Space charge distribution measurements in polymers under needle-plane electrode configurations by pulsed electro-acoustic method

The pulsed electro-acoustic method (PEA) and pressure wave propagation method (PWP) have been used to measure charge distributions under plane-plane and coaxial electrode configurations. This paper describes research on further developing the PEA method to measure the space charge distribution under the needle-plane electrode configuration where the space charge effect is crucial. This measurement is important but difficult due to the nonuniformity of the electric field. Based on the generation and propagation properties of the pressure wave, along with an electric field calculation, a measuring technique is proposed which seems to make the measurement of space charge distribution in nonuniform field possible. Besides, a simulation model is proposed to process the obtained signals and to improve the calibration accuracy of charge distributions obtained by the PEA method