A critical approach to measure streaming current: case of fuels flowing through conductive and insulating polymer pipes

Electrostatic charge generation phenomenon when hydrocarbons flowing through pipes has been studied for a long time. The charge generation depends on the nature of both the liquid and the solid. Because of the introduction of new plastic materials and due to fuel composition evolution, it became necessary to perform a comprehensive study of the subject in the particular case of automotive environment. The streaming current measurement permits to characterize charge generation when a fuel flows through a plastic pipe. However, this measurement must be carefully managed. We are working on the validity and the accuracy of such measurements. The case of conductive and insulating pipes, and the double layer development influence, are analyzed and discussed. In particular, we give a detailed methodology in order to measure reliable streaming currents and to wisely derive the space charge density at the wall (ρ_w). Experimental results are presented for some solid/liquid couples.