EP4237811A2 - Pressure measuring device - Google Patents

Pressure measuring device

Info

Publication number
EP4237811A2
EP4237811A2 EP21830587.8A EP21830587A EP4237811A2 EP 4237811 A2 EP4237811 A2 EP 4237811A2 EP 21830587 A EP21830587 A EP 21830587A EP 4237811 A2 EP4237811 A2 EP 4237811A2
Authority
EP
European Patent Office
Prior art keywords
pressure measuring
pressure
connection block
measuring device
connection
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.)
Pending
Application number
EP21830587.8A
Other languages
German (de)
French (fr)
Inventor
Wolfgang Sailer
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
AVL List GmbH
Original Assignee
AVL List GmbH
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by AVL List GmbH filed Critical AVL List GmbH
Publication of EP4237811A2 publication Critical patent/EP4237811A2/en
Pending legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
    • G01L13/00—Devices or apparatus for measuring differences of two or more fluid pressure values
    • G01L13/02—Devices or apparatus for measuring differences of two or more fluid pressure values using elastically-deformable members or pistons as sensing elements
    • G01L13/025—Devices or apparatus for measuring differences of two or more fluid pressure values using elastically-deformable members or pistons as sensing elements using diaphragms
    • 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
    • G01L19/04—Means for compensating for effects of changes of temperature, i.e. other than electric compensation
    • 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
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
    • G01L15/00—Devices or apparatus for measuring two or more fluid pressure values simultaneously
    • 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
    • G01L19/0007—Fluidic connecting means
    • 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
    • G01L19/0007—Fluidic connecting means
    • G01L19/0038—Fluidic connecting means being part of the housing
    • 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
    • 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
    • G01L19/14—Housings
    • G01L19/142—Multiple part housings
    • G01L19/144—Multiple part housings with dismountable parts, e.g. for maintenance purposes or for ensuring sterile conditions
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
    • G01L23/00—Devices or apparatus for measuring or indicating or recording rapid changes, such as oscillations, in the pressure of steam, gas, or liquid; Indicators for determining work or energy of steam, internal-combustion, or other fluid-pressure engines from the condition of the working fluid
    • G01L23/26—Details or accessories
    • G01L23/28—Cooling means

Definitions

  • the invention relates to a pressure measuring device with a pressure gauge with a pressure measuring element and a connection line via which the pressure gauge is connected to a measurement medium source.
  • Such pressure measuring devices are used, for example, to measure an oil pressure or a differential pressure of fluids in test benches.
  • the measurement of a hydrostatic pressure in an oil pan of a test bench should be mentioned.
  • pressure transmitter systems to determine a differential pressure between the oil in the oil pan and the gas in the part of the oil pan that is not filled with oil in order to determine the filling level of the oil pan.
  • a differential pressure in the line system of a test stand can be used to determine oil consumption, so that a measurement medium source can be understood as meaning both lines in which there is a flow and containers or tanks in which the measurement medium is essentially stationary only a small mass exchange takes place.
  • Either sensors or, in the case of most pressure transmitters, membranes are used as pressure measuring elements.
  • diaphragm seal systems are usually used for the measurement, in which the process pressure acts via a membrane on a liquid in a capillary tube, which in turn deflects the measuring body of the pressure transmitter, which serves as a measure for determining the process pressure. Accordingly, it is a closed measuring system in which there is no exchange of the fluid acting on the measuring body.
  • the measurement results of such a system due to the thermal expansion of the fluid in the Pressure transmitter system leads to errors in pressure measurement due to the changing density of the fluid. Attempts are being made to compensate for these errors, mostly using software-based compensation methods, but the results are mostly unsatisfactory, since measurement accuracies of up to 0.5 Pa are required.
  • the known designs have the disadvantage that a temperature influence on the measuring devices cannot be eliminated, in particular since the temperatures of the measuring medium do not correspond to the temperatures of the fluid on the measuring body.
  • the task is therefore to create a pressure measuring device that delivers exact measurement results independently of the temperature profile of the medium to be measured.
  • the pressure measuring device has a pressure gauge, which can be designed as a pressure sensor or pressure transmitter and has a pressure measuring element, such as a membrane. This can be arranged in a pressure gauge housing.
  • the pressure gauge is connected via a connecting line to a measuring medium source, i.e. in particular a fluid source, which can be formed both by a line through which the fluid flows and by a container or tank in which the fluid is stored and thus, with the exception of one low exchange due to existing consumption or refills.
  • the pressure gauge is fluidically connected to a connection block, the temperature of which can be regulated via heating and/or cooling elements and in which a section of the connection line connected to the pressure measuring element is formed.
  • the pressure gauge housing in which the pressure measuring organs are arranged, connected to the terminal block.
  • the connection block is regulated, for example, to an average temperature of the fluid that is to be expected. Since an exchange of fluid in the connecting line is possible because it is an open measuring system with mass exchange, but no larger volume flows occur in the connecting line, the average dwell time of the measuring fluid in the connection block is relatively high, so that from an almost constant temperature of the measuring medium can be assumed even if the process temperature changes at the measuring element.
  • the connection lines or the connection block thus serve as a buffer in the event of sudden temperature changes in the environment or the measuring medium.
  • the heating or cooling elements can be designed, for example, as heating cartridges, heating foils or as Peltier elements. Due to the design as an open system, the measuring medium in the connection lines can also be regulated to any temperature, which does not lead to any falsification of the measurement result, since mass balancing with the environment, i.e. with the lines or the tank, can take place.
  • connection block is preferably regulated to a constant temperature by means of the heating and/or cooling elements, so that no temperature changes have to be taken into account when measuring the pressure and temperature gradients on the membrane are prevented.
  • the pressure gauge is fastened to the connection block via a pressure gauge housing and is connected fluidly to the connection block via a connection opening in the connection block connected, which ensures that the pressure gauge is supplied with the fluid at the desired temperature and that subsequent changes in temperature are prevented by subsequent lines.
  • this structure reduces the space required.
  • connection lines preferably run horizontally or horizontally.
  • the reference point for this horizontal arrangement is the center of the earth. Accordingly, it is crucial that the same gravitational force acts in each duct section, which rules out density differences within the connection line, which could lead to a falsification of the measurement results. Such changes in density could be caused by temperature differences in the measuring medium as well as by diffusion processes or gas bubbles.
  • the connection line can be routed out of the connection block either at the front and thus opposite to the connection openings to the pressure gauge, or at the side.
  • connection block which branches off in an ascending manner from the connection line and ends above the connection line m.
  • one vent hole or preferably two vent holes is provided. If two ventilation bores are provided, two connection lines are preferably also provided. If, in contrast to this, only one ventilation hole is provided, this ends above, in particular, a single connecting line.
  • these ventilation holes can be made horizontally in the area close to the wall in the connection block in order to make it easier to close them.
  • the opening of the ventilation bore to the connection line is preferably in the area of the connection openings
  • Vent holes Connecting lines to the pressure gauge.
  • the closure of Vent holes are made during the measurement process. Gas bubbles present in the medium to be measured would be collected in the vent hole as the highest point.
  • the vent hole is opened between the measurements so that during a flushing process, gas bubbles can be removed from the measurement medium via the vent holes, since these bubbles rise in the medium due to the lower density. In this way, a compressible behavior of the measuring fluid due to the formation of heterogeneous mixtures due to gas bubbles present in the measuring medium is reliably prevented and the measurement results are thus improved.
  • the pressure gauge is preferably arranged in an outer housing which is connected to the connection block and which surrounds the pressure gauge. In this way, the pressure gauge is spatially separated from the external environment, so that heat flows from the outside to the pressure gauge are prevented.
  • connection block is preferably made of a material with a thermal conductivity of more than 100 W/mK, for example aluminum. As a result, the heat introduced into the connection block via the cooling or heating elements is quickly distributed in the connection block, so that short-term and rapid regulation is possible.
  • the outer housing is made of a material with a thermal conductivity in excess of 100 W/mK, which improves heat conduction from the terminal block to the outer housing and through the outer housing.
  • the temperature control of the connection block also controls the temperature of the outer housing.
  • the outer housing and/or the connection block have a reflective on the outside facing surface, so that the degree of absorption for thermal radiation is reduced, since most of it is reflected.
  • the outer housing and the connection block surround the pressure gauge on all sides, with side walls of the outer housing extending along side surfaces of the connection block. Surrounding it on all sides leads to a closed system into which energy can be introduced or released almost exclusively through the measuring medium, which makes it much easier to keep the temperature constant. Furthermore, due to the large-area attachment of the side faces of the outer housing to the connection block, good heat conduction over a large area is produced between the connection block and the outer housing, which again leads to a reduction in existing temperature gradients.
  • connection block is directed towards the interior of the outer housing.
  • These can be produced, for example, by milling the surface of the connection block and lead to an increase in surface area, which increases convection within the outer housing and correspondingly results in faster temperature equalization between the connection block and the interior of the housing.
  • the webs are designed as ribs or if they are replaced by an additional component such as a heat sink.
  • the pressure gauge is preferably a pressure transmitter with a membrane to which the fluid from the connection line is applied.
  • connection openings to the pressure transmitter in the connection block is at least as large as the diameter of the diaphragm, measurement errors caused by capillary effects in narrow gaps are prevented.
  • the connection openings can be expanded with simple countersunk holes.
  • the pressure gauge is advantageously a differential pressure gauge, with a section of the first connection line connected to the pressure gauge and a section of a second connection line connected to the pressure gauge being formed in the connection block.
  • the two connecting lines can either lead to different process line sections, so that a differential pressure is measured, or one connecting line is connected to the measuring fluid in a container and the other connecting line is connected to the space above, so that a filling level can be determined, for example can.
  • the differential pressure gauge is a differential pressure transmitter with two pressure measuring elements, the first pressure measuring element being acted upon by a fluid from the first connecting line and the second pressure measuring element being acted upon by a medium from the second connecting line. A differential pressure is then calculated in the pressure transmitter by forming the difference. A differential pressure between a liquid and a gas can also be measured and calculated. Furthermore, it is advantageous if a temperature sensor for controlling the temperature of the connection block with regard to the height is arranged in the middle of the pressure measuring element. In this way, the temperature, via which the temperature of the connection block is regulated, remains independent of temperature profiles within the connection block, if such should exist.
  • the temperature sensor is arranged symmetrically between the pressure measuring elements or centrally to the pressure measuring element, so that temperature gradients present laterally also have no influence on the regulation of the temperature of the connection block.
  • the two pressure measuring elements are arranged horizontally to one another, ie are arranged at the same height as the center of the earth, there are also no errors due to any vertical temperature gradients that may be present, which would result in different temperatures at the membranes. This improves the measurement results.
  • connection block is preferably designed in two parts, with a first connection block part having the connection openings to the pressure gauge and the second connection block part having the connections to the continuing connection lines. Due to this two-part design, the same block can always be used to connect the process lines, even when using different pressure transmitters or pressure sensors, in which the temperature sensors and the heating and cooling elements are also arranged. Furthermore, heating or cooling elements are preferably attached to the side surfaces of the connection block or in bores in the connection block, which are arranged symmetrically to the pressure-measuring element or symmetrically between the pressure-measuring elements. Both pressure measuring elements always have the same temperature.
  • a measuring device is thus created with which the real pressure equation is adjusted to the ideal pressure equation by constructive measures by measurements being carried out at a constant temperature by appropriate regulation of the temperature of the connection block and on homogeneous measurement media, with temperature gradients occurring in the connection block, in the outer housing or on the pressure measuring devices, which could falsify the measurements. In this way, very accurate measurement results are achieved regardless of temperature fluctuations in the measurement medium or the environment.
  • FIG. 1 shows a top view of a pressure measuring device according to the invention in a partially sectioned illustration.
  • FIG. 2 shows a side view of the pressure measuring device according to the invention from FIG.
  • FIG. 3 shows a perspective view of the pressure measuring device according to the invention from FIG.
  • FIG. 4 shows a front view of the pressure measuring device according to the invention from FIG.
  • the pressure measuring device 10 according to the invention shown in the figures has a pressure gauge 12 designed as a pressure transmitter with two pressure measuring elements 14, 16 in the form of membranes, via which a pressure signal is generated and converted into a pressure in an electronic unit 18 in the pressure gauge 12, see above that a differential pressure can be output by forming the difference in the electronics unit 18 .
  • the electronics unit 18 and the pressure measuring elements are arranged in a pressure gauge housing 19, which can consist of several parts.
  • the pressure gauge 12 is attached to the connection side, on which the pressure measuring elements 14, 16 are arranged, on a connection block 20, which is made of an aluminum alloy, for example, and accordingly has a thermal conductivity coefficient of approximately 200 W/mK.
  • an outer housing 22 composed of the same material is attached, the side walls 24 cover the entire surface of the outer side surfaces 26 of the terminal block 20 and are attached there.
  • the outer housing 22 has a bottom part 28, three side walls 24 and a cover part 30.
  • FIG. The fourth side surface is closed by the connection block 20, so that the pressure gauge is surrounded on all sides by the good heat-conducting material.
  • Insulation 32 is formed around terminal block 20 and outer housing 22 .
  • the terminal block 20 and the outer housing 22 have bare, outwardly facing surfaces 34 which are correspondingly highly reflective. Millings are formed on a side face 36 of the connection block 20 pointing inwardly of the outer housing 22, as a result of which webs 38 pointing inward are formed.
  • Connecting lines 42, 43 are formed, which open into a process line, which in the present exemplary embodiment forms a measurement media source 44, in which a unit 46 generating a pressure difference is arranged, with the first connecting line 42 ending in the process line upstream of the unit 46 and the second connecting line 43 ending in the process line downstream of the unit 46, so that there is a pressure difference between the opening points, which is measured by the pressure gauge.
  • connection block which is made of solid material, has bores to form the sections 40, 41 of the connection lines 42, 43, which extend from the side surfaces 26, to which the side walls 24 of the outer housing 22 are also attached, horizontally with respect to the center of the earth and perpendicularly to the side surfaces 26 extend into the interior of the connection block 20, have a 90° deflection there and then extend perpendicularly in the direction of the side surface 36 pointing into the interior of the outer housing 22, where they connect via connection openings 48, 49 to the manufacture pressure gauge 12 fastened in this position, the pressure measuring elements 14, 16 of which are formed opposite the connection openings 48, 49, which, like the pressure measuring elements 14, 16 when installed, are arranged at the same geodetic height, the connection openings 48, 49 each being concentric to the opposite pressure measuring elements 14, 16 are arranged.
  • the connection openings 48, 49 have countersinks, as a result of which the diameter of the connection opening 48, 49, which is arranged opposite the pressure measuring elements 14, 16, is increased somewhat, so that errors caused by capillar
  • a bore 50 for receiving a temperature sensor 52 is formed on the connection block 20, which is arranged exactly in the middle between the pressure measuring elements 14, 16, both with regard to the vertical and with regard to the horizontal direction. Furthermore, a bore 54 for receiving a heating cartridge serving as a heating element 56 is formed sym metrically to the pressure measuring elements 14 , 16 in the connection block 20 .
  • a Peltier element is attached to the side surface 58 opposite the side surface 36 and serves as a cooling element 60 of the connection block 20.
  • ventilation bores 62, 63 extend obliquely upwards and then horizontally to the side surfaces 26 of the connection block 20. in which corresponding openings are formed. These ventilation openings 62, 63 are opened for a flushing process in order to remove gas bubbles from the fluid and are closed during the measurement.
  • connection block is designed in two parts, with the connection openings 48, 49 for the pressure gauge 12 being formed on the first connection block part 64 and connections 68 for the connection lines 42, 43 and the bores 50, 54 for the heating elements 56 and the Tem peratursensoren 52 are formed. Accordingly, different pressure gauges 12 can be used, for which purpose only the first connection block part 64 has to be exchanged.
  • connection lines 42, 43 are first flushed, as a result of which gas bubbles are removed from the fluid via the ventilation bores 62, 63.
  • the ventilation holes are then sealed.
  • the connection block 20 can be heated or cooled to a desired temperature by the heating and/or cooling elements 56, 60 corresponding to the measured tem perature of the tem perature sensors 52 are energized until the target temperature is reached.
  • This temperature of the connection block 20 is also transferred to the outer housing 22 in a short time due to the large-area connection.
  • the pressure gauge 12 also heats up more quickly due to the large-area connection between the connection block 20 and the pressure gauge housing 19.
  • the desired temperature is set in the pressure gauge 12, which is also slightly due to the surrounding insulation 32 is to be maintained, since only small amounts of heat are transferred by radiation. Ingress of thermal radiation through the reflective surface 34 is also reduced. The following differential pressure measurement therefore takes place at constant temperatures.
  • connection block 20 also acts as a buffer with regard to the temperature changes in the event of rapid temperature fluctuations.
  • connection block can be designed in one or more parts.
  • the measurement can also be carried out as an absolute pressure measurement with only one pressure measuring element and only via one connection line.
  • One connection line can also be charged with a liquid and the other with a gas, as is the case, for example, with hydrostatic level measurement in an oil or fuel tank. In this case, there is no need for a vent hole on the gas side of the connection block.
  • a differential pressure gauge according to the invention can be used both on a line through which flow occurs and on a fluid that is essentially at a standstill.
  • Other changes, including structural changes, are also apparent to those skilled in the art.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Combustion & Propulsion (AREA)
  • Measuring Fluid Pressure (AREA)

Abstract

Pressure measuring devices (10) with a pressure gauge (12) with a pressure measuring member (14; 16), and a connector line (42; 43), via which the pressure gauge (12) is connected to a measured media source (44), are known. In order to obtain precise measured values, even if relatively high temperatures are present or there are temperature fluctuations, it is proposed according to the invention that the pressure gauge (12) is connected fluidically to a connector block (20), the temperature of which can be regulated via heating and/or cooling elements (56; 60) and in which a section (40; 41), connected to the pressure measuring member (14; 16), of the connector line (42; 43) is configured.

Description

Druckmessvorrichtung pressure gauge
Die Erfindung betrifft eine Druckmessvorrichtung m it einem Druckmesser m it einem Druckmessorgan und einer Anschlussleitung, über die der Druckmesser m it einer Messmedienquelle verbunden ist. The invention relates to a pressure measuring device with a pressure gauge with a pressure measuring element and a connection line via which the pressure gauge is connected to a measurement medium source.
Derartige Druckmessvorrichtungen werden beispielsweise zur Messung eines Öldrucks oder eines Differenzdruckes von Fluiden in Prüfständen verwendet. I nsbesondere ist die Messung eines hydrostatischen Drucks in einer Ölwanne eines Prüfstandes zu nennen. Auch ist es bekannt, zur Bestimm ung des Füllstandes der Ölwanne m ittels Druckm ittlersystemen einen Differenzdruck zwischen dem Öl in der Ölwanne und dem Gas in dem nicht m it Öl gefüllten Teil der Ölwanne zu bestim men. Des Weiteren kann ein Differenzdruck im Leitungssystem eines Teststandes genutzt werden, um einen Ölverbrauch zu bestim men, so dass unter einer Messmedienquelle sowohl Leitungen, in denen eine Ström ung vorliegt als auch Behälter oder Tanks zu verstehen sind, in denen das Messmedium im Wesentlichen stillsteht also nur ein geringer Massenaustausch stattfindet. Als Druckmessorgane dienen entweder Sensoren oder bei den meisten Drucktransm ittern Mem brane. Such pressure measuring devices are used, for example, to measure an oil pressure or a differential pressure of fluids in test benches. In particular, the measurement of a hydrostatic pressure in an oil pan of a test bench should be mentioned. It is also known to use pressure transmitter systems to determine a differential pressure between the oil in the oil pan and the gas in the part of the oil pan that is not filled with oil in order to determine the filling level of the oil pan. Furthermore, a differential pressure in the line system of a test stand can be used to determine oil consumption, so that a measurement medium source can be understood as meaning both lines in which there is a flow and containers or tanks in which the measurement medium is essentially stationary only a small mass exchange takes place. Either sensors or, in the case of most pressure transmitters, membranes are used as pressure measuring elements.
Für die Messung werden aufgrund der starken auftretenden Vibrationen für die Druckmessung zumeist Druckmittlersysteme verwendet, bei denen der Prozessdruck über eine Membran auf eine Flüssigkeit in einem Kapillarrohr wirkt, welche wiederum den Messkörper des Drucktransm itters auslenkt, was als Maß zur Bestimm ung des Prozessdrucks dient. Es handelt sich entsprechend um ein geschlossenes Messsystem , bei dem kein Austausch des auf den Messkörper wirkenden Fluids stattfindet. Es hat sich jedoch bei schnellen Tem peraturänderungen und hohen Tem peraturen herausgestellt, dass die Messergebnisse eines solchen Systems aufgrund der therm ischen Expansion des Fluids im Druckm ittlersystem zu Fehlern bei der Druckmessung durch die sich ändernde Dichte des Fluids führt. Es wird zwar versucht, diese Fehler durch zumeist softwarebasierte Kompensationsmethoden auszugleichen, jedoch sind die Ergebnisse zumeist nicht zufriedenstellend, da Messgenauigkeiten von bis 0,5Pa gefordert werden. Due to the strong vibrations that occur for pressure measurement, diaphragm seal systems are usually used for the measurement, in which the process pressure acts via a membrane on a liquid in a capillary tube, which in turn deflects the measuring body of the pressure transmitter, which serves as a measure for determining the process pressure. Accordingly, it is a closed measuring system in which there is no exchange of the fluid acting on the measuring body. However, in the case of rapid temperature changes and high temperatures, it has been found that the measurement results of such a system due to the thermal expansion of the fluid in the Pressure transmitter system leads to errors in pressure measurement due to the changing density of the fluid. Attempts are being made to compensate for these errors, mostly using software-based compensation methods, but the results are mostly unsatisfactory, since measurement accuracies of up to 0.5 Pa are required.
Entsprechend bestehen bei den bekannten Ausführungen die Nachteile, dass ein Tem peratureinfluss auf die Messvorrichtungen nicht elim iniert werden kann, insbesondere da die Tem peraturen des Messmediums nicht den Tem peraturen des Fluids am Messkörper entspricht. Correspondingly, the known designs have the disadvantage that a temperature influence on the measuring devices cannot be eliminated, in particular since the temperatures of the measuring medium do not correspond to the temperatures of the fluid on the measuring body.
Es stellt sich daher die Aufgabe, eine Druckmessvorrichtung zu schaffen, welche exakte Messergebnisse unabhängig vom Tem peraturverlauf des Messmediums liefert. The task is therefore to create a pressure measuring device that delivers exact measurement results independently of the temperature profile of the medium to be measured.
Diese Aufgabe wird durch eine Druckmessvorrichtung m it den Merkmalen des Hauptanspruchs 1 gelöst. This problem is solved by a pressure measuring device with the features of main claim 1 .
Die erfindungsgemäße Druckmessvorrichtung weist einen Druckmesser auf, der als Drucksensor oder Drucktransm itter ausgeführt sein kann und ein Druckmessorgan, wie eine Membrane aufweist. Diese kann in einem Druckmessergehäuse angeordnet sein. Der Druckmesser ist über eine Anschlussleitung mit einer Messmedienquelle, also insbesondere einer Fluidquelle verbunden, welche sowohl durch eine Leitung gebildet werden kann, durch die das Fluid strömt als auch durch einen Behälter oder Tank, in dem das Fluid aufbewahrt wird und somit, bis auf einen geringen Austausch durch vorliegende Verbräuche oder Nachfüllungen, steht. Der Druckmesser ist erfindungsgemäß fluidisch m it einem Anschlussblock verbunden, dessen Tem peratur über Heiz- und/oder Kühlelemente regelbar ist und in dem ein mit dem Druckmessorgan verbundener Abschnitt der Anschlussleitung ausgebildet ist. Entsprechend wird üblicherweise das Druckmessergehäuse, in dem die Druckmessorgane angeordnet sind, m it dem Anschlussblock verbunden. Dies hat zur Folge, dass das in den Anschlussblock einströmende Fluid, bevor es zum Druckmessorgan gelangt, auf die Temperatur des Anschlussblocks gekühlt oder geheizt wird, da es diesen durchströmen m uss. Der Anschlussblock wird beispielsweise auf eine m ittlere zu erwartende Tem peratur des Fluids geregelt. Da ein Austausch von Fluid in der Anschlussleitung zwar möglich ist, da es sich um ein offenes Messystem m it Massenaustausch handelt, jedoch keine größeren Volumenströme in der Anschlussleitung auftreten, ist auch die durchschnittliche Verweilzeit des Messfluids im Anschlussblock relativ hoch, so dass von einer beinahe konstanten Tem peratur des Messmediums auch bei Änderungen der Prozesstemperatur am Messorgan auszugehen ist. Die Anschlussleitungen beziehungsweise der Anschlussblock dienen som it als Puffer bei plötzlichen Temperaturänderungen der Umgebung oder des Messmediums. The pressure measuring device according to the invention has a pressure gauge, which can be designed as a pressure sensor or pressure transmitter and has a pressure measuring element, such as a membrane. This can be arranged in a pressure gauge housing. The pressure gauge is connected via a connecting line to a measuring medium source, i.e. in particular a fluid source, which can be formed both by a line through which the fluid flows and by a container or tank in which the fluid is stored and thus, with the exception of one low exchange due to existing consumption or refills. According to the invention, the pressure gauge is fluidically connected to a connection block, the temperature of which can be regulated via heating and/or cooling elements and in which a section of the connection line connected to the pressure measuring element is formed. The pressure gauge housing, in which the pressure measuring organs are arranged, connected to the terminal block. The consequence of this is that the fluid flowing into the connection block is cooled or heated to the temperature of the connection block before it reaches the pressure measuring element, since it has to flow through it. The connection block is regulated, for example, to an average temperature of the fluid that is to be expected. Since an exchange of fluid in the connecting line is possible because it is an open measuring system with mass exchange, but no larger volume flows occur in the connecting line, the average dwell time of the measuring fluid in the connection block is relatively high, so that from an almost constant temperature of the measuring medium can be assumed even if the process temperature changes at the measuring element. The connection lines or the connection block thus serve as a buffer in the event of sudden temperature changes in the environment or the measuring medium.
Entsprechend können sehr genaue Messergebnisse durch Elim inierung des Temperatureinflusses und der daraus folgenden Dichteänderung des Messmediums erzielt werden. Die Heiz- oder Kühlelemente können beispielsweise als Heizpatronen, Heizfolien oder als Peltier-Elemente ausgeführt werden. Durch die Ausbildung als offenes System kann das Messmedium in den Anschlussleitungen auch auf eine beliebige Temperatur geregelt werden, was zu keiner Verfälschung des Messergebnisses führt, da ein Massenausgleich zur Umgebung also zu den Leitungen oder dem Tank stattfinden kann. Accordingly, very precise measurement results can be achieved by eliminating the influence of temperature and the resulting change in density of the measurement medium. The heating or cooling elements can be designed, for example, as heating cartridges, heating foils or as Peltier elements. Due to the design as an open system, the measuring medium in the connection lines can also be regulated to any temperature, which does not lead to any falsification of the measurement result, since mass balancing with the environment, i.e. with the lines or the tank, can take place.
Vorzugsweise erfolgt die Regelung des Anschlussblocks m ittels der Heiz- und oder Kühlelemente auf eine konstante Tem peratur, so dass keine Temperaturänderungen bei der Druckmessung berücksichtigt werden m üssen und Tem peraturgradienten an der Membran verhindert werden. The connection block is preferably regulated to a constant temperature by means of the heating and/or cooling elements, so that no temperature changes have to be taken into account when measuring the pressure and temperature gradients on the membrane are prevented.
I n einer vorteilhaften Ausgestaltung der Erfindung ist der Druckmesser über ein Druckmessergehäuse am Anschlussblock befestigt, und über eine Anschlussöffnung im Anschlussblock fluidisch m it dem Anschlussblock verbunden, wodurch sichergestellt wird, dass dem Druckmesser das Fluid auch m it der gewünschten Tem peratur zur Verfügung gestellt wird und folgende Tem peraturänderungen durch Folgeleitungen verhindert werden. Zusätzlich wird durch diesen Aufbau der benötigte Bauraum reduziert. In an advantageous embodiment of the invention, the pressure gauge is fastened to the connection block via a pressure gauge housing and is connected fluidly to the connection block via a connection opening in the connection block connected, which ensures that the pressure gauge is supplied with the fluid at the desired temperature and that subsequent changes in temperature are prevented by subsequent lines. In addition, this structure reduces the space required.
Vorzugsweise verläuft die eine oder verlaufen die mehreren Anschlussleitungen horizontal beziehungsweise waagerecht. Bezugspunkt zu dieser horizontalen Anordnung ist der Erdm ittelpunkt. Entscheidend ist entsprechend, dass in jedem Kanalabschnitt eine gleiche Gravitationskraft wirkt, wodurch Dichteunterschiede innerhalb der Anschlussleitung, die zu einer Verfälschung der Messergebnisse führen könnten, ausgeschlossen werden. Solche Dichteänderungen könnten sowohl durch Temperaturdifferenzen des Messmediums entstehen als auch durch Diffusionsvorgänge oder Gasblasen. Die Anschlussleitung kann entweder frontseitig und somit gegenüberliegend zu den Anschlussöffnungen zum Druckmesser aus dem Anschlussblock herausgeführt werden oder seitlich. The one or more connection lines preferably run horizontally or horizontally. The reference point for this horizontal arrangement is the center of the earth. Accordingly, it is crucial that the same gravitational force acts in each duct section, which rules out density differences within the connection line, which could lead to a falsification of the measurement results. Such changes in density could be caused by temperature differences in the measuring medium as well as by diffusion processes or gas bubbles. The connection line can be routed out of the connection block either at the front and thus opposite to the connection openings to the pressure gauge, or at the side.
Des Weiteren ist es vorteilhaft, wenn im Anschlussblock eine verschließbare Entlüftungsbohrung ausgebildet ist, die von der Anschlussleitung aufsteigend abzweigt und oberhalb der Anschlussleitung m ündet. Es ist insbesondere eine Entlüftungsbohrung oder bevorzugt zwei Entlüftungsbohrungen vorgesehen. Sind zwei Entlüftungsbohrungen vorgesehen, so sind bevorzugt auch zwei Anschlussleitungen vorgesehen. Ist im Gegensatz dazu nur eine Entlüftungsbohrung vorgesehen, m ündet diese oberhalb insbesondere einer einzigen Anschlussleitung. Furthermore, it is advantageous if a closable ventilation hole is formed in the connection block, which branches off in an ascending manner from the connection line and ends above the connection line m. In particular, one vent hole or preferably two vent holes is provided. If two ventilation bores are provided, two connection lines are preferably also provided. If, in contrast to this, only one ventilation hole is provided, this ends above, in particular, a single connecting line.
I nsbesondere können diese Entlüftungsbohrungen im wandnahen Bereich waagerecht im Anschlussblock ausgeführt sein, um deren Verschluss zu erleichtern. In particular, these ventilation holes can be made horizontally in the area close to the wall in the connection block in order to make it easier to close them.
Des Weiteren befindet sich die Öffnung der Entlüftungsbohrung zur Anschlussleitung vorzugsweise im Bereich von Anschlussöffnungen derFurthermore, the opening of the ventilation bore to the connection line is preferably in the area of the connection openings
Anschlussleitungen zum Druckmesser. Der Verschluss der Entlüftungsbohrungen erfolgt während des Messvorgangs. I m Messmedium vorhandene Gasblasen würden in der Entlüftungsbohrung als höchsten Punkt gesammelt. Zwischen den Messungen wird die Entlüftungsbohrung geöffnet, so dass im Zuge eines Spülvorgangs Gasblasen über die Entlüftungsbohrungen aus dem Messmedium entfernt werden können, da diese aufgrund der geringeren Dichte im Medium aufsteigen. Auf diese Weise wird ein kom pressibles Verhalten des Messfluids durch heterogene Gem ischbildung aufgrund im Messmedium vorhandener Gasblasen zuverlässig verhindert und som it die Messergebnisse verbessert. Connecting lines to the pressure gauge. The closure of Vent holes are made during the measurement process. Gas bubbles present in the medium to be measured would be collected in the vent hole as the highest point. The vent hole is opened between the measurements so that during a flushing process, gas bubbles can be removed from the measurement medium via the vent holes, since these bubbles rise in the medium due to the lower density. In this way, a compressible behavior of the measuring fluid due to the formation of heterogeneous mixtures due to gas bubbles present in the measuring medium is reliably prevented and the measurement results are thus improved.
Vorzugsweise ist der Druckmesser in einem Außengehäuse angeordnet, das m it dem Anschlussblock verbunden ist und welches den Druckmesser umgibt. Auf diese Weise wird eine räumliche Trennung des Druckmessers von der äußeren Umgebung erzielt, so dass Wärmeström ungen von außen zum Druckmesser verhindert werden. The pressure gauge is preferably arranged in an outer housing which is connected to the connection block and which surrounds the pressure gauge. In this way, the pressure gauge is spatially separated from the external environment, so that heat flows from the outside to the pressure gauge are prevented.
Der Anschlussblock ist vorzugsweise aus einem Material m it einer Wärmeleitfähigkeit von über 100 W/m K hergestellt, beispielswiese aus Aluminium . Hierdurch wird die in den Anschlussblock über die Kühl- oder Heizelemente eingebrachte Wärme schnell im Anschlussblock verteilt, so dass kurzfristige und schnelle Regelungen möglich sind. The connection block is preferably made of a material with a thermal conductivity of more than 100 W/mK, for example aluminum. As a result, the heat introduced into the connection block via the cooling or heating elements is quickly distributed in the connection block, so that short-term and rapid regulation is possible.
Vorteilhafterweise ist das Außengehäuse aus einem Material m it einer Wärmeleitfähigkeit von über 100 W/m K, wodurch die Wärmeleitung vom Anschlussblock zum Außengehäuse und durch das Außengehäuse verbessert wird. Entsprechend erfolgt m it der Tem peraturregelung des Anschlussblocks auch eine Regelung der Außengehäusetem peratur. Advantageously, the outer housing is made of a material with a thermal conductivity in excess of 100 W/mK, which improves heat conduction from the terminal block to the outer housing and through the outer housing. Correspondingly, the temperature control of the connection block also controls the temperature of the outer housing.
I n einer weiterführenden Ausbildung der Erfindung weisen das Außengehäuse und/oder der Anschlussblock eine reflektierende, nach außen weisende Oberfläche auf, so dass der Absorptionsgrad für Wärmestrahlung verringert wird, da diese größtenteils reflektiert wird. In a further development of the invention, the outer housing and/or the connection block have a reflective on the outside facing surface, so that the degree of absorption for thermal radiation is reduced, since most of it is reflected.
Dabei ist es bevorzugt, wenn das Außengehäuse und der Anschlussblock den Druckmesser allseitig umgeben, wobei sich Seitenwände des Außengehäuses entlang von Seitenflächen des Anschlussblocks erstrecken. Das allseitige Umgeben führt zu einem geschlossenen System , in das fast ausschließlich durch das Messmedium Energie eingebracht oder austreten kann, wodurch das Konstanthalten der Tem peratur deutlich vereinfacht wird. Des Weiteren wird durch die großflächige Befestigung der Seitenflächen des Außengehäuses am Anschlussblock eine gute und großflächige Wärmeleitung zwischen dem Anschlussblock und dem Außengehäuse hergestellt, was erneut zu einer Verringerung vorhandener Temperaturgradienten führt. It is preferred here if the outer housing and the connection block surround the pressure gauge on all sides, with side walls of the outer housing extending along side surfaces of the connection block. Surrounding it on all sides leads to a closed system into which energy can be introduced or released almost exclusively through the measuring medium, which makes it much easier to keep the temperature constant. Furthermore, due to the large-area attachment of the side faces of the outer housing to the connection block, good heat conduction over a large area is produced between the connection block and the outer housing, which again leads to a reduction in existing temperature gradients.
Auch ist es vorteilhaft, wenn an einer Seitenfläche des Anschlussblocks, welche zum I nneren des Außengehäuses gerichtet ist, Stege ausgebildet sind. Diese können beispielweise durch Fräsungen in die Oberfläche des Anschlussblocks hergestellt werden und führen zu einer Vergrößerung der Oberflächen, wodurch die Konvektion innerhalb des Außengehäuses erhöht wird und entsprechend ein schnellerer Temperaturausgleich zwischen dem Anschlussblock und dem Gehäuseinneren entsteht. It is also advantageous if webs are formed on a side surface of the connection block which is directed towards the interior of the outer housing. These can be produced, for example, by milling the surface of the connection block and lead to an increase in surface area, which increases convection within the outer housing and correspondingly results in faster temperature equalization between the connection block and the interior of the housing.
Grundsätzlich kann es auch vorteilhaft sein, wenn die Stege als Rippen ausgebildet sind oder diese durch ein zusätzliches Bauteil wie einen Kühlkörper ersetzt werden. In principle, it can also be advantageous if the webs are designed as ribs or if they are replaced by an additional component such as a heat sink.
Wenn zusätzlich das Außengehäuse von einer Isolierung umgeben ist, wird auch ein Austausch thermischer Energie zwischen dem Außengehäuse beziehungsweise dem Anschlussblock und der Umgebung verringert, was das Konstanthalten der Tem peratur unabhängig von den Umgebungsbedingungen deutlich vereinfacht. Vorzugsweise ist der Druckmesser ein Drucktransmitter m it einer Mem brane, welche mit dem Fluid aus der Anschlussleitung beaufschlagt ist. Solche Drucktransm itter sind unempfindlich gegen Verschmutzungen oder Korrosion und werden kostengünstig als Massenprodukte hergestellt. If the outer housing is also surrounded by insulation, an exchange of thermal energy between the outer housing or the connection block and the environment is also reduced, which makes it much easier to keep the temperature constant, regardless of the environmental conditions. The pressure gauge is preferably a pressure transmitter with a membrane to which the fluid from the connection line is applied. Such Drucktransm itter are insensitive to contamination or corrosion and are mass-produced inexpensively.
I ndem der Durchmesser von Anschlussöffnungen zum Drucktransmitter im Anschlussblock zum indest so groß ist wie der Durchmesser der Membran, werden Messfehler durch auftretende Kapillareffekte in engen Spalten verhindert. Hierzu können die Anschlussöffnungen durch einfache Senkbohrungen erweitert werden. Since the diameter of the connection openings to the pressure transmitter in the connection block is at least as large as the diameter of the diaphragm, measurement errors caused by capillary effects in narrow gaps are prevented. For this purpose, the connection openings can be expanded with simple countersunk holes.
Vorteilhaftweise ist der Druckmesser ein Differenzdruckmesser, wobei im Anschlussblock ein m it dem Druckmesser verbundener Abschnitt der ersten Anschlussleitung und ein mit dem Druckmesser verbundener Abschnitt einer zweiten Anschlussleitung ausgebildet sind. Die beiden Anschlussleitungen können entweder zu unterschiedlichen Prozessleitungsabschnitten führen, so dass ein Differenzdruck gemessen wird oder aber eine Anschlussleitung ist m it dem Messfluid in einem Behälter verbunden und die andere Anschlussleitung ist m it dem darüber liegenden Raum verbunden, so dass beispielsweise ein Füllstand bestim mt werden kann. The pressure gauge is advantageously a differential pressure gauge, with a section of the first connection line connected to the pressure gauge and a section of a second connection line connected to the pressure gauge being formed in the connection block. The two connecting lines can either lead to different process line sections, so that a differential pressure is measured, or one connecting line is connected to the measuring fluid in a container and the other connecting line is connected to the space above, so that a filling level can be determined, for example can.
I n einer hierzu weiterführenden Ausführungsform ist der Differenzdruckmesser ein Differenzdrucktransmitter m it zwei Druckmessorganen, wobei das erste Druckmessorgan m it einem Fluid aus der ersten Anschlussleitung beaufschlagt ist und das zweite Druckmessorgan m it einem Medium aus der zweiten Anschlussleitung beaufschlagt ist. I m Drucktransmitter wird dann ein Differenzdruck durch Differenzbildung berechnet. Dabei kann auch ein Differenzdruck zwischen einer Flüssigkeit und einem Gas gemessen und berechnet werden. Des Weiteren ist es vorteilhaft, wenn ein Tem peratursensor zur Regelung der Tem peratur des Anschlussblocks bezüglich der Höhe m ittig zum Druckmessorgan angeordnet ist. Auf diese Weise bleibt die Tem peratur, über die die Tem peratur des Anschlussblocks geregelt wird unabhängig von Temperaturverläufen innerhalb des Anschlussblocks, falls solche vorhanden sein sollten. In a further embodiment, the differential pressure gauge is a differential pressure transmitter with two pressure measuring elements, the first pressure measuring element being acted upon by a fluid from the first connecting line and the second pressure measuring element being acted upon by a medium from the second connecting line. A differential pressure is then calculated in the pressure transmitter by forming the difference. A differential pressure between a liquid and a gas can also be measured and calculated. Furthermore, it is advantageous if a temperature sensor for controlling the temperature of the connection block with regard to the height is arranged in the middle of the pressure measuring element. In this way, the temperature, via which the temperature of the connection block is regulated, remains independent of temperature profiles within the connection block, if such should exist.
I n einer Weiterführung der Erfindung ist der Tem peratursensor symmetrisch zwischen den Druckmessorganen oder zentrisch zum Druckmessorgan angeordnet, so dass auch seitlich vorhandene Temperaturgradienten keinen Einfluss auf die Regelung der Tem peratur des Anschlussblocks haben. Bei dieser Anordnung ist im mer davon auszugehen, dass es sich um einen m ittlere Temperatur handelt, die gemessen wird, da an dieser Position der Anschlussblock immer eine m ittlere Temperatur aufweisen sollte. In a further development of the invention, the temperature sensor is arranged symmetrically between the pressure measuring elements or centrally to the pressure measuring element, so that temperature gradients present laterally also have no influence on the regulation of the temperature of the connection block. With this arrangement, it must always be assumed that the temperature being measured is an average, since the connection block should always have an average temperature at this position.
Wenn die beiden Druckmessorgane horizontal zueinander angeordnet sind, also auf gleicher Höhe zum Erdmittelpunkt angeordnet sind, entstehen auch keine Fehler durch gegebenenfalls vorhandene vertikale Temperaturgradienten, wodurch unterschiedliche Temperaturen an den Mem branen herrschen würden. So werden die Messergebnisse verbessert. If the two pressure measuring elements are arranged horizontally to one another, ie are arranged at the same height as the center of the earth, there are also no errors due to any vertical temperature gradients that may be present, which would result in different temperatures at the membranes. This improves the measurement results.
Vorzugsweise ist der Anschlussblock zweiteilig ausgeführt, wobei ein erstes Anschlussblockteil die Anschlussöffnungen zum Druckmesser aufweist und das zweite Anschlussblockteil die Anschlüsse zu den weiterführenden Anschlussleitungen aufweist. Durch diese Zweiteiligkeit kann auch bei Verwendung verschiedener Drucktransm itter oder Drucksensoren im mer ein gleicher Block zum Anschluss der Prozessleitungen verwendet werden, in dem auch die Tem peratursensoren und die Heiz- und Kühlelemente angeordnet sind. Des Weiteren sind vorzugsweise an den Seitenflächen des Anschlussblocks oder in Bohrungen im Anschlussblock Heiz- oder Kühlelemente befestigt, die sym metrisch zum Druckmessorgan oder sym metrisch zwischen den Druckmessorganen angeordnet sind. So weisen beide Druckmessorgane immer eine gleiche Tem peratur auf. The connection block is preferably designed in two parts, with a first connection block part having the connection openings to the pressure gauge and the second connection block part having the connections to the continuing connection lines. Due to this two-part design, the same block can always be used to connect the process lines, even when using different pressure transmitters or pressure sensors, in which the temperature sensors and the heating and cooling elements are also arranged. Furthermore, heating or cooling elements are preferably attached to the side surfaces of the connection block or in bores in the connection block, which are arranged symmetrically to the pressure-measuring element or symmetrically between the pressure-measuring elements. Both pressure measuring elements always have the same temperature.
Es wird som it eine Messvorrichtung geschaffen, mit der durch konstruktive Maßnahmen die reale Druckgleichung an die ideale Druckgleichung angeglichen wird, indem Messungen bei einer konstanten Temperatur durch entsprechende Regelung der Tem peratur des Anschlussblocks und an homogenen Messmedien durchgeführt werden, wobei auftretende Temperaturgradienten im Anschlussblock, im Außengehäuse oder an den Druckmessorganen verhindert werden, die die Messungen verfälschen könnten. Som it werden unabhängig von auftretenden Temperaturschwankungen des Messmediums oder der Umgebung sehr genaue Messergebnisse erzielt. A measuring device is thus created with which the real pressure equation is adjusted to the ideal pressure equation by constructive measures by measurements being carried out at a constant temperature by appropriate regulation of the temperature of the connection block and on homogeneous measurement media, with temperature gradients occurring in the connection block, in the outer housing or on the pressure measuring devices, which could falsify the measurements. In this way, very accurate measurement results are achieved regardless of temperature fluctuations in the measurement medium or the environment.
Ein Ausführungsbeispiel einer erfindungsgemäßen Druckmessvorrichtung ist in den Figuren dargestellt und wird nachfolgend beschrieben. An embodiment of a pressure measuring device according to the invention is shown in the figures and is described below.
Figur 1 zeigt eine Draufsicht auf eine erfindungsgemäße Druckmessvorrichtung in teilweise geschnittener Darstellung. FIG. 1 shows a top view of a pressure measuring device according to the invention in a partially sectioned illustration.
Figur 2 zeigt eine Seitenansicht der erfindungsgemäßen Druckmessvorrichtung aus Figur 1 . FIG. 2 shows a side view of the pressure measuring device according to the invention from FIG.
Figur 3 zeigt eine perspektivische Ansicht der erfindungsgemäßen Druckmessvorrichtung aus Figur 1 . FIG. 3 shows a perspective view of the pressure measuring device according to the invention from FIG.
Figur 4 zeigt eine Frontansicht der erfindungsgemäßen Druckmessvorrichtung aus Figur 1 . Die in den Figuren dargestellte erfindungsgemäße Druckmessvorrichtung 10 weist einen als Drucktransm itter ausgeführten Druckmesser 12 mit zwei Druckmessorganen 14, 16 in Form von Mem branen auf, über die jeweils ein Drucksignal erzeugt und in einer Elektronikeinheit 18 im Druckmesser 12 in einen Druck umgerechnet wird, so dass durch Differenzbildung in der Elektronikeinheit 18 ein Differenzdruck ausgegeben werden kann. Die Elektronikeinheit 18 und die Druckmessorgane sind in einem Druckmessergehäuse 19 angeordnet, welches aus mehreren Teilen bestehen kann. FIG. 4 shows a front view of the pressure measuring device according to the invention from FIG. The pressure measuring device 10 according to the invention shown in the figures has a pressure gauge 12 designed as a pressure transmitter with two pressure measuring elements 14, 16 in the form of membranes, via which a pressure signal is generated and converted into a pressure in an electronic unit 18 in the pressure gauge 12, see above that a differential pressure can be output by forming the difference in the electronics unit 18 . The electronics unit 18 and the pressure measuring elements are arranged in a pressure gauge housing 19, which can consist of several parts.
Der Druckmesser 12 ist mit der Anschlussseite, an der die Druckmessorgane 14, 16 angeordnet sind, an einem Anschlussblock 20 befestigt, der beispielsweise aus einer Alum inium legierung hergestellt ist und entsprechend einen Wärmeleitkoeffizienten von etwa 200 W/m K aufweist. The pressure gauge 12 is attached to the connection side, on which the pressure measuring elements 14, 16 are arranged, on a connection block 20, which is made of an aluminum alloy, for example, and accordingly has a thermal conductivity coefficient of approximately 200 W/mK.
An diesem Anschlussblock 20 ist eine aus dem gleichen Material zusam mengesetztes Außengehäuse 22 befestigt, dessen Seitenwände 24 vollflächig äußere Seitenflächen 26 des Anschlussblocks 20 bedecken und dort befestigt sind. Das Außengehäuse 22 weist ein Bodenteil 28, drei Seitenwände 24 und ein Deckelteil 30 auf. Die vierte Seitenfläche wird durch den Anschlussblock 20 geschlossen, so dass der Druckmesser allseitig durch das gut wärmeleitende Material umgeben ist. Um den Anschlussblock 20 und das Außengehäuse 22 herum ist eine Isolierung 32 ausgebildet. Der Anschlussblock 20 und das Außengehäuse 22 weisen blanke, nach außen weisende Oberflächen 34 auf, die entsprechend stark reflektieren. An einer zum I nneren des Außengehäuses 22 weisenden Seitenfläche 36 des Anschlussblocks 20 sind Einfräsungen ausgebildet, wodurch nach innen weisende Stege 38 entstehen. At this terminal block 20 is an outer housing 22 composed of the same material is attached, the side walls 24 cover the entire surface of the outer side surfaces 26 of the terminal block 20 and are attached there. The outer housing 22 has a bottom part 28, three side walls 24 and a cover part 30. FIG. The fourth side surface is closed by the connection block 20, so that the pressure gauge is surrounded on all sides by the good heat-conducting material. Insulation 32 is formed around terminal block 20 and outer housing 22 . The terminal block 20 and the outer housing 22 have bare, outwardly facing surfaces 34 which are correspondingly highly reflective. Millings are formed on a side face 36 of the connection block 20 pointing inwardly of the outer housing 22, as a result of which webs 38 pointing inward are formed.
I m Anschlussblock sind Abschnitte 40, 41 zweier horizontal verlaufenderIn the terminal block are sections 40, 41 of two horizontally extending
Anschlussleitungen 42, 43 ausgebildet, die in eine Prozessleitung münden, die im vorliegenden Ausführungsbeispiel eine Messmedienquelle 44 bildet, in der ein eine Druckdifferenz erzeugendes Aggregat 46 angeordnet ist, wobei die erste Anschlussleitung 42 stromaufwärts des Aggregats 46 in die Prozessleitung m ündet und die zweite Anschlussleitung 43 stromabwärts des Aggregats 46 in die Prozessleitung mündet, so dass zwischen den Mündungspunkten eine Druckdifferenz vorliegt, die über den Druckmesser gemessen wird. Connecting lines 42, 43 are formed, which open into a process line, which in the present exemplary embodiment forms a measurement media source 44, in which a unit 46 generating a pressure difference is arranged, with the first connecting line 42 ending in the process line upstream of the unit 46 and the second connecting line 43 ending in the process line downstream of the unit 46, so that there is a pressure difference between the opening points, which is measured by the pressure gauge.
Der aus Vollmaterial bestehende Anschlussblock weist zur Bildung der Abschnitte 40, 41 der Anschlussleitungen 42, 43 Bohrungen auf, die sich von den Seitenflächen 26, an denen auch die Seitenwände 24 des Außengehäuses 22 befestigt sind, waagerecht bezüglich des Erdm ittelpunkts und senkrecht zu den Seitenflächen 26 in das I nnere des Anschlussblocks 20 erstrecken, dort eine 90°-Um lenkung aufweisen und sich im Folgenden senkrecht in Richtung zu der ins I nnere des Außengehäuses 22 weisenden Seitenfläche 36 erstrecken, wo sie über Anschlussöffnungen 48, 49 eine Verbindung zu dem an dieser Position befestigten Druckmesser 12 herstellen, dessen Druckmessorgane 14, 16 gegenüberliegend zu den Anschlussöffnungen 48, 49 ausgebildet sind, die ebenso wie die Druckmessorgane 14, 16 im eingebauten Zustand auf einer gleichen geodätischen Höhe angeordnet sind, wobei die Anschlussöffnungen 48, 49 jeweils konzentrisch zu den gegenüberliegenden Druckmessorganen 14, 16 angeordnet sind. Die Anschlussöffnungen 48, 49 weisen Senkungen auf, durch die der Durchmesser der Anschlussöffnung 48, 49, der gegenüberliegend zu den Druckmessorganen 14, 16 angeordnet ist, etwas vergrößert ist, so dass Fehler durch auftretende Kapillarkräfte verm ieden werden. The connection block, which is made of solid material, has bores to form the sections 40, 41 of the connection lines 42, 43, which extend from the side surfaces 26, to which the side walls 24 of the outer housing 22 are also attached, horizontally with respect to the center of the earth and perpendicularly to the side surfaces 26 extend into the interior of the connection block 20, have a 90° deflection there and then extend perpendicularly in the direction of the side surface 36 pointing into the interior of the outer housing 22, where they connect via connection openings 48, 49 to the manufacture pressure gauge 12 fastened in this position, the pressure measuring elements 14, 16 of which are formed opposite the connection openings 48, 49, which, like the pressure measuring elements 14, 16 when installed, are arranged at the same geodetic height, the connection openings 48, 49 each being concentric to the opposite pressure measuring elements 14, 16 are arranged. The connection openings 48, 49 have countersinks, as a result of which the diameter of the connection opening 48, 49, which is arranged opposite the pressure measuring elements 14, 16, is increased somewhat, so that errors caused by capillary forces that occur are avoided.
Des Weiteren ist am Anschlussblock 20 eine Bohrungen 50 zur Aufnahme eines Tem peratursensors 52 ausgebildet, welcher genau mittig zwischen den Druckmessorganen 14, 16 angeordnet ist und zwar sowohl bezüglich der vertikalen als auch bezüglich der horizontalen Richtung. Des Weiteren ist sym metrisch zu den Druckmessorganen 14, 16 im Anschlussblock 20 eine Bohrung 54 zur Aufnahme einer als Heizelement 56 dienenden Heizpatrone ausgebildet. Ein Peltierelement wird an der zur Seitenfläche 36 gegenüberliegenden Seitenfläche 58 angebracht und dient als Kühlelement 60 des Anschlussblocks 20. Furthermore, a bore 50 for receiving a temperature sensor 52 is formed on the connection block 20, which is arranged exactly in the middle between the pressure measuring elements 14, 16, both with regard to the vertical and with regard to the horizontal direction. Furthermore, a bore 54 for receiving a heating cartridge serving as a heating element 56 is formed sym metrically to the pressure measuring elements 14 , 16 in the connection block 20 . A Peltier element is attached to the side surface 58 opposite the side surface 36 and serves as a cooling element 60 of the connection block 20.
Zusätzlich erstrecken sich von den im Anschlussblock 20 ausgebildeten Abschnitten 40, 41 der Anschlussleitungen 42, 43 und zwar insbesondere in unm ittelbarer Nähe der Anschlussöffnungen 48, 49 Entlüftungsbohrungen 62, 63 schräg nach oben und im weiteren Verlauf waagerecht zu den Seitenflächen 26 des Anschlussblocks 20, in denen entsprechende Öffnungen ausgebildet sind. Diese Entlüftungsöffnungen 62, 63 werden für einen Spülvorgang geöffnet, um Gasblasen aus dem Fluid zu entfernen und sind während der Messung verschlossen. In addition, from the sections 40, 41 of the connection lines 42, 43 formed in the connection block 20, in particular in the immediate vicinity of the connection openings 48, 49, ventilation bores 62, 63 extend obliquely upwards and then horizontally to the side surfaces 26 of the connection block 20. in which corresponding openings are formed. These ventilation openings 62, 63 are opened for a flushing process in order to remove gas bubbles from the fluid and are closed during the measurement.
Der Anschlussblock ist in vorliegendem Ausführungsbeispiel zweiteilig ausgebildet, wobei am ersten Anschlussblockteil 64 die Anschlussöffnungen 48, 49 für den Druckmesser 12 ausgebildet sind und am zweiten Anschlussblockteil 66 Anschlüsse 68 für die Anschlussleitungen 42, 43 sowie die Bohrungen 50, 54 für die Heizelemente 56 und die Tem peratursensoren 52 ausgebildet sind. Entsprechend können verschiedene Druckmesser 12 verwendet werden, wozu lediglich der erste Anschlussblockteil 64 ausgetauscht werden m uss. In the present exemplary embodiment, the connection block is designed in two parts, with the connection openings 48, 49 for the pressure gauge 12 being formed on the first connection block part 64 and connections 68 for the connection lines 42, 43 and the bores 50, 54 for the heating elements 56 and the Tem peratursensoren 52 are formed. Accordingly, different pressure gauges 12 can be used, for which purpose only the first connection block part 64 has to be exchanged.
Soll nun ein Differenzdruck m ittels der Druckmessvorrichtung 10 gemessen werden, wird zunächst ein Spülen der Anschlussleitungen 42, 43 vorgenommen, wodurch Gasblasen aus dem Fluid über die Entlüftungsbohrungen 62, 63 entfernt werden. Anschließend werden die Entlüftungsbohrungen verschlossen. Gleichzeitig kann der Anschlussblock 20 auf eine gewünschte Temperatur aufgeheizt oder abgekühlt werden, indem die Heiz- und/oder Kühlelemente 56, 60 entsprechend der gemessenen Tem peratur der Tem peratursensoren 52 bestromt werden bis die Solltemperatur erreicht ist. Diese Tem peratur des Anschlussblocks 20 überträgt sich auch in kurzer Zeit auf das Außengehäuse 22 durch die großflächige Anbindung. Auch entsteht eine schnellere Aufheizung des Druckmessers 12 durch die großflächige Anbindung zwischen dem Anschlussblock 20 und dem Druckmessergehäuse 19. Da zusätzlich das Außengehäuse 22 den Druckmesser 12 umgibt, stellt sich im Druckmesser 12 die gewünschte Temperatur ein, die durch die um liegende Isolierung 32 auch leicht zu halten ist, da lediglich geringe Wärmemengen durch Strahlung übertragen werden. Auch wird ein Eindringen von Wärmestrahlung durch die reflektierende Oberfläche 34 verringert. Die folgende Differenzdruckmessung findet somit bei konstanten Temperaturen statt. If a differential pressure is now to be measured by means of the pressure measuring device 10, the connection lines 42, 43 are first flushed, as a result of which gas bubbles are removed from the fluid via the ventilation bores 62, 63. The ventilation holes are then sealed. At the same time, the connection block 20 can be heated or cooled to a desired temperature by the heating and/or cooling elements 56, 60 corresponding to the measured tem perature of the tem perature sensors 52 are energized until the target temperature is reached. This temperature of the connection block 20 is also transferred to the outer housing 22 in a short time due to the large-area connection. The pressure gauge 12 also heats up more quickly due to the large-area connection between the connection block 20 and the pressure gauge housing 19. Since the outer housing 22 also surrounds the pressure gauge 12, the desired temperature is set in the pressure gauge 12, which is also slightly due to the surrounding insulation 32 is to be maintained, since only small amounts of heat are transferred by radiation. Ingress of thermal radiation through the reflective surface 34 is also reduced. The following differential pressure measurement therefore takes place at constant temperatures.
Sollten sich dennoch im Anschlussblock 20 Tem peraturgradienten und dadurch entstehende Dichteunterschiede im Fluid oder im Anschlussblock 20 ergeben, so haben diese auch keinen großen Einfluss auf die Messungen, da m it dieser Anordnung im mer Durchschnittswerte über die Mem branen erm ittelt werden, weil die Dichteunterschiede normalerweise durch die konzentrische Anordnung der Druckmessorgane 14, 16 zu den Anschlussleitungen 42, 43 und die horizontale Ausbildung der Anschlussleitungen 42, 43 sowie die zentrisch Anordnung der Messfühler des Tem peratursensors 52 zu den Druckmessorganen 14, 16 nur in vertikaler Richtung auftreten können. Dichteänderungen bewirken bei dieser horizontalen Ausführung der Anschlussleitungen 42, 43 keine Änderung des hydrostatischen Drucks. Der Anschlussblock 20 wirkt auch bei schnellen Tem peraturschwankungen als Puffer bezüglich der Temperaturänderungen. However, should there be temperature gradients in the connection block 20 and the resulting differences in density in the fluid or in the connection block 20, these do not have a major impact on the measurements, since with this arrangement average values are always determined across the membranes because the density differences normally due to the concentric arrangement of the pressure measuring elements 14, 16 to the connecting lines 42, 43 and the horizontal design of the connecting lines 42, 43 and the centric arrangement of the sensors of the temperature sensor 52 to the pressure measuring elements 14, 16 can only occur in the vertical direction. With this horizontal design of the connection lines 42, 43, changes in density cause no change in the hydrostatic pressure. The connection block 20 also acts as a buffer with regard to the temperature changes in the event of rapid temperature fluctuations.
Entsprechend wird eine offene Druckmessvorrichtung geschaffen, mit der m it hoher Genauigkeit der Druck eines Fluids gemessen werden kann, wobei Messfehler durch Dichteunterschiede aufgrund von Expansion durch auftretende Tem peraturunterschiede verm ieden werden. Es sollte deutlich sein, dass der Schutzbereich nicht auf das beschriebene Ausführungsbeispiel begrenzt ist. So kann der Anschlussblock sowohl ein- als auch mehrteilig ausgeführt werden. Die Messung kann auch als Absolutdruckmessung m it nur einem Druckmessorgan und nur über eine Anschlussleitung erfolgen. Auch kann eine Anschlussleitung mit einer Flüssigkeit und die andere m it einem Gas beaufschlagt werden, wie dies beispielsweise bei der hydrostatischen Füllstandsmessung in einem Öloder Kraftstofftank erfolgt. I n diesem Fall kann auf die Entlüftungsbohrung an der Gasseite des Anschlussblocks verzichtet werden. Som it kann ein erfindungsgemäßer Differenzdruckmesser sowohl an einer durchströmten Leitung als auch an einem im Wesentlichen stillstehenden Fluid genutzt werden. Weitere auch konstruktive Änderungen ergeben sich ebenfalls für den Fachmann. Accordingly, an open pressure measuring device is created with which the pressure of a fluid can be measured with high accuracy, measurement errors due to density differences due to expansion due to temperature differences occurring being avoided. It should be clear that the scope of protection is not limited to the described embodiment. The connection block can be designed in one or more parts. The measurement can also be carried out as an absolute pressure measurement with only one pressure measuring element and only via one connection line. One connection line can also be charged with a liquid and the other with a gas, as is the case, for example, with hydrostatic level measurement in an oil or fuel tank. In this case, there is no need for a vent hole on the gas side of the connection block. Thus, a differential pressure gauge according to the invention can be used both on a line through which flow occurs and on a fluid that is essentially at a standstill. Other changes, including structural changes, are also apparent to those skilled in the art.

Claims

Patentansprüche Druckmessvorrichtung (10) m it einem Druckmesser (12) m it einem Druckmessorgan (14; 16), einer Anschlussleitung (42; 43) , über die der Druckmesser ( 12) mit einer Messmedienquelle (44) verbunden ist, dadurch gekennzeichnet, dass der Druckmesser ( 12) fluidisch m it einem Anschlussblock (20) verbunden ist, dessen Tem peratur über Heiz- und/oder Kühlelemente (56; 60) regelbar ist und in dem ein m it dem Druckmessorgan (14; 16) verbundener Abschnitt (40; 41 ) der Anschlussleitung (42; 43) ausgebildet ist. Druckmessvorrichtung nach Anspruch 1 , dadurch gekennzeichnet, dass der Anschlussblock (20) m ittels der Heiz- und oder Kühlelemente (56;Pressure measuring device (10) with a pressure gauge (12) with a pressure measuring element (14; 16), a connecting line (42; 43) via which the pressure gauge (12) is connected to a measuring medium source (44), characterized in that the pressure gauge (12) is fluidically connected to a connection block (20), the temperature of which can be regulated via heating and/or cooling elements (56; 60) and in which a section (40 ; 41) of the connection line (42; 43). Pressure measuring device according to claim 1, characterized in that the connection block (20) by means of the heating and or cooling elements (56;
60) auf eine konstante Tem peratur geregelt ist. Druckmessvorrichtung nach Anspruch 1 oder 2, dadurch gekennzeichnet, dass der Druckmesser ( 12) über ein Druckmessergehäuse ( 19) am Anschlussblock (20) befestigt ist und über eine Anschlussöffnung (48; 49) im Anschlussblock (20) fluidisch mit dem Anschlussblock (20) verbunden ist. Druckmessvorrichtung nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass die Anschlussleitung (42; 43) horizontal verläuft. Druckmessvorrichtung nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass im Anschlussblock (20) zum indest eine verschließbare Entlüftungsbohrung (62; 63) ausgebildet ist, die von der60) is regulated to a constant temperature. Pressure measuring device according to Claim 1 or 2, characterized in that the pressure gauge (12) is attached to the connection block (20) via a pressure gauge housing (19) and is fluidically connected to the connection block (20) via a connection opening (48; 49) in the connection block (20). connected is. Pressure measuring device according to one of the preceding claims, characterized in that the connecting line (42; 43) runs horizontally. Pressure measuring device according to one of the preceding claims, characterized in that in the connection block (20) at least one closable ventilation hole (62; 63) is formed, which is from the
Anschlussleitung (42;43) aufsteigend abzweigt und oberhalb der Anschlussleitung (42; 43) m ündet. Druckmessvorrichtung nach Anspruch 3 und 5, dadurch gekennzeichnet, dass die Entlüftungsbohrung (62; 63) zur Anschlussleitung (42; 43) im Bereich der Anschlussöffnung (48; 49) der Anschlussleitung (42; 43) zum Druckmesser ( 12) offen ist. Druckmessvorrichtung nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass der Druckmesser ( 12) in einem Außengehäuse (22) angeordnet ist, das m it dem Anschlussblock (20) verbunden ist und welches den Druckmesser ( 12) umgibt. Druckmessvorrichtung nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass der Anschlussblock (20) aus einem Material mit einer Wärmeleitfähig 3keit von über 100 — mK ist. Druckmessvorrichtung nach Anspruch 7, dadurch gekennzeichnet, dass das Außengehäuse (22) aus einem Material m it einer Wärmeleitfähig 3keit von über 100 — mK ist. Druckmessvorrichtung nach einem der Ansprüche 7 bis 9, dadurch gekennzeichnet, dass das Außengehäuse (22) und/oder der Anschlussblock (20) eine reflektierende, nach außen weisende Oberfläche (34) aufweisen. 17 1 . Druckmessvorrichtung nach einem der Ansprüche 7 bis 10, dadurch gekennzeichnet, dass das Außengehäuse (22) und der Anschlussblock (20) den Druckmesser ( 12) allseitig umgeben, wobei sich Seitenwände (24) des Außengehäuses (22) entlang von Seitenflächen (26) des Anschlussblocks (20) erstrecken. 2. Druckmessvorrichtung nach einem der Ansprüche 7 bis 1 1 , dadurch gekennzeichnet, dass an einer Seitenfläche (36) des Anschlussblocks (20) , welche zum I nneren des Außengehäuses (22) gerichtet ist, Stege (38) ausgebildet sind. 3. Druckmessvorrichtung nach einem der Ansprüche 7 bis 12, dadurch gekennzeichnet, dass das Außengehäuse (22) von einer Isolierung (32) umgeben ist. 4. Druckmessvorrichtung nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass der Druckmesser ( 12) ein Drucktransmitter m it einer Membran als Druckmessorgan ( 14; 16) ist, welche m it dem Fluid aus der Anschlussleitung (42; 43) beaufschlagt ist. 5. Druckmessvorrichtung nach einem der Ansprüche 3 bis 14, dadurch gekennzeichnet, dass der Durchmesser der Anschlussöffnung (48; 49) zum Drucktransm itter im Anschlussblock (20) zumindest so groß ist wie der Durchmesser der Mem bran. 6. Druckmessvorrichtung nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass 18 der Druckmesser ( 12) ein Differenzdruckmesser ist, wobei im Anschlussblock (20) der m it dem Druckmesser (12) verbundene Abschnitt (40) der ersten Anschlussleitung (42) und ein m it dem Druckmesser ( 12) verbundener Abschnitt (41 ) einer zweiten Anschlussleitung (43) ausgebildet sind. Druckmessvorrichtung nach Anspruch 16, dadurch gekennzeichnet, dass der Differenzdruckmesser ein Differenzdrucktransm itter m it zwei Druckmessorganen ( 14; 16) ist, wobei das erste Druckmessorgan ( 14) m it einem Fluid aus der ersten Anschlussleitung (42) beaufschlagt ist und das zweite Druckmessorgan ( 16) mit einem Medium aus der zweiten Anschlussleitung (43) beaufschlagt ist. Druckmessvorrichtung nach Anspruch 17, dadurch gekennzeichnet, dass die zwei Druckmessorgane (14, 16) auf gleicher Höhe angeordnet sind. Druckmessvorrichtung nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass ein Tem peratursensor (52) zur Regelung der Tem peratur des Anschlussblocks (20) bezüglich der Höhe m ittig zum Druckmessorgan ( 14; 16) angeordnet ist. Druckmessvorrichtung nach Anspruch 18, dadurch gekennzeichnet, dass der Temperatursensor (52) zentrisch zum Druckmessorgan (14; 16) oder sym metrisch zwischen den Druckmessorganen (14, 16) angeordnet ist. Druckmessvorrichtung nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass 19 der Anschlussblock (20) zweiteilig ausgeführt ist, wobei ein erstes Anschlussblockteil (64) die Anschlussöffnung (48; 49) zum Druckmesser (12) aufweist und das zweite Anschlussblockteil (66) einen Anschluss (68) zu der weiterführenden Anschlussleitung (42; 43) aufweist. Druckmessvorrichtung nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass an den Seitenflächen (26) des Anschlussblocks (20) oder in Bohrungen (54) im Anschlussblock (20) Heiz- und/oder Kühlelemente (56; 60) befestigt sind, die sym metrisch zu den Druckmessorganen ( 14, 16) oder zentrisch zum Druckmessorgan ( 14; 16) angeordnet sind. Connecting line (42; 43) branches off in ascending order and ends above the connecting line (42; 43). Pressure measuring device according to Claims 3 and 5, characterized in that the ventilation bore (62; 63) to the connection line (42; 43) is open in the region of the connection opening (48; 49) of the connection line (42; 43) to the pressure gauge (12). Pressure measuring device according to one of the preceding claims, characterized in that the pressure gauge (12) is arranged in an outer housing (22) which is connected to the connection block (20) and which surrounds the pressure gauge (12). Pressure measuring device according to one of the preceding claims, characterized in that the connection block (20) made of a material with a Thermal conductivity 3 of over 100 - mK. Pressure measuring device according to claim 7, characterized in that the outer housing (22) made of a material m ith a Thermal conductivity 3 of over 100 - mK. Pressure measuring device according to one of Claims 7 to 9, characterized in that the outer housing (22) and/or the connection block (20) have a reflective surface (34) pointing outwards. 17 1 . Pressure measuring device according to one of Claims 7 to 10, characterized in that the outer housing (22) and the connection block (20) surround the pressure gauge (12) on all sides, with side walls (24) of the outer housing (22) extending along side surfaces (26) of the Terminal blocks (20) extend. 2. Pressure measuring device according to one of claims 7 to 11, characterized in that webs (38) are formed on a side surface (36) of the connection block (20) which is directed towards the inside of the outer housing (22). 3. Pressure measuring device according to one of claims 7 to 12, characterized in that the outer housing (22) is surrounded by insulation (32). 4. Pressure measuring device according to one of the preceding claims, characterized in that the pressure gauge (12) is a pressure transmitter with a membrane as the pressure measuring element (14; 16) which is acted upon by the fluid from the connecting line (42; 43). 5. Pressure measuring device according to one of claims 3 to 14, characterized in that the diameter of the connection opening (48; 49) to the pressure transmitter in the connection block (20) is at least as large as the diameter of the membrane. 6. Pressure measuring device according to one of the preceding claims, characterized in that 18 the pressure gauge (12) is a differential pressure gauge, with the section (40) of the first connection line (42) connected to the pressure gauge (12) and a section (41) connected to the pressure gauge (12) in the connection block (20). second connection line (43) are formed. Pressure measuring device according to Claim 16, characterized in that the differential pressure gauge is a differential pressure transmitter with two pressure measuring elements (14; 16), the first pressure measuring element (14) being acted upon by a fluid from the first connecting line (42) and the second pressure measuring element ( 16) is acted upon by a medium from the second connecting line (43). Pressure measuring device according to Claim 17, characterized in that the two pressure measuring elements (14, 16) are arranged at the same level. Pressure measuring device according to one of the preceding claims, characterized in that a temperature sensor (52) for controlling the temperature of the connection block (20) with respect to the height is arranged centrally to the pressure measuring element (14; 16). Pressure measuring device according to Claim 18, characterized in that the temperature sensor (52) is arranged centrally to the pressure measuring element (14; 16) or symmetrically between the pressure measuring elements (14, 16). Pressure measuring device according to one of the preceding claims, characterized in that 19 the connection block (20) is designed in two parts, with a first connection block part (64) having the connection opening (48; 49) to the pressure gauge (12) and the second connection block part (66) having a connection (68) to the continuing connection line (42; 43 ) having. Pressure measuring device according to one of the preceding claims, characterized in that on the side faces (26) of the connection block (20) or in bores (54) in the connection block (20) heating and/or cooling elements (56; 60) are fixed which are symmetrically to the pressure measuring elements (14, 16) or centrally to the pressure measuring element (14; 16).
EP21830587.8A 2020-11-11 2021-11-10 Pressure measuring device Pending EP4237811A2 (en)

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ATA50973/2020A AT524398B1 (en) 2020-11-11 2020-11-11 pressure gauge
PCT/AT2021/060426 WO2022099341A2 (en) 2020-11-11 2021-11-10 Pressure measuring device

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US3247717A (en) * 1962-04-05 1966-04-26 Litton Systems Inc Air data pressure transducer apparatus
US5625152A (en) * 1996-01-16 1997-04-29 Mks Instruments, Inc. Heated pressure transducer assembly
TW354371B (en) * 1997-01-09 1999-03-11 Peter B Hutton A module valve manifold, a valve module and an integral valve manifold/differential pressure transducer/differential pressure transmitter
US6901803B2 (en) * 2003-10-02 2005-06-07 Rosemount Inc. Pressure module
JP2005164538A (en) * 2003-12-05 2005-06-23 Nissan Motor Co Ltd Pressure sensor
TW200946888A (en) * 2008-01-31 2009-11-16 Eagle Ind Co Ltd Heating device for pressure measurement and pressure measuring device
DE102008054226B4 (en) * 2008-10-31 2013-05-29 Highterm Research Gmbh Pressure sensing device and pressure detection method
US10996124B2 (en) * 2016-12-28 2021-05-04 Tubitak High accuracy pressure transducer with improved temperature stability
CN110793711A (en) * 2020-01-02 2020-02-14 西安西派测控技术有限公司 High-precision pressure transmitter

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US20240003767A1 (en) 2024-01-04
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