Non-biological objects, biological specimens and living tissues are examined using electric fields to identify regions of differing permittivity and conductivity. Substantially parallel electrodes are deployed in capacitive alignment with an object and energization pulses are generated for application to any of the electrodes as a transmitter. Output signals from any remaining electrode are monitored, in which a peak value of an output signal is indicative of permittivity and a decay rate of an output signal is indicative of conductivity. A first set of n electrodes (one to fifteen) is selected, each of which is capacitively coupled with a second set of m electrodes (two to eight) that are the nearest neighbouring electrodes to an electrode selected from the first set.