本标准解释了在爆炸性气体和可燃性粉尘环境中使用光学辐射的设备的潜在点火危险。它包括EPLs Ma、Mb、Ga、Gb、Gc、Da、Db和Dc。它还包括设备本身位于外部，但其发射的光辐射进入此类大气。它描述了在爆炸性气体和可燃性粉尘环境中使用光辐射传输设备时应采取的预防措施和要求。它还概述了一种试验方法，如果无法通过评估或光束强度测量来保证光学极限值，则该方法可用于验证光束在选定的试验条件下无法点火。

This standard explains the potential ignition hazard from equipment using optical radiation intended for use in explosive gas and combustible dust atmospheres. It covers EPLs Ma, Mb, Ga, Gb, Gc, Da, Db and Dc. It also covers equipment, which itself is located outside but its emitted optical radiation enters such atmospheres. It describes precautions and requirements to be taken when using optical radiation transmitting equipment in explosive gas and combustible dust atmospheres. It also outlines a test method, which can be used to verify a beam is not ignition capable under selected test conditions, if the optical limit values cannot be guaranteed by assessment or beam strength measurement.