Pressure measuring system and method for producing a pressure measuring system

Abstract

The invention relates to a pressure measuring system (1) for determining and / or monitoring a first pressure (p1) of a medium (2), comprising - a process adapter (8) having a membrane system (9) with a first separating membrane (10) and a second separating membrane (11), which are arranged relative to each other such that the first separating membrane (10) faces the medium (2) and the second separating membrane (11) faces away from the medium (2) and between which a first intermediate space (12) is enclosed; - a double capillary (14) having an inner capillary (15) with an interior space (16) and an outer capillary (17) which surrounds the inner capillary (15) such that a second intermediate space (18) is formed between the inner capillary (15) and the outer capillary (17), the double capillary (14) being connected to the process adapter (8) in a first end region (14a) such that the first intermediate space (12) is fluidically connected to the second intermediate space (18), and the second end region (14b) of the double capillary (14) being connected to the sensor unit (3) such that the second intermediate space (18) is fluidically connected to a third intermediate space (19) of the sensor unit (3); and - a monitoring unit (20) which is designed to monitor the state of the third intermediate space (19).

Description

[0001] Pressure transmitter system and method for manufacturing a pressure transmitter system

[0002] The invention relates to a pressure transmitter system and a method for manufacturing a pressure transmitter system.

[0003] In pressure measurement technology, absolute pressure, differential pressure, and gauge pressure sensors are known. Absolute pressure sensors determine the prevailing pressure of a process medium absolutely, i.e., relative to a vacuum, while differential pressure sensors determine the difference between two different pressures of the process medium or media. With gauge pressure sensors, the pressure of the process medium to be measured is determined relative to a reference pressure, where the prevailing atmospheric pressure in the vicinity of the gauge serves as the reference pressure.

[0004] Pressure sensors have a pressure-sensitive measuring element, the so-called pressure sensor, on whose first and second surfaces pressure is applied. In the case of relative or absolute pressure sensors, the pressure of the process medium to be measured acts on the first surface of the pressure sensor, while an absolute or reference pressure acts on the second surface. In the case of differential pressure sensors, a first and a second pressure of the process medium are applied to each surface. The measuring element bends depending on the relative pressure, which is formed by the difference between the pressures applied to the two surfaces. This bending is converted by an electronic unit into an electrical signal dependent on the relative pressure, which is then available for further processing or evaluation. A distinction is made, among other things, between capacitive and piezoresistive pressure sensors.A large number of such pressure sensors are manufactured and distributed by companies of the Endress+Hauser Group.

[0005] A ceramic pressure sensor, for example, comprises a ceramic base and a ceramic measuring diaphragm, which is pressure-tightly bonded to the base using an active brazing alloy to form a measuring chamber. Silicon chips, typically bonded to a silicon substrate, are also known as pressure sensors. Furthermore, the pressure sensor usually includes a transducer for converting pressure-dependent deformation of the measuring diaphragm into a primary electrical signal, as well as a primary signal path extending through the base. The transducer can be, for example, a capacitive or a resistive transducer. The primary signal path usually includes at least one electrical feedthrough through the base.In the case of absolute and relative pressure sensors, the pressure of the medium is measured by means of one, and in the case of differential pressure sensors by means of two, pressure-sensitive diaphragms facing the process. Each diaphragm has an associated diaphragm bed, which typically serves to emboss the diaphragm and to limit its movement in case of overload. Additionally, a pressure transmission medium is used, which transmits the pressure of the medium acting on the diaphragm to one of the two surfaces of the pressure sensor via a pressure transmission path. The diaphragm is usually mounted on a process adapter.

[0006] If the diaphragm breaks or is damaged, the medium can penetrate the pressure sensor and contaminate and / or even damage it. To prevent this, German patent application DE 199 49 831 B4 discloses a diaphragm system consisting of two parallel diaphragms, one facing the medium and the other facing the pressure fluid. A vacuum-sealed space is provided between the two diaphragms. A sensing device monitors changes in the vacuum within this space. Because the sensing device is mounted on the process flange and thus close to the process, it is exposed to potentially high process temperatures. Therefore, such a pressure sensor can only be used at low process and ambient temperatures.

[0007] It is therefore an object of the present invention to provide a pressure transmitter system which can also be used at high process and ambient temperatures.

[0008] The problem is solved according to the invention by a pressure transmitter system according to claim 1 and a method according to claim 6.

[0009] With regard to the pressure transmitter system, the object of the invention is achieved by a pressure transmitter system for determining and / or monitoring a first pressure of a medium, comprising a sensor unit with a first pressure sensor which can be subjected to the first pressure of the medium on a first surface, a process adapter with a membrane system comprising a first separating membrane and a second separating membrane which are arranged relative to each other such that the first separating membrane faces the medium and the second separating membrane faces away from the medium and a first space is enclosed between the first separating membrane and the second separating membrane, wherein the first separating membrane and the second separating membrane are attached to the process adapter in a pressure-tight manner, forming a pressure chamber between the second separating membrane and the process adapter, and wherein the membrane system is designed to transmit the first pressure to the pressure chamber.a double capillary with an inner capillary having an interior space and an outer capillary surrounding the inner capillary, such that a second space is formed between the inner capillary and the outer capillary, wherein the double capillary is connected to the process adapter in a first end region such that the pressure chamber is fluidly connected to the interior space and that the first space is fluidly connected to the second space, wherein the double capillary is connected to the sensor unit in a second end region such that the interior space is fluidly connected to the first surface and that the second space is fluidly connected to a third space of the sensor unit, and a monitoring unit arranged in the sensor unit which is configured to monitor a state of the third space.

[0010] By using the double capillary, the sensor unit can be spaced apart from the first pressure sensor and the monitoring unit, or arranged remotely from the process. The double capillary is specifically positioned between the sensor unit and the process adapter. The double capillary can have a length of at least 30 cm, particularly 50 cm, and especially 70 cm. The double capillary is specifically designed to be flexible. In particular, one wall of the inner capillary and one of the outer capillaries are thinner than the inner diameter of the inner capillary and the outer capillary, respectively. The second end of the double capillary, particularly the inner capillary, can be positioned in the third space between the two capillaries.

[0011] The first, second, and third spaces are fluidically connected. In particular, the first, second, and third spaces are evacuated or contain a vacuum. Therefore, absolute pressure zero prevails in the first, second, and third spaces, where "absolute pressure zero" as used in the application refers to a technically feasible vacuum with a pressure of less than 100 mbar, and in particular less than 10 mbar. The sensor unit may have an access bore designed to allow the evacuation of the first, second, and third spaces. After the vacuuming process, the access bore is closed, for example, with a bolt or pin. A fluidic connection may be pneumatically designed, in particular, when a gas or a vacuum is present.

[0012] The second space is arranged around the perimeter of the inner capillary. The pressure chamber and the interior are fluidically connected and can be filled with a pressure transmission fluid, particularly a hydraulic fluid. The first pressure sensor is, in particular, a silicon chip. The first pressure sensor can have a second surface that can be subjected to a second pressure. The first surface can be arranged opposite the second surface. The first and second separating membranes can be connected to the process adapter at a circumferential edge. Optionally, the sensor unit can have a pressure transmission line that fluidly connects the interior to the first surface.

[0013] In the event of a leak, i.e., damage to the first separating membrane, medium will enter the first, second, and third intermediate spaces. This is detected by the monitoring unit. Optionally, the pressure transmitter system can include a display unit designed to receive a signal from the monitoring unit and display a warning in the event of a leak. The monitoring unit can be configured to send a signal to the display unit indicating a leak. The monitoring unit can also be configured to monitor the condition of the first intermediate space.

[0014] In one embodiment, the monitoring unit is a second pressure sensor. Alternatively, the monitoring unit can be a conductivity sensor or a capacitive sensor. Regarding a possible embodiment of the monitoring unit as a second pressure sensor, reference is made to patent application DE 102024123597.7. Other pressure sensors, such as mechanical pressure switches, can also be used as alternatives.

[0015] In one embodiment, the inner and outer capillaries are aligned coaxially. For the purposes of the application, coaxial means that two components, in particular the inner and outer capillaries, have the same axis of rotation. The axis of rotation can be identical to the longitudinal axis of the inner and / or the outer capillary.

[0016] In one embodiment, the monitoring unit is arranged in the third space. In another embodiment, the process adapter has a first adapter, arranged in a first recess, with a first through-bore, wherein the first adapter is arranged and configured such that the first through-bore is fluidically connected to the pressure chamber. Optionally, the first adapter can be arranged and configured such that a fourth space is formed between the process adapter, in particular the first recess, and the first adapter, which is fluidically connected to the first and second spaces. The first adapter serves to transmit the first pressure of the medium from the process adapter to the double capillary, in particular from the pressure chamber to the interior. If necessary,The process adapter may contain a first pressure transmission line designed to transmit the first pressure from the pressure chamber to the first through-bore.

[0017] In one embodiment, the sensor unit has a second adapter, arranged in a second recess, with a second through-hole, wherein the second adapter is arranged and configured such that the second through-hole is fluidically connected to the interior and the first surface. Optionally, the second adapter is arranged and configured such that a fifth space is formed between the process adapter, in particular the second recess, and the second adapter, which is fluidically connected to the second and third spaces. The second adapter can be arranged in the third space or in a second recess, which is fluidically connected to the third space. The first adapter serves to transmit the first pressure of the medium from the double capillary to the pressure sensor, in particular from the interior to the first surface.A second pressure transmission line may be arranged in the sensor unit, which is designed to transmit the first pressure from the second through-hole to the first surface.

[0018] In one embodiment, the process adapter has a channel that fluidically connects the first and second spaces. Specifically, the channel leads from a region between the first and second separating membranes to an end face of the process adapter facing the sleeve.

[0019] In one embodiment, the process adapter is connected to the inner capillary and the outer capillary by means of a circumferential, in particular orbital, weld.

[0020] In one embodiment, the sensor unit is connected to the inner and outer capillaries by means of a circumferential, particularly orbital, weld. In one embodiment, the outer tube has at least two tube sections. Preferably, the outer tube has three or more tube sections. The at least two tube sections are configured such that at least one of the tube sections can be at least partially inserted into another tube section. At least one tube section can have an inner diameter that is larger than the outer diameter of an adjacent tube section. In the case of two tube sections, a first tube can have an inner diameter that is larger than the outer diameter of the second tube.In the case of three pipe sections, one of the pipe sections, for example a middle pipe section, may have an inner diameter that is larger than the outer diameter of an adjacent pipe section. Optionally, at least one pipe section may be designed as a union or a sleeve. The at least two pipe sections are, in particular, fixed relative to each other, i.e., prevented from moving relative to each other.

[0021] With regard to the method, the problem underlying the present invention is further solved according to the invention by a method for manufacturing a pressure transmitter system according to one of the previous embodiments, wherein the method comprises at least the following steps:

[0022] Providing process adapter, sensor unit and double capillary, connecting the process adapter and the first end region of the double capillary, in particular by welding, connecting the sensor unit and the second end region of the double capillary, in particular by welding.

[0023] When connecting the process adapter to the double capillary, it is advantageous to first connect the inner capillary to the process adapter, before connecting the outer capillary. Then, the inner capillary can be connected to the sensor unit, followed by the outer capillary to the sensor unit. Alternatively, the double capillary can first be connected to the sensor unit, followed by the connection to the process adapter.

[0024] In one embodiment, connecting the process adapter of the first end section of the double capillary comprises the following steps:

[0025] Connecting a first end region of the inner capillary to the process adapter, wherein at least one pipe section of the outer capillary is moved, in particular partially moved into an adjacent pipe section, such that the first end region of the inner capillary is exposed and in particular subsequently the first end region of the inner capillary is connected to the process adapter,

[0026] Connecting the outer capillary, in particular a first end region of the outer capillary, to the process adapter.

[0027] For example, the outer tube as a whole can be moved so that the first end of the inner capillary is exposed. This is particularly possible if the double capillary is not yet connected to the sensor unit. If the double capillary is already connected to the sensor unit and is designed such that the first end of the inner capillary is surrounded by the outer capillary, it is advantageous to move at least one section of the outer capillary tube so that the first end of the inner capillary is exposed and a connection between the inner capillary and the process adapter is made possible. After connecting the first end of the inner capillary to the process adapter, the outer capillary is connected to the process adapter. If necessary,The at least one pipe section can be moved in such a way that the outer capillary surrounds the first end region of the inner capillary and then the outer capillary is connected to the process adapter.

[0028] The outer capillary can have at least two tube sections. At least one tube section can be movable relative to another tube section of the outer tube, in particular, it can be at least partially inserted into another tube section. For example, the outer tube can be formed from two sections, one of which is movable relative to the other, such that the first tube section has an inner diameter larger than the outer diameter of the second tube section, allowing the second tube section to be partially inserted into the first tube section. The outer tube can also be formed from more than two tube sections.For example, the outer pipe can have three pipe sections arranged one behind the other to form the outer pipe, and of which, for example, the middle pipe section has an inner diameter that is larger than the outer diameter of one of the outer pipe sections or larger than the outer diameters of both outer pipe sections combined. In this case, one or both of the outer pipe sections can be partially moved into the middle pipe section.

[0029] In one embodiment, connecting the sensor unit and the second end region of the double capillary comprises the following steps:

[0030] Connecting a second end region of the inner capillary to the sensor unit, wherein at least one pipe section of the outer capillary is moved, in particular partially moved into an adjacent pipe section, such that the second end region of the inner capillary is exposed and in particular subsequently the first end region of the inner capillary is connected to the sensor unit, connecting the outer capillary, in particular a second end region of the outer capillary, to the sensor unit.

[0031] For example, the outer tube as a whole can be moved so that the first end of the inner capillary is exposed. This is particularly possible if the double capillary is not yet connected to the process adapter. If the double capillary is already connected to the process adapter and is designed such that the first end of the inner capillary is surrounded by the outer capillary, it is advantageous to move at least one section of the outer capillary tube so that the first end of the inner capillary is exposed and a connection between the inner capillary and the sensor unit is made possible. After connecting the first end of the inner capillary to the sensor unit, the outer capillary is connected to the sensor unit. If necessary,The at least one pipe section can be moved in such a way that the outer capillary surrounds the first end region of the inner capillary and then the outer capillary is connected to the sensor unit.

[0032] In one embodiment, the outer tube comprises at least two tube sections, which are fixed relative to each other after connecting the process adapter and a first end section of the double capillary, and after connecting the sensor unit and a second end section of the double capillary. After the double capillary has been connected to both the process adapter and the sensor unit, the tube sections of the outer tube are joined together so that they are no longer movable relative to each other. This can be achieved by means of one or more welds.

[0033] The present invention will now be explained in more detail with reference to the following figures, Figs. 1-8. They show:

[0034] Fig. 1 : an embodiment of a pressure transmitter system according to the invention.

[0035] Fig. 2: one embodiment of the membrane system.

[0036] Fig. 3: a detailed view of the pressure transmitter system according to the invention.

[0037] Fig. 4: One embodiment of the double capillary. Figs. 5-8: One embodiment of the connection between the double capillary and the process adapter and the sensor unit.

[0038] Figure 1 shows an embodiment of the pressure transmitter system 1 according to the invention. The pressure transmitter system 1 comprises a sensor unit 3 with a first pressure sensor 5, which may optionally be arranged in a measuring unit 4 of the sensor unit 3. The pressure sensor 5 has a first surface 6 which can be subjected to the first pressure p1 of the medium 2. The pressure sensor 5 may have a second surface 7 which can be subjected to a second pressure. The second pressure may be ambient pressure, absolute pressure, or another pressure of the medium 2. The pressure sensor 5 may be connected to an evaluation unit 35, which determines the first pressure p1 based on a measured value generated by the pressure sensor 5. The evaluation unit 35 may be connected to a display unit 36, which is configured to display the first pressure p1.The pressure transmitter system 1 further comprises a process adapter 8 with a membrane system 9, which is designed to transmit the first pressure p1 of the medium 2 to a pressure chamber 13.

[0039] The membrane system 9 is shown in more detail in Fig. 2 and comprises a first separating membrane 10 and a second separating membrane 11, which are arranged relative to each other such that the first separating membrane 10 faces the medium 2 and the second separating membrane 11 faces away from the medium 2, and a first intermediate space 12 is enclosed between the first separating membrane 10 and the second separating membrane 11. The first separating membrane 10 and the second separating membrane 11 are pressure-tightly attached to the process adapter 8, in particular at their respective circumferential edges 10a, 11a, forming a pressure chamber 13. The membrane system 9 is designed to transmit the first pressure p1 to the pressure chamber 13. The process adapter 9 can further comprise a channel 30, which is designed to fluidically connect the first intermediate space 12 with the second intermediate space 18.

[0040] The pressure transmitter system 1 further comprises a double capillary 14 with an inner capillary 15 and an outer capillary 17, which surrounds the inner capillary 15. The inner capillary 15 has an interior space 16, and a second space 18 is arranged between the inner capillary 15 and the outer capillary 17. The double capillary 14 is generally considerably longer than schematically shown in Fig. 1. In particular, the double capillary 14 can be bent or coiled in loops. A detailed view of the double capillary 14 is shown in Fig. 4.The double capillary 14 is connected at a first end region 14a to the process adapter 8 and at a second end region 14b to the sensor unit 3, such that the pressure chamber 13 is fluidically connected to the interior 16 and to the first surface 6, and also such that the first space 12 is fluidically connected to the second space 18 and to a third space 19 of the sensor unit 3. In this way, the first pressure p1 can be transmitted to the first surface 6 via the pressure chamber 13 and the interior 16. Furthermore, the first space 12, the second space 18, and the third space 19 are fluidically connected.

[0041] A monitoring unit 20 arranged in the sensor unit 3 is configured to monitor the state of the third intermediate space 19. Since the third intermediate space 19 is fluidically connected to the first intermediate space 12, the monitoring unit 20 can also monitor the state of the first intermediate space 12. Preferably, the first intermediate space 12, the second intermediate space 18, and the third intermediate space 19 are evacuated. The monitoring unit 20 can be configured as a second pressure sensor, which is particularly configured to monitor a third pressure in the third intermediate space 19. In particular, the monitoring unit 20 is arranged in the third intermediate space 19. The monitoring unit 20 can also be electrically connected to the evaluation unit 35 and / or the display unit 36.The monitoring unit 20 can thus be configured to determine a measurement signal that corresponds to the state, in particular the third pressure, of the second intermediate space 18, and to transmit the measurement signal to the evaluation unit 35 and / or the display unit 36. The evaluation unit 35 can be configured to detect a leak based on the transmitted measurement signal and to send a warning to the display unit 36. The display unit 36 ​​can be configured to display the warning that a leak is present.

[0042] The double capillary 14 can be connected to the process adapter 8 or the sensor unit 3 by means of a first adapter 22 and / or a second adapter 26. The first adapter 22 and the second adapter 26 serve to transmit the first pressure p1 of the medium from the process adapter 9 to the interior 16 and from the interior 16 to the first surface 6, respectively. The first adapter 22 has a first through-bore 23 and is arranged and configured such that the first through-bore 23 is fluidically connected to the pressure chamber 13. In the example of Fig. 3, the first adapter 22 is further arranged and configured such that a fourth space 24 is formed between the process adapter 8 and the first adapter 22, which is fluidically connected to the first space 12 and the second space 18, in particular by means of the channel 30. The first adapter 22 can be arranged in a first recess 21 of the process adapter 8.The fourth space 24 can be arranged in a section of the first adapter 22 facing the double capillary 14. As shown by way of example in Fig. 1, the first adapter 22 can be inserted into the first recess 21 with a section facing away from the double capillary 14.

[0043] The second adapter 26 has a second through-hole 27 and is arranged and configured such that the second through-hole 27 is fluidically connected to the interior 16 and the first surface 6. The second adapter 26 can be arranged in the third space 19. In particular, the inner capillary 15 can be partially arranged in the third space 19, as shown by way of example in Fig. 1. Optionally, a fifth space (not shown) can be formed between the sensor unit 3 and the second adapter 26, which is fluidically connected to the second space 18 and the third space 19. Optionally, the sensor unit can have a second pressure transmission line 32, which is configured to transmit the first pressure 1 of the medium 2 from the second through-hole 27 to the first surface 6.

[0044] An embodiment of the double capillary 14 is also shown in Fig. 4. Among other things, it can be seen how the fourth space 24 is fluidically connected to the second space 18. A clearance fit can exist between the adapter 22 and the process adapter 8, so that the fourth space 24 is partially configured as a gap 37.

[0045] Figure 4 shows the pressure transmitter system 1 after connecting the double capillary 14 to the process adapter 8 and the sensor unit 3. Optionally, the double capillary 14 is connected to the first adapter 22 and the second adapter 26. In the example shown, the inner capillary 15 is connected at its first end 15a to the first adapter 22 and at its second end 15b to the second adapter 26. The outer capillary 17 has three pipe sections 29a-c, of which the first pipe section 29a is connected to the process adapter 8 and the third pipe section 29c to the sensor unit 3. The round, filled dots in Figures 5-8 represent welds by way of example. The second pipe section 29b is designed by way of example as a sleeve or coupling. In particular, the second pipe section 29b has an inner diameter that is larger than the outer diameters of the first and third pipe sections 29a and 29c.

[0046] Figures 5-8 show how the double capillary 14 can be connected to the process adapter 8 and the sensor unit 3. First, the double capillary 14 is connected to the process adapter 8 and then to the sensor unit 3; however, it is also possible to connect the double capillary 14 first to the sensor unit 3 and then to the process adapter 8. Figure 5 shows a first possible process step for connecting the process adapter 8 and the double capillary 14. In this step, at least one pipe section, here the first pipe section 29a, is moved such that the first end region 15a of the inner capillary 15 is exposed. In particular, the outer capillary 17 is moved back from the first end region 15a of the inner capillary 15. For this purpose, the first pipe section 29a can be partially moved into the second pipe section 29b. Subsequently, the first end section 15a of the inner capillary 15 can be connected to the process adapter 8 orto be connected to the first adapter 22.

[0047] In a further step, at least one pipe section, here pipe section 29a, can be moved such that the first end region 17a of the outer capillary 17 surrounds the inner capillary 15. Alternatively, the at least one pipe section can be moved such that it rests on a surface provided for connection with the process adapter or contacts the process adapter, and then the first end region 17a of the outer capillary 17 can be connected to the process adapter 8. This is shown in Fig. 6.

[0048] After connecting the double capillary 14 to the process adapter 8, the connection between the double capillary 14 and the sensor unit 3 can then be made. For this purpose, at least one pipe section, in this case the third pipe section 29c, can be moved such that the second end section 15b of the inner capillary 15 is exposed. The third pipe section 29c can then be partially moved into the second pipe section 29b. Subsequently, the second end section 15b of the inner capillary 15 can be connected to the sensor unit 3 or the second adapter 26.

[0049] In a further step, at least one pipe section, here pipe section 29c, can be moved such that the second end region 17b of the outer capillary 17 contacts the sensor unit 3. Subsequently, the second end region 17b of the outer capillary 17 can be connected to the sensor unit 3. Finally, the pipe sections 29 of the outer capillary 17 can be fixed relative to each other, in particular in such a way that further movement of pipe sections 29 is prevented. Reference numeral list

[0050] 1 Pressure transmitter system

[0051] 2 Medium

[0052] 3 Sensor unit

[0053] 4 Measuring instrument

[0054] 5 first pressure sensor

[0055] 6 first area

[0056] 7 second area

[0057] 8 process adapters

[0058] 9 Membrane system

[0059] 10 first separation membrane

[0060] 10a circumferential edge of the first T separating membrane

[0061] 11 second separating membrane

[0062] 11a circumferential edge of the second separating membrane

[0063] 12 first space

[0064] 13 Pressure chamber

[0065] 14 double capillaries

[0066] 14a first end area

[0067] 14b second end area

[0068] 15 inner capillaries

[0069] 15a first end area

[0070] 15b second end area

[0071] 16 Interior

[0072] 17 outer capillaries

[0073] 17a first end region of the outer capillary

[0074] 18 second space

[0075] 19 third space

[0076] 20 monitoring units

[0077] 21 first exception

[0078] 22 first adapter

[0079] 23 first through hole

[0080] 24 fourth space

[0081] 25 second exception

[0082] 26 second adapter

[0083] 27 second through hole

[0084] 29a first pipe section

[0085] 29b second pipe section

[0086] 29c third pipe section

[0087] 30-channel

[0088] 31 first pressure transmission line second pressure transmission line evaluation unit display unit gap

Claims

Patent claims 1. Pressure transmitter system (1) for determining and / or monitoring a first pressure (p1) of a medium (2), comprising a sensor unit (3) with a first pressure sensor (5) which can be subjected to the first pressure (p1) of the medium (2) on a first surface (6), a process adapter (8) with a membrane system (9) comprising a first separating membrane (10) and a second separating membrane (11) which are arranged relative to each other such that the first separating membrane (10) faces the medium (2) and the second separating membrane (11) faces away from the medium (2) and a first space (12) is enclosed between the first separating membrane (10) and the second separating membrane (11), wherein the first separating membrane (10) and the second separating membrane (11) are pressure-tightly attached to the process adapter (8) forming a pressure chamber (13) between the second separating membrane (11) and the process adapter (8), wherein the membrane system (9) is designed toto transmit the first pressure (p1) to the pressure chamber (13), a double capillary (14) with an inner capillary (15) having an interior space (16) and an outer capillary (17) which surrounds the inner capillary (15) such that a second space (18) is formed between the inner capillary (15) and the outer capillary (17), wherein the double capillary (14) is connected in a first end region (14a) to the process adapter (8) such that the pressure chamber (13) is fluidically connected to the interior space (16) and that the first space (12) is fluidly connected to the second space (18), wherein the double capillary (14) is connected in a second end region (14b) to the sensor unit (3) such that the interior space (16) is fluidically connected to the first surface (6) and that the second space (18) is fluidically connected to a third space (19) of the sensor unit (3). is a monitoring unit (20) arranged in the sensor unit (3), which is designed toto monitor a state of the third interspace (19).

2. Pressure transmitter system (1) according to claim 1, wherein the monitoring unit (20) is a second pressure sensor.

3. Pressure transmitter system (1) according to one of claims 1-2, wherein the monitoring unit (20) is arranged in the third space (19).

4. Pressure transmitter system (1) according to one of claims 1-3, wherein the process adapter (8) has a first adapter (22) with a first through-bore (23), wherein the first adapter (22) is arranged and designed such that the first through-bore (23) is fluidically connected to the pressure chamber (13).

5. Pressure transmitter system (1) according to claim 4, wherein the first adapter (22) is arranged and designed such that a fourth space (24) is formed between the process adapter (8) and the first adapter (22), which is fluidically connected to the first space (12) and the second space (18).

6. Pressure transmitter system (1) according to one of claims 1-5, wherein the sensor unit (3) has a second adapter (26) with a second through-hole (27), wherein the second adapter (26) is arranged and designed such that the second through-hole (27) is fluidically connected to the interior (16) and the first surface (6).

7. Method for manufacturing a pressure transmitter system (1) according to any one of the preceding claims, wherein the method comprises at least the following steps: Provision of process adapter (8), sensor unit (3) and double capillary (14), Connecting the process adapter (8) and the first end section (14a) of the double capillary (14), Connecting the sensor unit (3) and the second end area (14b) of the double capillary (14).

8. Method according to claim 7, wherein connecting the process adapter (8) to a first end region (14a) of the double capillary (14) comprises the following steps: Connecting a first end region (15a) of the inner capillary (15) to the process adapter (8), wherein at least one pipe section (29) of the outer capillary (17) is moved such that the first end region (15a) of the inner capillary (15) is exposed, Connecting the outer capillary (17) to the process adapter (8).

9. Method according to one of claims 7-8, wherein connecting the sensor unit (3) and the second end region (14b) of the double capillary (14) comprises the following steps: Connecting a second end region (15b) of the inner capillary (15) to the sensor unit (3), wherein at least one tube section (29) of the outer capillary (17) is moved such that the second end region (15b) of the inner capillary (15) is exposed, - Connecting the outer capillary (17) to the sensor unit (3).

10. Method according to one of claims 8-9, wherein the at least one pipe section (29a, b,c) is designed as a union or a sleeve.

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