL ( 1. ) , 2. 表示空气浓度为25 μ g SO 2. /m 3. (0.01 ppm（v）），或13 μ g SO 2. /m 3. （0.005 ppm（v））在24小时样品中。 1.4 这些试验方法包括30分钟至24小时的取样。 1.5 这些试验方法描述了采集（撞击）样品的测定。描述了方法A和方法B。 1.6 方法A优于方法B，因为它具有更高的灵敏度，但具有更高的空白。 手动方法B取决于pH值，但更适用于光谱带宽大于20 nm的光谱仪。 注1: 这些试验方法适用于低于25%的浓度 μ 克/米 3. 如果首先确定了特定系统的吸收效率，则通过采样更大体积的空气，如中所述 附件A4 . 注2: 浓度高于1000 μ 克/米 3. 可以通过使用较小的气体体积、较大的收集体积或在分析之前用吸收溶液适当稀释收集的样品来确定。 1.7 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。 1.8 警告- 许多监管机构已将汞指定为一种危险物质，可导致严重的医疗问题。汞或其蒸汽已被证明对健康有害，并对材料具有腐蚀性。处理汞和含汞产品时应小心。有关更多信息，请参阅适用的产品安全数据表（SDS）。 用户应意识到，法律可能禁止向您所在的州或国家销售汞和/或含汞产品。 1.9 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。 有关具体预防说明，请参阅 8.3.1 部分 9 和 A3.1.3 . 1.10 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 二氧化硫是一种主要的空气污染物，通常由含硫燃料燃烧形成。环境保护局（EPA）制定了一级和二级空气质量标准 ( 7. ) 是为了保护公众健康和福利。 5.2 职业安全与健康管理局（OSHA）颁布了工作场所大气中二氧化硫的接触限值 ( 8. ) . 5.3 这些方法对于测量环境和工作场所大气中的二氧化硫在以下相关范围内是令人满意的: 5.1 和 5.2 . 5.4 方法A的设计符合EPA指定的参考方法 ( 7. ) 用于二氧化硫的测定。

1.1 These test methods cover the bubbler collection and colorimetric determination of sulfur dioxide (SO 2 ) in the ambient or workplace atmosphere. 1.2 These test methods are applicable for determining SO 2 over the range from approximately 25 μ g/m 3 (0.01 ppm(v)) to 1000 μ g/m 3 (0.4 ppm(v)), corresponding to a solution concentration of 0.03 μ g SO 2 /mL to 1.3 μ g SO 2 /mL. Beer's law is followed through the working analytical range from 0.02 μ g SO 2 /mL to 1.4 μ g SO 2 /mL. 1.3 The lower limit of detection is 0.075 μ g SO 2 /mL ( 1 ) , 2 representing an air concentration of 25 μ g SO 2 /m 3 (0.01 ppm(v)) in a 30-min sample, or 13 μ g SO 2 /m 3 (0.005 ppm(v)) in a 24-h sample. 1.4 These test methods incorporate sampling for periods between 30 min and 24 h. 1.5 These test methods describe the determination of the collected (impinged) samples. A Method A and a Method B are described. 1.6 Method A is preferred over Method B, as it gives the higher sensitivity, but it has a higher blank. Manual Method B is pH-dependent, but is more suitable with spectrometers having a spectral band width greater than 20 nm. Note 1: These test methods are applicable at concentrations below 25 μ g/m 3 by sampling larger volumes of air if the absorption efficiency of the particular system is first determined, as described in Annex A4 . Note 2: Concentrations higher than 1000 μ g/m 3 can be determined by using smaller gas volumes, larger collection volumes, or by suitable dilution of the collected sample with absorbing solution prior to analysis. 1.7 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.8 Warning— Mercury has been designated by many regulatory agencies as a hazardous material that can cause serious medical issues. Mercury, or its vapor, has been demonstrated to be hazardous to health and corrosive to materials. Caution should be taken when handling mercury and mercury containing products. See the applicable product Safety Data Sheet (SDS) for additional information. Users should be aware that selling mercury and/or mercury containing products into your state or country may be prohibited by law. 1.9 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. For specific precautionary statements, see 8.3.1 , Section 9 , and A3.1.3 . 1.10 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 Sulfur dioxide is a major air pollutant, commonly formed by the combustion of sulfur-bearing fuels. The Environmental Protection Agency (EPA) has set primary and secondary air quality standards ( 7 ) that are designed to protect the public health and welfare. 5.2 The Occupational Safety and Health Administration (OSHA) has promulgated exposure limits for sulfur dioxide in workplace atmospheres ( 8 ) . 5.3 These methods have been found satisfactory for measuring sulfur dioxide in ambient and workplace atmospheres over the ranges pertinent in 5.1 and 5.2 . 5.4 Method A has been designed to correspond to the EPA-Designated Reference Method ( 7 ) for the determination of sulfur dioxide.