IEC 62990-2:2021给出了用于测量工作场所大气中有毒气体和蒸汽的电气设备的选择、安装、使用和维护指南。此类设备的主要目的是通过提供有毒气体或蒸汽浓度指示和存在警告，确保人员和财产安全。 本文件适用于提供指示、警报或其他输出功能的设备，以警告大气中存在有毒气体或蒸汽，并在某些情况下启动自动或手动保护措施。适用于有气体时传感器自动产生电信号的设备。 就本文件而言，设备包括: a） 固定设备； b） 可运输设备，以及 c） 便携式设备。 本文件旨在涵盖IEC 62990中定义的设备- 1，但可提供该文件未涵盖的设备的有用信息。

IEC 62990-2:2021 gives guidance on the selection, installation, use and maintenance of electrical equipment used for the measurement of toxic gases and vapours in workplace atmospheres. The primary purpose of such equipment is to ensure safety of personnel and property by providing an indication of the concentration of a toxic gas or vapour and warning of its presence. This document is applicable to equipment whose purpose is to provide an indication, alarm or other output function to give a warning of the presence of a toxic gas or vapour in the atmosphere and in some cases to initiate automatic or manual protective actions. It is applicable to equipment in which the sensor automatically generates an electrical signal when gas is present. For the purposes of this document, equipment includes: a) fixed equipment; b) transportable equipment, and c) portable equipment. This document is intended to cover equipment defined within IEC 62990-1, but can provide useful information for equipment not covered by that document.