A Method for Calculating Characteristic Value to Characterize the Induced Charge in Electrostatic Tomography

Abstract

Electrostatic tomography (EST) is a technology that uses the induced charge on the electrode surface to reconstruct the parameter distribution of gas-solid two-phase flow. The induced signal is dynamic, whereas the induced charge required in the image reconstruction theory is static. Therefore, it is necessary to calculate the characteristic value of the signal to characterize the induced charge before image reconstruction. However, the calculation methods of characteristic value are different at present, and there is a lack of unified understanding. For the above problem, this article analyzes the mechanism of signal induced by the charged single particle, compares the differences between the charge-sensitive and current-sensitive preamplifiers, and comes to the conclusion that the current-sensitive preamplifier is more suitable for the measurement of induced charge. By further studying the output signal of the conditioning circuit with the current-sensitive preamplifier, root mean square of charge (RMSCE) is proposed to characterize the induced charge. Simulation and experimental results show that RMSCE has stronger characterization ability for the induced charge and can be used in EST system to obtain high-quality reconstructed images.