GOST R 52138-2003 可燃气体检测与测量用电气设备.第3部分:显示空气中甲烷体积分数达100%的Ⅰ组设备的性能要求
Electrical apparatus for the detection and measurement of flammable gases. Part 3. Performance requirements for group I apparatus indicating a volume fraction up to 100 % methane in air