Endress + Hauser Gmbh + Co. Kg

Endress+hauser Gmbh+co.

Endress + Hauser Flowtec Ag

Endress + Hauser Gmbh & Co. Kg

Dietfried Burczyk

Wolfgang Dannhauer

Thomas Velten

Ralf Nürnberger

Ralf N&uuml;rnberger

Anh Tuan Tham

Oliver Graf

Karl Fl&ouml;gel

Dieter Stolze

Thiérry Moser

Wolfgang Woest

Stefan Muth

Harri Notacker

Friedrich Schwabe

Raphael Erni

Tanja St&ouml;cklin

Ralf Nuernberger

Frank L&ouml;ffler

A pressure sensor comprises a sensor platform; a measuring membrane, or diaphragm, which is held by the sensor platform, and can have a pressure applied to it and is deformable as a function of pressure; and at least two resistance elements having an AlGa&#x2014;N layer. At least a first resistance element of the at least two resistance elements is arranged on the measuring membrane, or diaphragm and has a deformation-dependent resistance value. The pressure sensor can be operated using a measurement circuit to register a signal which depends on the resistance values of the at least two resistance elements in the plane of the AlGa&#x2014;N layer. Four resistance elements are preferably provided in a full bridge.

Pressure-measuring cell

A pressure difference transducer includes a hydraulic body, in which is formed an overload chamber containing an overload membrane. The overload chamber divides the overload chamber into a high-pressure chamber portion and a low-pressure chamber portion. The high-pressure chamber portion communicates with a first hydraulic path, which extends between a first diaphragm seal and a high-pressure side of a pressure measuring cell, and the low-pressure chamber portion communicates with a second hydraulic path, which extends between a second diaphragm seal and a low-pressure side of the pressure measuring cell. The low-pressure chamber portion has an essentially convex membrane bed, against which the overload membrane lies in a rest position.

Pressure differential sensor comprising an excess-load membrane

A pressure-difference pickup includes a hydraulic body, in which an overload chamber, with an overload membrane, or diaphragm, is formed, which divides the overload chamber into a first half-chamber and a second half-chamber, wherein the first half-chamber is in communication with a first hydraulic measuring path extending between a first pressure intermediary and a first side of a pressure-difference measuring cell, and the second half-chamber is in communication with a second hydraulic path extending between a second pressure intermediary and a second side of the pressure measuring cell. Additionally, between at least the first half-chamber and the first hydraulic measuring path, there are arranged, on the one hand, a first hydraulic overload element having a snap-disc behavior relative to an excess pressure from the first hydraulic measuring path, and, on the other hand, a first hydraulic balancing path extending parallel to the first hydraulic measuring path. The hydraulic resistance of the first hydraulic balancing path is greater than the resistance of the first hydraulic measuring path.

Pressure-difference pickup with dynamic overload protection

A pressure transmitter for registering the pressure of a medium. The pressure transmitter includes a transmitter body, a dividing membrane attached to the transmitter body forming thereby a pressure chamber, a first pressure canal and a second pressure canal. The two pressure canals exhibit different hydraulic properties.

Dynamic pressure transmitter

A measurement pickup is provided offering a high measure of safety and having a measurement pickup housing, a sensor element arranged in the measurement pickup, at least one connection element closing the measurement pickup housing, and an excess-pressure protection device, especially a burst disk or a pressure relief valve, integrated in the connection element, which serves to effect a pressure equalization with an environment of the measurement pickup in the case of a pressure overload in the measurement pickup.

Measurement pickup

A pressure-difference sensor, which is asymmetrical by design, includes a measuring apparatus having a first half-chamber with a first volume V, which is sealed by a first separating membrane having a first membrane stiffness E, and a second half-chamber with a second volume V, which is sealed by a second separating membrane having a second membrane stiffness E, wherein the first half-chamber is separated from the second half-chamber by a pressure sensitive element, especially a measuring membrane, and the first half-chamber is filled with a first transfer liquid having a first coefficient of thermal expansion &#x3b1;and the second half-chamber is filled with a transfer liquid having a second coefficient of thermal expansion &#x3b1;. For making the temperature-dependent, separating-membrane pressure-error dP symmetrical, the design is so embodied that a first product of the first membrane stiffness, the first volume and the first coefficient of thermal expansion is essentially equal to a second product of the second membrane stiffness, the second volume and the second coefficient of thermal expansion (E*V*&#x3b1;=E*V*&#x3b1;), wherein, additionally, at least one factor of the first product deviates, by design, from the corresponding factor of the second product.

Differential pressure sensor comprising a symmetric error in the separating bodies

A pressure pickup, having a pressure chamber, which is located between a separating membrane and a platform. A pressure canal for hydraulic transmission of pressure to a measuring cell, includes, for dynamic overload protection, a Venturi throttle implemented by providing that the pressure canal has at least one segment whose flow cross section is variable. Such segment is preferably provided in the form of an annular canal. The flow cross section can be changed, for example, by an axial shifting of a conical inner wall relative to a complementary, conical outer wall, or by the deforming of an elastic inner or outer wall of the annular canal.

Pressure and differential pressure gauge with overload protection

pressure mediator comprising a base body having a membrane bed, wherein said base body has a first material with a first thermal expansion coefficient, in addition to a separating membrane having a second material with a second thermal expansion coefficient that is smaller than the first thermal expansion coefficient The separating membrane is fixed to the base body by its edge area in such a way that the membrane bed is covered by the separating membrane, and the separating membrane also has a relief that is formed by embossing against the membrane bed after the separating membrane was fixed to the base body. Embossing of the membrane relief is carried out at a temperature below critical temperature of less than approximately 10&#xb0; C. This makes it possible to obtain a constant membrane characteristic line at low temperatures.

Pressure mediator with separating membrane and method for the production thereof

A relative pressure sensor comprises two chambers and two separating membranes respectively provided for a process pressure and an ambient pressure. The chambers are separated by a pressure-sensitive element and are filled with a transmission medium. In order to attenuate process-side overload pulses, which act upon the first separating membrane, a hydraulic damper is provided that is placed on the side of the atmosphere between the second separating membrane and the pressure-sensitive element. The pressure-sensitive element is a piezoresistive silicon chip, the transmission medium consists of silicone oil, and the damper is comprised of a filter element made of sintered bronze having 29% porosity and an 11 micrometer pore diameter. The filter element has a length of 8 mm and a diameter of 2 mm.

Relative pressure sensor having an atmosphere-side damper

A differential pressure sensor includes a measuring mechanism having a chamber on the high-pressure side that is sealed by a first dividing membrane, and a chamberon the low-pressure side that is sealed by a second dividing membrane. The first dividing membrane is loadable with a pressure acting on the high-pressure side and the second dividing membrane with a pressure acting on the low-pressure side, and the chamber on the high-pressure side is separated from the chamber on the low-pressure side by a pressure-sensitive element, especially a measuring membrane, and the chambers of the high- and low-pressure sides are filled with a transfer medium. For damping of overload pulses acting on the first dividing membrane on the high-pressure side, a hydraulic throttle is provided, which is arranged on the low-pressure side between the second dividing membrane and the pressure-sensitive element.

Differential pressure sensor with overload damping

For avoiding the evaporation of volatile components of a fill oil and for avoiding contamination of the fill oil with ambient air, a method for the filling of hydraulic pressure measurement mechanisms by means of a readied filling chamber. The method includes the following steps: (I) Evacuating the filling chamber by means of a vacuum pump over a first path of a first conductivity, extending between the vacuum chamber and the vacuum pump; (II) ending the evacuation of the filling chamber over the first path; (III) continued evacuating of the filling chamber by means of the pump over a second path of a second conductivity, extending between the filling chamber and the vacuum pump, wherein the second conductivity is smaller than the first conductivity; (IV) feeding the fill oil into the evacuated fill chamber and (V) filling the measurement mechanisms.

Device and method for filling of hydraulic pressure measurement mechanisms

A relative pressure measuring instrument has a reference pressure feed that offers a high measure of safety and is easy to produce. Included is a relative pressure measuring cell having a pressure sensitive element, on whose process-facing side there is present during operation a pressure (p) to be measured, on whose process-averted side there is present during operation a reference pressure (p ) to which the pressure (p) to be measured is to be referred, a support on which the relative pressure measuring cell is arranged and which is enclosed in a housing, a process connection, that is connected to a process-facing end of the housing, a measuring instrument housing that is arranged at a process-averted end of the housing, and a reference pressure feed through which during operation the reference pressure (p ) is led to the process-averted side of the pressure sensitive element, and which leads completely out of the relative pressure measuring instrument laterally through the support and a single bore through the housing.

Relative pressure measuring instrument

A pressure sensor element for mounting in a connecting element comprises an isolator body with a laterally projecting membrane. The laterally projecting membrane covering an opening of a passage through which the pressure present at the surface of the membrane is conveyed to a pressure transducer element by means of a hydraulic fluid. In order to mount the pressure sensor element, it is secured in a mounting aperture of the connecting element. The projecting perimeter of the membrane is secured to the surface surrounding the mounting aperture of the connecting element by means of a continuous seam. A membrane type ring in combination with a conventional membrane may be substituted for the projecting membrane, wherein the membrane type ring covers the gap between the pressure sensor element and the adapter element.

Pressure sensor, and a method for mounting it

A differential pressure pickup with a small hysteresis volume which has a sensor element, two pressure measuring chambers adjacent thereto, two pressure receiving chambers closed off by separating diaphragms and two overload chambers separated from each other by an overload diaphragm, in which pickup the overload diaphragm has a closed outer edge and a closed inner edge and is firmly restrained along its outer edge and its inner edge.

Differential pressure pickup

A differential pressure sensor, for determining the differential pressure between two measuring points, comprises a pressure vessel which is filled with a transfer fluid; a measuring cell which is arranged in the pressure vessel and is surrounded by the transfer fluid, with two half-cells; a diaphragm-like deforming body which separates the two half-cells from each other in a pressuretight manner; two pressure supply lines, which respectively feed the pressure from one of the two measuring points outside the pressure vessel to one of the two half-cells; and at least one pressure accumulator, the pressure of which acts on the transfer fluid in the vessel. Elastic or compressible bodies with a linear or degressive characteristic are suitable as the pressure accumulator. The pressure accumulator compensates for changes in volume of the transfer fluid on account of temperature fluctuations.

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Teltow, Germany

Dietfried Burczyk