EP4070059A1 - Pressure measuring sensor - Google Patents
Pressure measuring sensorInfo
- Publication number
- EP4070059A1 EP4070059A1 EP20811284.7A EP20811284A EP4070059A1 EP 4070059 A1 EP4070059 A1 EP 4070059A1 EP 20811284 A EP20811284 A EP 20811284A EP 4070059 A1 EP4070059 A1 EP 4070059A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- pressure
- transducer
- pressure sensor
- temperature
- measuring
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
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- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 claims description 17
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-UHFFFAOYSA-N 0.000 claims description 17
- 238000009530 blood pressure measurement Methods 0.000 claims description 12
- HBVFXTAPOLSOPB-UHFFFAOYSA-N nickel vanadium Chemical compound [V].[Ni] HBVFXTAPOLSOPB-UHFFFAOYSA-N 0.000 claims description 12
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 claims description 10
- 229910052751 metal Inorganic materials 0.000 claims description 6
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- 229910001092 metal group alloy Inorganic materials 0.000 claims description 6
- 229910044991 metal oxide Inorganic materials 0.000 claims description 6
- 150000004706 metal oxides Chemical class 0.000 claims description 6
- 239000010931 gold Substances 0.000 claims description 5
- 229910052697 platinum Inorganic materials 0.000 claims description 5
- 238000001514 detection method Methods 0.000 claims description 4
- 229910003336 CuNi Inorganic materials 0.000 claims description 3
- 229910000570 Cupronickel Inorganic materials 0.000 claims description 3
- YOCUPQPZWBBYIX-UHFFFAOYSA-N copper nickel Chemical compound [Ni].[Cu] YOCUPQPZWBBYIX-UHFFFAOYSA-N 0.000 claims description 3
- 238000000151 deposition Methods 0.000 claims description 3
- 230000008021 deposition Effects 0.000 claims description 3
- WNGVEMKUAGHAGP-UHFFFAOYSA-N oxotungsten;titanium Chemical compound [Ti].[W]=O WNGVEMKUAGHAGP-UHFFFAOYSA-N 0.000 claims description 3
- 238000004544 sputter deposition Methods 0.000 claims description 3
- 150000001875 compounds Chemical class 0.000 claims description 2
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 claims description 2
- 229910052737 gold Inorganic materials 0.000 claims description 2
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- 238000009529 body temperature measurement Methods 0.000 description 3
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Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L19/00—Details of, or accessories for, apparatus for measuring steady or quasi-steady pressure of a fluent medium insofar as such details or accessories are not special to particular types of pressure gauges
- G01L19/0092—Pressure sensor associated with other sensors, e.g. for measuring acceleration or temperature
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L9/00—Measuring steady of quasi-steady pressure of fluid or fluent solid material by electric or magnetic pressure-sensitive elements; Transmitting or indicating the displacement of mechanical pressure-sensitive elements, used to measure the steady or quasi-steady pressure of a fluid or fluent solid material, by electric or magnetic means
- G01L9/12—Measuring steady of quasi-steady pressure of fluid or fluent solid material by electric or magnetic pressure-sensitive elements; Transmitting or indicating the displacement of mechanical pressure-sensitive elements, used to measure the steady or quasi-steady pressure of a fluid or fluent solid material, by electric or magnetic means by making use of variations in capacitance, i.e. electric circuits therefor
- G01L9/125—Measuring steady of quasi-steady pressure of fluid or fluent solid material by electric or magnetic pressure-sensitive elements; Transmitting or indicating the displacement of mechanical pressure-sensitive elements, used to measure the steady or quasi-steady pressure of a fluid or fluent solid material, by electric or magnetic means by making use of variations in capacitance, i.e. electric circuits therefor with temperature compensating means
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
- G01K7/00—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements
- G01K7/02—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements using thermoelectric elements, e.g. thermocouples
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
- G01K7/00—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements
- G01K7/02—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements using thermoelectric elements, e.g. thermocouples
- G01K7/04—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements using thermoelectric elements, e.g. thermocouples the object to be measured not forming one of the thermoelectric materials
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L9/00—Measuring steady of quasi-steady pressure of fluid or fluent solid material by electric or magnetic pressure-sensitive elements; Transmitting or indicating the displacement of mechanical pressure-sensitive elements, used to measure the steady or quasi-steady pressure of a fluid or fluent solid material, by electric or magnetic means
- G01L9/0041—Transmitting or indicating the displacement of flexible diaphragms
- G01L9/0072—Transmitting or indicating the displacement of flexible diaphragms using variations in capacitance
- G01L9/0075—Transmitting or indicating the displacement of flexible diaphragms using variations in capacitance using a ceramic diaphragm, e.g. alumina, fused quartz, glass
Definitions
- the present invention relates to a pressure measuring transducer with a ceramic pressure sensor arranged in a housing, the pressure sensor comprising a measuring membrane that can be pressurized through an opening in the housing and an electromechanical transducer for the metrological detection of a deflection of the measuring membrane dependent on the pressure acting on the measuring membrane , a support ring arranged on an outer edge of a rear side of the pressure sensor facing away from the membrane, and a clamping device by means of which an outer edge region of the pressure sensor is clamped in the housing together with the support ring arranged thereon.
- the pressure measuring transducers mentioned at the beginning are, for example, in the
- ceramic pressure sensors can be acted upon directly by a medium which is under a pressure that is to be detected by measurement.
- this inevitably means that both the ambient temperature in the vicinity of the pressure transducer and the medium temperature of the medium under the pressure to be measured have an effect on the measuring properties of the pressure sensor and thus also on the measurement accuracy that can be achieved with the pressure transducer.
- the pressure sensor of the pressure measuring transducer described in DE 10 2015 122 220 A mentioned at the beginning comprises a temperature measuring transducer for providing an electrical variable that is dependent on the temperature of the pressure sensor or on a temperature gradient along the pressure sensor.
- This temperature transducer comprises at least one thermocouple that has a galvanic contact between a first conductor and having a second conductor.
- a thermocouple arranged in the pressure sensor near the measuring membrane can be used to quickly register temperature jumps occurring on the membrane side.
- thermocouples with two series-connected thermocouples, each of which includes a galvanic contact between a conductor of the respective thermocouple and a connecting conductor connecting the contacts of both thermocouples, a direct measurement of a temperature gradient present in the pressure sensor or along the pressure sensor can be carried out .
- a temperature gradient compensation of the pressure measured by means of the pressure sensor can be carried out by means of an operating circuit connected to the electromechanical transducer of the pressure sensor and the temperature measuring transducer.
- thermocouples in the pressure sensor and to connect the temperature measuring transducer of the pressure sensor and the electromechanical transducer of the pressure sensor to the operating circuit. Both lead to restrictions with regard to the sensor structure and, if necessary, also with regard to the materials used in the pressure sensor, which restrict the freedom of design in this regard.
- the invention comprises a pressure measuring transducer with a ceramic pressure sensor arranged in a housing, the pressure sensor comprising a measuring membrane that can be pressurized through an opening in the housing and an electromechanical transducer for the metrological detection of a deflection of the measuring membrane dependent on the pressure acting on the measuring membrane , a support ring arranged on an outer edge of a rear side of the pressure sensor facing away from the membrane, a clamping device by means of which an outer edge area of the pressure sensor is clamped in the housing together with the support ring arranged thereon, and a temperature transducer for providing a thermal voltage dependent on a temperature gradient along the pressure sensor, which comprises two series-connected thermocouples, each of which has a galvanic contact between an electrical conductor of the respective thermocouple and one of the galvanic contacts of the comprise electrical connecting conductors connecting both thermocouples, which is characterized in that an electrically conductive layer extending parallel to the surface normal to the measuring membrane is arranged on a jacket surface of the support ring
- the temperature transducer is designed in such a way that the thermal voltage that can be tapped between the conductors and, accordingly, also the temperature gradient that can be measured by means of the temperature transducer, occur within the pressure transducer along the temperature transducer or at least along a section of the temperature transducer in a direction running parallel to the surface normal to the measuring membrane Corresponds to temperature gradients.
- This temperature gradient is dependent on a temperature profile that, when there is a temperature difference between the medium temperature and the ambient temperature, is formed due to the conditions inside the pressure measuring transducer along the pressure measuring transducer.
- the temperature gradient can be used to compensate for a measurement error caused by the temperature profile in the pressure measurement that can be carried out by means of the pressure sensor.
- the arrangement of the temperature transducer outside the pressure sensor offers the advantage that the temperature transducer and its contacting do not result in any restrictions with regard to the sensor structure and / or the materials used in the pressure sensor.
- the extension of the temperature transducer which is predetermined by the positioning of the two contacts, in a direction running parallel to the surface normal to the measuring membrane offers the advantage that this temperature gradient is recorded in the spatial direction in which the greatest temperature gradient is present when there is a temperature difference between the medium temperature and the ambient temperature occurs.
- the temperature gradient detectable by means of the temperature transducer correlates with the temperature gradient present along the pressure sensor due to the spatial proximity between the pressure sensor and the connecting conductor extending over the support body arranged on the pressure sensor.
- the temperature gradient that can be detected by means of the temperature measuring transducer forms a direct measure of the temperature along the pressure sensor in applications in which the temperature profile formed along the pressure measuring transducer does not change at all or only comparatively slowly over time occurring temperature gradients that have a decisive influence on the measurement error caused by the temperature profile.
- a temperature profile that does not change at all or only slowly over time is present, for example, in applications in which the medium temperature and the ambient temperature change in terms of amount by less than one degree Celsius per minute or a few degrees Celsius per minute.
- a compensation of the pressure measurement error caused by the temperature profile based on the temperature gradient measured according to the invention outside the pressure sensor leads to an improvement in the measurement accuracy that is comparable to the improvement that can be achieved with the temperature transducer integrated in the pressure sensor described in DE 102015 122 220 A .
- pressure measuring transducers according to the invention can of course also be used in applications in which the medium temperature and / or the ambient temperature and thus also the temperature profile along the pressure measuring transducer change more rapidly over time.
- a measurement error caused by the temperature profile can be compensated for using the temperature gradient detected by means of the temperature measuring transducer.
- a first development is characterized in that at least one of the two galvanic contacts is arranged on the conductive layer of the support ring, and / or the galvanic contact facing away from the process is on an area of the conductive layer facing away from the pressure sensor and the galvanic contact facing the process is on one facing the pressure sensor Area of the conductive layer is arranged.
- a second development is characterized in that the connecting conductor comprises at least one further line section in addition to the line section formed by the layer or encompassed by the layer, and at least one of the two contacts is arranged on the further line section or on one of the further line sections.
- connection ring is arranged on an end face of the support ring facing away from the pressure sensor, On the connection ring a further line section of the connection line forming or comprehensive conductive coating is arranged, which is in electrically conductive connection to the layer arranged on the support ring, and the process-remote galvanic contact is arranged on the coating of the connection ring.
- the layer arranged on the support ring comprises a layer region extending over an end face of the support ring facing the connection ring, on which a coating region of the coating of the connection ring rests over an end face of the connection ring facing the support ring, the galvanic contact facing away from the process is arranged on a layer region of the coating of the connection ring that extends over an inner jacket surface of the connection ring, and / or the connection ring is clamped in the housing by means of the clamping device.
- a fourth further development is characterized in that an electrically conductive sensor coating, which forms or encompasses a further line section of the connecting conductor, is arranged on a rear side of the pressure sensor facing away from the membrane, the sensor coating is in electrically conductive connection to the layer arranged on the support ring, and the galvanic layer facing the process Contact is arranged on the sensor coating.
- the layer comprises a layer area extending over an end face of the support body facing the pressure sensor, which lies on a coating area of the sensor coating, the galvanic contact facing the process is arranged on a layer area of the sensor coating that is spaced from the support body, and / or the sensor coating is designed as an electromagnetic shielding of the electromechanical transducer of the pressure sensor, which comprises a coating area which surrounds an outside lateral surface of the pressure sensor on the outside on all sides.
- a fifth development is characterized in that at least one of the two conductors is a) designed as a contact pad, b) comprises an electrically conductive metal, a metallic alloy and / or a metal oxide, c) a titanium oxide (TiOx) or a Titanium-Tungsten Oxide (TiWOx) includes, and / or d) an electrically conductive conductor material comprises the Seebeck coefficient of which is different from the Seebeck coefficient of the material of the line section in direct contact with the respective conductor.
- a sixth further development is characterized in that at least one line section of the connecting conductor, the layer, the coating of the connection ring and / or the sensor coating each a1) comprises an electrically conductive material which, compared to platinum, has a Seebeck coefficient with a value greater than or equal to 6 pV / K or greater than or equal to 10 pV / K, a2) comprises an electrically conductive metal, a metallic alloy and / or a metal oxide, a3) a titanium oxide (TiOx), a copper-nickel compound (CuNi), a nickel Vanadium compound (NiV) or a compound (NiV / Au) comprising nickel-vanadium and gold, and / or a4) as applied by sputtering or by deposition from the gas phase and / or as a layer thickness of greater than or equal to 100 nm or of 1 pm to 2 pm having layer is formed.
- connection conductor comprises the line section formed by the layer or encompassed by the layer and at least one further line section, these line sections of the connection conductor either all consist of the same material or comprise two or more line sections made of different materials, and a combination of the same or different Seebeck coefficients of the materials of the line sections of the connecting conductor and / or a spatial extension of the further line section or at least one of the further line sections in a direction running parallel and / or perpendicular to the surface normal to the measuring membrane is designed such that a Sum of all partial thermal voltages formed along the temperature transducer, the direction in the pressure transducer running parallel to the surface normal to the measuring membrane of the pressure sensor along the Temperature measuring transducer or at least along a section of the temperature measuring transducer corresponds to the temperature gradient present.
- An eighth development is characterized in that the support body and / or the connection ring are made of ceramic, and / or a distance between the galvanic contact facing the process and the galvanic contact facing away from the process in the direction parallel to the surface normal to the measuring membrane is greater than or equal to a minimum distance of a simple one
- a ninth further training is characterized by the fact that The temperature transducer is designed in such a way that the thermal voltage that can be tapped between the conductors corresponds to the temperature gradient that can be measured by means of the temperature transducer, the temperature gradient corresponding to a temperature gradient occurring within the pressure transducer along the temperature transducer or at least along a section of the temperature transducer in the direction parallel to the surface normal to the measuring membrane .
- the pressure measuring transducer comprises a compensation device which is designed in such a way that it uses the pressure detected by means of the pressure sensor and the temperature gradient detected by means of the temperature transducer on the basis of calibration data and / or characteristics stored in a memory determines and provides the compensated pressure measurement result with respect to a measurement error dependent on the temperature gradient
- the compensation device either directly or via a pressure measurement circuit connected to the transducer of the pressure sensor, which is designed to generate a pressure measurement signal corresponding to the pressure detected by means of the transducer of the pressure sensor and to make available, is connected to the transducer of the pressure sensor, and wherein the compensation device is either directly or via a connected to the temperature transducer Closed temperature measuring circuit, which is designed to generate and make available a temperature measuring signal corresponding to the temperature gradient detected by means of the temperature measuring transducer, to which the temperature measuring transducer is connected.
- a development of the pressure measuring transducer according to the third development and the fourth development is characterized in that the coating of the connecting ring consists of a material comprising a nickel-vanadium compound, the layer of the support body consists of a material comprising at least one titanium oxide and the sensor coating consists of a material a material comprising a nickel-vanadium compound.
- FIG. 1 shows: a pressure measuring transducer
- FIG. 2 shows an equivalent circuit diagram of the temperature measuring transducer from FIG. 1;
- Fig. 3 shows. a pressure measuring transducer in which the contact facing away from the process is arranged on a connecting ring and the contact facing the process is arranged on a rear side of the pressure sensor facing away from the diaphragm, and
- FIG. 4 shows an equivalent circuit diagram of the temperature measuring transducer from FIG. 3.
- Fig. 1 shows an embodiment of a pressure transducer according to the invention with a ceramic pressure sensor 3 arranged in a housing 1.
- the pressure sensor 3 comprises a measuring membrane 7 that can be acted upon by a pressure p through an opening 5 of the housing 1 and an electromechanical transducer for the metrological detection of a the pressure p acting on the measuring membrane 7 depends on the deflection of the measuring membrane 7.
- FIG. 1 shows a pressure sensor 3, the measuring membrane 7 of which is connected to a base body 13 by means of a joint 9, such as active brazing, including a pressure chamber 11.
- Converters known from the prior art can be used as electromechanical converters.
- 1 shows, as an example, a capacitive transducer which comprises a measuring electrode 15 arranged on a surface of the base body 13 facing the measuring membrane 7, which together with a counter electrode 17 arranged on an inside of the measuring membrane 7 facing the base body 13 has a capacitor with one of the Pressure-dependent deflection of the measuring membrane 7 forms dependent measuring capacity.
- the converter can additionally include a reference capacitor with an essentially pressure-independent reference capacitance.
- FIG. 1 shows a reference electrode 19 and the counter electrode 17 formed by a reference electrode 19 that surrounds the measuring electrode 15 on the outside and is spaced apart from the measuring electrode 15.
- a differently designed capacitive transducer a transducer based on a different transducer principle, e.g. a resistive or an optical transducer, and / or ceramic pressure sensors having a different sensor structure can also be used in pressure measuring transducers according to the invention.
- the pressure measuring transducer comprises a support ring 21 arranged on an outer edge of a rear side of the pressure sensor 3 facing away from the membrane and a clamping device by means of which an outer edge region of the pressure sensor 3 is clamped in the housing 1 together with the support ring 21 arranged thereon.
- a suitable clamping device is, for example, a device in which the pressure sensor 3 and the support body 21 are positioned between a bearing 23, such as the one shown in FIG on the side of the pressure sensor 3 facing away from the diaphragm, the counter bearing 25 inserted into the housing 1, such as a pressure ring shown in FIG. 1, is clamped in a direction running parallel to the surface normal to the measuring diaphragm 7.
- a seal 29 such as a flat seal, is optionally also arranged between the end face of the support ring 21 facing away from the pressure sensor 3 and the counter bearing 25.
- the pressure measuring transducer comprises a temperature measuring transducer for providing a thermal voltage U th which is dependent on a temperature gradient along the pressure measuring transducer and which comprises two thermocouples connected in series.
- thermocouples each include a galvanic contact K1, K2 between an electrical conductor 31, 33 of the respective thermocouple and a connecting conductor 35 which connects the galvanic contacts K1, K2 of the two thermocouples to one another in an electrically conductive manner.
- an electrically conductive layer 37 extending parallel to the surface normal to the measuring membrane 7 is arranged on a jacket surface of the support ring 21.
- This layer 37 is designed in such a way that it forms or includes the connecting conductor 35 or a line section 39 of the connecting conductor 35.
- the two galvanic contacts K1, K2 connected to one another via the layer 37 include a contact K1 facing the process and a contact K2 facing away from the process. These two contacts K1, K2 are both arranged in the housing 1 outside the pressure sensor 3 and are spaced apart from one another in a direction running parallel to the surface normal to the measuring membrane 7.
- a thermal voltage U th that can be tapped off between the two conductors 31, 33 is available, which corresponds to a temperature gradient DT present in the pressure measuring transducer along the area of the pressure measuring transducer that is covered by the temperature transducer in the direction parallel to the surface normal to the measuring membrane 7 .
- connection lines L1, L2 can be tapped thermal voltage U th and / or th reference to the thermal voltage U, measurable or detected temperature gradient DT to compensate for by the temperature profile T (z) measurement error caused by means of the Pressure sensor 3 executable or executed pressure measurement are used.
- Pressure measuring transducers according to the invention have the advantages mentioned at the beginning. Individual components can each have different configurations that can be used individually and / or in combination with one another. Some currently preferred optional configurations are described below with reference to the pressure measuring transducers shown in FIGS. 1 and 3, designed in the manner described above.
- One embodiment variant provides that at least one of the two contacts K1, K2 is arranged on the conductive layer 37 of the support ring 21.
- the conductive layer 37 forms or comprises the connecting conductor 35 to which the conductors 31, 33 of the two thermocouples are connected.
- the connecting conductor 35 here comprises only a single line section 39 formed by the layer 37 or encompassed by the layer 37.
- FIG. 2 shows an equivalent circuit diagram of the temperature measuring transducer shown in FIG. 1.
- the thermal voltage U th that can be tapped off between the two conductors 31, 33 via the connecting lines L1, L2 connected to them is equal to the sum of the temperature-dependent partial thermal voltages formed via the contacts K1, K2. Consequently, the temperature gradient DT that can be measured or detected by means of the thermal voltage U th corresponds here to the temperature difference between the temperature T1 at the position of the contact K1 facing the process and the temperature T2 at the position of the contact K2 remote from the process.
- the conductors 31, 33 each comprise a conductor material whose Seebeck coefficient is different from a Seebeck coefficient of the material of the line section 39 of the connecting conductor 35 directly adjoining it.
- the conductive layer 37 preferably comprises a material which, compared to platinum, has a Seebeck coefficient, the magnitude of which is as large as possible.
- particularly suitable materials are at least one titanium oxide TiOx comprising materials, a copper-nickel compound comprising CuNi, materials comprising a nickel-vanadium compound NiV, and materials comprising a nickel-vanadium and gold compound NiV / Au.
- a material combination is preferably used in the pressure measuring transducers according to the invention in which the magnitude of the difference between the Seebeck coefficients of the respective conductor material and the material of the line section 39 of the connecting conductor 35 in direct contact with the respective conductor 31, 33 is as large as possible is.
- a titanium oxide TiOx or a titanium-tungsten oxide TiWOx comprising conductor materials are suitable.
- conductor materials with a corresponding Seebeck coefficient such as, for example, electrically conductive metals, metallic alloys and / or materials comprising metal oxides with a corresponding Seebeck coefficient, can also be used.
- the two conductors 31, 33 can consist of different conductor materials. However, they are preferably made of the same conductor material.
- Both the Seebeck coefficient of the material of the conductive layer 37 which is large in magnitude compared to platinum, as well as the alternatively or additionally provided, large differences in magnitude between the Seebeck coefficient of the material of the layer 37 and the Seebeck coefficient of the conductor materials of the layer 37
- Adjacent conductors 31, 33 each cause an increase in the thermal voltage U t h that can be tapped off via the two conductors 31, 33 and thus improve the measurement sensitivity and the measurement accuracy of the temperature transducer.
- the contact K1, K2 facing away from the process and / or the contact K1, K2 facing the process according to the invention can also be arranged at another location within the housing 1.
- the connecting conductor 35 connecting the two contacts K1, K2 comprises, in addition to the line section 39 formed by the layer 37 or encompassed by the layer 37, at least one further line section 41, 43 and at least one of the two contacts K1, K2 is on one of the further line sections 41, 43 are arranged.
- 3 shows an example of a pressure measuring transducer, the connecting conductor 35 of which comprises three line sections 39, 41, 43.
- the further line sections 41, 43 each preferably consist of the same material as the line section 39 formed by the layer 37 or encompassed by the layer 37.
- the connecting conductor 35 behaves at least approximately as the connecting conductor 35 described above with reference to FIGS. 1 and 2, comprising only a single line section 39.
- the line sections 39, 41, 43 of the connecting conductor 35 can also comprise two or more line sections 39, 41, 43 made of different materials.
- Suitable materials for the individual further line sections 41, 43 are, for example, those previously given as examples for the Material of the layer 37 named materials.
- each area of the connecting conductor 35 in which two line sections 39, 41, 43 made of materials with different Seebeck coefficients adjoin each other acts like an additional thermocouple connected in series to the two thermocouples comprising the galvanic contacts K1, K2 that a partial thermal voltage develops.
- the size and polarity of these partial thermal voltages are dependent on the temperature profile T (z) present in the area of the respective additional thermocouple and the difference in the Seebeck coefficients of the materials of the respective adjoining line sections 39, 41,
- the temperature transducer is to be designed in such a way that the sum of all the partial thermal voltages formed along the temperature transducer is in the direction parallel to the surface normal to the measuring membrane 7 of the pressure sensor 3 in the pressure transducer along the temperature transducer or at least along a section of the temperature transducer corresponds to the present temperature gradient DT.
- This can be done, for example, by a corresponding combination of the Seebeck coefficients of the materials of the line sections 39, 41, 43 of the connecting conductor 35 and / or a corresponding spatial extension of at least one of the further line sections 41, 43 parallel and / or perpendicular to the surface normal to the measuring membrane 7 running direction are effected.
- material combinations are used in which the conductors 31, 33 each comprise a conductor material whose Seebeck coefficient is different from a Seebeck coefficient of the material of the directly adjoining line section 41, 43 of the connecting conductor 35 is different.
- material combinations are preferably used in which the magnitude of the difference between the Seebeck coefficients of the respective conductor material and the material of the line section 41, 43 of the connecting conductor 35 in direct contact with the respective conductor 31, 33 is as large as possible.
- the conductor materials mentioned above in connection with the pressure measuring transducer shown in FIG. 1 are also suitable here.
- the pressure measuring transducer shown in FIG. 3 comprises a connection ring 45 arranged on an end face of the support ring 21 facing away from the pressure sensor 3.
- a conductive coating 47 is arranged on the connection ring 45 and is in electrically conductive connection with the layer 37 arranged on the first support ring 21 .
- This connection is achieved in the example shown in FIG. 3 in that the layer 37 arranged on the support ring 21 comprises a layer region extending over an end face of the support ring 21 facing the connecting ring 45, on which a layer region extends over an end face facing the support ring 21 of the connecting ring 45 extending coating area of the coating 47 of the connecting ring 45 rests.
- the electrically conductive connection brought about by resting is also here reinforced by the fact that the layer area and the coating area resting on it are pressed against one another by the clamping device which also causes the connection ring 45 to be clamped in here.
- the coating 47 of the connection ring 45 forms or comprises the further line section 41 of the connecting conductor 35, on which the galvanic contact K2 of the temperature transducer remote from the process is arranged.
- 3 shows an example of this, in which the galvanic contact K2 remote from the process is arranged on a layer region of the coating 47 of the connection ring 45 that extends over an inner circumferential surface of the connection ring 45.
- the associated conductor 33 is arranged on the coating area extending over the inner circumferential surface of the connection ring 45.
- the contact K1 facing the process can of course also be arranged on a further line section 43 of the connecting conductor 35.
- 3 shows an example of this, in which a conductive sensor coating 49 is arranged on a rear side of the pressure sensor 3 facing away from the membrane and is in electrically conductive connection with the layer 37 arranged on the support ring 21.
- the sensor coating 49 forms or comprises the further line section 43 of the connecting conductor 35, on which the process-facing galvanic contact K1 of the temperature transducer is arranged.
- the associated conductor 33 is arranged here on a layer region of the sensor coating 49 that is spaced apart from the support body 21.
- the electrically conductive connection between the sensor coating 49 and the layer 37 arranged on the support body 21 is preferably achieved in that the layer 37 comprises a layer area extending over an end face of the support body 21 facing the pressure sensor 3 and on a coating area of the sensor coating 49 rests.
- the coating area of the sensor coating 49 and the layer area of the layer 37 resting thereon are pressed against one another by the clamping device.
- the equivalent circuit diagram shown in FIG. 4 results.
- a material combination is suitable in which the coating 47 of the connecting ring 45 consists of a material comprising a nickel-vanadium compound NiV, the layer 37 of the support body 21 consists of a material comprising at least one titanium oxide TiOx and the sensor coating 49 consists of a material a material comprising nickel-vanadium compound NiV.
- the sensor coating 49 can at the same time also be designed as an electromagnetic shield for the electromechanical transducer of the pressure sensor 3.
- the sensor coating 49 preferably comprises a coating area 51, also shown as an option in FIG. 3, which surrounds an outside jacket surface of the pressure sensor 3 on all sides on the outside.
- the shape of the associated conductors 31, 33 can be freely selected within comparatively wide limits and can thus be flexibly adapted to the conditions in the housing 1.
- 1 and 3 show an example in which the conductors 31, 33 are each designed as contact pads. This offers the advantage that they take up very little space in the housing 1 and can be applied, eg soldered, to the connecting conductor 35, for example on the layer 37, on the coating 47 of the connecting ring 45, or on the sensor coating 49 without any problems .
- the distance between the contact K1, K2 facing away from the process and facing away from the process, in the direction running parallel to the surface normal to the measuring membrane 7, is preferably greater than or equal to a minimum distance of a simple height of the pressure sensor 3 running parallel to the surface normal to the measuring membrane 7 and / or less than or equal to a maximum distance of three times this height.
- the pressure sensor 3 can have an overall height that is quite common for ceramic pressure sensors 3, such as, for example, an overall height of the order of one or more centimeters.
- the minimum distance offers the advantage that it ensures that when a temperature profile T (z) is present along the temperature transducer that adversely affects the measuring accuracy of the pressure measurement, a sufficiently large one can be detected by means of the temperature transducer Temperature gradient DT occurs.
- the maximum distance offers the advantage that the expansion of the temperature transducer is limited to an area of the pressure transducer in which the temperature profile T (z) is closely related to the temperature gradient that forms across the pressure sensor 3.
- the support body 21 preferably consists of a material whose thermal properties are essentially the same as the thermal properties of the ceramic pressure sensor 3 or are at least as similar as possible.
- the support body 21 is preferably made of ceramic, whereby it is preferably made of the same ceramic as the pressure sensor 3, especially its measuring membrane 7 and its base body 13.
- the optionally provided connection ring 45 is also preferably made of this material.
- At least one line section 39, 41, 43 of the connecting conductor 35, the layer 37 of the support body 21, the coating 47 of the connecting ring 45 and / or the sensor coating 49 are each as applied by sputtering or by deposition from the gas phase and / or a layer thickness of greater than or equal to 100 nm, preferably from 1 pm to 2 pm, having a layer formed.
- the temperature gradient DT that can be determined or determined by means of the temperature measuring transducer is dependent on the temperature profile T (z) formed along the pressure measuring transducer and, due to the temporally unchangeable structural conditions within the pressure measuring transducer, correlates with the temperature gradient present along the pressure sensor 3.
- the thermal voltage U t h provided by the temperature transducer and / or the temperature gradient DT corresponding to the thermal voltage U t h can be used to compensate for the measurement error caused by the temperature profile T (z) in the pressure p which can be measured or recorded by the pressure sensor 3.
- This compensation can of course be carried out outside of the pressure measuring transducer. However, it is preferably carried out by means of a compensation device 53 integrated in the pressure measuring transducer.
- a compensation device 53 integrated in the pressure measuring transducer.
- 1 and 3 show an example in which the compensation device 53 is arranged in the housing 1 of the pressure measuring transducer.
- the compensation device 53 is connected to the temperature measuring transducer and to the electromechanical transducer.
- the compensation device 53 is designed such that it determines and provides a pressure measurement result compensated for a measurement error dependent on the temperature gradient DT based on the pressure p measured by means of the pressure sensor 3 and the temperature gradient DT measured by the temperature transducer.
- the compensation is preferably based on calibration data and / or characteristic curves stored in a memory 55 of the pressure measuring transducer which reproduce the dependence of the pressure p detected by means of the pressure sensor 3 on the temperature gradient DT detected by means of the temperature transducer.
- These calibration data and / or characteristic curves preferably include calibration data and / or characteristic curves determined in a calibration method, which were recorded along the pressure measuring transducer while different, respectively essentially stationary, temperature profiles T (z) were present.
- connection of the compensation device 53 to the transducer of the pressure sensor 3 can take place directly. However, this connection is preferably made via a pressure measuring circuit 57 connected to the transducer of the pressure sensor 3, which generates and makes available a pressure measurement signal S (P) corresponding to the pressure p detected by the transducer of the pressure sensor 3.
- connection of the compensation device 53 to the temperature transducer can also take place directly.
- this connection is preferably made via a temperature measuring circuit 59 connected to the conductors 31, 33 of the temperature transducer via the connecting lines L1, L2, which is designed such that it generates a temperature gradient DT based on the thermal voltage U th applied between the two conductors 31, 33 Temperature measurement signal S (AT) is generated and made available.
- the pressure measuring circuit 57 can be arranged a short distance from the pressure sensor 3 and / or the temperature measuring circuit 59 can be arranged a short distance from the temperature measuring transducer. In this way, impairments of the electrical variable (s) provided by the respective transducer are largely avoided, caused by long transmission paths or external interference.
Abstract
Description
Claims
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE102019133325.3A DE102019133325A1 (en) | 2019-12-06 | 2019-12-06 | Pressure transducer |
PCT/EP2020/082853 WO2021110433A1 (en) | 2019-12-06 | 2020-11-20 | Pressure measuring sensor |
Publications (1)
Publication Number | Publication Date |
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EP4070059A1 true EP4070059A1 (en) | 2022-10-12 |
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ID=73543256
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
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EP20811284.7A Withdrawn EP4070059A1 (en) | 2019-12-06 | 2020-11-20 | Pressure measuring sensor |
Country Status (5)
Country | Link |
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US (1) | US20220404223A1 (en) |
EP (1) | EP4070059A1 (en) |
CN (1) | CN114746733A (en) |
DE (1) | DE102019133325A1 (en) |
WO (1) | WO2021110433A1 (en) |
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US11692884B2 (en) * | 2020-08-17 | 2023-07-04 | Rosemount Inc. | Thermowell with pressure sensing capabilities |
Family Cites Families (27)
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SE9700612D0 (en) * | 1997-02-20 | 1997-02-20 | Cecap Ab | Sensor element with integrated reference pressure |
EP0995979B1 (en) | 1998-10-23 | 2003-07-23 | Endress + Hauser GmbH + Co. KG | Pressure sensor |
US6510740B1 (en) * | 1999-09-28 | 2003-01-28 | Rosemount Inc. | Thermal management in a pressure transmitter |
US6698294B2 (en) * | 2000-09-07 | 2004-03-02 | Vega Grieshaber Kg | Pressure cell with temperature sensors and pressure measuring method |
DE10044078A1 (en) * | 2000-09-07 | 2002-04-04 | Grieshaber Vega Kg | Pressure measuring cell with temperature sensors and pressure measuring method |
GB2383415B (en) * | 2000-09-08 | 2005-02-23 | Automotive Tech Int | Vehicle wireless sensing and communication system |
DE10334854A1 (en) | 2003-07-29 | 2005-03-10 | Endress & Hauser Gmbh & Co Kg | pressure sensor |
DE102004057967A1 (en) | 2004-11-30 | 2006-06-01 | Endress + Hauser Gmbh + Co. Kg | Pressure sensor comprises a pressure measuring cell and a counter-body provided with planar sealing surfaces and an interposed flat seal |
DE102004058504B4 (en) * | 2004-12-04 | 2009-06-04 | Meier, Vladislav, Dipl.-Ing. | Temperature sensor, its manufacturing processes and applications |
DE102009002662B4 (en) * | 2009-04-27 | 2022-11-24 | Ifm Electronic Gmbh | Capacitive pressure sensor as a combination sensor for recording other measured variables |
DE102009027899A1 (en) * | 2009-07-21 | 2011-01-27 | Endress + Hauser Gmbh + Co. Kg | Method for pressure measurement at variable temperatures and pressure transducer for pressure measurement at variable temperatures |
CH707387B1 (en) * | 2012-12-24 | 2017-01-13 | Inficon Gmbh | Measuring cell arrangement and method for vacuum pressure measurement. |
EP2967373A4 (en) * | 2013-03-12 | 2016-11-02 | Guided Interventions Inc | System including guidewire for detecting fluid pressure |
CH708708A1 (en) * | 2013-10-03 | 2015-04-15 | Kistler Holding Ag | Measuring element for measuring a pressure and pressure measuring sensor. |
DE102013114062A1 (en) * | 2013-12-16 | 2015-06-18 | Endress + Hauser Gmbh + Co. Kg | pressure sensor |
DE102013114407A1 (en) * | 2013-12-18 | 2015-06-18 | Endress + Hauser Gmbh + Co. Kg | pressure sensor |
DE102013114734A1 (en) * | 2013-12-20 | 2015-07-09 | Endress + Hauser Gmbh + Co. Kg | Capacitive pressure cell with at least one temperature sensor and pressure measuring method |
DE102014115802A1 (en) * | 2014-10-30 | 2016-05-04 | Endress + Hauser Gmbh + Co. Kg | Capacitive pressure sensor and method for its manufacture |
CN204831163U (en) * | 2015-06-30 | 2015-12-02 | 綦新桥 | Two capacitive sensor of capacitanc are closed in bat |
EP3124937B1 (en) * | 2015-07-29 | 2018-05-02 | VEGA Grieshaber KG | Method for determining a pressure and measuring assembly for same |
DE102015119272A1 (en) * | 2015-11-09 | 2017-05-11 | Endress+Hauser Gmbh+Co. Kg | Capacitive pressure sensor and method for its manufacture |
DE102015122220A1 (en) * | 2015-12-18 | 2017-06-22 | Endress + Hauser Gmbh + Co. Kg | Ceramic pressure measuring cell with at least one temperature transducer and pressure transducer with such a pressure measuring cell |
DE102015122553A1 (en) * | 2015-12-22 | 2017-06-22 | Endress+Hauser Flowtec Ag | Converter device and by means of such a transducer device formed measuring system |
DE102016105001A1 (en) * | 2016-03-17 | 2017-09-21 | Endress + Hauser Gmbh + Co. Kg | Pressure measuring device |
DE202016101491U1 (en) * | 2016-03-17 | 2016-04-04 | Endress + Hauser Gmbh + Co. Kg | Pressure measuring device |
DE102017012057A1 (en) * | 2017-12-28 | 2019-07-04 | Endress+Hauser SE+Co. KG | Capacitive pressure sensor |
DE102018106563B4 (en) * | 2018-03-20 | 2019-11-14 | Vega Grieshaber Kg | Method for measured value compensation for capacitive pressure cells |
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2019
- 2019-12-06 DE DE102019133325.3A patent/DE102019133325A1/en active Pending
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2020
- 2020-11-20 US US17/756,929 patent/US20220404223A1/en active Pending
- 2020-11-20 EP EP20811284.7A patent/EP4070059A1/en not_active Withdrawn
- 2020-11-20 CN CN202080083541.9A patent/CN114746733A/en active Pending
- 2020-11-20 WO PCT/EP2020/082853 patent/WO2021110433A1/en unknown
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WO2021110433A1 (en) | 2021-06-10 |
US20220404223A1 (en) | 2022-12-22 |
DE102019133325A1 (en) | 2021-06-10 |
CN114746733A (en) | 2022-07-12 |
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