NF C23-541-2:2005 Specification for open path apparatus for the detection of combustible or toxic gases and vapours - Part 2 : performance requirements for apparatus for the detection of combustible gases.
2005NF C23-541-2:2005 Specification for open path apparatus for the detection of combustible or toxic gases and vapours - Part 2 : performance requirements for apparatus for the detection of combustible gases.