A personal monitoring system to be worn by an individual in a hazardous situation comprises an enclosed face mask which includes a transparent shield over at least the eves a sensor module secured to the individual which includes a plurality of sensors, a microprocessor and an RF transmission means operable to transmit data obtained by the sensors. The conductive plane is formed of several separate conductive elements, the connection of which is performed by conductive tracks connecting at least one conductive element to a contact point M of the conductive plane. The device has a unit for continuously forming an operating value of recovery time for the semiconductor element of a decommutating valve, and a unit for forming the minimum reference value of the extinction angle in dependence of the operating value. The first distribution device can determine that the second distribution device is not identified in the first header as receiving the payload data.