NOISE EQUALIZATION WITHIN EIT IMAGES

We first describe experiments designed to measure the spatial distribu tion of noise within an electrical impedance tomographic image of a sa line-filled tank. These experiments show that the noise increases by a factor of up to 30 from the periphery towards the centre of the image . We then propose a method of noise equalization that depends upon spe nding longer collecting the smaller potentials than the larger potenti als. The method is tested and shown to give an improvement in noise un iformity of about 16 dB.