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 and setting 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, thus enabling individual room control. A battery change that is due soon is signaled on the sensor.