  The gas and effective electron temperatures have been estimated for
atmospheric microplasma by means of optical emission spectroscopy. The results
have shown that the microplasma exhibits nonequilibrium and, as its size is
reduced, the two temperatures depart from each other, enhancing the
nonequilibrium characteristic. The effect of methane and oxygen concentrations
has also been studied, showing that gas mixtures have an important effect on
the microplasma state.
