Pressure sensor

Patent metadata

Field	Value
Publication number	US-10345180-B2
Application number	US-201415103016-A
Country	US
Kind code	B2
Filing date	Nov 14, 2014
Priority date	Dec 18, 2013
Publication date	Jul 9, 2019
Grant date	Jul 9, 2019

Abstract

A pressure sensor comprising: a solid metal sensor body, having a front region and a base adjoining thereto, which has an outer edge, which can be clamped by means of a fastening device; a recess, which is provided in the front region and is open towards a front side of the front region that faces away from the base; a metal measuring diaphragm, to which a pressure is applied from outside during measurement operation and which can be deformed elastically depending upon the pressure, is arranged on the front side of the sensor body, closes off the recess from the outside, and is spaced apart from the outer edge of the front region; and an electromechanical transducer for detection, by means of measuring the pressure-dependent deformation of the measuring diaphragm, having at least one measuring element, which is electrically insulated from the measuring diaphragm and the sensor body by means of an insulating element.

First claim

The invention claimed is:

1. A pressure sensor, comprising:
a solid metal sensor body having a front region and a base adjoining thereto, said front region of having a larger cross-sectional area than said base, and said front region of having an outer edge, that is clamped by means of a fastening device to install the pressure sensor at a location of use;
a recess provided in said front region and open toward a front side of said front region that faces away from said base;
an insulating element;
a metallic measuring diaphragm, to which a pressure to be measured is applied from outside during a measurement operation and which can be deformed elastically depending upon the pressure, is arranged on the front side of said sensor body, and closes off said recess towards the outside, said metallic measuring diaphragm consists of the same metal as said sensor body, and is spaced apart from the outer edge of said front region; and
an electromechanical transducer for metrologically detecting the pressure-dependent deformation of said metallic measuring diaphragm, having at least one measuring element, which is electrically insulated from said metallic measuring diaphragm and said sensor body by means of said insulating element,
wherein said insulating element is a body, which is inserted into said recess and which, in particular, is anchored in said recess by means of an active hard solder joint and the front side of which is facing said measuring diaphragm, runs parallel to said measuring diaphragm, and is spaced apart from it; and one of said measuring elements is a measuring electrode mounted to the front side of said insulating element, said measuring electrode, together with said measuring diaphragm serving as a counter electrode, forming a capacitor having a capacity that depends upon the pressure-dependent bending of said measuring diaphragm, and
wherein said insulating element has, on the front side that faces said measuring diaphragm, a wave profile forming a diaphragm bed for said measuring diaphragm and consisting of waves that are arranged concentrically to the center of said measuring diaphragm; and said measuring diaphragm is designed as a wave diaphragm having a wave profile that is the same as the wave profile of said insulating element and that is, in particular, produced by impressing said measuring diaphragm on the diaphragm bed.

2. The pressure sensor according to claim 1 , wherein:
on the front side of said sensor body between said measuring diaphragm and said outer edge, a groove enclosing said measuring diaphragm from all sides is provided.

3. The pressure sensor according to claim 1 , wherein:
said front region on said front side of said outer edge has a metallic sealing lip of a metallic cutting ring seal, which encloses said measuring diaphragm from all sides, is spaced apart from said measuring diaphragm, and protrudes outwards.

4. The pressure sensor according to claim 1 , wherein:
said the measuring diaphragm consists of a metal—in particular, titanium, tantalum, a titanium alloy, or a tantalum alloy—having a percentage expansion (ε) greater than or equal to 10% in a temperature range that includes temperatures below −70° C. and in which the pressure sensor may be used—in particular, in a temperature range from −165° C. to −70° C.

5. The pressure sensor according to claim 1 , wherein:
said insulating element consists of a material—in particular, of ceramics or sapphire—which has a thermal expansion coefficient adapted to the thermal expansion coefficient of the metal of said sensor body and said measuring diaphragm in a temperature range that includes temperatures below −70° C. and in which the pressure sensor may be used—in particular, in a temperature range from −165° C. to −70° C.

6. The pressure sensor according to claim 1 , further comprising:
an electric component, wherein:
said electromechanical transducer is connected via at least one connecting line to said electronic component—in particular, to an electronic component equipped with a heater—that is arranged at a distance to said measuring diaphragm.

7. A pressure measuring arrangement with a pressure sensor according to claim 1 , comprising:
a connecting element—in particular, a connecting pipe, a connecting piece, or a connecting flange;
which has a central recess exposing said measuring diaphragm; and
a fastening device for attaching the pressure sensor to said connecting element, said fastening device exclusively rests on the outer edge of the front region of the pressure sensor, and which, in particular, exclusively exerts forces on the edge that act parallel to the surface normal to said measuring diaphragm.

8. The pressure measuring arrangement according to claim 7 , with a pressure sensor having said front region on said front side of said outer edge has a metallic sealing lip of a metallic cutting ring seal, which encloses said measuring diaphragm from all sides, is spaced apart from said measuring diaphragm, and protrudes outwards;
said connecting element has a metallic sealing contour, which is complementary to said sealing lip of said sensor body, in an area opposite said sealing lip;
a metallic seal—in particular, a seal coated on the outside with a coating of polytetrafluoroethylene—made of a more ductile metal—especially, of gold or copper—than the metal of said sealing lip and the sealing contour, is arranged between said sealing lip and said sealing contour; and
said fastening device comprises a sleeve, which is slid onto said pressure sensor from the side that faces away from said measuring diaphragm and which is connected to said connecting element by means of a screw connection.

9. The pressure sensor arrangement according to claim 7 , wherein:
said connecting element comprises an annular circumferential groove on its front side opposite said outer edge, and
an annular circumferential sealing spring, in particular, a sealing spring with a c-shaped cross-sectional profile;
made of a resilient metal—especially, of a metal coated on the outside with a coating of polytetrafluoroethylene—is inserted into the groove; and
said fastening device comprises a sleeve, which is slid onto the pressure sensor from the side that faces away from said measuring diaphragm and which is connected to said connecting element by means of a screw connection.

10. A pressure sensor, comprising:
a solid metal sensor body having a front region and a base adjoining thereto, said front region of having a larger cross-sectional area than said base, and said front region of having an outer edge, that is clamped by means of a fastening device to install the pressure sensor at a location of use;
a recess provided in said front region and open toward a front side of said front region that faces away from said base;
an insulating element;
a metallic measuring diaphragm, to which a pressure to be measured is applied from outside during a measurement operation and which can be deformed elastically depending upon the pressure, is arranged on the front side of said sensor body, and closes off said recess towards the outside, said metallic measuring diaphragm consists of the same metal as said sensor body, and is spaced apart from the outer edge of said front region; and
an electromechanical transducer for metrologically detecting the pressure-dependent deformation of said metallic measuring diaphragm, having at least one measuring element, which is electrically insulated from said metallic measuring diaphragm and said sensor body by means of said insulating element,
wherein:
said insulating element is a disk that is arranged on an inner surface of said measuring diaphragm facing the inside of said recess and that is laminar

Assignees

• Endress Hauser Gmbh Co Kg
• Endress Hauser Se Co Kg

Inventors

• Becher Raimund
• Tham Anh Tuan
• Rossberg Andreas
• Schmidt Elke

Classifications

• G01L19/142 Primary

  Multiple part housings · CPC title

• G01L9/0075

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