Gas thermal conductivity measurement based on the three-omega method

Preliminary investigations have been conducted to discuss the possibility of using a micro-machined suspended wire as a 3ω based sensor for the measurement of gas thermal conductivities. Thermal responses of various pure gases and helium-nitrogen mixtures have been measured using a 3ω setup and compared to an one-dimensional analytical model derived by Yusibani et al. Deviation of the measured thermal conductivities compared to reference values led us to consider an empirical approach which offers the possibility of estimating the studied gas thermal conductivity by measuring the out-of-phase cut-off frequency.