1.1本规程涵盖了电子发射器常用热离子常数的定义和解释 ( 1. , 2. , 3. ) , 2. 随附标准测量方法。 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和健康实践，并确定监管限制的适用性。

1.1 This practice covers the definition and interpretation of the commonly used thermionic constants of electron emitters ( 1 , 2 , 3 ) , 2 with appended standard methods of measurement. 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 and health practices and determine the applicability of regulatory limitations prior to use.