1.1 本试验方法 2. 包括二氧化氮（NO）的手动测定 2. )在4到10000μg/m的大气中 3. （0.002至5 ppm（v）），当在烧结尖端起泡器中进行取样时。 1.2 对于NO浓度 2. 超过10毫克/米 3. （5 ppm（v）），如在工业大气、燃气燃烧器烟囱或汽车排气中出现，或对于二氧化硫含量相对较高的样品，应采用其他方法。参见测试方法示例 D1608 . 1.3 流速为0.4升/分钟时，最大采样周期为60分钟。 1.4 以国际单位制表示的数值应视为标准值。括号中给出的值是英寸-磅单位的数学转换，仅供参考，不被视为标准值。 1.5 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。 另请参见 7.2.2 其他注意事项。 1.6 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 二氧化氮在光化学烟雾形成反应中起着重要作用，如果浓度足够，则对健康、农业、材料和能见度有害。 5.2 在燃烧过程中，大气氮和氧的结合可能会产生大量的一氧化氮（NO）；在环境温度下，NO可以转化为NO 2. 通过氧气和其他大气氧化剂。硝酸、硝酸盐、炸药的使用和焊接过程也可能产生二氧化氮。

1.1 This test method 2 covers the manual determination of nitrogen dioxide (NO 2 ) in the atmosphere in the range from 4 to 10 000 μg/m 3 (0.002 to 5 ppm(v)) when sampling is conducted in fritted-tip bubblers. 1.2 For concentrations of NO 2 in excess of 10 mg/m 3 (5 ppm(v)), as occur in industrial atmospheres, gas burner stacks, or automotive exhaust, or for samples relatively high in sulfur dioxide content, other methods should be applied. See for example Test Method D1608 . 1.3 The maximum sampling period is 60 min at a flow rate of 0.4 L/min. 1.4 The values stated in SI units are to be regarded as standard. The values given in parentheses are mathematical conversions to inch-pound units that are provided for information only and are not considered 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 establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. See also 7.2.2 for other precautions. 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 ====== 5.1 Nitrogen dioxide plays an important role in photochemical smog-forming reactions and, in sufficient concentrations, is deleterious to health, agriculture, materials, and visibility. 5.2 In combustion processes, significant amounts of nitric oxide (NO) may be produced by combination of atmospheric nitrogen and oxygen; at ambient temperatures NO can be converted to NO 2 by oxygen and other atmospheric oxidants. Nitrogen dioxide may also be generated from processes involving nitric acid, nitrates, the use of explosives, and welding.