constituents of the sample gas. Using this technique many unknown gas samples can be identified by comparing their thermal conductivity with other reference gas of known thermal conductivity. The most commonly used reference gas is nitrogen; as the thermal conductivity of most common gases (except hydrogen and helium) are similar to that of nitrogen. See also List of thermal conductivities Electrical conduction Convection diffusion equation R-value (insulation) Heat pipe Fick's law of diffusion Relativistic heat conduction Churchill–Bernstein equation Fourier number Biot number False diffusion References Dehghani, F 2007, CHNG2801 – Conservation and Transport Processes: Course Notes, University of Sydney, Sydney John H Lienhard IV and John H Lienhard V, 'A Heat Transfer Textbook', Fifth Edition, Dover Pub., Mineola, NY, 2019 External links Heat conduction – Thermal-FluidsPedia Newton's Law of Cooling by Jeff Bryant based on a program by Stephen Wolfram, Wolfram Demonstrations Project. be-x-old:Цеплаправоднасьць Heat conduction Heat transfer Physical quantities be:Цеплаправоднасць bg:Топлопроводимост Transport phenomena