Other

Endress + Hauser Gmbh + Co. Kg

Envec Mess- Und Regeltechnik Gmbh + Co.

Norbert Gill

Olaf Krusemark

J&uuml;rgen Lange

Rolf Schade

Volker Schrobel

Arno Donner

A relative pressure sensor includes: a pressure measuring transducer having a measuring membrane of a semiconductor chip and a platform, wherein, between both of these, a reference pressure chamber is formed; a support body, connected with the platform by means of a pressure-bearing adhesion, wherein a reference pressure path extends through the two former elements into the reference pressure chamber; and a sensor outer body, in which a transducer chamber with a first opening and a second opening is formed. The pressure measuring transducer is brought into the transducer chamber through the first opening, and is held therein by means of the support body. The support body pressure-tightly seals the first opening, and a side of the measuring membrane facing away from the reference pressure chamber is contactable with the media pressure through the second opening. The reference pressure path has a gas-filled, sealed section, which extends from the reference pressure chamber at least through the pressure bearing adhesion, and wherein the sealed section is gas-tightly sealed by means of a flexible, metallized plastic foil.

Relative pressure sensor

In order to avoid short-circuits between the electrodes, the pressure sensor comprises: a substrate (,) made of ceramic material, on one surface of which an electrode (,) and a glass layer (,) formed from an original glass frit are disposed; a diaphragm (,) made of ceramic material, which is permanently joined and pressure-sealed to the substrate by means of the original glass frit acting as a spacer (,) holding the diaphragm and the substrate from each other to form a cavity (,), and which on the cavity side is provided with an electrode (,); and leads (,) which extend inwards and/or through the diaphragm (,) to the electrodes (,) in the region of the spacer (,). The differential pressure sensor is formed in a mirror-inverted arrangement in relation to the centre plane of the substrate, so that it carries two pressure sensors. These are pressure-linked by a hole (,) filled with oil and connecting the two cavities and leading through the substrate and outwards. In a further development, thin insulating layers (,&prime;) made of the material of the ceramic of the substrate or of a high-temperature glass can be fixed on the glass layer(s), respectively.

Capacitive pressure sensors or capacitive differential pressure sensors

To ensure insensitivity to electromagnetic interference and to charge influences from the oil fill and achieve good long-term stability, this pressure-measuring arrangement comprises: a pressure sensor having a base and an associated diaphragm with strain gages deposited thereon; a header of insulating material with leads and with an oil filler neck, said header of insulating material having the base mounted thereon, and said leads making electrical contacts to the strain gages; a metal body having a first central recess in a first cross-sectional surface, a second central recess in a second cross-sectional surface facing away from the first cross-sectional surface, and a hole connecting the first recess with the second recess, said first cross-sectional surface being tightly joined at its edge to the header of insulating material, and said first recess accommodating the substrate and diaphragm without touching them; an electrically conductive foil having an opening, said foil being disposed in the first recess as close as possible to, and covering but not touching, the strain gages and connected to ground; a metallic separating diaphragm fitted in the second recess and closing the latter at its edge; and an oil fill in the recesses and in the hole.

Pressure-measuring arrangement with conductive foil shielding

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Vellmar, Germany

Norbert Gill