Verfahren und Vorrichtung zur Bestimmung eines Stroemungspotentials

A process and a device serve to determine the streaming potential, in particular to record the surface characteristics of a sample or to record a component contained in a sample fluid. The device comprises a flow section, a reference electrode which is in contact with the fluid, a first ion-sensitive field effect transistor which generates a first measuring signal, a second ion-sensitive field effect transistor which generates a second measuring signal and an evaluating device which determines the streaming potential from the difference of the measuring signals. The flow section to determine the surface characteristics of a sample is designed in such as way that fluid is caused to flow past the surface of a sample, or the flow section is designed to detect components contained in a sample fluid in such as way that a coating is provided at the section of the inner wall of the flow section, to which said coating components contained in the sample fluid can adhere