Dielectric sample with two-layer charge distribution for space charge calibration purposes

In the present paper is described a dielectric test sample with two very narrow concentrations of bulk charges, achieved by two internal electrodes not affecting the acoustical properties of the sample, a fact important for optimal application of most space charge measuring systems. Space charge formation was investigated under different electrical conditions by means of the laser induced pressure pulse (LIPP) method and the pulsed electro-acoustic method (PEA).