Moisture sensor, and method for determining a moisture amount

Abstract

The invention relates to a moisture sensor (1), with: an adhesive layer (2); a perforation element (3) which projects from the adhesive layer (2); at least one opening (4) which penetrates a wall of the perforation element (3); an absorption material (5) which is arranged in an interior of the perforation element (3), is in fluidic connection with the at least one opening (4) and the volume of which enlarges through the absorption of a moist medium; a switch (6) which is mechanically coupled to the absorption material (5) such that it performs a switching operation as a result of the enlargement of the volume of the absorption material (5); and a switching circuit (7) which emits a signal in the event of the switching operation of the switch (6).

Description

[0001] Humidity sensor and method for determining a

[0002] Humidity menu

[0003] The present invention relates to a humidity sensor and a method for determining a moisture amount using such a humidity sensor.

[0004] In particular, the invention relates to the detection of water in a roof with a slight or steep slope. The roof structure contains an insulation layer intended to reduce temperature equalization between the ambient temperature and the interior of the roof. The invention is intended to detect water preferably in the insulation between the rafters, preferably on the underside of the roof. The underside of the roof can consist of a vapor retarder or vapor barrier or similar. The top side of the roof consists of a roof covering and a second water-conducting layer, which can be realized by an underlayment.

[0005] For pitched roofs, no detectors are yet known that can detect moisture in the insulation layer and can be installed anywhere. Instead, a method is known that measures and detects moisture by installing and wiring moisture sensors in a wooden beam. A moisture sensor for flat roofs and floor areas is also known, but its sensor data must be evaluated manually.

[0006] There is also no known way to detect water in a pitched roof at any location. The installation and routing of cables and screw connections in the wood is extremely time-consuming and labor-intensive. In addition, a continuous power supply for the sensor technology must be guaranteed in some cases, and in some cases, the sensor data must be read manually. If water penetrates the insulation layer, it can lead to a loss of insulation function and mold growth. The mold can be harmful to the health of the building's residents and can also infest the wooden structure, and in the worst case, lead to a loss of structural capacity. The damage costs increase the later the water retention is detected.

[0007] EP 3 333 330 B1, for example, discloses a sensor device, in particular a hygrothermal sensor device, for detecting air humidity and / or temperature measurement data in a building envelope insulation system, such as a thermal insulation composite system, an interior insulation system, a roof insulation system, or the like, comprising: a temperature sensor and / or a humidity sensor; radio electronics, such as RFID transponder electronics, for transmitting sensor data to a reader, such as an RFID reader; and a support structure carrying the temperature and / or humidity sensor and the radio electronics for embedding in the building envelope insulation system. The support structure has a protruding sensor head portion on which the temperature and / or humidity sensor is arranged.

[0008] It is an object of the present invention to provide an easy-to-install humidity sensor and a method for reliably determining a moisture quantity.

[0009] This object is achieved by the subject matter having the features according to the independent patent claims. Further embodiments are shown in the dependent claims.

[0010] According to a first aspect of the present invention, a humidity sensor comprises an adhesive layer; a perforation element protruding from the adhesive layer; at least one opening penetrating a wall of the perforation element; an absorption material disposed within the perforation element, fluidly connected to the at least one opening, and increasing its volume by absorbing a moist medium; a switch mechanically coupled to the absorption material such that it performs a switching operation by increasing the volume of the absorption material; and a circuit that emits a signal upon the switching operation of the switch. The humidity sensor can be designed as either a tape or a patch.

[0011] The humidity sensor can comprise an absorption material, such as a superabsorbent, which increases in volume upon contact with water. The increase in volume activates a switch, such as a microswitch, which can close a previously opened circuit, for example, thereby transmitting a signal. The signal is preferably transmitted via Bluetooth®, and the power supply is preferably provided by a button battery. The humidity sensor can comprise a long needle as the perforation element, which contains the volume-increasing absorption material and is pierced, for example, through a vapor barrier. The needle can comprise elongated openings through which water reaches the volume-increasing material. The needle can be made of either plastic or metal.The moisture sensor can be sealed airtight and windproof using a sealing adhesive patch as the adhesive layer. The moisture sensor is preferably installed on the underside of the roof truss, below the vapor retarder or vapor barrier. Only the needle with the volume-increasing absorption material is located within the roof truss, i.e., where the insulation material is located. The circuit or the entire electronics can be installed behind the adhesive patch on the other side of the lowest roof layer, on the attic side. To test the functionality of the moisture sensor, the switch can be manually operated, the circuit is closed, and the signal is transmitted. The moisture sensor of the present invention enables the rapid, location-variable detection of water in pitched roofs. Installation is more intuitive and quicker than previous solutions.The moisture sensor can be retrofitted with minimal effort, without removing the waterproofing layer during installation and thus compromising the roof's watertightness. Installation requires minimal skill from the installer. Due to its non-electronic detection method, the sensor is extremely low-energy, consuming only when water enters, the normally open switch closes, and a signal is sent. Furthermore, no cables are required, which simplifies installation and reduces labor.

[0012] In locations with a high risk of water ingress, multiple sensors can be installed closer together. The sensor can be installed during new construction or easily and inexpensively retrofitted to existing buildings at a later date.

[0013] When water enters the roof, the moisture sensor detects it and sends out a signal. The signal can be read by a receiver unit, allowing immediate countermeasures to be initiated to minimize the damage and restore the previously impaired function of the roof. The moisture sensor can solve the problem of poor and late detection of water retention in a roof, which can be caused by roof leaks. Water ingress can thus be detected quickly, easily, inexpensively, and reliably.

[0014] According to one embodiment of the present invention, the circuit comprises a wireless transmission unit that transmits the signal wirelessly. For example, the circuit uses the Bluetooth® protocol. According to one embodiment, the humidity sensor further comprises a battery, preferably a button cell, for powering the humidity sensor.

[0015] According to one embodiment, the switch, the circuit and / or a battery for powering the humidity sensor are arranged within the perforation element, so that the humidity sensor is particularly compact.

[0016] According to one embodiment, a non-adhesive layer is arranged on the adhesive layer, facing away from the perforation element. For example, the non-adhesive layer forms part of a flexible printed circuit board.

[0017] According to one embodiment, the switch, the circuit and / or a battery for powering the humidity sensor are arranged on the non-adhesive layer.

[0018] According to one embodiment, the humidity sensor further comprises at least one further switch that is mechanically coupled to the absorption material in such a way that it performs a further switching operation upon a further increase in the volume of the absorption material; and at least one further circuit that emits a further signal upon the switching operation of the at least one further switch; wherein the switch performs the switching operation upon a first increase in the volume of the absorption material, and the at least one further switch performs the further switching operation upon the further increase in the volume of the absorption material, wherein the first increase in volume is smaller than the further increase in volume. This makes it possible to effect cascade-like switching operations, wherein more and more of the further switches are switched on as the absorption material increases in size.

[0019] According to one embodiment, the humidity sensor further comprises a controller for determining the amount of moisture in the humidity sensor. According to one embodiment, the switch is a microswitch, preferably a normally open one.

[0020] According to one embodiment, the moist medium is guided to the absorption material due to a capillary action of the perforation element.

[0021] According to one embodiment, the humidity sensor is powered by harvesting a quantity of electrical energy, preferably from sources such as ambient temperature, vibrations, or air currents (energy harvesting). This provides a maintenance-free humidity sensor.

[0022] According to one embodiment, the perforation element can be removed from the adhesive layer and attached to the adhesive layer, so that the perforation element is replaceable. Preferably, the perforation element can be replaceably attached to and removed from the adhesive layer using a bayonet lock, a clip connection, or a threaded connection. This makes it possible to insert the perforation element into the substrate to a desired length or depth, so that the desired location in the substrate can be monitored. For example, the appropriate, replaceable perforation element can be attached to the adhesive layer with the desired length, for example so that it is located in front of an underlayment of an insulation layer.

[0023] According to a second aspect of the present invention, a set comprises the moisture sensor and another perforation element that has a different length than the perforation element. This makes it possible to insert the appropriate perforation element into the substrate with a desired length or depth, so that the desired location in the substrate can be monitored. For example, the perforation element can be attached to the adhesive layer with the desired length, for example, so that it is located in front of an underlay membrane of an insulation layer.According to a third aspect of the present invention, a method is provided for determining a moisture quantity by means of a moisture sensor comprising an adhesive layer; a perforation element protruding from the adhesive layer; at least one opening penetrating a wall of the perforation element; an absorption material arranged in an interior of the perforation element, in fluid communication with the at least one opening, and increasing its volume by absorbing a moist medium; a switch mechanically coupled to the absorption material such that it performs a switching operation by increasing the volume of the absorption material; and a switching circuit that emits a signal upon the switching operation of the switch.The method comprises the following steps: piercing the perforation element into a permeable substrate; adhering the moisture sensor to a surface of the substrate using the adhesive layer; and coupling the circuit to a receiver such that the receiver can receive the signal.

[0024] According to one embodiment, the adhesive layer is part of a single-sided adhesive tape, wherein a protective layer is removed from the single-sided adhesive tape before the moisture sensor is adhered to the surface of the substrate by means of the adhesive layer.

[0025] According to one embodiment, the substrate is an insulating layer with an insulating material, preferably in a roof structure, wherein the surface of the insulating layer is formed by a vapor barrier or vapor barrier.

[0026] According to one embodiment, a tip of the perforation element is inserted so deeply that it is located in front of an underlayment of the insulation layer.

[0027] According to one embodiment, the method may use the set described above and further comprises a step of selecting either the perforation element or the further perforation element, and a step of attaching the selected perforation element to the adhesive layer.

[0028] In the following, exemplary embodiments of the present invention are described in detail with reference to the following figures.

[0029] Figure 1 shows a cross section of a humidity sensor according to an embodiment.

[0030] Figure 2 shows the functional principle of the humidity sensor according to an embodiment.

[0031] Figure 3 shows a cross section through a substrate and a moisture sensor according to an embodiment.

[0032] Figure 4 shows a cross section through a substrate and a moisture sensor according to an embodiment.

[0033] Figure 5 shows a cross section through a substrate and a moisture sensor according to an embodiment.

[0034] The same or similar components in different figures are provided with the same reference numerals.

[0035] Figure 1 shows a cross-section of a humidity sensor 1 according to one embodiment. The humidity sensor 1 has an adhesive layer 2 and a perforation element 3 protruding from the adhesive layer 2. This means that the adhesive layer 2 has an adhesive property on the side toward which the perforation element 3 protrudes. The perforation element 3 itself can be glued to the adhesive layer 2.

[0036] At least one opening 4 penetrates a wall of the perforation element 3. An absorption material 5 is arranged in an interior of the perforation element 3 such that it is in fluid communication with the at least one opening 4. The absorption material 5 increases its volume by absorbing a moist medium. The absorption material 5 can comprise, for example, acrylonitrile butadiene styrene. Preferably, an internal geometry of the perforation element 3 is designed such that moisture spreads within the perforation element 3 due to a capillary action of the perforation element 3.

[0037] The humidity sensor 1 further comprises a switch 6, preferably a normally open microswitch for low energy consumption, which is mechanically coupled to the absorption material 5 in such a way that it performs a switching operation by increasing the volume of the absorption material 5, and a switching circuit 7 which emits a signal when the switch 6 switches.

[0038] Preferably, the circuit 7 has a wireless transmitting unit such as a Bluetooth® device that transmits the signal wirelessly.

[0039] Preferably, the humidity sensor 1 further comprises a battery 8, preferably a button cell, for powering the humidity sensor 1. Alternatively or additionally, the humidity sensor 1 can be powered by obtaining an amount of electrical energy (energy harvesting), preferably from sources such as ambient temperature, vibrations or air currents.

[0040] The switch 6, the circuit 7 and the battery 8 for powering the humidity sensor 1 are located above the adhesive layer 2. For a compact design, the switch 6, the circuit 7 and the battery 8 can alternatively be arranged within the perforation element 3.

[0041] A non-adhesive layer can be arranged on the adhesive layer 2, which faces away from the perforation element 3. The circuit 7 and the battery 8, and optionally other components such as devices for energy generation, can be attached to the non-adhesive layer. The non-adhesive layer can be a flexible printed circuit board (flex PCB). The humidity sensor 1 can further comprise a plurality of further switches, which are mechanically coupled to the absorption material 5 in such a way that they each perform a further switching operation by further increasing the volume of the absorption material 5. The humidity sensor 1 has a further circuit for each additional switch, which emits a further signal upon the switching operation of the respective additional switch.While switch 6 carries out the switching process by a first increase in the volume of absorption material 5, the respective additional switches carry out the respective further switching process by further increasing the volume of absorption material 5, wherein the first increase in volume is smaller than the respective further increases in volume at the respective additional switches. The respective additional switches can be triggered one after the other during a continuous increase in the volume of absorption material 5. This can cause cascade-like switching processes, with more and more of the additional switches being switched on as the absorption material 5 increases in size. Depending on the number of additional switches closed, an absolute amount of moisture in humidity sensor 1 can be determined.The humidity sensor 1 may have a controller for determining an amount of moisture in the humidity sensor 1.

[0042] In the embodiment of Figure 1, the humidity sensor 1 is designed as a so-called patch, i.e. there is only one perforation element 3 on the adhesive layer 2. In an alternative embodiment, the humidity sensor 1 can be designed as a so-called tape, i.e. the humidity sensor 1 has several of the perforation elements 3, each of which protrudes from the adhesive layer 2; several of the switches 6, which are mechanically coupled to a respective absorption material 5 of a respective perforation element 3 in such a way that they carry out a respective switching operation by increasing the volume of the respective absorption material 5. Each switch 6 is assigned to a respective circuit 7, which emits a signal when the respective switch 6 switches.

[0043] Figure 2 shows the operating principle of humidity sensor 1 according to one exemplary embodiment. In the left image, absorption material 5 is dry, so switch 6 keeps circuit 7 open. In the right image, water has been added to absorption material 5, causing its volume to increase. This causes absorption material 5 to press against switch 6, which in turn closes circuit 7. Circuit 7 then transmits the signal.

[0044] Figure 3 shows a cross-section through a substrate 10 and a moisture sensor 1 according to one exemplary embodiment. In the following exemplary embodiments, the substrate 10 is an insulating layer with an insulating material 11 in a roof truss, wherein the surface of the insulating layer is formed by a vapor retarder 12 or vapor barrier. The insulating material 11 is composed of an inter-rafter insulation 11A on an inner side and an insulating board 11B on an outer side. An underlay membrane 13 is arranged on the side of the insulating material 11 opposite the vapor retarder 12 or vapor barrier. A roof covering 20 is located outside the underlay membrane 13.

[0045] In the embodiment of Figure 3, a tip of the perforation element 3 is pierced through the vapor barrier 12 or vapor barrier and into the insulation material 11 so deeply that it is still in front of the underlay 13 of the insulation layer. More precisely, the tip of the perforation element 3 is located within the insulation between the rafters 11A without having reached the insulation board 11B. After the perforation element 3 has been fully pierced, the moisture sensor 1 is simultaneously adhered to the vapor barrier 12 or vapor barrier using the adhesive layer 2.

[0046] The circuit 7 is then coupled to a receiver such that the receiver can receive the signal. The circuit 7 may comprise a Bluetooth® device, and the receiver may be a Bluetooth®-enabled smartphone or a receiver of a so-called smart home device.

[0047] Figure 4 shows a cross-section through a substrate 10 and a moisture sensor 1 according to one embodiment. Unlike the embodiment of Figure 3, the tip of the perforation element 3 is pierced through the vapor retarder 12 or vapor barrier and into the insulation material 11 so deeply through the inter-rafter insulation 11A that it is still in front of the underlay membrane 13 but within the insulation panel 11B.

[0048] Figure 5 shows a cross-section through a substrate 10 and a moisture sensor 1 according to one exemplary embodiment. Here, the perforation element 3 is pierced from the opposite side of the insulation layer, namely through the underlay membrane 13. The tip of the perforation element 3 is located within the insulation board 11B. Alternatively, the perforation element 3 can be pierced so far that the tip is located within the insulation between the rafters 11A.

[0049] The various embodiments can be achieved by providing different moisture sensors 1 with different lengths of the perforation element 3. For example, a set can be used that includes the moisture sensor 1 with interchangeable perforation elements 3. The appropriate perforation element 3 can be selected depending on the desired monitoring depth in the subsurface and attached to the adhesive layer 2.

[0050] In a further modification, the adhesive layer 2 can be a double-sided adhesive tape, with another adhesive layer being applied on top instead of the non-adhesive layer. At least the switch 6, the circuit 7, or the battery 8 for powering the humidity sensor 1 can be glued on top of the additional adhesive layer. It should also be noted that "comprising" does not include any other

[0051] excludes elements or steps, and "one" or "an" does not exclude a plurality. Furthermore, it should be noted that features or steps described with reference to one of the above embodiments may also be used in combination with other features or steps of other embodiments described above. Reference signs in the claims are not to be considered as limitations.

Claims

Patent claims 1. Humidity sensor (1), comprising: an adhesive layer (2); a perforation element (3) protruding from the adhesive layer (2); at least one opening (4) penetrating a wall of the perforation element (3); an absorption material (5) arranged in an interior of the perforation element (3), in fluid communication with the at least one opening (4), and increasing its volume by absorbing a moist medium; a switch (6) mechanically coupled to the absorption material (5) such that it performs a switching operation by increasing the volume of the absorption material (5); and a switching circuit (7) emitting a signal upon the switching operation of the switch (6).

2. Humidity sensor (1) according to the preceding claim, wherein the circuit (7) comprises a wireless transmitting unit which transmits the signal wirelessly.

3. Humidity sensor (1) according to one of the preceding claims, further comprising a battery (8), preferably a button cell, for supplying power to the humidity sensor (1).

4. Humidity sensor (1) according to one of the preceding claims, wherein the switch (6), the circuit (7) and / or a battery (8) for supplying power to the humidity sensor (1) are arranged within the perforation element (3).

5. Humidity sensor (1) according to one of the preceding claims, wherein a non-adhesive layer is arranged on the adhesive layer (2) which faces away from the perforation element (3).

6. Humidity sensor (1) according to the preceding claim, wherein the switch (6), the circuit (7) and / or a battery (8) for supplying power to the humidity sensor (1) are arranged on the non-adhesive layer.

7. Humidity sensor (1) according to one of the preceding claims, further comprising: at least one further switch which is mechanically coupled to the absorption material (5) in such a way that it carries out a further switching operation by a further increase in the volume of the absorption material (5); and at least one further circuit which emits a further signal upon the switching operation of the at least one further switch; wherein the switch (6) carries out the switching operation by a first increase in the volume of the absorption material (5) and the at least one further switch carries out the further switching operation by the further increase in the volume of the absorption material (5), wherein the first increase in the volume is smaller than the further increase in the volume.

8. Humidity sensor (1) according to the preceding claim, further comprising a controller for determining an amount of moisture in the humidity sensor (1).

9. Humidity sensor (1) according to one of the preceding claims, wherein the switch (6) is a microswitch, preferably a normally open one.

10. Humidity sensor (1) according to one of the preceding claims, wherein the moist medium is guided to the absorption material (5) due to a capillary action of the perforation element (3).

11. Humidity sensor (1) according to one of the preceding claims, wherein a power supply of the humidity sensor (1) is effected by obtaining an amount of electrical energy, preferably from sources such as ambient temperature, vibrations or air currents.

12. Humidity sensor (1) according to one of the preceding claims, wherein several of the perforation elements (3) protrude from the adhesive layer (2); several switches (6) are mechanically connected to a respective Absorption material (5) in a respective perforation element (3) are coupled in such a way that they carry out a respective switching operation by increasing the volume of the respective absorption material (5); and each switch (6) is assigned to a respective circuit (7) which emits a signal during the switching operation of the respective switch (6).

13. Humidity sensor (1) according to one of the preceding claims, wherein the perforation element (3) is removable from the adhesive layer (2) and attachable to the adhesive layer (2) so that the perforation element (3) is replaceable.

14. Humidity sensor (1) according to the preceding claim, wherein the perforation element (3) is interchangeably attachable to and removable from the adhesive layer (2) by means of a bayonet lock, a clip connection or a threaded connection.

15. Set comprising the humidity sensor (1) according to the previous claim and a further perforation element which has a different length than the perforation element (3).

16. A method for determining a moisture quantity by means of a moisture sensor (1) according to one of the preceding claims, the method comprising the following steps: piercing the perforation element (3) into a permeable substrate (10); Adhering the moisture sensor (1) to a surface of the substrate (10) by means of the adhesive layer (2); and Coupling the circuit (7) to a receiver such that the receiver can receive the signal.

17. Method according to the preceding claim, wherein the adhesive layer (2) is part of a single-sided adhesive tape, wherein a protective layer attached to the adhesive layer (2) is removed from the single-sided adhesive tape before the moisture sensor (1) is adhered to the surface of the substrate (10) by means of the adhesive layer (2).

18. Method according to one of claims 16 and 17, wherein the substrate (10) is an insulating layer with an insulating material (11), preferably in a roof truss, wherein the surface of the insulating layer is formed by a vapor barrier (12) or vapor barrier.

19. Method according to the preceding claim, wherein a tip of the perforation element (3) is pierced so deeply that it is located in front of an underlayment (13) of the insulation layer.

20. Method according to one of the preceding claims 16 to 19 using a set according to claim 15, further comprising a step of selecting either the perforation element (3) or the further perforation element, and with a step for attaching the selected perforation element to the adhesive layer (2).

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