Abstract: An apparatus is furnished for sensing the tire pressure and for generating a signal by way of an actuator. If the tire pressure drops below the predetermined reference tire pressure, then this is signalled immediately and instantly within a relatively small pressure tolerance threshold. The pressure sensitive device 1 includes a valve device 7. The valve device 7 connects the tire pressure, applied to the actuator 4 and acting against the force of the compression spring 6, to the atmosphere if the tire pressure drops below a predetermined reference tire pressure. The apparatus is suitable for generating a permanent signal, even in case no further pressure remains in a tire.

Abstract: A device for monitoring the sealing properties of a gas-filled chamber is provided. The temperature-sensitive device is formed out of a thermally-reacting element (14, 19, 20, 24). The element changes its dimensional length depending on a temperature change. The element (14, 19, 20, 24) is disposed between a pressure measurement device (6, 11) and a valve (7, 8; 9, 10), serving as a signal generator. The device can be used for a monitoring of the pressure in a vehicle tire or of the gas density in a vehicle tire.