1.1 这些试验方法包括连续测定总二氧化氮（NO）的程序 2. )一氧化氮（NO）为NO x ，或单独使用一氧化氮（NO）或二氧化氮（NO 2. )单独，在下表所示的范围内: 近似浓度范围 （25°C和101.3 kPa（1 atm）） 气体 周围大气 工作场所气氛 微克/米 3. （ppm） 毫克/米 3. （ppm） 不 10至600（0.01至0.5） 0.6至30（0.5至25） （否+否 2. )=否 x 20至1000（0.01至0.05） 1至50（0.5至25） 不 2. 20至1000（0.01至0.5） 1至50（0.5至25） 1.2 测试方法基于一氧化氮和臭氧之间的化学发光反应。 1.3 以国际单位制表示的数值应视为标准值。国际单位制后括号中给出的值仅供参考，不被视为标准值。 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。 有关具体的预防说明，请参阅第节 9 . 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====== 5.1 大多数氮氧化物是在高温下形成的- 燃烧温度。美国环境保护局（EPA）为NO 2. 旨在保护公众健康和公共福利（40 CFR，第50部分）。 5.2 氮氧化物由许多工业过程产生，可能导致员工暴露。这些由职业安全与健康管理局（OSHA）监管，该局已颁布了工业工作环境的接触限值（29 CFR，第1910部分）。 5.3 经证明，这些试验方法适用于在所示范围内测量环境和工作场所大气中的氮氧化物 1.1 .

1.1 These test methods cover procedures for the continuous determination of total nitrogen dioxide (NO 2 ) and nitric oxide (NO) as NO x , or nitric oxide (NO) alone or nitrogen dioxide (NO 2 ) alone, in the ranges shown in the following table: Approximate Range of Concentration (25°C and 101.3 kPa (1 atm)) Gas Ambient Atmosphere Workplace Atmosphere μg/m 3 (ppm) mg/m 3 (ppm) NO 10 to 600 (0.01 to 0.5) 0.6 to 30 (0.5 to 25) (NO + NO 2 ) = NO x 20 to 1000 (0.01 to 0.05) 1 to 50 (0.5 to 25) NO 2 20 to 1000 (0.01 to 0.5) 1 to 50 (0.5 to 25) 1.2 The test methods are based on the chemiluminescent reaction between nitric oxide and ozone. 1.3 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered 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 establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. For specific precautionary statements, see Section 9 . 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 ====== 5.1 Most oxides of nitrogen are formed during high-temperature combustion. The U.S. Environmental Protection Agency (EPA) has set primary and secondary air quality standards for NO 2 that are designed to protect the public health and the public welfare (40 CFR, Part 50). 5.2 Oxides of nitrogen are generated by many industrial processes that can result in employee exposures. These are regulated by the Occupational Safety and Health Administration (OSHA), which has promulgated exposure limits for the industrial working environment (29 CFR, Part 1910). 5.3 These test methods have been found to be satisfactory for measuring oxides of nitrogen in ambient and workplace atmospheres over the ranges shown in 1.1 .