IEC 60721-3-0:20 20为IEC 60721-3所有部分的使用提供了指导。它包含背景信息，包括IEC 60721-3各部分中给出的类别的应用和限制信息，可用于设备的设计、条件限制和保护。 这第二版取消并取代了1984年出版的第一版和修正案1:19 87。本版构成技术修订版。 与上一版相比，此版本包括以下重大技术变更: a)该版本已被广泛简化，仅提供与IEC 60721-3其他部分给出的工艺相关的必要信息，并且更新了有关等级严重性的信息。

IEC 60721-3-0:2020 provides guidance on the use of all parts of IEC 60721-3. It contains background information including information on the application and limitation of the classes given in various parts of IEC 60721-3 which can be used in the design, limitation of conditions and protection of equipment.
This second edition cancels and replaces the first edition published in 1984 and Amendment 1:1987. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous edition:
a) This edition has been extensively simplified to only provide necessary information with regard to the process given in the other parts of IEC 60721-3 and information on class severity has been updated.