Flow measurement device, equipped with an electrical connection element

Abstract

Flow measurement device, equipped with an electrical connection element. Said flow measurement device (490) comprises a measuring bridge (400) and an electrical connection element (49) for a flow detector designed according to a hot-wire anemometry measurement principle, for the purpose of flow measurement. Multiple electrical contact assemblies (46), mounted on a substrate element (200) having a common equipotential surface (22), are intended to establish electrical contact between support elements (44) and resistance sensors C1 (55), W2 (66), and W1 (77) of said flow detector. Figure to be published with the abbreviation: Fig. 2

Description

Title of the invention: Flow measurement device, equipped with an electrical connection element

[0001] The present invention relates to a flow measurement device equipped with a flow detector, provided with an electrical connection element.

[0002] The operation of the flow detector is based on thermal anemometry, in particular in a design as a thermal anemometry comprising a plurality of hot metal wires implanted on support elements, designated as "hot wire anemometry".

[0003] Document DE 25 05 669 C3 discloses a sensor specifically used in medical technology to compensate, when measuring the volumetric flow of respiratory gas in a Wheatstone bridge setup, for the influence that the temperature of the measured gas, detected by means of a resistance measuring sensor designed as a metal wire, exerts on the measurement signal of the hot metal wire.

[0004] Measuring the volumetric flow rate of respiratory gas is an integral part of virtually all current respiratory and anesthesia devices. In hot-wire anemometry, a thin, heated metal wire, referred to as the "hot wire," is cooled by the measured volumetric flow rate of the gas, or circulating respiratory gas. The change in resistance of this hot wire then constitutes an estimation of said circulating volumetric flow rate.

[0005] According to document DE 101 33 120 Al, a circuit arrangement is known which includes two measuring bridges and is capable of determining, on the basis of three resistance measuring sensors, made as platinum wires arranged in a flow chamber designed as a measuring basin, both a flow rate and the direction of flow of the latter.

[0006] Within the platinum wires, as described in the aforementioned document DE 25 05 669 C3, two are used to measure the flow and the third resistance measuring sensor is used to compensate for the temperature.

[0007] The circuit arrangement of said document DE 101 33 120 Al makes it possible to compensate the temperature using a single resistance measuring sensor with respect to the temperatures of the gases present in the flow chamber for the two resistance measuring sensors.

[0008] A shadow-generating body is provided in the flow chamber to determine the flow direction, such that one of the three platinum wires, located in the shadow of said body in a given flow direction, receives an influx other than in the opposite flow direction. The drawback then lies in The situation arises where the shadow-generating body contributes to a significant voltage drop in the measuring basin, particularly at high flow rates. Consequently, it is advantageous to determine the flow direction by evaluating heat transfer between two resistance sensors of the flow detector, without necessarily resorting to a shadow-generating body.

[0009] To allow an evaluation of heat transfer with good reproducibility and sufficient accuracy, it is essential that the electrical signals between the resistance measuring sensors, in the flow detector and in the electronic components, be subject to modest influences, denaturations or losses.

[0010] Based on the prior art, the present invention aims to provide an electrical connection design between a flow detector and a measuring bridge which allows, with a minimum of errors, the evaluation of the determination of a flow rate and the determination of a flow direction.

[0011] According to a first aspect of the invention, the desired objective is achieved by a measuring device equipped with support elements, a minimum of four, on which at least two resistance measuring sensors are mounted. The device according to the invention comprises a measuring bridge and an electrical connection element, which serves to establish multiple pluggable electrical connections between said measuring bridge and a flow detector. Said flow detector is designed equipped with at least two resistance measuring sensors for the purpose of measuring flow rates according to the principle of hot-wire anemometry.

[0012] The measuring device according to the first aspect of the invention is provided with at least four support elements on which the resistance measuring sensors of the flow detector are implanted, with a minimum number of two.

[0013] According to an additional aspect of the invention, the targeted object is reached by a measuring device having a minimum of six support elements, on which at least three resistance measuring sensors are implanted.

[0014] Just like the measuring device according to the first aspect, this measuring device according to the additional aspect of the invention comprises a measuring bridge and an electrical connection element, the latter serving to establish a multiplicity of pluggable electrical connections between said measuring bridge and a flow detector, which flow detector is designed equipped with resistance measuring sensors of at least three, for the purpose of measuring flow rates according to the principle of hot-wire anemometry.

[0015] The objects, similarly achieved in the solutions conforming to the first aspect and the additional aspect of the invention, will now be discussed in more detail in a common context, in support of a common description in which common advantages are mentioned and differences, between the aforementioned aspects, are appropriately stated when noted.

[0016] The measuring device equipped with the measuring bridge is designed according to the principle of a Wheatstone bridge, also commonly referred to as a "Wheatstone resistance measuring bridge." A Wheatstone bridge is an electrical connection used for precise measurements of unknown resistance values. It normally consists of four resistors forming such a bridge configuration.

[0017] One of the resistors is frequently a temperature-sensitive resistor, generally a very precise platinum resistor, so that by means of the bridge assembly itself, minute temperature variations occurring on said platinum resistor can be technically detected and evaluated by a highly precise measurement. In thermal anemometry, a measuring bridge equipped with at least one hot metal wire is combined as a resistance measuring sensor.

[0018] The hot-wire sensor is most often made of a very thin platinum wire that is heated during the operation of the bridge assembly until it reaches a temperature above ambient temperature. If the hot wire is exposed to a flow, heat is transferred to the flow by the wire. This heat transfer results in a change in the resistance of the hot wire, which acts as a measuring effect in the bridge assembly and can be evaluated, depending on the operating mode of the measuring bridge, in constant current anemometry (CCA) or constant temperature anemometry (CTA) mode, in order to determine a flow velocity or flow rate in a flow channel of the flow detector.

[0019] The support elements are components of the flow detector and protrude, along with the resistance measuring sensors, into the flow channel of said flow detector on the detection side. Therefore, these elements can also be referred to as support elements located on the detection side. The support elements are brought into contact via the electrical connection element. This contact established via said connection element may then include, in addition to establishing the electrical contact, a mechanical coupling of the flow detector with the measuring bridge.

[0020] The arrangement of the measuring sensors, made for example and preferably as platinum wires, can be designed as a tensioned installation on the support elements, oriented towards the flow channel of the flow detector. The fixing of said resistance measuring sensors on the support elements or to the at the level of the latter, can be realized, for example and preferably, by means of a welding connection or a brazing connection.

[0021] The electrical connection element comprises a substrate element, which is provided with at least one common equipotential surface.

[0022] In accordance with the first inventive aspect, the electrical connection element has at least four electrical contact sets implanted on the substrate element. According to said first inventive aspect, this equipotential surface connects, with electrical conductivity, at least two of the four contact sets arranged on said substrate element.

[0023] In accordance with the additional inventive aspect, the electrical connection element has at least six electrical contact assemblies implanted on the substrate element.

[0024] This equipotential surface conforming to the additional inventive aspect connects to each other, with electrical conductivity, contacting assemblies with a minimum number of three within the six contacting assemblies implanted on the substrate element.

[0025] The electrical contact assemblies allow for direct electrical contact of the support elements, or alternatively, for electrical contact of said support elements with an optional line connection such as a cable power supply, for example. By means of this line connection, preferably and in particular of flexible design, the electrical connection element, and therefore also the flow detector, can be located at a distance from the measuring bridge, for example, positioned near the head region or the mouth / nose region of a patient.

[0026] In an arrangement of this type, the measuring device can allow, with the help of the electrical connection element, electrical contact sets, line connections and the measuring bridge, a flow measurement close to the patient operated, for example, on the "Y-piece".

[0027] The measuring bridge can then be designed as an integral part of a medical measuring device, an integral part of a breathing device or an integral part of an anesthesia device.

[0028] As an integral part of the substrate element in the electrical connection element, the equipotential surface creates a connection with a very low ohmic value and establishes, therefore, an equilibrium between the electrical potentials of the electrical contacts of the support elements electrically connected to each other, each time, through said equipotential surface.

[0029] Due to the grouping of several support elements in the equipotential surface, the electrical potentials of these support elements are combined with each other with a low ohmic value to obtain a common electrical potential.

[0030] This connection with very low ohmic value, by means of the equipotential surface, confers the advantage of the fact that the action exerted by contact resistance effects which may prove to be different, variable and random at the level of the contacting assemblies during the operation of the measuring device, following a plugging and unplugging, in particular a multiple plugging of the support elements at the level of said contacting assemblies, can be reduced with regard to the accuracy of the flow measurement.

[0031] In the measuring device, the equipotential surface makes it possible to ensure that the delivery of the supply energy from the measuring bridge to the resistance measuring sensors from said measuring bridge can take place, at the level of the electrical connection element, without potential differences between the support elements of the flow detector which are electrically connected in common.

[0032] An additional advantage of the arrangement of the equipotential surface in the electrical connection element, or even as an integral part of said connection element, results from the fact that comparatively, when all the support elements are individually brought into contact, a separate extension of one and / or two strand(s) in a wired junction, in the direction of the measuring bridge, would respectively result in a multi-strand cable having a multiplicity of strands.

[0033] An example in this regard is provided below in support of the measuring device having six support elements.

[0034] When making individual contact using two respective strands, with two contacting sets for each support element, a cable dedicated to the junction of the connecting element would give a number of twelve strands.

[0035] In the case of grouping of contact sets of three support elements, in the equipotential surface, two strands are necessary and there remain, each time, two strands at a rate of two contact sets for three respective support elements, therefore a number of six strands, which gives a total number of eight strands for the six support elements.

[0036] A direct advantage thus obtained lies in the fact that the diameter of such a cable, having eight strands, can be reduced by approximately fifty percent. As a result, such a cable can be lighter, more flexible, and less expensive, and offers improved handling for the user.

[0037] In a particularly preferred embodiment according to the invention, the electrical connection element is provided with contacting assemblies comprising double contact elements. These electrical contact assemblies are present in pairs, as double contact elements, and are mounted on the substrate element. Each of these double contact elements is designed to receive, each time, the same support element of the corresponding resistance measuring sensor.

[0038] In this way, the support elements are electrically connected to the measuring bridge via two electrical contacts each time. Line connections, respectively guided separately by means of the double contact elements and appearing, for example, as strands or as bundles of a connecting cable, can reach said measuring bridge at least from the support elements not connected to each other via the equipotential surface.

[0039] The connections of lines guided separately make it possible to obtain, over the entire connection from the support elements and reaching the measuring bridge, a separation of conduction paths of measuring lines which are assigned to the supply of current, i.e. to the supply of energy, so that said measuring lines are not subject to voltage drops of an order of magnitude likely to negatively influence, in terms of accuracy, the operation of said measuring bridge dedicated to the measurement of flow rates.

[0040] The combination of the double contact elements and the equipotential surface provides a cumulative advantage in the ability to guide measurement signals to the measurement bridge from the flow detector, without disturbing influence, by compensating currents between the cable junction and the measuring sensors in the connection element.

[0041] In a particularly preferred embodiment of the measuring device according to the invention, the double contact elements can be designed for connection, by means of the substrate element, to line connections of a connecting cable. Said connecting cable is designed to establish electrical contact with the measuring bridge by means of said line connections.

[0042] In a particularly preferred embodiment of the measuring device according to the invention, an arrangement may be provided consisting of a verification electrical contact element and a verification contact located on the detection side. Said verification electrical contact element may be mounted on the electrical connection element or on the substrate element and is designed to establish, at the level of said substrate element, an electrical connection between a measuring bridge and said verification contact located on the detection side. Said verification electrical contact element is then configured, relative to the support elements and said verification contact located on the detection side, such that, upon connection, a connection is made between said verification contact located on the detection side and said verification electrical contact element. of the flow detector to said electrical connection element, an electrically timed connection relative to the electrical connection established between all double contact elements and associated support elements.This design of a contacting configuration, consisting of the verification contact located on the detection side and the verification contact element on the connecting element, has the effect of ensuring that it is possible to detect, during a plugging process, a complete plugging and a connection of the support elements to the double contact elements with the establishment of a stable electrical contact, i.e. free from jiggle, of all the support elements with said double contact elements since the electrical connection, including the verification contact element and the verification contact located on the detection side, is established only when the complete plugging and the connection of the support elements to the double contact elements have already taken place.An interrogation of this electrical connection, including the verification contact element and the verification contact located on the detection side, using a continuity test, makes it possible to verify if, or even that, the said plugging process was successful with the establishment of an electrically conductive link between said verification contact element and said verification contact located on the detection side.

[0043] In a particularly preferred embodiment of the measuring device according to the invention, a control unit can be provided which, during the connection of the flow detector to the electrical connection element, upon closure of the circuit between the verification contact located on the detection side and the electrical verification contact element, triggers the activation of an electrical power supply or a voltage supply to the measuring bridge. This advantageously results in the aspect, described below, specifically concerning the functional reliability of said measuring device.The control unit can then be made in such a way that it is capable of conducting an electrical continuity test or a resistance measurement of the connection of the checking contact element and the checking contact located on the sensing side, for the purpose of verifying whether, or even that, the plugging process between said checking contact element and said checking contact located on the sensing side has been carried out successfully.

[0044] In the event that the insertion process between the verification contact element and the verification contact located on the detection side has been successfully carried out, such that a stable electrical connection has also been established between the support elements and the double contact elements, the control unit triggers an activation of the electrical power supply or the electrical voltage supply to the bridge of measure.

[0045] The control unit thus causes, for example by means of an electronic switching element (field-effect transistor, FET) or mechanical (relay), a switching of the electrical power supply in the combination including the measuring bridge, the wired junction and the flow detector equipped with the support elements and the resistance measuring sensors.

[0046] In a particularly preferred embodiment of the measuring device according to the invention, the control unit can be arranged for measuring electrical resistance. This unit can trigger, or perform, a resistance measurement at at least one of the resistance measuring sensors Cl, W2, and W1 of the flow detector, and specify and maintain, on this basis, a set of data concerning specific real-time values ​​of said detector.

[0047] The control unit is then improved accordingly to perform, in addition to and / or as an alternative to the electrical continuity test between the verification contact element and the verification contact located on the detection side, an electrical resistance measurement of the resistance measuring sensors placed on the support elements.

[0048] The control unit can, in addition, be designed to index and detect voltage signals from the measuring bridge, for example, technically detectable voltage signals by measurement carried out at the level of a precision measuring resistor or several precision measuring resistors; a current flow circulating in the measuring bridge, via the precision measuring resistor(s); and resistance measuring sensors, namely, for example, heated platinum wires connected in series with the precision measuring resistor or with several precision measuring resistors, and to determine, on this basis, a real-time flow state at the level of a resistance measuring sensor or real-time flow states at the level of several resistance measuring sensors.Based on the flow state determined in real time, or on the flow states determined in real time, said control unit can concretely specify a flow measurement or flow measurement function, and then represent globally the flow measurement device, i.e. a flow detector, using the support elements, the resistance measuring sensors, the electrical connection element, the line connections, the double contacts and the equipotential surface.

[0049] In an optional design, such a flow detector may be supplemented by a pairing or combination of the checking contact element and the checking contact located on the detection side.

[0050] In advantageous arrangements of the embodiments shown, the double contacts can be used in such a way that, under the action of one of the contacts established by said double contacts, the service current emanating from the measuring bridge is sent to the sensor considered to measure resistance on the support elements, via the line connections and the electrical connection element, and the electrical resistance measurement is performed by the other respective contact established by said double contacts.

[0051] A measurement technique of this type is also designated as a "four-conductor measuring device," equipped with four lines (drive_L, drive_2, sense_l, sense_2). In said four-conductor device, a known measuring electric current flows through the resistance to be measured via two current supply lines (drive_l, drive_2'). The voltage drop across this resistance is measured, with a high ohmic value, via two additional lines (sense_l, sense_2). The ultimate advantage is that voltage drops caused by resistances in said current supply lines (drive_l, drive_2') do not distort the measured resistive value of said resistance to be measured.

[0052] The control unit may also be designed to detect, by means of measurement techniques, other voltage signals from the measuring bridge in addition to the resistance measurement of the resistance measuring sensors and the measurement voltages at the precision measuring resistors. The supply voltage and / or the supply voltage of said measuring bridge are, for example, included in these considerations.

[0053] Details concerning the measuring bridge, such as measuring voltages at precision measuring resistors, supply voltage or supply voltage of said bridge, will be highlighted below by [Fig.4] of the accompanying drawings, in support of the numerical references and associated designations set forth in the appropriate list, as well as in support of the description relating to the figures.

[0054] In a particularly preferred embodiment of the measuring device according to the invention, a set of comparative data can be stored in a data storage element. This storage element can be designed to complement the verification contact located on the detection side, or to be coupled to said verification contact located on the detection side, or even to the substrate element.

[0055] Such a data storage element can, for example, take the form of an Eprom, an EEProm or an RFID tag, and be assigned to the storage of a set of data.

[0056] Data such as a manufacturing date for the flow detector, an obsolescence date for said flow detector, characteristic data, or at least a characteristic curve for said flow detector, may, for example, be stored or memorized in the dataset. Said dataset may also be designed as a comparative dataset that can be used, by the control unit, for the purpose of comparison with data specified in real time during the operation of said flow detector, or with other data.

[0057] In a particularly preferred embodiment of the measuring device according to the invention, the control unit can be designed to perform, using the dataset concerning specific real-time values ​​of the detector, a comparison with values ​​from a comparative dataset. Such a comparison can serve, particularly with the addition of characteristic data or characteristic curves, on the one hand to potentially correct flow measurement values ​​and also, on the other hand, to determine a state of the flow detector or to specify a functional capability of said detector. For this purpose, said comparative dataset may, for example, include the following data: - specific detector data that can be specified during a check, as part of a zero balancing of said flow detector; - specific detector data that can be specified during a check, as part of the production of said flow detector; - specific historical data from the detector that could be specified during operation in measurement mode of said flow detector; and - typical operational data for said flow detector or for the measuring bridge when operating in measurement mode.

[0058] In a particularly preferred embodiment of the measuring device according to the invention, the specific detector data or typical operational data may include the following parameters: - cold resistance measurement values ​​of Cl, W2 and W1 resistance measuring sensors Or - hot resistance measurement values ​​of said Cl, W2 and W1 resistance measuring sensors Or - voltage signals from the measuring bridge, indicating current flow in one of the said resistance measuring sensors; - voltage signals from said measuring bridge, indicative of current flow in a precision measuring resistor; and - voltage signals of said measuring bridge, indicative of a functional state of said measuring bridge.

[0059] Within the voltage signals, mention will be made for example of a supply voltage of the power supply (U+) and / or a supply voltage of the bridge, as well as measurement voltages at the level of the precision measurement resistors of said measurement bridge.

[0060] In the spirit of the present invention, "cold resistances" should be understood as the resistance measurement values ​​of the resistance measuring sensors, that is to say, in particular, platinum resistance wires, which have been specified, during an electrical supply, by a measurement current causing a temperature level of said measuring sensors substantially identical to the ambient temperature in a range of about 20 °C to 30 °C, or up to about 10 °C above said ambient temperature.

[0061] For the purposes of this invention, "hot resistances" should be understood as resistance measurement values ​​of resistance measuring sensors that have been specified, during an electrical supply, by a measurement current causing a temperature level of said measuring sensors located in a range of about 50 °C to 150 °C above ambient temperature.

[0062] Regarding detailed information about voltages in the measuring bridge, measurement voltages at the precision measuring resistors, supply voltage, bridge supply voltage and other aspects of said measuring bridge, it is likewise appropriate, at this stage of the description, to refer to [Fig.4] of the drawings attached in support of the reference list, and to the descriptions relating to the figures.

[0063] In a particularly preferred embodiment of the measuring device according to the invention, the control unit can be designed to specify, based on comparison, an indicative estimating criterion for the functional availability of the flow detector, and to provide an output signal indicative of said functional availability. This output signal can deliver, to a user as well as to a system operating over the measuring device, such as, for example, a respiratory system or an anesthesia system, or even a data network, information to establish whether said measuring device and / or the flow detector is (are) functionally available in principle, and / or information establishing the measurement accuracy of said flow detector operating in real time, or the expected accuracy during subsequent operation.

[0064] It is now appropriate to comment on the invention in more detail with support of the figures set forth below and the associated description, without imposing any restrictions on the inventive idea in its generality.

[0065] On the attached drawings:

[0066] [Fig.1] is a schematic illustration of a pluggable electrical connection;

[0067] [Fig.2] is a schematic overview view of said pluggable electrical connection featuring a measuring bridge;

[0068] [Fig.3] is a schematic representation of a variant of the plug-in electrical connection according to [Fig.1]; and

[0069] [Fig.4] 4 shows a flow detector integrated into a measuring bridge.

[0070] Figure 1 is a schematic illustration of a pluggable electrical connection 49 having a redundant contact assembly 45, 46, 47, for a flow detector. The representation shows resistance measuring sensors Cl 55, W2 66 and W1 77 designed as platinum wires stretched over support elements 44, attached by brazing or welding and provided with contact assemblies 46 adapted to said support elements 44 and comprising two double contact elements 45 and 47. If, in an example design, the support elements 44 are made in the form of round rods or pins 44', the contacting assemblies 46 are designed as round female sockets 46' appearing, for example, as a female socket 45' applying to all the contacting assemblies 46 and 46' illustrated, by way of example, only on the W1 77 resistance measuring sensor in order to provide visibility on this [Fig.1].

[0071] The two double contact elements 45 and 47 establish contact with each of the support elements 44, so that a double contact is established and each of the resistance measuring sensors Cl 55, W2 66 and W1 77 (i.e. each of the platinum wires) is connected with electrical conductivity, by means of four contacting sets, to a common connecting element 48.

[0072] From the common connection element 48, the resistance measuring sensors Cl 55, W2 66 and W1 77 are electrically connected, by means of contact areas 42, 43 and line connections 41, 41', to a measuring bridge 400 only evoked by some electronic components 56, 57, 58, 80, 80' and 90 on the [Fig.1].

[0073] The contact zones 42 electrically connect, each time, the double contact elements 45 and 47 (as illustrated, by way of example, in [Fig. 1] for a support element 44 of the Cl 55 resistance measuring sensor), via an equipotential surface 22 located in the common connection element 48, until reaching the measuring bridge 400 by way of the line connections 4L

[0074] The contact areas 43 guide the double contact elements 45 and 47 (which [Fig.1] represents, by way of example, for a support element 44 of the W2 77 resistance measuring sensor), each time distinctly in the common connection element 48, until reaching the measuring bridge 400 via the line connections 41'.

[0075] Other illustrations and comments, relating to the pluggable electrical connection 49 provided with the equipotential surface 22, are highlighted by [Fig.2],

[0076] Other representations and comments, concerning the measuring bridge 400 in detail, are highlighted by [Fig.2] and by [Fig.4] in particular.

[0077] Figure 2 is a schematic illustration of the electrical connection element 48 according to Figure 1, equipped with an equipotential surface 22 forming part of a pluggable electrical connection 49 for a flow detector, for contacting the resistance measuring sensors Cl 55, W2 66, and W1 77, as shown in Figure 1, with a measuring bridge 400. This bridge 400, connection 49, and sensors Cl 55, W2 66, and W1 77 together form a measuring device 490 for measuring flow rates. In Figures 3 and 4, elements identical to those in Figures 1 and 2 are designated by the same reference numerals.

[0078] The electrical connection element 48 forms one side of a connecting cable having line connections 41, 41' and 81 ([Fig.3]) and allows contact, on the detection side, of three sensors Cl 55, W2 66 and W1 77 measuring the resistance of a flow detector.

[0079] The other end of the connecting cable is connected by contact areas 40, the type and arrangement of which are not precisely defined, by means of line connections 41, 41' and 81 ([Fig.3]), to a measuring bridge 400 having a control unit 100 and electronic components 56, 57, 58, 67, 75, 78, 79, 80 and 80', with a voltage supply (U+) 90 and a ground potential (0V) 99.

[0080] In addition, schematically referred to are electrical connection zones which also ensure the contact of the resistance measuring sensors of the flow detector and, by way of example, some electronic components of the measuring bridge 400 such as resistors, resistor networks, amplification circuits [operational amplifiers (OP AMP)] and field-effect transistors (FET) targeting a visualization of how the electrical contacts and connections with the resistance measuring sensors Cl 55, W2 66, W1 77 and with a measuring bridge 400, 408 ([Fig.3]) can cooperate, for example, to perform a function as a flow detector.

[0081] The principle function as a flow detector equipped with a measuring bridge 400 is explained with regard to [Fig.4], so that, in the description relating to [Fig.2], the main objective is focused on explanations relating to a cooperation bringing into contact the resistance measuring sensors Cl 55, W2 66 and W1 77, with said measuring bridge 400, via electrical contact zones 42 and 43 and via the equipotential surface 22.

[0082] Electrical contacts of the type illustrated in [Fig. 1], and described in detail, are shown for the redundant connection of three resistance measuring sensors Cl 55, W2 66 and W1 77. Each of the three sensors Cl 55, W2 66 and W1 77 is fixed, in an electrically conductive manner, to two respective support elements 44.

[0083] Within the support elements 44, of which there are six in total, three elements 44 are each time brought into contact with double contact elements 45 and 47 (preferably designed as female sockets), distinctly via the contact areas 43, and are connected to the measuring bridge 400, each time distinctly, via individual line connections 41'.

[0084] Of the six support elements 44, three elements 44 are each brought into contact with double contact elements 45 and 47 (preferably implemented as female connectors) via the equipotential surface 22, and are centrally grouped such that the three resistance measuring sensors Cl 55, W2 66, and W1 77 each have an identical voltage potential on their respective sides. The contact areas 42 electrically group said elements 45 and 47, each time via said surface 22, and guide them to the measuring bridge 400 through the line connections 4L

[0085] The voltage drops occurring at the resistors 75 and 67, in the measuring bridge 400, are delivered to the control unit 100 as voltage signals Ui 71 and U2 62 and are evaluated, by said unit 100, for a qualitative determination 103 of the flow rate and a directional identification 102 thereof. Said unit 100 may further be designed to integrate, for evaluation purposes, data and / or information relating to the flow detector such as, for example, parameters or properties of the three resistance measuring sensors Cl 55, W2 66 and W1 77; and to specify or detect therefor, by means of an indicator 104, a functional state and / or defective states of said flow detector comprising said sensors Cl 55, W2 66 and W1 77, said measuring bridge 400, the line connections 41, 41' and 81 ([Fig.3]), of the contact areas 40, 42, 43 and 82 ([Fig.3]), and the contacting assemblies 46 featuring double contact elements 45 and 47 in cooperation with support elements 44. .

[0086] Examples will be cited as properties of the three resistance measuring sensors Cl 55, W2 66 and W1 77, resistive values ​​such as hot platinum resistances, cold platinum resistances, characteristic curves or support points of characteristic curves of said sensors Cl 55, W2 66 and W1 77, or even typical voltage signals 62 and 71 of the measuring bridge 400.

[0087] Data and / or information relating to the flow detector, such as properties of the three Cl 55, W2 66 and W1 77 resistance measuring sensors, may then be stored in a data memory 101 which can, for example, be jointly arranged in the form of an EEProm on said flow detector, and is designed to provide data and / or information in the form of a data set Z, in an extended measuring bridge 408 ([Fig.3]) of the control unit 100, by means of the pluggable electrical connection 49 and contact areas 82 ([Fig.3]).

[0088] The common connection element 48, comprising the double contact elements 45, 46, the equipotential surface 22 and the contact areas 42, 43, can be materialized by a substrate element 200 having, for example, the form of a printed circuit board (PCB) and being able to be located in the pluggable electrical connection 49. Said connection 49 can preferably be designed as an electrical connection element provided with a multi-pole housing in which said substrate element 200 is jointly located.

[0089] Figure 3 is a schematic representation of a variant of the plug-in electrical connection 49 according to Figure 1, dedicated to a flow detector, comprising a test contact element 33, a test contact 88 located on the detection side, the measuring bridge 400 conforming to Figure 2, and an extended measuring bridge 408. The reference numeral 300 is assigned to a difference in height between the support elements 44 and said test contact 88. In Figures 1, 2, and 3, identical elements are designated by the same numerical reference numerals.

[0090] The schematic illustration shows how, when the support elements 44 of the resistance measuring sensors Cl 55, W2 66 and W1 77 are connected to the double contact elements 45 and 47, following the electrical contact established between said support elements 44 and said double contact elements 45 and 47, an electrical contact is established between the verification contact 88 located on the sensing side and the verification contact element 33, either in the sequence or at a later stage. The closure of the circuit between said verification contact 88 and said element 33, by means of contact areas 82 and connecting lines 81, can be evaluated by the extended measuring bridge 408, using a comparator circuit equipped with electronic components 83 and 84, and then delivered to the control unit 100 in the form of a status signal 85.

[0091] The control unit 100 can convert the status signal 85 into a switching signal 85' and activate a switching element 89, using said signal 85', in order to directly switch the supply voltage 90 from the measuring bridge 400 to the resistance measuring sensors Cl 55, W2 66 and W1 77, and to validate said voltage, thereby starting the operation of the flow detector. This results in the advantageous situation whereby electrical power is supplied to said sensors Cl 55, W2 66 and W1 77 only when a connection is present. electrically safe and successful, with said measuring bridge 400, of all contact areas 42 and 43 of the common connection element 48 of the pluggable electrical connection 49. This effectively prevents potential contact establishment problems occurring during the electrical connection between said bridge and said common element 48, and the resulting potential malfunctions or damage affecting said sensors Cl 55, W2 66 and W1 77.

[0092] Figure 4 schematically represents, by way of example, a basic function of a flow detector integrated into a measuring bridge 400. The illustration shows said detector equipped with three resistance measuring sensors Cl 55, W2 66, and W1 77, in a configuration with electronic components, without representation of a measuring cup fulfilling the function of a measuring chamber and without explicit representation of the pluggable electrical connections as shown in Figures 1, 2, and 3. In Figures 1, 2, 3, and 4, identical elements are designated by the same numerical references. This illustrated configuration can, in principle, be used in an operating mode applied to constant temperature anemometry (CTA).

[0093] The illustration shows three resistance measuring sensors Cl 55, W2 66 and W1 77, made as platinum wires stretched over support elements 44 ([Fig. 1]) and attached by brazing or welding. The three sensors Cl 55, W2 66 and W1 77 are arranged together in a measuring cup that can be traversed in two flow directions.

[0094] The Cl 55 resistance measuring sensor is used, in detection mode, as a resistance measuring sensor dedicated to temperature compensation of a measurement gas circulating in the measurement bowl of the flow detector.

[0095] The W1 77 resistance measuring sensor is used, in detection mode of the measuring bridge 400, to detect the flow rate of the measurement gas circulating in the measurement basin of the flow detector. The W2 66 resistance measuring sensor is used, in detection mode, to detect the flow direction of the measurement gas circulating in said measurement basin of said flow detector.

[0096] The electronic components, including a balancing resistor 56, additional resistors 67 and 75, resistor networks 57, 58, 78 and 79, a circuit (operational amplifier) ​​80' assigned to the formation of a regulation difference and an active element (field-effect transistor) 80 for adjustment and switching, allow a supply 90' of the measuring bridge 400 to be regulated in such a way that there is, at the level of the resistance measuring sensor W1 77, a temperature having a constant difference above the temperature of the measuring gas circulating in the measuring basin.

[0097] The balancing resistor 56 is dedicated to balancing, at a well-defined working point, the components 57, 58, 67, 75, 78, 79, 80 and 90 of the circuit including the resistance measuring sensors Cl 55, W2 66 and W1 77, without any flow at the level of said sensors Cl 55, W2 66 and W1 77.

[0098] In one design variant, the balancing resistor 56 can be made in the form of a balancing element, for example as an analog or digital potentiometer, or even as an arrangement with a digital / analog converter, with the help of which automated balancing can be carried out via a control unit 100 ([Fig.2]), by means of a microcontroller pC for example.

[0099] Resistors 67 and 75 are preferably designed as precision measuring resistors since the voltage signals Ui 71 and U2 62, applied to these resistors, correspond to the variations in electric current which flow into the measuring bridge 400, during a variation in the flow, and represent an estimating criterion of variations or increases in flow at the level of the resistance measuring sensors W2 66 and W1 77.

[0100] A qualitative determination 102 ([Fig.2]) of the flow rate can be carried out by a control unit 100 ([Fig.2]) in support of an evaluation of the voltage signals Ui 71 and U2 62.

[0101] A directional identification 102 ([Fig.2]) of the flow can be carried out by a control unit 100 ([Fig.2]) by means of a comparison of the voltage signals Ui 71 and U2 62. These signals Ui 71 and U2 62 make it possible to detect whether there is a heat transfer caused by the flow in a flow state towards the resistance measuring sensor W1 77 from the resistance measuring sensor W2 66, or towards said sensor W2 66 from said sensor W1 77.

[0102] It is thus possible to detect, in addition to a quantitative state 103 ([Fig.2]) of the flow, a flow direction 102 ([Fig.2]) of the latter in the flow detector.

[0103] It is understood that many modifications can be made to the invention as described and illustrated, without departing from the scope of the content disclosed in this memorandum.

[0104] Thus, the above-described embodiments represent, in each case, particular designs considered in themselves, as well as in a combination or in mutual combinations. All possible additional embodiments and their advantages, resulting from a combination or combinations of several embodiments, are likewise encompassed in the inventive idea, even if all the possible combinations of embodiments are not respectively described in detail.

[0105] The elements, objects, indications and information illustrated in the figures are referenced as follows:

[0106] 22: equipotential surface

[0107] 33: monitoring contact, checking contact element

[0108] 40: contact areas of the connecting cable

[0109] 41, 41': Connections of the connecting cable lines with the measuring bridge

[0110] 42, 43: contact areas with the measuring bridge [YES] 44, 44': support elements, pins

[0112] 45, 45': double contact elements, elements with double female sockets

[0113] 46, 46': contacting assembly, assemblies with female sockets and pins

[0114] 47: double contact elements, elements with double female sockets

[0115] 48: common connection element

[0116] 49: electrical connection element, pluggable electrical connection

[0117] 55: Cl resistance measuring sensor

[0118] 56: balancing resistor, balancing element

[0119] 57, 58: network of resistors, resistors

[0120] 62: bridge measurement voltage U2

[0121] 66: W2 resistance measuring sensor

[0122] 67: resistance, precision measuring resistance

[0123] 71: bridge measurement voltage Ui

[0124] 75: resistance, precision measuring resistance

[0125] 77: W1 resistance measuring sensor

[0126] 78, 79: network of resistors, resistors

[0127] 80, 80': active element (FET, OP AMP) for adjustment and switching

[0128] 81: Junction cable line connections

[0129] 82: Data memory contact areas

[0130] 83, 84: electronic components, comparator circuit resistors

[0131] 85: contact closure status signal

[0132] 85': switching signal

[0133] 88: Verifier contact located on the detection side

[0134] 89: switching element

[0135] 90: supply voltage, power supply, voltage source, U+

[0136] 90': bridge supply voltage

[0137] 99: ground potential, 0V

[0138] 100: measuring bridge control unit

[0139] 101: data memory, EPROM, EEPROM, RFID

[0140] 102: flow direction

[0141] 103: magnitude of the flow

[0142]

[0143]

[0144]

[0145]

[0146]

[0147]

[0148] 104: indicator of a functional or defective state 200: substrate element, plate 300: contact difference between the detection side and the verification contact <-> support elements 400: measuring bridge 408: extended measuring bridge 490: flow measurement device Of course, the invention is not limited to the embodiments described and shown in the accompanying drawings. Modifications remain possible, particularly with regard to the construction of the various elements or by substitution of technical equivalents, without departing from the scope of protection of the invention.

Claims

Demands

1. A measuring device (490) comprising a measuring bridge (400) and an electrical connection element (49) for a flow detector, for establishing multiple pluggable electrical connections between said measuring bridge (400) and support elements (44), a minimum of four, of at least two resistance sensors Cl (55) and W1 (77) of said flow detector designed according to a hot-wire anemometry measurement principle, for the purpose of measuring flow rates, having a minimum of four electrical contact assemblies (46) mounted on a substrate element (200), the measuring device characterized in that the substrate element (200) is provided with at least one common equipotential surface (22) which electrically conducts between the contact assemblies (46), a minimum of two within the four contact assemblies (46). contact.

2. A measuring device (490) comprising a measuring bridge (400) and an electrical connection element (49) for a flow detector, for establishing multiple pluggable electrical connections between said measuring bridge (400) and support elements (44), a minimum of six, of at least three resistance sensors Cl (55), W2 (66) and W1 (77) of said flow detector designed according to a hot-wire anemometry measurement principle, for the purpose of measuring flow rates, having a minimum of six electrical contact assemblies (46) mounted on a substrate element (200), the measuring device characterized in that the substrate element (200) is provided with at least one common equipotential surface (22) which electrically conducts between the assemblies (46), a minimum of three of which are within the six assemblies (46) of making contact.

3. A measuring device (490) according to claim 1, characterized in that the electrical contact assemblies (46) are present in two forms, as double contact elements (45, 47), and are mounted on the substrate element (200), each of said double contact elements (45, 47) being designed to receive, at each time, the same support element (44) of the corresponding resistance measuring sensor.

4. Measuring device (490) according to claim 3, characterized in that the double contact elements (45, 47) are designed for connection, by means of the substrate element (200), to line connections (41, 41') of a connecting cable; and in that said connecting cable is designed to establish electrical contact with the measuring bridge (400) by means of said line connections (41, 41').

5. A measuring device (490) according to any one of claims 1 to 4, characterized in that a verifying electrical contact element (33) is implanted on the electrical connection element (49) or on the substrate element (200) in order to establish, at the level of said substrate element (200), an electrical connection between a measuring bridge (400; 408) and a verifying contact (88) located on the detection side, said verifying electrical contact element (33) being configured, relative to the support elements (44) and said verifying contact (88) located on the detection side, such that, when the flow detector is connected to said electrical connection element (49), there results in an electrically timed connection between said verifying contact (88) and said verifying contact element (33) that is timed relative to the electrical connection established between all the double contact elements (45, 47) and the support elements. (44) associates.

6. Measuring device (490) according to claim 5, characterized in that said measuring device (490) is equipped with a control unit (100) which, during the connection of the flow detector to the electrical connection element (49), upon closure of the circuit between the verification contact (88) located on the detection side and the verification contact element (33), triggers the activation of an electrical power supply or an electrical voltage supply (90) to the measuring bridge (400; 408).

7. A measuring device (490) according to claim 6, characterized in that the control unit (100) is designed to trigger or perform an electrical resistance measurement at at least one of the flow detector resistance sensors Cl (55), W2 (66) and W1 (77), and to specify and maintain on this basis, a set of data concerning specific real-time values ​​of said detector is available.

8. Measuring device (490) according to any one of claims 5 to 7, characterized in that a comparative data set is stored in a data storage element (101), knowing that said element (101) complements the verification contact (88) located on the detection side, or that said element (101) is coupled to said verification contact (88) located on the detection side, or even to the substrate element (200).

9. Measuring device (490) according to claim 7 and claim 8, characterized in that the control unit (100) is designed to perform, using the dataset concerning specific real-time values ​​of the detector, a comparison with values ​​from a comparative dataset, which comparative dataset comprises: - specific detector data that can be specified during a check, within the framework of a zero balancing of said flow detector; - specific detector data that can be specified during a check, within the framework of a production of said flow detector; - specific historical detector data that could be specified during operation in measurement mode of said flow detector;and - typical operational data for said flow detector or for the measuring bridge (400) during operation in measurement mode.;

10. Measuring device (490) according to claim 9, characterized in that the detector-specific data or typical operating data include: - cold resistance measurement values ​​of the Cl (55), W2 (66) and W1 (77) resistance measuring sensors or - hot resistance measurement values ​​of said Cl (55), W2 (66) and W1 (77) resistance measuring sensors or - voltage signals (62, 71) from the measuring bridge (400) indicating current flow in one of said resistance measuring sensors; - voltage signals from said measuring bridge, indicating current flow in a precision measuring resistor; and - voltage signals (90, 90') from said measuring bridge (400), indicating a functional state of said measuring bridge.

11. Measuring device (490) according to claim 9 or claim 10, characterized in that the control unit (100) is designed to specify, on the basis of comparison, an indicative estimating criterion of a functional availability of the flow detector, and to provide an output signal indicative of said functional availability.

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