Abstract: A rheometer and a method for measuring viscosity of a specimen include a motor-driven measuring shaft, a first measuring part fastened to the shaft, a second measuring part below the first measuring part, the measuring parts defining a measuring gap receiving the specimen and having a thickness set by the measuring parts. A heating or temperature-control unit below the second measuring part temperature-controls the second measuring part. The measuring parts rotate or rotate-oscillate relative to each other about an axis. A hood has an internal contour at the second measuring part and/or the heating or temperature-control unit. The internal contour surrounds and covers the first measuring part and the measuring gap and forms a measuring space. A duct near the temperature-control unit opens into the space, allowing the temperature-control unit to control a temperature of temperature-control medium in the duct.

Abstract: A microwave heating system comprises a bowl, dome and rotor device. The dome is fit to the bowl. The bowl and dome form a volume. The bowl is connected to a microwave source such that a microwave field is supplied to the volume. The microwave field is attenuated in a region between the rotor device and the dome compared to a region between the bowl and the rotor device. The rotor device is rotatably supported by the bowl and supports a reaction vessel. The rotor device includes a base plate with a through-hole and a tubular member that receives the reaction vessel. The base plate and tubular member are metal. The rotor device is coupled to the base plate so that a longitudinal axis of the tubular member passes through the through-hole.

Abstract: A microwave heating system comprises a bowl, dome and rotor device. The dome is fit to the bowl. The bowl and dome form a volume. The bowl is connected to a microwave source such that a microwave field is supplied to the volume. The microwave field is attenuated in a region between the rotor device and the dome compared to a region between the bowl and the rotor device. The rotor device is rotatably supported by the bowl and supports a reaction vessel. The rotor device includes a base plate with a through-hole and a tubular member that receives the reaction vessel. The base plate and tubular member are metal. The rotor device is coupled to the base plate so that a longitudinal axis of the tubular member passes through the through-hole.

Abstract: There is described a device for rotatably supporting at least one reaction vessel in a microwave heating apparatus. The described device comprises (a) a base plate comprising at least one through-hole, and (b) at least one tubular member having a longitudinal axis and being adapted to receive a reaction vessel and to be coupled to the base plate in such a way that the longitudinal axis of the at least one tubular member passes through the at least one through-hole, wherein the at least one tubular member comprises metal. Furthermore, there is described a system for performing digestion or synthesis comprising a microwave heating apparatus and a device as described above.

Abstract: The present invention relates a microwave applicator for heating a sample by microwave radiation which is transmitted via an at least partially tapering transmission duct from a microwave source to a cavity adapted to receive the sample to be heated. The transmission duct has at least one external wall, said wall defining an internal space for the propagation of said microwave radiation and comprising an interface which is at least partially permeable to said microwave radiation. The interface is at least partially arranged within said tapering portion of the duct. The duct is adapted to form a jacket surrounding the cavity with said interface forming an inner wall of said jacket.

Abstract: The present invention concerns a device for heating a sample by microwave radiation comprising a source of microwave radiation, a first waveguide for guiding said microwave radiation to an applicator space adapted to receive said sample to be heated, wherein said applicator space is defined by a terminal portion of said first waveguide and an initial portion of a second waveguide extending from said terminal portion of said first waveguide and being arranged at an angle with respect to said first waveguide.

Abstract: The present invention concerns a method and a device for uniformly heating a sample by microwave radiation. According to the invention, at least one stirring element is immersed at least partly in a sample to be heated, said stirring element comprising a magnetic or magnetisable material. A rotating or oscillating magnetic field interacting with said stirring element is generated in a cavity adapted to receive the sample to be heated in order to impart a rotational or translational movement to said stirring element. The rotational or translational movement of said stirring element is contactlessly detected while applying microwave radiation to said sample.

Abstract: The present invention concerns a method and a device for uniformly heating a sample by microwave radiation. According to the invention, at least one stirring element is immersed at least partly in a sample to be heated, said stirring element comprising a magnetic or magnetisable material. A rotating or oscillating magnetic field interacting with said stirring element is generated in a cavity adapted to receive the sample to be heated in order to impart a rotational or translational movement to said stirring element. The rotational or translational movement of said stirring element is contactlessly detected while applying microwave radiation to said sample.

Abstract: The present invention concerns a device for heating a sample by microwave radiation comprising a source of microwave radiation, a first waveguide for guiding said microwave radiation to an applicator space adapted to receive said sample to be heated, wherein said applicator space is defined by a terminal portion of said first waveguide and an initial portion of a second waveguide extending from said terminal portion of said first waveguide and being arranged at an angle with respect to said first waveguide.

Abstract: The present invention relates a microwave applicator for heating a sample by microwave radiation which is transmitted via an at least partially tapering transmission duct from a microwave source to a cavity adapted to receive the sample to be heated. The transmission duct has at least one external wall, said wall defining an internal space for the propagation of said microwave radiation and comprising an interface which is at least partially permeable to said microwave radiation. The interface is at least partially arranged within said tapering portion of the duct. The duct is adapted to form a jacket surrounding the cavity with said interface forming an inner wall of said jacket.

Abstract: The invention relates to apparatus for extracting solvents in a microwave field, having a microwave oven (11) which comprises at least one microwave generator (12), a control unit (13) and at least one microwaving chamber (14), said chamber being fitted with venting apertures (23) and at least one suction exhaust aperture (24) which is connected by an exhaust air line (25) to a source of partial vacuum (26), further comprising a rotor (16) rotatably mounted in said chamber and fitted with several specimen receptacles (18) that may be loaded with solvent. The apparatus is characterized in that a flow detector (28) is mounted downstream of the suction exhaust aperture (24), said detector reducing or preferably shutting off the power output of the microwave generator (12) when detecting a flow of air which is less than a predetermined limit value, said airflow limit value being selected in a manner precluding forming an explosive mixture of solvent and air in said chamber.

Abstract: The present invention concerns a device for monitoring the pressure in at least two pressure-tight analysis vessels, that have been sealed by means of lids, whereby heat is supplied to the analysis vessels by means of a heating apparatus. The internal pressure of the analysis vessel acts on its lid. The lid is connected to a piston in a closed hydraulic system. The force, that is dependent on the internal pressure of the analysis vessel, is transferred by the lid to the piston in the hydraulic system. A lid and a piston are assigned to every analysis vessel. In addition, a stop device is assigned to each piston, whereby the stop device limits the outward movement of the piston in the event of excess pressure in the hydraulic system relative to the internal pressure of the analysis vessel. The pistons are connected to one another via the hydraulic system.

Abstract: The present invention concerns a device for measuring the pressure and temperature in at least one pressure-tight analysis vessel, that has been sealed by means of a lid, whereby heat is supplied to the analysis vessel by means of a microwave oven. The device comprises a measurement device that is connected to a unit for controlling the microwave oven. In this regard, the measurement device is arranged in a microwave-tight housing inside the microwave field that is produced by the microwave oven. The housing is constructed in such a way that it forms a shield that is impermeable for the microwave field. A microwave-free zone is produced inside the housing. Electronic, current-carrying components can be arranged in the microwave-tight housing without, as a result, generating interference in the microwave field.