Abstract: A diaphragm pressure measuring cell arrangement has a housing body at least partly made of sapphire material and a planar sapphire diaphragm with a peripheral edge joined by a first edge seal to the housing body to form a reference vacuum chamber. An outer surface of the diaphragm is exposed to a medium to be measured. A ceramic supporting body is attached to the back side of the housing body by sealing glass and includes a surface area overhanging that surrounds the housing body to form a first sealing surface. A tubular sensor casing incorporates the measuring cell for mounted the ceramic support body, the casing including an inside second surrounding sealing surface corresponding to the first sealing surface. A metal ring seal is between the sealing surfaces and a pressing member presses sealing surfaces together.

Abstract: Introduced is a method for the production of a diaphragm vacuum measuring cell, wherein on the one side of the diaphragm (2) at a spacing a first housing plate (1) is disposed sealing in the margin region with a joining means (3), and that on the other side of the diaphragm (2) at a spacing a second housing plate (4) is disposed sealing in the margin region with a joining means (3), and that the second housing plate (4) has an opening at which a connection means (5) is disposed sealing with joining means (3) for the connection of the measuring cell (8) with the medium to be measured, wherein the diaphragm (2) and the two housing plates (1, 4) are comprised of a metal oxide.

Abstract: A manufacturing method for a vacuum measuring cell provides first and second Al2O3 ceramic or sapphire housing bodies on opposite sides of an Al2O3 ceramic or sapphire membrane sealed to the bodies at its opposite peripheral edges. A reference vacuum chamber and a measuring vacuum chamber are on opposite sides of the membrane. An optical transparent window is provided in the first housing body and an optically reflective material is provided on a central region of the membrane. A lens is above the optical transparent window for optically linking to the optically reflective material on the membrane and an optical fiber outside the reference vacuum chamber and at a distance from the optical transparent window feeds light through the lens and window and in and out onto the optically reflective material on the membrane so that the level of membrane deflection is detected by a Fabry-Perot Interferometer.

Abstract: A shield arrangement for a vacuum measuring cell has a tubular shield housing encompassing a shield and an exit port for connection to a vacuum measuring cell and a connection opening for the object space to be measured. The shield is between the two openings and is implemented as a screw shield with spiral convolutions, its thread flange in the outer diameter being in contact on the inner wall of the shield housing such that a gas throughflow between the outer diameter of the thread flange and the inner wall is inhibited and is substantially forced into the spiral thread flight, and the exit port is on one side of the tubular section and the connection opening is on the other, opposite side and the screw shield is implemented such that in the axial line of vision the shield arrangement between the two openings is optically tight.

Abstract: A vacuum measuring cell has a first housing body and a membrane, both of Al2O3 ceramic or sapphire. The membrane is planar with a peripheral edge joined by a first seal to the first housing body to form a reference vacuum chamber. A second housing body of Al2O3 ceramic or sapphire opposite the membrane, is joined to the peripheral edge of the membrane by a second seal to form a measurement vacuum chamber. A port connects the vacuum measuring cell to a medium to be measured. At least in the central area of the first housing body, an optical transparent window is formed and at least the central region of the membrane has an optically reflective surface. Outside the reference vacuum chamber, in opposition to and at a distance from the window, an optical fibre is arranged for feeding in and out light onto the surface of the membrane.

Abstract: A capacitive vacuum measuring cell includes first and second ceramic housing bodies (1, 4) joined by an edge seal (3). A thin ceramic membrane (2) is supported between first and second housing bodies (1, 4) by the edge seal (3) at a small distance from the first housing body (1) creating a reference vacuum chamber (25) therebetween. An electrically conductive material (7) coats opposing surfaces of the first housing body (1) and the membrane (2) to form a capacitor. A measurement vacuum chamber (26) is provided between the membrane (2) and the second housing body (4). A port (5) communicates with the second housing body (4) to connect the measurement vacuum chamber (26) of the measuring cell to the medium to be measured. The membrane (2) is made from an Al2O3 slurry that is sintered in a first heating step, cooled, and then reheated to smooth the membrane.

Abstract: A ceramic membrane for a capacitive vacuum measuring cell includes a thin ceramic membrane with a thickness of <250 ?m, in particular less than 120 ?m. The membrane is produced from a ribbon-shaped green body of Al2O3, and is given high planarity by smoothing the membrane after sintering. The green body is sintered at a sintering temperature that is higher than the smoothing temperature applied following sintering.

Abstract: A capacitive vacuum measuring cell includes first and second ceramic housing bodies (1, 4) joined by an edge seal (3). A thin ceramic membrane (2) is supported between first and second housing bodies (1, 4) by the edge seal (3) at a small distance from the first housing body (1) creating a reference vacuum chamber (25) therebetween. An electrically conductive material (7) coats opposing surfaces of the first housing body (1) and the membrane (2) to form a capacitor. A measurement vacuum chamber (26) is provided between the membrane (2) and the second housing body (4). A port (5) communicates with the second housing body (4) to connect the measurement vacuum chamber (26) of the measuring cell to the medium to be measured. The membrane (2) is made from an Al2O3 slurry that is sintered in a first heating step, cooled, and then reheated to smooth the membrane.

Abstract: A pressure sensor has a baseplate and a support plate with a membrane. Layers on the membrane and the support plate are connected to a circuit for capacitively measuring pressure to generate a first pressure signal. A thermal conductivity measuring element that generates a second pressure signal has a heating element connected to the baseplate adjacent the support plate at a location opposite from the membrane for protecting the membrane from thermal effects. The method uses the sensor apparatus to generate an output signal representing a measured result when the measured result is above a transition value, on the basis of the first pressure signal and, when the pressure falls below a threshold value, any offset of the first pressure signal is compensated in such a way that determination of the output signal on the basis of the first pressure signal leads to the same result as determination of the output signal on the basis of the second pressure signal.

Abstract: A capacitive vacuum measuring cell includes first and second ceramic housing bodies (1, 4) joined by an edge seal (3). A thin ceramic membrane (2) is supported between first and second housing bodies (1, 4) by the edge seal (3) at a small distance from the first housing body (1) creating a reference vacuum chamber (25) therebetween. An electrically conductive material (7) coats opposing surfaces of the first housing body (1) and the membrane (2) to form a capacitor. A measurement vacuum chamber (26) is provided between the membrane (2) and the second housing body (4). A port (5) communicates with the second housing body (4) to connect the measurement vacuum chamber (26) of the measuring cell to the medium to be measured. The membrane (2) is made from an Al2O3 slurry that is sintered in a first heating step, cooled, and then reheated to smooth the membrane.

Abstract: A ceramic membrane for a capacitive vacuum measuring cell includes a thin ceramic membrane with a thickness of <250 &mgr;m, in particular less than 120 &mgr;m. The membrane is produced from a ribbon-shaped green body of Al2O3, and is given high planarity by smoothing the membrane after sintering. The green body is sintered at a sintering temperature that is higher than the smoothing temperature applied following sintering.

Abstract: A ceramic membrane for a capacitive vacuum measuring cell includes a thin ceramic membrane with a thickness of <250 &mgr;m, in particular less than 120 &mgr;m. The membrane is produced from a ribbon-shaped green body of Al2O3, and is given high planarity by smoothing the membrane after sintering. The green body is sintered at a sintering temperature that is higher than the smoothing temperature applied following sintering.