Abstract
A newly developed electro-acoustic transducer technique is applied to the measurement of electric field intensity at a dielectric/electrode interface. This report describes the principles of this new technique as applied to: the residual electric field intensity by a sheet charge and its location in PET film, to the amount of residual charge density and its polarity in PET thermal electret, and to the electric field intensity at electrode surfaces, including the effects of homo-charge injected from electrodes for PET, PS, and PE films, hetero-charge generated from impurities in epoxy resin, and dipole polarization in PVDF film and tricresyl-phosphate liquid.