1.1 这种做法提供了对空气污染和气象界成员有用的单位和因素。 1.2 此做法与 IEEE/ASTM SI-10标准 ，其中讨论了国际单位制，并包含国际单位制和一些常用非公制单位之间相互关系的选定换算系数。 1.3 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====== 3.1 ASTM要求在其所有出版物中使用SI单位，并在报告大气测量数据时使用SI单位。然而，有历史数据，甚至目前报告的数据都是基于各种计量单位的。本规程列出了将此类数据转换为SI和其他计量单位所需的因素。 3.2 IEEE/ASTM SI-10标准 没有列出空气污染和气象领域常用的所有换算系数。 本实践补充 IEEE/ASTM SI-10标准 . 3.3 此处报告的值是从许多标准出版物中获得的。他们被调整到五位数，并按照合理的顺序组织起来。所有数值都反映了1979年举行的第16届重量和测量大会的最新信息。 3.4 中的因素 表1 用于将测量单位从一个系统更改为其他系统中的相关单位，以及更改为同一系统中的较小或较大单位。 3.5 左栏中的单位值可以通过乘以中间栏中提供的换算系数转换为右栏中的单元值。 （A） 有关具体应用和例外情况，请参阅术语 D1356型 .

1.1 This practice provides units and factors useful for members of the air pollution and meteorological communities. 1.2 This practice is used together with IEEE/ASTM SI-10 , which discusses SI units and contains selected conversion factors for inter-relation of SI units and some commonly used non-metric units. 1.3 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 ====== 3.1 ASTM requires the use of SI units in all its publications and their use in reporting atmospheric measurement data. However, there are historic data and even data currently reported that are based on a variety of units of measurement. This practice tabulates factors that are necessary to convert such data to SI and other units of measurement. 3.2 IEEE/ASTM SI-10 does not list all the conversion factors commonly used in air pollution and meteorological fields. This practice supplements IEEE/ASTM SI-10 . 3.3 The values reported here were obtained from a number of standard publications. They were adjusted to five figures and organized in a rational order. All values reflect the latest information from the 16th General Conference on Weights and Measurements held in 1979. 3.4 The factors in Table 1 are provided to change units of measurement from one system to related units in other systems, as well as to smaller or larger units in the same system. 3.5 Values of units in the left column may be converted to values of units in the right column merely by multiplying by the conversion factor provided in the center column. (A) For specific applications and exceptions, see Terminology D1356 .