Pressure measuring sensor

Patent metadata

Field	Value
Publication number	US-12031878-B2
Application number	US-202017756929-A
Country	US
Kind code	B2
Filing date	Nov 20, 2020
Priority date	Dec 6, 2019
Publication date	Jul 9, 2024
Grant date	Jul 9, 2024

Abstract

A pressure measuring sensor having a ceramic pressure sensor includes a temperature transducer to provide a thermovoltage dependent on a temperature gradient. The temperature transducer includes two series-connected thermoelements, each of which has a galvanic contact between a wire of the thermoelement and a connecting conductor connecting the galvanic contacts of the two thermoelements to one another. The temperature transducer enables the compensation for a measuring error caused by a temperature gradient occurring along the pressure measuring sensor.

First claim

The invention claimed is:

1. A pressure measuring sensor, comprising:
a ceramic pressure sensor arranged in a housing, wherein the pressure sensor includes a measuring diaphragm to which can be applied a pressure through an opening in the housing;
an electromechanical transducer for metrologically capturing a deflection of the measuring diaphragm dependent upon the pressure acting on the measuring diaphragm;
a thrust ring arranged on an outer edge of a rear side and facing away from the measuring diaphragm of the pressure sensor;
a clamping device by which an outer edge region of the pressure sensor is clamped in the housing together with the thrust ring arranged thereon;
a temperature transducer for providing a thermovoltage dependent upon a temperature gradient, wherein the temperature transducer includes two series-connected thermoelements, each of which includes a galvanic contact between a conductor of the respective thermoelement and a connecting conductor connecting the galvanic contacts of the two thermoelements to one another;
an electrically conductive layer extending in a direction parallel to a surface normal of the measuring diaphragm and arranged on a lateral surface of the thrust ring, wherein the electrically conductive layer forms or includes the connecting conductor or a conducting portion of the connecting conductor, and
wherein the two galvanic contacts include one contact facing the process and one contact facing away from the process, wherein the two contacts are both arranged in the housing outside the pressure sensor and are spaced apart from each other in the direction parallel to the surface normal to the measuring diaphragm.

2. The pressure measuring sensor according to claim 1 ,
wherein at least one of the two galvanic contacts is arranged on the conductive layer of the thrust ring, and/or
wherein the galvanic contact facing away from the process is arranged on a region of the conductive layer facing away from the pressure sensor, and the galvanic contact facing the process is arranged on a region of the conductive layer facing the pressure sensor.

3. The pressure measuring sensor according to claim 2 , wherein the connecting conductor further includes at least one further conducting portion, and
wherein at least one of the two contacts is arranged on the at least one further conducting portion.

4. The pressure measuring sensor according to claim 3 , further comprising:
a connection ring arranged on an end face of the thrust ring and facing away from the pressure sensor; and
a conductive coating which forms or comprises a further conducting portion of the connecting line, wherein the conductive coating is arranged on the connection ring and is in electrically-conducting connection to the layer arranged on the thrust ring,
wherein the galvanic contact facing away from the process is arranged on the coating of the connection ring.

5. The pressure measuring sensor according to claim 4 ,
wherein the layer arranged on the thrust ring includes a layer region extending over an end face of the thrust ring facing the connection ring and on which rests a coating region, extending over an end face, facing the thrust ring, of the connection ring, of the coating of the connection ring,
wherein the galvanic contact facing away from the process is arranged on a layer region, extending over an inner lateral surface of the connection ring, of the coating of the connection ring, and/or
wherein the connection ring is clamped in the housing by the clamping device.

6. The pressure measuring sensor according to claim 5 , further comprising:
an electrically conductive sensor coating that forms or includes a further conducting portion of the connecting conductor, wherein the electrically conducting sensor coating is arranged on a rear side of the pressure sensor facing away from the diaphragm,
wherein the sensor coating is in electrically-conducting connection to the layer arranged on the thrust ring, and
wherein the galvanic contact facing the process is arranged on the sensor coating.

7. The pressure measuring sensor according to claim 6 ,
wherein the layer includes a layer region that extends over an end face of the support body facing the pressure sensor and rests on a coating region of the sensor coating,
wherein the galvanic contact facing the process is arranged on a layer region of the sensor coating spaced apart from the thrust ring, and/or
wherein the sensor coating is designed as an electromagnetic shielding of the electromechanical transducer of the pressure sensor, wherein the shielding includes a coating region that surrounds an external lateral surface of the pressure sensor on the outside on all sides.

8. The pressure measuring sensor according to claim 6 , wherein the coating of the connection ring includes a nickel-vanadium compound (NiV), the layer of the support body includes of a material comprising at least one titanium oxide (TiOx), and the sensor coating includes a material comprising a nickel-vanadium compound (NiV).

9. The pressure measuring sensor according to claim 1 ,
wherein at least one of the two conductors in each case:
is designed as a contact pad,
includes an electrically-conductive metal, a metallic alloy, and/or a metal oxide,
comprises a titanium oxide (TiOx) or a titanium-tungsten oxide (TiWOx), and/or
includes an electrically-conductive conductor material having Seebeck coefficient that differs from a Seebeck coefficient of the material of the conducting portion that is in direct contact with the respective conductor.

10. The pressure measuring sensor according to claim 1 ,
wherein at least one conducting portion of the connecting conductor, the layer, the coating of the connection ring, and/or the sensor coating in each case:
includes an electrically-conductive material that, in comparison to platinum, has a Seebeck coefficient with a magnitude of greater than or equal to 6 μV/K or greater than or equal to 10 μV/K,
includes an electrically-conductive metal, a metallic alloy, and/or a metal oxide,
includes a titanium oxide (TiOx), a copper-nickel compound (CuNi), a nickel-vanadium compound (NiV), or a compound comprising nickel-vanadium and gold (NiV/Au), and/or
is designed as a layer that is applied by sputtering or by deposition from the gas phase and/or has a layer thickness of greater than or equal to 100 nm or of 1 μm to 2 μm.

11. The pressure measuring sensor according to claim 1 ,
wherein the connecting conductor includes the conducting portion formed by the layer and at least one further conducting portion,
wherein the conducting portions of the connecting conductor either all consist of the same material or comprise two or more conducting portions made of different materials, and
wherein a combination of the same or different Seebeck coefficients of the materials of the conducting portions of the connecting conductor and/or a spatial extension of the further conducting portion or at least one of the further conducting portions is formed in the direction parallel and/or perpendicular to the surface normal to the measuring diaphragm such that a sum of all the partial thermovoltages that form along the temperature transducer corresponds to the temperature gradients present in the pressure measuring sensor along the temperature transducer or at least along a portion of the temperature transducer in the direction parallel to the surface normal to the measuring diaphragm of the pressure sensor.

12. The pressure measuring sensor according to claim 1 ,
wherein the thrust ring and/or the connection ring consist of ceramic, and/or
wherein a distance between the galvanic contact faci

Assignees

• Endress Hauser Se Co Kg

Inventors

• Rossberg Andreas
• Ponath Nils

Classifications

• G01K7/04

  the object to be measured not forming one of the thermoelectric materials · CPC title

• G01K7/02

  using thermoelectric elements, e.g. thermocouples · CPC title

• G01L9/125 Primary

  with temperature compensating means (non electric temperature compensating means G01L19/04) · CPC title

• G01L9/0075

  using a ceramic diaphragm, e.g. alumina, fused quartz, glass · CPC title

• G01L19/0092 Primary

  Pressure sensor associated with other sensors, e.g. for measuring acceleration or temperature (G01L9/025, G01L9/045, G01L9/065, G01L9/085, G01L9/105, G01L9/125, G01L19/02, G01L19/04 take precedence; measuring two or more variable G01D21/02; temperature sensors with pressure compensation G01K1/26) · CPC title