Abstract: A sensor for monitoring a cooling liquid circulating in a circuit of a heat exchanger of an automobile, for example, includes a support for mounting the sensor on a pipe of the circuit so that the liquid is in contact with at least a part of the sensor, a corrodible membrane in contact with the liquid, and a visual indicator reacting to the degree of corrosion of the liquid. The visual indicator includes a piston movable under the combined effect of the breaking of the corrodible membrane and of the pressure difference between inside and outside of the pipe, at least one seal mounted on the movable piston, and the visual indicator protruding from the pipe and/or from the support when the membrane is corroded.

Abstract: The present invention relates to a device for monitoring the aging of coolants circulating in heat exchange circuits. It includes an element (4) in contact with said liquid to be monitored, an electric element (51) separated from element (4) in contact with the liquid by an insulating volume (6) containing a fluid at a given pressure, said electric element reacting to the corrosion level of the element in contact, and an alarm (8) reacting to a signal variation of the electric element. According to the invention:the element in contact with the liquid to be monitored consists of at least one pellet (41) made from a material also present in the circuit and in contact with said fluid (3) in the circuit, andthe electric element consists of an element made from a piezoelectric material whose frequency varies with a pressure variation in the insulating volume (6).

Abstract: A process and device is provided for automatically regulating the running conditions of an internal combustion engine. The engine is of the type fed with different fuels, and in accordance with the nature and the composition of the fuel or fuel mixture contained in the feed tank of the engine, at any moment, including that of a new fuel supply at a filling station, the regulator is monitored by a data processing unit delivering signals representative of the amount and the characteristics of the fuel contained in the tank before and after a new fuel supply.