DE102022120418A1 - Device and method for calibrating a level measuring device - Google Patents

Abstract

The invention relates to a device (1, 20, 30) and a method (100, 200) for calibrating a level measuring device (2) with a sensor (3) for monitoring the level. The device has a calibration housing (4) with a connection side (5) for arranging the level measuring device (2), at least one reflector (recorded in the calibration housing (4) and arranged at a fixed distance (d, d2, d3) from the connection side (5). 6, 21, 22) in order to reflect waves (7) emitted by the sensor (3) to the level measuring device (2) when the level measuring device (2) is arranged on the connection side (5), and an evaluation unit (8) which is set up , to receive a measurement result of a level measurement carried out by the sensor (3) in the state of the level measuring device (2) arranged on the connection side (5), to compare the measurement result with the specified distance (d, d2, d3) and a result of the comparison using a Signaling unit (9) to signal.

Description

The invention relates to a device and a method for calibrating a level measuring device which has a sensor for level monitoring.

Level measuring devices are usually used in containers, which can be designed as tanks or silos for storing various materials. For example, food, drinks, medicines or fuel are stored in such tanks or silos, so non-contact level measurement is necessary. In the prior art, for example, level determinations based on radar waves or ultrasonic waves are known as non-contact level measurement techniques. Due to their high measurement accuracy and low susceptibility to interference, radar level measuring devices are widely used.

It may be necessary to check the calibration of sensors from time to time and possibly take countermeasures if deviations are detected, for example readjusting or replacing the sensor. To do this, it may be necessary to remove the sensor from the measuring point and check it in a separate measuring device, which is naturally very time-consuming.

For example, the patent describes a functional check of a sensor for level measurement directly at the measuring point EP 2 829 852 B1 . This stipulates that a reflector is automatically brought into the beam path of the radar wave-based fill level sensor automatically by means of a drive at a detection distance of a safety-relevant maximum fill level. The signal reflected by the reflector is used to determine whether the sensor can reliably detect the maximum fill level.

Against this background, the invention is based on the object of providing a device and a method for calibrating a level measuring device with a sensor for level monitoring, which work reliably and accurately and enable the need for calibration of the level measuring device without a lot of assembly and time effort. They should continue to be flexible to use and easy to use and implement.

This object is achieved by a device with the features of claim 1 and by a method with the features of claim 13. Further, particularly advantageous embodiments of the invention are disclosed in the respective subclaims.

It should be noted that the features listed individually in the claims can be combined with one another in any technically sensible manner (including across category boundaries, for example between method and device) and show further refinements of the invention. The description additionally characterizes and specifies the invention, particularly in connection with the figures.

It should also be noted that a conjunction “and/or” used here between two features and linking them together must always be interpreted in such a way that only the first feature can be present in a first embodiment of the subject matter according to the invention, and only in a second embodiment the second feature can be present and in a third embodiment both the first and the second feature can be present.

Additionally, as used herein, a term “about” is intended to indicate a range of tolerances that would be considered common to those skilled in the art. In particular, the term “approximately” is understood to mean a tolerance range of the related size of up to a maximum of +/-20%, preferably up to a maximum of +/-10%.

According to the invention, a device for calibrating (herein also referred to as a calibration device for simplicity) a level measuring device with a sensor for level monitoring has a calibration housing with a connection side for arranging the level measuring device, further at least one reflector accommodated in the calibration housing and arranged at a fixed distance from the connection side, in order to Arrangement of the level measuring device on the connection side to reflect waves emitted by the sensor (in particular electromagnetic or acoustic waves) to the level measuring device, and an evaluation unit which is set up to receive a measurement result of a level measurement carried out by the sensor in the state of the level measuring device arranged on the connection side, the measurement result to compare with the specified distance and to signal a result of the comparison using a signaling unit.

Level measuring devices are used to record filling levels and levels by measuring the distance to the filling material. These level measuring devices must be checked (herein also referred to as calibrating) and possibly (re)adjusted (herein also referred to as correcting) at certain intervals. For non-contact level measuring devices, especially those that use ultrasound or free radiation To work with radar (i.e. microwave-based), the reflector is arranged at a certain distance on the level measuring device in such a way that it generates an echo signal, and the measured value determined from this is compared with the actual distance. The result of this comparison, in particular whether a deviation of the distance measured with the sensor from the distance determined by the calibration device is within predetermined limits or not, is signaled by the calibration device. This means that a function check of the sensor can be carried out quickly and easily, in particular without removing the sensor, and any necessary adjustment can be initiated or carried out automatically. The calibration device is particularly easy to operate because it only needs to be positioned on its connection side on the level measuring device. In general, no other devices such as laptops or smartphones are necessary for calibration (i.e. checking) or adjustment (i.e. correction) or sensor testing. After a correction/adjustment has been made, a new calibration/check can be initiated.

The signaling of the comparison result can only include exceeding or not exceeding a predetermined maximum difference between the measurement result of the sensor and the specified distance of the reflector to the connection side, for example optically by means of a signaling light (e.g. LED) arranged on the calibration device and/or acoustically by means of a Signaling sounds and/or haptic by vibrating. Additionally or alternatively, quantitative signaling of the difference determined by the evaluation unit can also take place, for example by means of an (alpha) numerical display, a gradient fill (brightness and/or color) of a graphic display element or similar. A signaling light or display can be freely configurable be, e.g. E.g. steady on, flashing, color, etc. Different feedback statuses can also be visually represented by different colors or color gradients, e.g. E.g. “Calibration distance 1 OK”, “Overall status OK”, “Adjustment required”, “Adjustment successful” etc.

According to the invention, the signaling can also include remote signaling directly on the calibration device as an alternative or in addition to an optical, acoustic or haptic signaling described above. This includes one using remote data transmission, e.g. B. Bluetooth, WLAN, LoraWan, NB-IOT, NFC etc. to understand the signaling of the event to be signaled. For example, the signaling event can be transmitted in this way to a mobile terminal (physically separate from the calibration device) (e.g. smartphone) and communicated optically, acoustically and/or haptically to a user on the mobile terminal.

It should be understood that the calibration housing does not necessarily have to be designed to be completely closed. It is conceivable, for example, that the calibration housing can essentially also be designed in the form of a frame. However, the calibration housing can also be completely closed - except for the connection side or a part of it for the arrangement of the level measuring device/sensor - in order, for example, to optimally protect the reflector from contamination and the distance measurement from external interference.

The communication between the calibration device and the level measuring device can preferably be wireless via known radio standards such as. E.g. Bluetooth, WLAN, LoraWan, NB-IOT, NFC, etc. These radio standards can preferably also be used to implement data communication between the calibration device and a higher-level control center/level, computer/server, cloud, etc. For example, the comparison result can also be automatically transmitted to these higher-level receiving units in this way.

In any case, the evaluation unit assigns the signaling unit (e.g. lamp, display, haptic switching device, remote signaling device, etc.), a comparison or computing unit (e.g. microcontroller, microprocessor, etc.) and a communication module (e.g. radio module). Communication with the level measuring device at least to transmit the sensor measurement result. It should be noted that if remote signaling is provided, the communication module can be used for this purpose, but is not necessarily limited to this. For example, the communication module can provide a different radio standard or a different radio range than is desired for remote signaling, so that remote signaling in such a case can be carried out using a separate data transmission unit.

According to an advantageous embodiment of the subject matter of the invention, the evaluation unit is arranged behind the reflector when viewed from the connection side. In this way, a compact design of the calibration device can be achieved. Since the evaluation unit is covered by the reflector and is therefore not in the beam path of the sensor, the evaluation unit accommodated and arranged in the calibration housing does not cause any interference in the distance measurement. For example, the evaluation unit can be on one side of a circuit board be arranged and connected, while the reflector is formed (e.g. as a metal layer) and/or arranged (e.g. in the form of a metal plate) on the opposite side of the circuit board. In any case, the reflector can be permanently installed in the calibration housing. An arrangement of the evaluation unit on the side of the reflector is also conceivable.

According to another preferred development, a thread for screwing the level measuring device is formed on the connection side. In this way, a precise arrangement and attachment of the level measuring device to the calibration housing can be achieved. Furthermore, the calibration housing can be connected to the level measuring device with the interposition of an adapter piece, whereby different screw-in threads and/or flanges of level measuring devices can be easily adapted to the calibration housing via the adapter piece. This means that different types of level measuring devices can be reliably checked using the calibration housing.

As an alternative to screw fastening, the level measuring device can be arranged and fastened to the calibration device using a clamping or clamping device or using magnets.

The calibration housing is preferably tubular. In combination with the thread provided on the connection side, the calibration housing can be designed as a tube that can be screwed onto the level measuring device to be tested.

The inner walls of the calibration housing can be provided with an absorber to reduce interference signals, so that the result of the distance measurement is further improved.

According to a preferred development of the subject matter of the invention, a measuring device for determining an actual distance between the reflector and the sensor of the level measuring device is accommodated in the calibration housing when the level measuring device is arranged on the connection side of the calibration housing. In this case, the specified distance used for the comparison with the sensor measurement result corresponds to the actually determined distance. Accordingly, the accuracy of the calibration or testing of the level measuring device can be increased even further. In particular, minor deviations from the ideal position of the arrangement of the level measuring device relative to the reflector are automatically taken into account in every test, which not least also further simplifies the handling of the calibration device. The measuring device can have, for example, a laser distance sensor.

In another preferred embodiment, the calibration device has a holding rod mounted on the calibration housing. This means that the calibration device can also be arranged on the level measuring device from a remote position, for example a tank opening, a bridge or similar. In this sense, the holding rod has a length that significantly exceeds the size of the calibration device in any of the three spatial dimensions. The holding rod can therefore have a length that is greater than approximately 1 m and can be up to a few meters, e.g. B. between about 2 m and about 10-15 m.

Further preferably, the holding rod and/or the bearing on the calibration housing can have at least one joint. The joint can allow rotation about just one axis or about several axes, e.g. B. a ball joint. This makes it possible to easily arrange the calibration device even on level measuring devices whose direct access is blocked by obstacles.

According to a further advantageous embodiment, at least one additional reflector is provided in the calibration housing, which can be arranged at a further (e.g. second) specified distance from the connection side, either between the connection side and the reflector. It is understood that the second specified distance of the additional reflector differs from the (first) specified distance of the (first) reflector in the calibration housing, in particular is shorter than the (first) specified distance.

The optional adjustment of at least one additional reflector enables simple multi-point calibration, e.g. B. a 3-point adjustment if two additional reflectors can be arranged at different distances from the connection side of the calibration housing in the beam path of the sensor of the level measuring device. In any case, the different calibration distances enable the level sensor to be adjusted over several measuring points or measuring distances.

The at least one additional reflector can be designed, for example, as a surface reflector or angle reflector.

The optional arrangement of the at least one additional reflector can be automatic, e.g. B. via a drive, cylinder or similar, or done manually. A drive energy required for the optional arrangement can come from an energy source such as a battery or accumulator or one Mains supply must be provided. In the case of a rechargeable energy storage device, this can be done using an optionally provided energy harvesting system, e.g. B. be automatically charged from sources such as ambient temperature, vibrations, air currents, electromagnetic waves, photovoltaics and the like in order to achieve self-sufficient operation of the calibration device even over long periods of time (e.g. several weeks, several months or even several years).

The optional arrangement of the at least one additional reflector can be recognized automatically, for example by the evaluation unit. This makes it possible to automatically assign the respective defined reflector distance to the corresponding distance measurement of the sensor of the level measuring device.

To further increase the reliability of the calibration and to further facilitate the handling of the calibration device, the evaluation unit is designed and set up according to a further advantageous embodiment to check and recognize a proper arrangement of the level measuring device on the connection side of the calibration housing. For example, a correct arrangement position of the level measuring device on the connection side of the calibration housing can be detected using NFC (Near Field Communication), a proximity sensor, switching contact and the like. The correct arrangement can also be signaled by the evaluation unit using the signaling unit, for example. B. displayed, acoustically and/or haptically reported, remotely communicated, etc. If the level measuring device is correctly arranged on the calibration device, the calibration of the sensor can be released and carried out.

Alternatively or additionally, the correct arrangement position can also be checked on the measuring device side, i.e. H. by the level measuring device.

The automatic recognition of the successful arrangement of the level measuring device on the calibration device can, if necessary, also automatically trigger a measuring process to determine the deviation of the sensor measurement result from the distance determined by the calibration device or the calibration housing. Depending on whether the evaluation unit of the calibration device and/or the level measuring device recognizes the correct arrangement, the respective device can automatically start the measuring process.

The calibration device is preferably designed and set up to trigger a level measurement of the sensor of the level measuring device. For example, this can be done by a request using wireless short-range communication (NFC) between the evaluation unit and the level measuring device, or by a signal from a proximity sensor, switching contact or similar. Proximity sensor, switching contact and the like can be provided on the calibration housing and/or on the level measuring device, which is why the level measurement can also be triggered indirectly by the calibration device if the correct arrangement of the level measuring device on the calibration housing is recognized, for example by the level measuring device.

Furthermore, the evaluation unit is preferably designed and set up to store the result of the comparison between the sensor measurement result (i.e. level measurement) and the distance determined by the calibration device, e.g. B. as a qualitative (e.g. Boolean) and/or quantitative (i.e. numerical) value in a storage unit, e.g. B. RAM, Flash or similar, particularly preferably permanently, i.e. H. non-volatile even without power supply. In addition to the comparison result, a time stamp (e.g. date, time) can be saved as to when the measurement process was carried out. In addition, the result can also be stored in the level measuring device when it is transmitted from the evaluation unit to the level measuring device, for example by means of the radio transmission techniques already mentioned herein. A stored comparison result can also be remotely signaled at any time upon request or automatically in an event-controlled manner, regardless of the actual location of its storage, that is to say transmitted to a terminal device (preferably wirelessly) that is remote from the calibration device.

According to an advantageous development of the subject matter of the invention, the evaluation unit is designed and set up to receive an identifier that uniquely identifies the level measuring device and to store it with the result of the comparison. This means that each calibration result is clearly assigned to the respective sensor or level measuring device. The identifier can be, for example, a serial number of the level measuring device. The calibration device can therefore be used to carry out calibration measurements on several different level measuring devices one after the other before the results are read out or sent to a higher-level system, e.g. B. master computer, cloud or similar. The transmission can, for example, be bundled in a data packet instead of after a single calibration measurement. The identifier is transmitted from the level measuring device to the evaluation unit, with the radio transmission techniques already mentioned being preferably used.

According to another advantageous development of the invention, the evaluation unit is designed and set up to determine at least one correction value based on the result of the comparison and to transmit it to the level measuring device. This enables automatic adjustment/correction of the level measuring device. The correction value can preferably be transmitted from the evaluation unit to the level measuring device using wireless short-range communication (NFC), Bluetooth, WLAN, LoraWan, NB-IOT, etc.

The calibration device can be powered from an energy source such as. B. battery, accumulator and the like can be supplied. This enables the calibration device to operate autonomously over a certain period of time. In the case of a rechargeable energy storage device, the period of self-sufficient operation can be significantly extended by using the energy storage device, for example, by means of an optionally provided energy harvesting system, for example. B. is automatically charged from sources such as ambient temperature, vibrations, air currents, electromagnetic waves, photovoltaics and the like.

• - Anordnen des Füllstandmessgeräts an eine Anschlussseite eines Kalibriergehäuses der Kalibriervorrichtung, wobei in dem Kalibriergehäuse in einem festgelegten Abstand zur Anschlussseite wenigstens ein Reflektor aufgenommen ist, um bei Anordnung des Füllstandmessgeräts an die Anschlussseite vom Sensor abgestrahlte Wellen zum Füllstandmessgerät zu reflektieren,
• - Durchführen einer Füllstandmessung durch den Sensor im an die Anschlussseite angeordneten Zustand des Füllstandmessgeräts,
• - Empfangen eines Messergebnisses der durchgeführten Füllstandmessung durch eine Auswerteeinheit der Kalibriervorrichtung,
• - Vergleichen des Messergebnisses mit dem festgelegten Abstand und
• - Signalisieren eines Ergebnisses des Vergleichs mittels einer Signalisierungseinheit der Kalibriervorrichtung.

According to a further aspect of the invention, a method for calibrating a level measuring device with a sensor for level monitoring by means of a calibration device, preferably by means of a device according to one of the embodiments disclosed herein, has the steps:

• - arranging the level measuring device on a connection side of a calibration housing of the calibration device, at least one reflector being accommodated in the calibration housing at a fixed distance from the connection side in order to reflect waves emitted by the sensor to the level measuring device when the level measuring device is arranged on the connection side,
• - Carrying out a level measurement by the sensor in the state of the level measuring device arranged on the connection side,
• - receiving a measurement result of the level measurement carried out by an evaluation unit of the calibration device,
• - Comparing the measurement result with the specified distance and
• - Signaling a result of the comparison by means of a signaling unit of the calibration device.

It is to be understood that with regard to process-related definitions of terms as well as the effects and advantages of features according to the process, full recourse can be made to the disclosure of corresponding definitions, effects and advantages of the device according to the invention. Accordingly, disclosures herein regarding the device according to the invention can also be used in a corresponding manner to define the method according to the invention, so that at this point a repetition of explanations of similar features, their effects and advantages is dispensed with in favor of a more compact description, without such omissions being considered restriction would have to be interpreted.

Preferably, the calibration device can be screwed to the level measuring device to be tested/calibrated, with the connection side of the calibration housing having a thread in this case.

A measuring device for determining an actual distance between the reflector and the sensor of the level measuring device can be accommodated in the calibration housing, so that before or after a level measurement is carried out by the sensor, the actual distance of the reflector to the sensor is determined by means of the measuring device and the comparison of the Sensor measurement result with the specified distance includes the comparison with the actually determined distance.

The calibration device can also be arranged on the level measuring device from a remote position by means of a holding rod mounted on the calibration housing, which can have one or more joints.

Alternatively, at least one additional reflector can be arranged at a further (second) fixed distance, which differs from the fixed distance of the (first) reflector, in the calibration housing between the connection side and the (first) reflector, so that the level measuring device has several measuring points or Measuring distances are calibrated.

A proper arrangement of the level measuring device on the connection side of the calibration housing is preferably recognized, for example by the evaluation unit of the calibration device and/or by the level measuring device. This makes it possible, for example, to automatically trigger a level measurement by the level measuring device, in particular to trigger it by the calibration device.

Furthermore, the result of the comparison is preferably stored by the evaluation unit. A time stamp can be saved with the respective measurement. In addition, an identifier that uniquely identifies the level measuring device (e.g. serial number) can advantageously be used. received by the evaluation unit and stored with the result of the comparison.

Particularly preferably, at least one correction value can be determined based on the result of the comparison, which is transmitted to the level measuring device, so that an automatic adjustment of the level measuring device can be carried out directly on site by the calibration device.

The calibration measurement results of the calibration device can be transferred to a higher-level system, e.g. E.g. control level/master computer, server, cloud etc. For example, several calibration results stored by the evaluation unit in the calibration device or the storage unit can be transmitted bundled in a data packet and stored centrally in a database of the higher-level system for documentation purposes, for example. A clear assignment of the measurement results to different level measuring devices can be done using the unique identifier of the respective level measuring device.

• 1 eine Seitenansicht eines Ausführungsbeispiels einer Kalibriervorrichtung gemäß der Erfindung,
• 2 eine Seitenansicht der Vorrichtung aus 1 bei einer Anordnung an einem Füllstandmessgerät,
• 3 eine Seitenansicht eines weiteren Ausführungsbeispiels einer Kalibriervorrichtung gemäß der Erfindung,
• 4 eine Seitenansicht eines noch weiteren Ausführungsbeispiels einer Kalibriervorrichtung gemäß der Erfindung,
• 5 ein Flussdiagramm eines Ausführungsbeispiels eines Kalibrierverfahrens gemäß der Erfindung und
• 6 ein Flussdiagramm eines weiteren Ausführungsbeispiels eines Kalibrierverfahrens gemäß der Erfindung.

Further features and advantages of the invention result from the following description of exemplary embodiments of the invention, which are not to be understood as limiting, which are explained in more detail below with reference to the drawing. This drawing shows schematically:

• 1 a side view of an embodiment of a calibration device according to the invention,
• 2 a side view of the device 1 when arranged on a level measuring device,
• 3 a side view of a further embodiment of a calibration device according to the invention,
• 4 a side view of yet another embodiment of a calibration device according to the invention,
• 5 a flowchart of an exemplary embodiment of a calibration method according to the invention and
• 6 a flowchart of a further exemplary embodiment of a calibration method according to the invention.

In the different figures, parts that are equivalent in terms of their function are always provided with the same reference numbers, so that they are usually only described once.

1 shows schematically a side view of an exemplary embodiment of a device 1 for calibrating a level measuring device 2 (cf. 2 ) with a sensor 3 for level monitoring according to the invention. 2 turns off the device 1 1 in conjunction with the level measuring device 2 in a state arranged as intended on the calibration device 1.

The calibration device 1 has a calibration housing 4 with a connection side 5 for arranging the level measuring device 2. Furthermore, the calibration device 1 shown has at least one reflector 6, which is accommodated in the calibration housing 4 and arranged at a fixed distance d from the connection side 5, in order to emit radiation from the sensor 3 by means of a radiation device 12 (e.g. antenna) when the level measuring device 2 is arranged on the connection side 5 To reflect waves 7 (e.g. radar or ultrasonic waves) to the level measuring device 2. The reflector 6 can be designed as a surface reflector or angle reflector. As in 1 , 2 As can be seen, the evaluation unit 8 of the present calibration device 1 is arranged behind the reflector 6 when viewed from the connection side 5.

Furthermore, in 1 and 2 an evaluation unit 8 of the calibration device 1, which is set up to receive a measurement result of a level measurement carried out by the sensor 3 in the state of the level measuring device 2 arranged on the connection side 5, to compare the measurement result with the specified distance d and a result of the comparison by means of a Signaling unit 9 to signal. For these purposes, the evaluation unit 8 can use a digital computing unit (not shown), such as. B. microcontroller, microprocessor or similar.

In the present calibration device 1, the measurement result of the level measurement is received wirelessly by means of a radio module 10, which can provide data transmission according to one or more radio standards such as NFC, Bluetooth, WLAN, LoraWan, NB-IOT and the like. In addition to communication with the level measuring device 2, the radio module 10 can also be used for wireless data transmission with a higher-level system (not shown), e.g. E.g. control level, server, cloud etc. can be used.

The signaling by means of the signaling unit 9 can take place, for example, optically (e.g. LED) and/or acoustically by means of a signaling tone and/or haptically by vibrating. Additionally or alternatively, quantitative signaling of the deviation determined by the evaluation unit 8 can also take place, for example by means of an (alpha) numeric display, a gradient fill (brightness and/or color) of a graphic display element or similar. A signaling light or display can be freely configurable, e.g. E.g. steady on, flashing, color, etc. Different feedback statuses can also be visually represented by different colors or color gradients, e.g. E.g. “Calibration distance 1 OK”, “Overall status OK”, “Adjustment required”, “Adjustment successful” etc.

As an alternative or in addition to the optical, acoustic and/or haptic feedback directly on the calibration device 1, the signaling can also include remote signaling, as has already been explained in the general part of this description. In this way, the signaling event can be transmitted to a mobile end device (e.g. smartphone), in particular one that is physically separate from the calibration device, and communicated there to a user visually, acoustically and/or haptically. In this case, signaling can take place via the radio module 10, but without necessarily being limited to its use. A separate signaling radio module (not shown) can be provided.

In the example shown of the calibration device 1, the evaluation unit 8 is also designed and set up to store the result of the comparison in a storage unit 11, e.g. B. RAM, Flash (i.e. permanent, non-volatile even without power supply) and the like. If necessary, the calibration result can also be stored in the level measuring device 2 by transmitting it from the evaluation unit 8 to the level measuring device 2 using the radio module 10.

Furthermore, the evaluation unit 8 can be designed and set up to have an identifier that clearly identifies the level measuring device 2, such as. B. a serial number, from the level measuring device 2 and stored together with the result of the comparison in the storage unit 11. The radio module 10 is preferably used for this purpose.

A transmission of the calibration measurement results of the calibration device 1 to a higher-level location (not shown), e.g. B. control level/master computer, server, cloud, etc., can be provided. For example, several calibration results stored by the evaluation unit 8 in the storage unit 11 can be transferred bundled in a data packet and stored centrally in a database of the higher-level system for documentation purposes, for example. A clear assignment of the measurement results to different level measuring devices 2 can be established via the unique identifier of the respective level measuring device 2.

The evaluation unit 8 can be further designed and set up to determine at least one correction value based on the result of the comparison and to transmit this to the level measuring device 2 by means of the radio module 10. In this way, the level measuring device 2 or the sensor 3 can be automatically adjusted by the calibration device 1 and, if necessary, then recalibrated (i.e. checked).

On the connection side 5 of the exemplary calibration device 1, a thread for screwing the level measuring device 2 can be formed. As an alternative to screw fastening, the arrangement or fastening of the level measuring device 2 to the calibration device 1 can be realized by means of a clamping or clamping device (not shown) or by means of magnets (also not shown).

More preferably, the evaluation unit 8 can be designed and set up to recognize a proper arrangement of the level measuring device 2 on the connection side 5 of the calibration device 1. For example, by means of NFC (Near Field Communication), a proximity sensor, switching contact or similar, a correct arrangement position of the level measuring device 2 on the connection side 5 of the calibration housing 4 can be detected and taken into account by the evaluation unit 8. An optional device for position detection is included 1 and 2 at 13 shown. The correct arrangement can be additionally signaled by the evaluation unit 8 by means of the signaling unit 9, ie visually displayed, acoustically and/or haptically reported back and/or communicated remotely. If the level measuring device 2 is correctly arranged on the calibration device 1, the calibration of the sensor 3 can be released and carried out. The calibration device 1 or evaluation unit 8 can preferably be designed and set up to automatically trigger a level measurement of the sensor 3.

Alternatively or additionally, the check of the correct arrangement position of the calibration device 1 on the level measuring device 2 can also be carried out on the measuring device side, as in 2 is indicated by an optional device 13 for position detection in the level measuring device 2.

3 shows a side view of a further exemplary embodiment of a calibration device 20 according to the invention. The calibration device 20 differs from the calibration device 1 1 essentially in that in the calibration housing 4 of the device 20 at least one Additional reflector, in this case a first additional reflector 21 and a second additional reflector 22, are provided. These can each be designed as surface reflectors or angle reflectors. As in 3 is indicated, the additional reflectors 21 and 22 are each at a further, second fixed distance d2 or a further, third fixed distance d3 to the connection side 5 of the calibration housing 4 between the connection side 5 and the reflector 6 (also referred to herein as the first reflector) can be arranged. For example, a drive 23 (e.g. cylinder) can be provided to either transport the respective additional reflector 21 or 22 into the space between the connection side 5 and the reflector 6 or to remove it from there again. The additional reflectors 21, 22 can optionally also be arranged manually in front of the reflector 6. The calibration device 20 enables a simple multi-point calibration, in this case a 3-point calibration of a sensor for level measurement of a level measuring device, such as the level measuring device 2 2 . The distances d, d2 and d3 differ significantly from each other, as in 3 is at least presented qualitatively. The different calibration distances d, d2 and d3 enable the level sensor to be adjusted over several measuring points or measuring distances.

4 shows a side view of yet another exemplary embodiment of a device 30 for calibrating a level measuring device 2 according to the invention. In contrast to devices 1 and 20, the calibration device 30 has a holding rod 31 mounted on the calibration housing 4. Furthermore, the holding rod 31 and/or the mounting on the calibration housing 4 can have at least one joint 32. This means that the calibration device 30 can also be arranged on the level measuring device 2 from a remote position, for example a tank opening, a bridge or the like. The holding rod can have a length in the range from about 1 m to about 10-15 m. The at least one joint 32 expands the possibilities of the arrangement on the level measuring device 2 by means of the holding rod 31 if direct access to the level measuring device 2 is restricted or prevented, for example by an obstacle.

In addition, the in 4 Calibration device 30 shown by a measuring device 33, which is also accommodated in the calibration housing 4, with which an actual distance d between the reflector 6 and the sensor 3 can be determined. For this purpose, the measuring device 33 can, for example, have a laser distance sensor. The actually determined distance d is used to compare the sensor measurement result of the level measurement. Since the measuring device 33 in the exemplary embodiment shown is arranged behind the reflector 6 like the evaluation unit 8, the latter has a breakthrough through which the measuring device 33 determines the distance d from the top of the reflector 6 to the sensor 3 of the level measuring device 2.

5 represents a flowchart of an exemplary embodiment of a calibration method 100 according to the invention.

In a first step 101, a level measuring device, e.g. B. the level measuring device 2 2 , arranged as intended on a connection side of a calibration housing of a calibration device. At least one reflector is accommodated in the calibration housing at a fixed distance from the connection side. When the level measuring device is arranged on the connection side, the reflector reflects waves emitted by the sensor to the level measuring device.

In the next step 102, the calibration measurement is started by carrying out a level measurement by the sensor in the state of the level measuring device arranged on the connection side.

In a subsequent step 103, a measurement result of the level measurement carried out is received by an evaluation unit of the calibration device.

Optionally, in an intermediate step 104, if the calibration device is a measuring device such as in 4 shown, a distance measurement can be carried out by the calibration device in order to determine the actual distance of the reflector from the sensor of the level measuring device.

In a subsequent step 105, the measurement result of the level measurement is compared by the sensor of the level measuring device with the specified or previously determined actual distance and in step 106 the result of this comparison is signaled by means of a signaling unit of the calibration device.

In an optional step 107, the comparison result can be stored in a storage unit of the calibration device, if it has one.

6 represents a flowchart of a further exemplary embodiment of a calibration method 200 according to the invention.

In addition to the in 5 Steps 101 to 107 already described, the method carries out a check in step 201 as to whether the deviation the distance measured with the sensor of the level measuring device during the level measurement from the distance set or self-determined by the calibration device (step 104) is within predetermined limits or not. If the limit value is met, the method 200 continues with step 106 or the optional step 107.

Otherwise, in step 202 a difference between the measured value received from the sensor and the fixed or determined distance is calculated and in step 203 at least one correction value is determined, which is transmitted to the level measuring device for adjustment in step 204. The calibration is then restarted and the method 200 returns to step 102.

The device according to the invention disclosed herein for calibrating a level measuring device and the associated method according to the invention are not limited to the specific embodiments described herein, but also include further embodiments with the same effect, which result from technically sensible further combinations of the features of all the subject matter of the invention described herein. In particular, the features and feature combinations mentioned above in the general description and the description of the figures and/or shown in the figures alone can be used not only in the combinations explicitly stated herein, but also in other combinations or on their own, without departing from the scope of the present invention leave.

Reference symbol list

1

Calibration device

2

Level measuring device

3

sensor

4

Calibration housing

5

Connection side

6

reflector

7

Wave

8th

Evaluation unit

9

Signaling unit

10

Radio module

11

Storage unit

12

Radiation device

13

Position detection device

20

Calibration device

21

First additional reflector

22

Second additional reflector

30

Calibration device

31

holding rod

32

joint

33

Measuring device

100

Calibration procedure

101

Place the level measuring device on the calibration device

102

Carry out level measurement

103

Measurement result received

104

Determine actual distance

105

Compare measurement result with fixed/determined distance

106

Signal comparison result

107

Save comparison result

200

Calibration procedure

201

Check calibration result

202

Calculate difference value

203

Determine correction value

204

Send correction value

d

Fixed distance

d2

Second specified distance

d3

Third set distance

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 2829852 B1 [0004]

Claims (13)

Device (1, 20, 30) for calibrating a level measuring device (2) with a sensor (3) for level monitoring, characterized by a calibration housing (4) with a connection side (5) for arranging the level measuring device (2), at least one in the calibration housing ( 4) recorded and arranged at a fixed distance (d, d2, d3) from the connection side (5) in order to emitted by the sensor (3) when the level measuring device (2) is arranged on the connection side (5). to reflect waves (7) to the level measuring device (2), and an evaluation unit (8) which is set up to receive a measurement result of a level measurement carried out by the sensor (3) in the state of the level measuring device (2) arranged on the connection side (5), to compare the measurement result with the specified distance (d, d2, d3) and to signal a result of the comparison by means of a signaling unit (9). Device according to Claim 1 , characterized in that the evaluation unit (8) is arranged behind the reflector (6) as seen from the connection side (5). Device according to Claim 1 or 2 , characterized in that a thread for screwing the level measuring device (2) is formed on the connection side (5). Device according to one of the preceding claims, characterized in that a measuring device (33) for determining an actual distance (d) between the reflector (6) and the sensor (3) of the level measuring device (2) is accommodated in the calibration housing (4), wherein the specified distance (d) used for the comparison corresponds to the actually determined distance. Device according to one of the preceding claims, characterized by a holding rod (31) mounted on the calibration housing (4). Device according to the preceding claim, characterized in that the holding rod (31) and/or the bearing on the calibration housing (4) has or have at least one joint (32). Device according to one of the preceding claims, characterized in that at least one additional reflector (21, 22) is provided in the calibration housing (4), which is at a further fixed distance (d2, d3) from the connection side (5) optionally between the connection side (5). and the reflector (6) can be arranged. Device according to one of the preceding claims, characterized in that the evaluation unit (8) is designed and set up to recognize a proper arrangement of the level measuring device (2) on the connection side (5). Device according to one of the preceding claims, characterized in that the device (1, 20, 30) is designed and set up to trigger a fill level measurement of the sensor (3). Device according to one of the preceding claims, characterized in that the evaluation unit (8) is designed and set up to store the result of the comparison. Device according to the preceding claim, characterized in that the evaluation unit (8) is designed and set up to receive an identifier that uniquely identifies the level measuring device (2) and to store it with the result of the comparison. Device according to one of the preceding claims, characterized in that the evaluation unit (8) is designed and set up to determine at least one correction value based on the result of the comparison and to transmit it to the level measuring device (2). Method (100, 200) for calibrating a level measuring device (2) with a sensor (3) for level monitoring, by means of a calibration device (1, 20, 30), in particular device according to one of the preceding claims, comprising the steps: - Arranging the level measuring device ( 2) to a connection side (5) of a calibration housing (4) of the calibration device (1, 20, 30), at least one reflector ( 6, 21, 22) is included in order to reflect waves (7) emitted by the sensor (3) to the level measuring device (2) when the level measuring device (2) is arranged on the connection side (5), - carrying out a level measurement by the sensor (3 ) in the state of the level measuring device (2) arranged on the connection side (5), - receiving a measurement result of the level measurement carried out by an evaluation unit (8) of the calibration device (1, 20, 30), - comparing the measurement result with the specified distance (d, d2, d3) and - Signaling a result of the comparison by means of a signaling unit (9) of the calibration device (1, 20, 30).

Images