Valve for a pressurized fluid cylinder, comprising a sensor for sensing the position of the control member, said sensor being configured to generate an electric signal indicative of the position or of the fluid flow rate and/or pressure set by a regulating member for regulating flow rate/pressure, the sensor (9) for sensing the position of the control member comprising a conductive circuit having a given electrical resistance, a member for measuring an electric variable of the conductive circuit and a wiper, the conductive circuit and the wiper being movable relative to one another during the movement of the control member with respect to the body of the valve into different configurations in which the wiper modifies the shape and/or area of the conductive circuit measured by the measuring member.