IEC 61779-2:1998
可燃性气体的检测和测量用电气设备 第2部分:I类设备(指示空气中甲烷的体积百分率最大为5%)的性能要求
Electrical apparatus for the detection and measurement of flammable gases - Part 2: Performance requirements for group I apparatus indicating a volume fraction up to 5 % methane in air