Abstract: A system for measuring a conduit surrounded by an insulator provided with a first conductor, a second conductor and one or more third conductors includes a control and measuring circuit configured to determine a value which is representative of the capacitive coupling between the first conductor and the second conductor and one or more of said third conductors. At least a first switching means is configured for electrically connecting the second conductor to a third conductor of said one or more third conductors in a first state and for electrically disconnecting the second conductors from the third conductor of said one or more of third conductors in a second state. A control means is configured for controlling the control and measuring circuit and the first switching means such that the measurements are performed in the first and second state of the first switching means.