Abstract: A water sensor for detecting water in gas oil filters having a first and a second electrode a first and a second earth connection for earthing the first electrode and the second electrode; a first switch arranged in the first earth connection; a second switch arranged in the second earth connection; a first and a second current connection for injecting a first current into the first electrode and a second current into the second electrode; and a current-generating circuit connected to the first electrode and to the second electrode through the first current connection and the second current connection respectively, and designed to inject the first current into the first electrode and the second current into the second electrode, the first current and the second current being the same.

Abstract: A water sensor for detecting water in gas oil filters is provided. It has a first and a second electrode; a first and a second earth connection for earthing the first electrode and the second electrode; a first switch arranged in the first earth connection; a second switch arranged in the second earth connection; a first and a second current connection for injecting a first current into the first electrode and a second current into the second electrode; and a current-generating circuit connected to the first electrode and to the second electrode by means of the first current connection and the second current connection respectively, and designed to inject the first current into the first electrode and the second current into the second electrode, the first current and the second current being the same.

Abstract: The invention relates to a capacitive level sensor for liquids with foaming agent in tanks, having a sensor element to establish physical contact with the liquid that can be deposited in a tank and generate a signal as a function of the physical contact, a control unit configured to receive the signal that can be generated by the sensor element and carry out a determination concerning the presence of liquid as a function of the signal, and a main body for housing the control unit, avoiding contact with the liquid. The invention is characterized in that it additionally has a surrounding structure configured to be arranged surrounding the sensor element inside the tank; such that the surrounding structure is available, acting as a separation element between the sensor element and the foam that can be generated from the liquid.