Radio sensors for the usual level of pollution in living rooms, offices and hotels. Mainly used in renovation work or for heating system extensions. Radio room temperature sensor for recording the room temperature. When used with alre radio actuators and the b@home-Gate, individual room temperature control is achieved. The sensor can also be connected directly to the actuators without the b@home-Gate and thus realize averaging or central control. An imminent need to be changed battery is signaled on the sensor.