Verification for Electrical Tomography in Flame Monitoring by Ion Probe

Electrical tomography has been used to monitor the processes of flame ignition, fluctuation and extinction. To obtain more quantitative and key information of the flame from images of conductivity and permittivity distributions, a calibration method is necessary for studies on different combustors. In this paper, the ion probe sensor is proposed as a means of verification for electrical tomography in flame monitoring. From the impedance data of the ion probe, the local conductivity and permittivity can be calculated. Both an ion probe sensor and an electrical tomography system were experimented on an alcohol lamp. The ion probe experiment results are that the conductivity increased from 2 x 10(-6) to 9 x 10(-6) S/m, while the relative permittivity increased from 1 to 4 in the flame. The ranges of electrical tomography images are that conductivity from 0 to 6 x 10(-6) S/m and relative permittivity from 1 to 4.5, which are consistent with the data acquired from the ion probe.