Endress + Hauser Gmbh + Co. Kg

Endress + Gmbh + Co. Kg

Endress+hauserse+co. Kg

Elmar Wosnitza

Thomas Uehlin

Olaf Textor

Igor Getman

Sergej Lopatin

Andreas Rossberg

Michael Hugel

Michael Hügel

Davide Parrotto

Lars Karweck

Ulrich Buder

Hansjörg Brock

Manuel Bondi-Liedtke

Manuel Liedtke

A pressure sensor comprises a deformable measuring diaphragm, and a mating body connected in a pressure-tight manner and forms a measuring chamber in which a reference pressure is present. A pressure can be applied to an outside of the measuring diaphragm. The pressure sensor has a capacitive transducer having at least one mating body electrode and at least one diaphragm electrode. Above a pressure limit value for the pressure, at least one central surface section of the measuring diaphragm rests against the mating body with a contact surface area, the size of which is dependent on the pressure. The pressure sensor also has a resistive transducer for converting a pressure-dependent deformation of the measuring diaphragm, when pressed in a range of values above the pressure limit value, into an electrical signal using an electrical resistance which is dependent on the contact surface area of the measuring diaphragm on the mating body.

Multilevel pressure sensor

A pressure transducer comprising a resistive pressure sensor element with a measurement membrane which has at least four resistor elements. The resistor elements are arranged in a full-bridge circuit, having a longitudinal direction in which the full bridge circuit is to be supplied with a constant current. When being supplied with the constant current, a longitudinal voltage has a first pressure dependency and a first temperature dependency, and a diagonal voltage has a second pressure dependency and a second temperature dependency, the second pressure dependency being greater than the first pressure dependency at a given temperature. The pressure transducer has a processing circuit which is designed to determine a measured pressure value at least using the diagonal voltage and optionally the longitudinal voltage. The processing circuit is further designed to check whether a value pair of a longitudinal voltage and a diagonal voltage corresponds to an expected functional relationship at a current temperature.

Pressure transducer

A method for operating a pressure sensor, which includes a measuring membrane, at least one platform and a capacitive transducer having two pressure dependent capacitances between electrodes on the measuring membrane. The measuring membrane divides a volume pressure-tightly into two volume portions, wherein the second volume portion is enclosed in a measuring chamber between the measuring membrane and the platform. A deflection of the measuring membrane depends on a pressure measurement variable p, which is a difference between a first pressure pand second pressure pin the volume portions. The pressure measurement variable p follows from both capacitances, wherein, for an intact pressure sensor, the second capacitance is a predetermined function of the first capacitance and, in given cases, the temperature. The method has steps as follows: registering value pairs of both capacitances; testing whether the value pairs correspond within a tolerance range to the predetermined function; and determining a change, respectively damage, of the sensor, when this is too long not the case.

Method for operating an absolute, or relative, pressure sensor having a capacitive transducer

A gauge pressure sensor for determining the pressure of a medium by means of a housing and by means of a measuring element, which is positioned in the housing, wherein an outwards facing side of the measuring element is in contact with the medium and is exposed to the pressure, which is to be measured. A tube for a reference pressure is provided, which conducts ambient air to the measuring element, and by means of at least one dehumidifying chamber, positioned in the housing, for the collection of air moisture. The dehumidifying chamber contains a moisture adsorbing material or is primarily composed of a moisture adsorbing material, in that the moisture adsorbing material is at least, in sections, enclosed by a wall, which is composed of a first moisture permeable material, or is at least, in sections, free from a wall, and in that the reference pressure supply tube is at least, in sections, fabricated from a first or second moisture permeable material or in that the reference pressure supply tube has an aperture.

Gauge pressure sensor

A method for the compensating temperature gradient influences on a pressure measuring transducer, comprising the steps of: registering a pressure signal S(t); registering a temperature signal T(t); ascertaining a pressure measured value p(S(t), T(t)); determining the time derivative of the temperature signal dT/dt; correcting the pressure measured value with a correction function, which depends on the time derivative, wherein, as a function of the sign of the time derivative, another correction function is selected, or other coefficients in a function of equal type are selected.

Method for pressure measurement in the case of variable temperatures and pressure measuring sensor for pressure measurement in the case of variable temperatures

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Freiburg, Germany

Elmar Wosnitza