Level measuring device

Abstract

Level measuring device (10) for measuring or monitoring the level of media (1), in particular liquids or bulk materials, with a substantially rod-shaped probe (2) which, depending on the level during operation, is more or less surrounded by the medium (1) to be measured, wherein the probe (2) detects level-dependent capacitance changes of the probe (2) as a function of the immersion depth of the probe (2) in the medium (1), and with a measuring and evaluation unit (3, 4) cooperating with the probe (2) and with an electrical energy storage device (5) for supplying the probe (2) and the measuring and evaluation unit (3, 4) with electrical energy, wherein the level-dependent electrical measurement quantity detected by the probe (2) is converted by means of the evaluation unit (4) into an electrical output signal representing the level, wherein the probe (2) is surrounded by a housing (6) on which a foot part (7) is arranged for attaching the device (10) to or in the subsoil / ground (8) for carrying out the measurement or monitoring of the level.

Description

[0001] The invention relates to a level measuring device according to the preamble of claim 1.

[0002] Devices for measuring the fill level of a medium located in a container are known from the prior art.

[0003] Such measurements can be carried out, for example, mechanically with a float arrangement, pressure-based by measuring the hydrostatic pressure at the bottom of the liquid container, or without contact.

[0004] A non-contact level measurement device is known from DE 10 2007 057 211 A1. Other measuring devices determine a container level by measuring electrical resistance at immersion electrodes or are based on radar measurements in surface conductors that are immersed in the medium in the container. For example, DE 102 13 746 A1 discloses a device with radar measurement.

[0005] From EP 0 029 485 A1, a device for capacitive level measurement and a corresponding measuring method are known, comprising a measuring capacitor immersed in the medium to be measured, means for generating an electrical quantity corresponding to the level, and means for compensating for different dielectric constants of the medium. The latter are formed by one or more compensation capacitors immersed in the medium. Furthermore, the known measuring device includes means for generating the electrical quantity corresponding to the level and for compensating for different dielectric constants of the medium. In this way, it becomes possible to measure the fill level of fuels with different compositions, e.g., methanol contents, even though the dielectric constant of the fuel changes depending on its composition.

[0006] A disadvantage of known devices and methods for measuring water levels is their complex, elaborate, and comparatively expensive design, requiring additional brackets and fasteners as well as connections to external power supplies. This makes simple and, above all, mobile use impossible.

[0007] Based on this, the invention aims to provide a cost-effective level measuring device that allows for simple and uncomplicated assembly and commissioning, as well as autonomous and mobile use.

[0008] This problem is solved with a level measuring device according to claim 1.

[0009] The invention relates to a level measuring device for measuring or monitoring the level of media, in particular liquids or bulk materials, with a substantially rod-shaped probe or measuring probe which, depending on the level, is more or less surrounded by the medium to be measured during operation.

[0010] These media can include, for example, snow, water (such as groundwater or water in rivers and lakes), but also bulk materials (such as feed in feed silos or pellets).

[0011] Furthermore, it is also conceivable to use the measuring probe in agriculture, for example to measure soil moisture depth. Based on these measurements, a decision could then be made as to which seeds are suitable for the soil and whether irrigation is necessary.

[0012] According to the invention, the device detects level-dependent capacitance changes of the probe as a function of the probe's immersion depth in the medium. The probe is thus triggered for measurement in the medium. In other words, the level measuring device is designed for monitoring or measuring the level of a medium by utilizing the level- or immersion-depth-dependent capacitance of a measuring probe immersed in the medium.

[0013] The device further comprises a measuring and evaluation unit that interacts with the probe and an electrical energy storage device for supplying the probe and the measuring and evaluation unit with electrical energy. The device operates autonomously, often for several years. An external power supply (as in the prior art) is advantageously not required. This ensures particularly simple and mobile use of the device according to the invention.

[0014] The level-dependent electrical measurement detected by the probe is converted by the evaluation unit into an electrical output signal representing the level. The accuracy of the measurements depends on the probe length. For example, 95,000 AD values ​​can be distributed along the probe's length (approximately 1 m to 2.5 m).

[0015] The A / D value can be a value between, for example, 0 and 95,000, determined by an analog-to-digital converter (ADC) as a measurement from the capacitive probe. A value of 95,000 could, for instance, correspond to a probe length of 2.5 meters, in which case the 95,000 values ​​are evenly distributed along this probe length. The comparison table (probe length / A / D value) can be stored in the device's electronics. This A / D value-to-length mapping can be changed at the factory if necessary. By default, this is a linear table, where A / D0 = 0 mm (length) and A / D 95,000 = 2500 mm. Both values, the A / D value and the length, can be transmitted to the evaluation unit.

[0016] According to the invention, the probe is surrounded by a housing to which a base is attached for mounting the device on or in the ground for measuring or monitoring the water level. This allows for easy mobile use. The ground mounting can also be integrated into the housing.

[0017] Advantageously, the device can be used very simply to measure water levels, e.g., in streams, rivers, or watercourses, simply by attaching it to or on the ground, without any further external mechanical connections, such as external brackets, and without additional electrical connections or data lines. In particular, the device can also be easily disassembled or relocated without leaving any residue. Thanks to the base of the housing according to the invention, the device can be positioned without much effort, for example, near the bank.

[0018] The device can replace complex and expensive radar probes and ultrasonic sensors.

[0019] The device according to the invention is therefore a cost-effective sensor that, for example, capacitively measures a water level cyclically and detects flood hazards at an early stage.

[0020] According to a first advantageous embodiment of the invention, the probe, the measuring and evaluation unit and the base are mechanically connected to each other to form an assembly unit, so that the level measuring device can be used as a mobile unit.

[0021] In particular, it can be transported very easily and used in different locations.

[0022] The advantage of the device according to the invention is therefore, in particular, its simple assembly and commissioning, since the integrated assembly unit only needs to be mounted in such a way that the capacitive measuring probe protrudes far enough into the medium to allow a level measurement in the relevant area. Separate assembly or commissioning steps for connecting the measuring probe and the evaluation unit are unnecessary, which makes the device particularly attractive, especially for laypersons.

[0023] According to a further advantageous embodiment of the invention, the base part has a point, in particular a metal point, preferably made of hardened steel, for insertion into the ground. Points of different designs are conceivable, which are adapted to various conditions (substrates), such as sand, gravel or other bulk material (e.g. pellets).

[0024] The spikes may also have a thread for screwing the base into the ground.

[0025] Due to the design of the base with a spike or metal tip, the level measuring device can be mounted particularly easily by inserting the base into the ground, for example near the shore of a lake or river, in order to monitor the water levels of the lake or river.

[0026] The device can, of course, also be easily pulled out of the ground and repositioned, for example. This simple insertion of the device's base underscores its mobile and self-contained design.

[0027] For even better anchoring, the tip can have at least one barb for securing it in the ground. This significantly improves the device's stability, even in choppy waters. The barbs also serve as theft protection, as they make it more difficult to remove the device.

[0028] A particularly advantageous variant is one in which the foot section has at least one element, for example a tab, for fastening, especially for screwing onto or to the floor.

[0029] This design allows for attachment to other surfaces, such as solid surfaces like concrete (e.g., in water pipes or ducts). The tip of the device's base cannot simply be inserted into a concrete floor. Therefore, a fastening element, such as a tab, is provided to secure the base to the solid surface. For installation in pipes or ducts, the fastening element can first be attached to the floor, for example, by screwing it in place, and then screwed to the rest of the device. Alternatively, the base can be attached to a support bracket.

[0030] It is also conceivable that the foot part can be removed from the housing of the device or probe, and in particular connected to the housing by means of a screw connection.

[0031] This is particularly advantageous because the base can then be screwed into or attached to the ground even without the probe or housing. This allows for very simple installation of the device. Furthermore, the length of the probe housing can be adjusted to the desired level measurement range without modifying the base or having to remove the already attached base. The base with the lower tube can be mounted separately on the ground. Depending on the application, the measuring probe of varying lengths can then be inserted into the tube. The guide tube can be welded to the base and galvanized. For example, sensor lengths from 100 cm to 250 cm are possible.

[0032] According to a further advantageous embodiment of the invention, the device includes an accelerometer for measuring changes in the flow of the medium. The accelerometer can be positioned on top of an electronic circuit board and detect the vibration and tilt of the measuring probe. Furthermore, the accelerometer detects when the entire unit is disassembled (e.g., in case of theft). The moment no movement is detected, a GPS signal from the device can transmit its precise location, for example, to a web application.

[0033] In a particularly advantageous manner, the device includes a communication module, in particular a radio module, for wirelessly forwarding the level readings and / or GPS data output by the evaluation unit to a communication device, preferably a cloud or a mobile device (smartphone, tablet).

[0034] With such a module, the collected and stored measured values ​​can be cyclically transmitted to a suitable receiver for the permanent monitoring of water levels.

[0035] Since the level measuring device is particularly suitable for mobile use, the communication module allows for remote control of the device (e.g., changes to settings and parameters). Remote operation of the device is also possible. Furthermore, measurement data can also be read out via the communication module, for example, wirelessly.

[0036] For example, when used as a flood detector or flood warning system, the reporting frequency can be changed in the event of a flood risk and measurement data can be sent more frequently.

[0037] It can use established mobile communication technologies such as CATM1, also known as LTE-M or LTE Cat-M1. GPS data can also be transmitted.

[0038] The level measuring device can be personalized (e.g., SID, customer ID, parameters), so that evaluation can be carried out, for example, via a cloud-based web app with API interface.

[0039] The probe housing can be made primarily of plastic and / or the base primarily of metal. In particular, the materials used must be compatible with groundwater and / or UV-resistant.

[0040] Further objectives, advantages, features, and applications of the present invention will become apparent from the following description of an exemplary embodiment with reference to the drawing. All features described and / or illustrated, individually or in any meaningful combination, constitute the subject matter of the present invention, even independently of their compilation in the claims or their cross-references.

[0041] This shows, in part schematically: Fig. 1. A perspective view of a level measuring device in a cutaway view and Fig. 2 a) a perspective view of another design variant with a fastening element and b) a sectional view of the design variant according to Fig. 2 a).

[0042] Identical or equivalent components are identified in the following figures of the drawing by reference numerals based on an embodiment, in order to improve readability.

[0043] The Fig. Figure 1 shows a level measuring device 10 for measuring or monitoring the level of media 1.

[0044] These media 1 can be, for example, snow, water, such as groundwater or water in rivers and lakes, but also bulk materials, such as feed in feed silos or pellets.

[0045] Furthermore, it is also conceivable to use the level measuring device 10 in the agricultural sector, for example to measure the depth of soil moisture.

[0046] The level measuring device 10 has a substantially rod-shaped probe or measuring probe 2, which in operation is more or less surrounded by the medium 1 to be measured, depending on the level.

[0047] The probe 2 detects level-dependent capacitance changes of the probe 2 as a function of the immersion depth of the probe 2 in the medium 1.

[0048] The device 10 is therefore designed to perform a measurement in the medium 1. In other words, the level measuring device 10 is designed for monitoring or measuring the level of a medium 1 by utilizing the level- or immersion-depth-dependent capacity of the measuring probe 2 immersed in the medium 1.

[0049] Also in Fig. Figure 1 shows a measuring and evaluation unit 3, 4 interacting with the probe 2 and an electrical energy storage device 5 for supplying the probe 2 and the measuring and evaluation unit 3, 4 with electrical energy. An external power supply is not required. This enables particularly simple mobile use of the device 10 according to the invention. The electrical energy storage device 5 can be easily replaced or recharged. The evaluation unit 4 is arranged on a circuit board 16.

[0050] The level-dependent electrical measurement detected by probe 2 is converted by evaluation unit 4 into an electrical output signal representing the water level. Thus, when the medium being measured, for example, the water of a river, reaches probe 2, a signal is output indicating that a specific water level has been reached. Depending on the positioning of the (mobile) devices 10, a warning can therefore be issued very early before a critical water level of the river is exceeded and thus before flooding occurs.

[0051] Fig. Figure 1 further shows that the probe 2 is housed in a casing 6. A base 7 for mounting on or in the substrate / ground 8 for measuring or monitoring the water level is attached to the casing 6. The probe 2, the measuring and evaluation unit 3, 4, and the base 7 are mechanically connected to each other to form an assembly unit.

[0052] In this case, the foot part 7 has a point 9, in particular a metal point, for insertion into the ground 8.

[0053] In the present embodiment, the tip has 9 barbs 12 for anchoring in the ground 8.

[0054] The foot part 7 can be detachably connected to the housing 6 of the probe 2, in particular the foot part 7 can be removed from the housing 6 of the probe 2, for example by means of a screw connection 15 connected to the housing 6.

[0055] The base 7 can then be screwed or attached to the base 8 even without probe 2. Furthermore, the length of the probe 2 housing 6 can be adjusted according to the desired level measurement range without making any changes to the base 7 or having to disassemble the already attached base 7. For example, sensor lengths from 100 cm to 250 cm are possible.

[0056] Different tip types are conceivable, which are adapted to different conditions (substrates), such as sand, gravel or other bulk material (e.g. pellets).

[0057] Due to the design of the base 7 with its spike 9 or metal tip, the level measuring device 10 can be inserted into the ground 8, for example near the shore of a lake or river, to monitor the water levels. The device 10 can, of course, also be easily pulled out of the ground and repositioned, for example.

[0058] The level measuring device 10 is typically inserted into the ground 8 and anchored therein, so that the probe 2 can be surrounded by the medium to be measured, for example, the water of a river. It is conceivable to arrange several of these devices 10 near the banks of a river in order to obtain information about different water levels, for example, at different warning levels.

[0059] In the Fig. In the embodiment shown in Figures 2 a) and b), the foot section 7 has a fastening element 11, for example a tab, for fastening, in particular for screwing, to or with the base 8. Fig. 2 a) shows a perspective view of this design variant with fastening element 11 and Fig. 2 b) a sectional view of the execution variant according to Fig. 2 a).

[0060] In the present case, the fastening element 11 is plate-shaped and has through holes for screwing it to the base 8. Other fastening options are also conceivable and are within the scope of the invention.

[0061] For fastening in tubes or channels, the fastening element 11 can first be attached to the base 8, for example by screwing it on, and then screwed to the rest of the device 10.

[0062] In the present embodiment, the level measuring device 10 includes an accelerometer 13 for measuring changes in the flow of the medium 1. The accelerometer serves to measure movements or vibrations by converting the physical motion into an electrical signal suitable for measurement, recording, analysis, and / or control. The sensitivity can be adjusted depending on the application.

[0063] The accelerometer 13 can detect the vibration and tilt of the probe 2. Furthermore, the accelerometer detects when the device 10 is disassembled (e.g., in case of theft). The moment no further movement is detected, a GPS signal from the device can transmit its precise location, for example, to a web application. The accelerometer 13 is located on the circuit board 16.

[0064] For wireless signal transmission, a communication module 14, in particular a radio module, is provided for wirelessly forwarding the level values ​​and / or GPS data output by the evaluation unit 4 to a communication device, preferably to a cloud.

[0065] It is also conceivable that several level measuring devices 10 are networked together wirelessly.

[0066] Since the level measuring device 10 is particularly suitable for mobile use, the communication module 14 allows the device 10 to be controlled remotely (e.g., by changing settings and parameters). Remote control of the device 10 is also possible. Furthermore, measurement data can also be read out using the communication module 14, for example, via radio.

[0067] For example, when used as a flood detector or flood warning system, the probe can change its reporting frequency in the event of a flood risk and, in particular, send measurement data more frequently.

[0068] It can use well-known mobile communication technologies, such as CATM1, also known as LTE-M or LTE Cat-M1.

[0069] The housing 6 of the probe 2 can be made essentially of plastic and / or the foot part 7 can be made essentially of metal. Reference symbol list 1 Medium 2 probes 3 Unit of measurement 4 evaluation units 5 electrical energy storage 6 cases 7 Foot section 8 Soil / Subsoil 9. Tip of the foot section 10 Level measuring device 11 Fastening element 12 barbs 13 Accelerometer 14 Communication module 15 screw connections 16 circuit boards QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2007 057 211 A1

[0004] DE 102 13 746 A1

[0004] EP 0 029 485 A1

[0005]

Claims

[1] Level measuring device (10) for measuring or monitoring the level of media (1), in particular liquids or bulk materials, with a substantially rod-shaped probe (2) which, depending on the level during operation, is more or less surrounded by the medium (1) to be measured, wherein the probe (2) detects level-dependent capacitance changes of the probe (2) as a function of the immersion depth of the probe (2) in the medium (1), and with a measuring and evaluation unit (3, 4) cooperating with the probe (2) and with an electrical energy storage device (5) for supplying the probe (2) and the measuring and evaluation unit (3, 4) with electrical energy, wherein the level-dependent electrical measurement quantity detected by the probe (2) is converted by means of the evaluation unit (4) into an electrical output signal representing the level, wherein the probe (2) is surrounded by a housing (6) on which a foot part (7) is arranged for attaching the device (10) to or in the subsoil / ground (8) for carrying out the measurement or monitoring of the level. [2] Level measuring device (10) according to claim 1, characterized by , that the probe (2), the measuring and evaluation unit (3, 4) and the foot part (7) are mechanically connected to each other to form an assembly unit. [3] Level measuring device (10) according to claim 1 or 2, characterized by that the foot part (7) has a point (9), in particular a metal point, for insertion into the ground (8). [4] Level measuring device (10) according to claim 3, characterized by that the tip (9) has at least one barb (12) for anchoring in the ground (8). [5] Level measuring device (10) according to one of claims 1 to 3, characterized bythat the foot part (7) has at least one fastening element (11) for fastening, in particular for screwing, to or with the floor (8). [6] Level measuring device (10) according to one of claims 1 to 4, characterized by , that the foot part (7) is removable from the housing (6) of the probe (2), in particular that it can be connected to the housing (6) by means of a screw connection (15). [7] Level measuring device (10) according to one of the preceding claims, characterized by , that the device (10) has an acceleration sensor (13) for measuring changes in the flow of the medium (1). [8] Level measuring device (10) according to one of the preceding claims, characterized by , that the device (10) has a communication module (14), in particular a radio module, for wirelessly forwarding the level values ​​output by the evaluation unit (4) and / or GPS data to a communication device, preferably to a cloud. [9] Level measuring device (10) according to one of the preceding claims, characterized by , that the housing (6) of the probe (2) is made essentially of plastic and / or wherein the foot part (7) is made essentially of metal.

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