Endress + Hauser Gmbh + Co. Kg

Endress + Hauser Flowtec Ag

Endress+hauser Gmbh+co.

Endress U. Hauser Gmbh U.co. Kg

Wolfgang Dannhauer

Dietfried Burczyk

Ralf Nürnberger

Anh Tuan Tham

Michael Philipps

Harri Notacker

Friedrich Schwabe

Ralf N&uuml;rnberger

Igor Getman

Oliver Graf

Dieter Stolze

Thiérry Moser

Stefan Muth

Ralf Nuernberger

Raphael Erni

Frank L&ouml;ffler

A pressure difference measuring cell for registering pressure difference between a first pressure and a second pressure, comprises: an elastic measuring arrangement having at least one measuring membrane, or diaphragm, that comprises silicon; a platform, which is pressure-tightly connected with the elastic measuring arrangement; a first hydraulic path for transferring a first pressure onto a first surface section of the elastic measuring arrangement; and a second hydraulic path for transferring a second pressure onto a second surface section of the elastic measuring arrangement. The first pressure opposes the second pressure, and the elastic deflection of the measuring arrangement is a measure for the difference between the first and the second pressure, wherein the pressure difference measuring cell has additionally at least one hydraulic throttle, characterized in that the at least one hydraulic throttle comprises porous silicon.

Pressure difference measuring cell

A method for embossing a separating membrane of a pressure transfer means including a membrane carrier having a membrane bed. With the method, an optimal forming of the separating membrane matched to the form of the membrane bed is achievable. The method includes steps of: welding a planar, separating membrane blank onto the membrane carrier; filling with a lubricant a pressure receiving chamber enclosed by the welded, separating membrane blank and the membrane carrier; producing the separating membrane from the separating membrane blank by embossing the separating membrane blank by pressing it against the membrane bed while lubricant is present in the pressure receiving chamber.

Method for embossing a separating membrane of a pressure transfer means

A pressure measuring device for measuring and/or monitoring the pressure of a measured medium. The pressure measuring device includes a sensor housing and a measurement transmitter, wherein assigned to the sensor housing is a pressure measuring cell with a pressure sensitive measuring element. Assigned to the pressure measuring cell is a temperature sensor, and assigned to the measurement transmitter is a control/evaluation unit. In order to increase the measurement accuracy of the pressure measuring device, it is provided, that the control/evaluation unit, in the case of an abrupt change of the temperature registered by the temperature sensor, ascertains, or provides, a step response, wherein the step response has a sensor-type-specific, settling time, and the control/evaluation unit, on the basis of the ascertained, or provided, step response, references the corresponding time-dependent integral temperature of the pressure measuring cell, in order to eliminate, or to compensate, the temperature influence on the pressure measurement signal provided by the measuring element.

Pressure gauge

A method and apparatus for diagnosis of liquid losses in pressure measuring transducers including a pressure sensor arranged in a pressure measuring chamber, and a pressure transfer structure connected to the pressure measuring chamber A sealed inner space of a separating diaphragm is composed of the inner spaces of the pressure transfer structure and the pressure measuring chamber and is filled with a pressure transmitting liquid, which, serves for transmitting pressure acting on the separating diaphragm to the pressure sensor. An apparatus for detecting liquid losses. The apparatus for detecting liquid losses includes a test element arranged in the sealed inner space. The outer volume of the test element is reducible for diagnosis of liquid losses. An evaluating unit, which serves, during diagnosis, for registering, as a function of a volume reduction of the test element, a pressure measured by the pressure sensor, and, on the basis of this pressure measured as a function of the volume reduction, for detecting whether liquid has escaped.

Method and apparatus for diagnosis of liquid losses in pressure measuring transducers filled with pressure transmitting liquids

A hydraulic pressure intermediary includes: a platform, which has a bowl-shaped surface having an annular, platform-surface edge region, a platform-surface central region depressed relative to the platform-surface edge region and surrounded by the platform-surface edge region, and an annular platform-surface transition region, which borders, on its inner side, the platform-surface central region and, on its outer side, the platform-surface edge region; a bowl-shaped, separating membrane having a flat, annular, separating-membrane edge region, a separating-membrane central region depressed relative to the separating-membrane edge region and an annular separating-membrane transition region, which borders, on its inner side, the separating-membrane central region and, on its outer side, the separating-membrane edge region. The separating membrane is connected with the platform-surface edge region within the separating-membrane edge region along a surrounding joint. Further, the separating-membrane transition region includes an annular moat having a moat outer side, a moat inner side, and a moat transition zone, wherein the moat outer side has a first annular inclined surface, which borders on the separating-membrane edge region, the moat inner side includes a second annular inclined surface, which borders on the separating-membrane central region, and the moat transition zone extends between the first and the second inclined surfaces.

Hydraulic pressure intermediary

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.

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Teltow, Germany

Wolfgang Dannhauer