PRESSURE TRANSDUCER FOR DETERMINING AND/OR MONITORING THE PRESSURE OF A MEDIUM

Abstract

A pressure measuring transducer for determining and/or monitoring pressure of a medium, comprises a measuring unit and, arranged in the measuring unit, a first pressure sensor which is supplied on a first face with the pressure of the medium and on a second face with a second pressure, and an isolating diaphragm system having a first isolating diaphragm and a second isolating diaphragm which each have an axisymmetric deflection, on which is superimposed a non-axisymmetric, especially antisymmetric, deflection, for achieving a volume change in a pressure chamber.

Claims

1. A pressure measuring transducer for determining and/or monitoring a pressure of a medium, comprising: a measuring unit and, arranged in the measuring unit, a first pressure sensor, which is supplied on a first face with the pressure of the medium and on a second face with a second pressure; and an isolating diaphragm system having a first isolating diaphragm and a second isolating diaphragm that are arranged relative to one another such that the first isolating diaphragm faces the medium and the second isolating diaphragm faces away from the medium and further having between the first isolating diaphragm and the second isolating diaphragm an intermediate space that is evacuated such that the intermediate space has a vacuum, wherein the first and second isolating diaphragms are secured on a peripheral edge pressure-tightly to the measuring unit to form a pressure chamber between the second isolating diaphragm and the measuring unit, wherein the pressure of the medium is transferred via the first isolating diaphragm and the second isolating diaphragm to the pressure chamber and the pressure of the medium is transferred via the pressure chamber to the first face of the first pressure sensor, wherein the first and second isolating diaphragms each has a deflectable, mutually differing, working range and an embossed contour, wherein the pressure chamber is filled with a reference volume such that the first and second isolating diaphragms form a reference position, wherein the first and second isolating diaphragms are deflectable from the reference position in two directions such that the volume of the pressure chamber can be varied, and wherein the first and second isolating diaphragms each has an axisymmetric deflection on which is superimposed a non-axisymmetric deflection for achieving the volume change in the pressure chamber.

2. The pressure measuring transducer as claimed in claim 1, wherein the first and second isolating diaphragms have different thicknesses.

3. The pressure measuring transducer as claimed in claim 1, wherein the first and second isolating diaphragms are formed in such a manner that the intermediate space is evacuable without an annular gap.

Description

BRIEF DESCRIPTION OF THE DRAWING

[0017] The present disclosure will now be explained in greater detail based on the appended drawing, the sole figure of which shows as follows:

[0018] FIG. 1 shows a schematic view of a pressure measuring transducer of the present disclosure.

DETAILED DESCRIPTION

[0019] FIG. 1 shows a schematic view of a pressure measuring transducer 1 of the present disclosure serving for determining and/or monitoring a pressure p of a medium 2. An isolating diaphragm system 5 is arranged facing the medium 2. The isolating diaphragm system 5 includes a first isolating diaphragm 6 and a second isolating diaphragm 7, which are connected with a measuring unit 3 pressure-tightly in the edge region. In such case, the first isolating diaphragm 6 faces toward the medium 2 and the second isolating diaphragm 7 faces away from the medium 2. Between the first isolating diaphragm 6 and the second isolating diaphragm 7, the pressure tight connection with the measuring unit encloses an intermediate space 8, in which a vacuum reigns. In the vicinity of the second isolating diaphragm 7, an isolating diaphragm bed 11 can be formed in the measuring unit 3.

[0020] The two isolating diaphragms 6, 7 have mutually differing deflectable working ranges and embossed contours and are connected at a peripheral edge with the measuring unit 3 to form a pressure chamber 10. Pressure chamber 10 is filled with a reference volume, such that the first and second isolating diaphragms 6, 7 assume a reference position, out of which the two isolating diaphragms 6, 7 can be deflected in both directions, such that a volume of the pressure chamber 10 can be varied. The first and second isolating diaphragms 6, 7 are formed according to the present disclosure in such a manner that each has, for achieving the volume change in the pressure chamber 10, an axisymmetric deflection, on which a non-axisymmetric, especially antisymmetric, deflection is superimposed. Especially, the first and second isolating diaphragms 6, 7 are formed according to the teachings of EP 2 300 739 B1, to which comprehensive reference is taken. Especially, reference is taken to the contents of paragraphs 25 to 81 of the description of EP 2 300 739 B1.

[0021] Via the pressure chamber 10 and a first pressure transfer duct, or-path, 9a, the pressure of the medium 2 is transferred to a first face 4a of a pressure sensor 4 arranged in the measuring unit 3. Pressure sensor 4 is supplied on a second face 4b opposite the first face 4a with a second pressure. The pressure measuring transducer 1 can be embodied as a relative pressure measuring transducer, which transfers an ambient pressure to the second area 4b of the pressure sensor via a second pressure transfer duct, or -path, 9b. Alternatively, the pressure measuring transducer 1 can be embodied as an absolute pressure measuring transducer, wherein the second pressure is then a vacuum. Furthermore, the pressure measuring transducer can also be embodied as a pressure difference measuring transducer, wherein the second pressure is then in contact with the medium in pressure transferring manner likewise via a, preferably embodied equally, isolating diaphragm system.

[0022] The measurement signal of the pressure sensor 4 can be transmitted, for example, to an evaluation unit 12, which is embodied, based on the measurement signal of the pressure sensor 4, to determine the pressure p of the medium 2.