Abstract: A pressure monitoring system in which pressure in a container causes a slide which extends out from the container, to be moved against a group of springs in cascade formation and which are screened from microwave radiation. The extent of such movement, which corresponds to changes in container pressure, is measured by means of a light transmitter and a receiver which cause light to be reflected off a reflective surface of the slide and then analyzed. Also disclosed is a process in which the heating of a container is controlled as a function of the differential quotient of pressure over time.

Abstract: In a device (1) for the treatment of materials under the action of heat, and if appropriate also pressure, in a heating chamber consisting of a housing (2), containing the heating chamber, having a charging opening for the heating chamber which can be selectively opened or closed by means of a door (4), and a heating device (6), in particular a microwave heating device, for the heating chamber (7), the door (4) is so mounted that when a particular pressure in the heating chamber is exceeded it lifts off from the door frame (2) and is movable into a relief-opening position, out of which position it is moveable back into the original-closed position--after reduction of pressure--either automatically or by the application of force.