GB 20936.4-2008
Electrical apparatus for the detection and measurement of flammable gases—Part 4:Performance requirements for group Ⅱ apparatus indicating a volume fraction up to 100% gas
GB/T 20936.3-2009
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
GB 20936.2-2009
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
32002L0070
32005L0007