Combustible gases; Fuel gas; Gas (fuel); Gas fuels; Gas mixtures; Gases for flame heating; Gases for use as fuel; Gases for use in cooking; Gases for use in heating; Gases for use in lighting; Liquefied gas; Liquefied natural gas; Liquid gas; Natural gas; Synthetic gas (fuel)

Combustible gases; fuel gas; gas (fuel); gas fuels; gas mixtures; gases for flame heating; gases for use as fuel; gases for use in cooking; gases for use in heating; gases for use in lighting; liquefied gas; liquefied natural gas; liquid gas; natural gas; synthetic gas (fuel)

Apparatus for measurement of gas components in air; apparatus for monitoring gas in the atmosphere; apparatus for the analysis of gas; apparatus for the testing of gas; electrochemical gas sensors; electrochemical gas separators; gas flow meters; gas separation membranes; gas testing instruments; meters for measuring gaseous flow