Humidity sensor, method for providing a humidity sensor and method for evaluating the state of a humidity sensor

Abstract

Face covering comprehensive: a humidity sensor, with: a moisture-sensitive element (12) designed to permanently transition from a first state (161) to a second (162) state under the influence of moisture (14); and with an information device (18) configured to provide wireless communication for remote querying, to wirelessly transmit at least one of the first state (161) and the second state (162); or to indicate a position on the humidity sensor where at least one of the first state (161) and the second state (162) is optically detectable for remote querying.

Description

[0001] The present invention relates to a humidity sensor, in particular to a humidity sensor with a memory, to a face covering and a transport monitoring device with such a humidity sensor, as well as to a device configured to evaluate the state of a humidity sensor and to associated methods and a computer program product. The present invention particularly relates to a humidity monitor and a system for checking the humidity in assemblies and objects with remote interrogation.

[0002] In various applications or systems, monitoring the moisture content of system components is useful or even necessary. If moisture levels reach a certain level, the effectiveness of the system can be impaired or jeopardized.

[0003] Numerous electronic sensor technologies are known and commercially available for determining humidity. A variety of well-known wireless transmission methods can be used to transmit the sensor values ​​to an evaluation station. Transponder systems are particularly suitable for this purpose, as they allow both power and data to be transmitted wirelessly, thus eliminating the need for a power supply to the transponder. However, existing electronic sensors and transmission systems are complex, and it seems almost impossible to bring them down to a cost level that would prevent the costs of the products equipped with them, especially in the "disposable" sector, from rising disproportionately.

[0004] US 2013 / 0063602 A1 discloses a device for monitoring the humidity exposure of system components, the device comprising sensor modules for collecting environmental data and a monitoring module with a humidity indicator and an electrical monitoring component sealed from the environment that reads a physical change in the humidity indicator.

[0005] US 9,488,504 B2 discloses electronic devices that may contain sensitive circuitry. To determine whether an electronic device has been exposed to excessive amounts of moisture, the electronic device may be equipped with a moisture indicator.

[0006] EP 1 493 352 A1 discloses a kit containing a hygrometry sensor integrated into a packaging of a cosmetic product.

[0007] US 2018 / 0357884 A1 discloses a sensor system for detecting the moisture level of a working fluid comprising a body in which a moisture indicator is located, which changes its color in the presence of moisture.

[0008] US 5 341 649 A discloses a method and apparatus for remotely monitoring the condition of a heat transfer fluid in the fluid line of a heat transfer system.

[0009] US 9 430 930 B2 describes herein a device comprising a collection element having a base with an upper surface surrounded by one or more raised edges near a periphery of the base, the upper surface having a concavity.

[0010] WO 2019 / 089522 A1 discloses a wound dressing comprising a superabsorbent pad, a cover layer, a humidity chamber, a wick and a humidity colorimeter sensor.

[0011] US 2017 / 0045461 A1 discloses a humidity indicator card comprising a humidity indicator and a safety device.

[0012] US 2010 / 0109685 A1 discloses: A wireless moisture monitoring device that measures the dielectric constant of a material to provide an indication of the water or moisture content of a material.

[0013] US 10 297 135 B1 discloses a dryness sensor that uses a block of superabsorbent polymer that absorbs liquid and increases in size when absorbing liquid.

[0014] US 2007 / 0044802 A1 discloses a filtering and humidifying face mask. The face mask comprises a base mask and an outer mask that is removably attached to the base mask.

[0015] US 2019 / 0188989 A1 discloses a system and method for indicating the dryness of a sterilization product, comprising taking a first moisture reading before starting a sterilization cycle, taking a second moisture reading after completion of the sterilization cycle, and indicating the dryness of the sterilization product to a user based on the first moisture reading and the second moisture reading.

[0016] US 2019 / 0254583 A1 discloses: A system for detecting an incontinence event comprises an insert which can be inserted on a mattress and which, when inserted, has a first and a second conductor and in which the first and the second conductor are not in electrical connection with each other.

[0017] US 2019 / 0060136 A1 discloses a moisture-sensing article comprising a moisture-sensing module attached to a garment and intended to absorb and retain body fluids excreted by an animal.

[0018] JP 2015-021972 A addresses the problem of how to provide a moisture detector.

[0019] There is therefore a need for simple and cost-effective yet reliable humidity sensors, disposable articles, in particular face coverings or transport monitoring devices, a device for evaluating a state of a humidity sensor, methods for providing a humidity sensor for remote interrogation, methods for evaluating a state of a humidity sensor and a computer program that enable simple and reliable monitoring of humidity.

[0020] The object of the present invention is therefore to provide a humidity sensor, a disposable article, in particular a face covering or face mask, with such a humidity sensor, a device for monitoring the transport of goods, a device for evaluating a state of a humidity sensor, a method for providing a humidity sensor for remote interrogation, a method for evaluating a state of a humidity sensor and a computer program which enable simple and reliable monitoring of the humidity.

[0021] This problem is solved by the subject matter of the independent patent claims.

[0022] The inventors have recognized that, on the one hand, the use of a humidity-sensitive element designed to permanently change a state of the element under the influence of humidity can provide a simple and reliable way of monitoring the influence of humidity, wherein, furthermore, by means of an information device for wireless communication and / or displaying a position for querying the state on the humidity sensor, a remote query of the humidity-sensitive element or the humidity sensor is possible, so that overall a simple and reliable remote query of influencing humidity is possible.

[0023] According to one embodiment, a humidity sensor for remote interrogation comprises a humidity-sensitive element configured to permanently transition from a first state to a second state under the influence of moisture. The humidity sensor further comprises an information device configured to provide wireless communication for the remote interrogation in order to wirelessly transmit at least one of the first state and the second state. Alternatively or additionally, the information device is configured to indicate a position on the humidity sensor at which at least one of the first state and the second state can be optically detected for the remote interrogation.

[0024] According to one embodiment, a disposable article, in particular a face covering or face mask, is equipped with such a moisture sensor. This enables monitoring or surveillance of when the disposable article needs to be replaced, which can prevent both premature and late replacement, thus avoiding waste and costs on the one hand, and ensuring the appropriate functionality, for example, a hygienic property, on the other.

[0025] According to one embodiment, a transport monitoring device comprises a humidity sensor as described herein. This enables continuous monitoring of the humidity of the transported goods, even without active data storage or data loggers, since reaching a certain humidity level can be detected by the permanently changing state of the humidity-sensitive element.

[0026] According to one embodiment, a device for evaluating the state of a humidity sensor is equipped with a camera configured to capture an object region in order to obtain image information of the object region. The device comprises an evaluation device configured to evaluate the image information for reference information indicating the presence and position of sensor information of the humidity sensor. The evaluation device is configured to evaluate the image information at the indicated position for the sensor information and to output an evaluation result based on the sensor information.

[0027] This enables robust and easy detection of the reference information, which then provides insight into where in the image information the sensor information is contained, enabling robust and reliable detection as random or irrelevant information at other locations can be excluded from consideration.

[0028] According to one embodiment, a method for providing a humidity sensor for remote interrogation comprises combining a humidity-sensitive element that is designed to permanently transition from a first state to a second state under the influence of moisture, with an information device that is designed to provide wireless communication for the remote interrogation, to wirelessly transmit at least one of the first state and the second state, and / or to indicate a position on the humidity sensor at which at least one of the first state and the second state is optically detectable for the remote interrogation.

[0029] According to one embodiment, a method for evaluating a state of a humidity sensor comprises detecting an object area to obtain image information of the object area, evaluating the image information for reference information indicating the presence and a position of sensor information of the humidity sensor, evaluating the image information at the indicated position for the sensor information, and outputting an evaluation result based on the sensor information.

[0030] According to one embodiment, a computer program is provided with a program code that has instructions configured to carry out such a method.

[0031] Further advantageous embodiments are the subject of some patent claims.

[0032] Particularly advantageous embodiments of the present invention are explained in more detail below with reference to the accompanying drawings. In the drawings: Fig. 1 is a schematic block diagram of a remote humidity sensor according to an embodiment; Fig. 2a is a schematic block diagram of a humidity monitoring system using backscattering according to an embodiment; Fig. 2b is a schematic block diagram of a humidity monitoring system according to another embodiment, in which the transponder technology for transmitting the sensor data to the reader is implemented via an inductive coupling; Fig. 3 shows a schematic representation of a humidity-sensitive element according to an embodiment in the first state and in the second state; Fig. 4 is a schematic block diagram of a humidity monitoring system according to an embodiment of a first implementation; Fig. 5 is a schematic block diagram of a humidity monitoring system according to an embodiment of a second implementation; Fig. 6 is a schematic block diagram of a positioning of the humidity-sensitive element with respect to the information device according to an embodiment; Fig. 7a-b show schematic block diagrams of a system for evaluating a humidity sensor according to an embodiment of a third implementation; Fig. 8a-c show schematic representations of a conductor track in the first state and in the second state according to an embodiment; Fig. 9a-b are schematic representations of embodiments in connection with the third implementation, which are provided with the design of the conductor track according to the Fig. 8c; Fig. 10 is a schematic flow diagram of a method for providing a humidity sensor according to an embodiment; and Fig. 11 is a schematic flow diagram of a method according to an embodiment, as it can be used, for example, to evaluate a state of a humidity sensor.

[0033] Before exemplary embodiments of the present invention are explained in more detail below with reference to the drawings, it is pointed out that identical, functionally equivalent or equivalent elements, objects and / or structures in the different figures are provided with the same reference numerals, so that the description of these elements shown in different exemplary embodiments is interchangeable or can be applied to one another.

[0034] The embodiments described below are described in conjunction with numerous details. However, embodiments may also be implemented without these detailed features. Furthermore, for clarity, embodiments are described using block diagrams instead of detailed illustrations. Furthermore, details and / or features of individual embodiments may be readily combined with one another, unless explicitly described otherwise.

[0035] The exemplary embodiments described below are described with reference to disposable articles, including in particular face coverings or face masks. However, the present invention is not limited to this, but is transferable to any concepts in which the effects of moisture are to be monitored over a certain period of time. This includes other disposable articles, in particular hygiene articles, which may also include incontinence articles, for example. However, the present invention can also be used in other areas, for example in logistics to monitor the transport of goods, where the effects of moisture are to be monitored, for example in the food sector but also during the transport of technical equipment.A corresponding humidity sensor can be inserted, attached or arranged in a corresponding transport volume, such as a container or box, in order to monitor several transported goods simultaneously for the effects of humidity.

[0036] Fig. 1 shows a schematic block diagram of a humidity sensor 10 for remote interrogation according to one exemplary embodiment. The humidity sensor 10 comprises a humidity-sensitive element 12, which is designed to permanently transition from a first state 161 to a second state 162 under the influence of moisture 14. A state is understood to be a property of the humidity-sensitive element 12 that is reversible without active intervention or possibly not at all, so that it is only possible to return from state 162 to state 161 with the expenditure of the active steps. Anticipating later detailed explanations, the humidity-sensitive element 12 can, for example, be designed to permanently change color under the influence of moisture. The first state 161 can be associated with a first color or a colorless state, and the second state with a second color.An example of such a moisture-sensitive element is so-called silica gel. Alternatively or additionally, the moisture-sensitive element can be designed to permanently change its electrical conductivity under the influence of moisture, in order to provide a first electrical conductivity in the first state and to provide a different second electrical conductivity in the second state. An example of such a change is, for example, that the first state is an electrically non-conductive state and the second state is an electrically conductive state, or that the first state is an electrically conductive state and the second state is an electrically non-conductive state.These can also be so-called limit value considerations of resistance changes, which are also fulfilled by such embodiments, for example by increasing an ohmic resistance by a factor of 2, 3, 4 or higher or by multiplying it by a reciprocal thereof in order to reduce the ohmic resistance value.

[0037] In some embodiments, gels may be used, such as silica gels, which in some applications can or are intended to protect moisture-sensitive goods from moisture by absorbing moisture penetrating the packaging. These may also be provided with a color indicator that changes color when a certain moisture saturation is reached. Even if some of the embodiments do not provide protection against any amount of moisture, moisture penetration can at least be detected.

[0038] Humidity 14 is understood to mean the water content or the content of another corresponding liquid in a substance or gas volume. In the case of face coverings or face masks, this is relevant, for example, to ambient air and especially breathing air, which will be discussed in more detail below.

[0039] The humidity sensor 10 further comprises an information device 18, which is informationally coupled to the humidity-sensitive element 12 via a connection 22. According to one embodiment, the information device 18 is designed to provide wireless communication for remote interrogation in order to wirelessly transmit the state 161 and / or 162. Alternatively or additionally, the information device 18 can be designed to indicate a position on the humidity sensor 10 at which the state 161 and / or 162 can be optically detected for remote interrogation. For example, when the color of the humidity-sensitive element 12 changes to transition between the states 161 and 162, both the state 161 and the state 162 can be optically detected.However, if state 161 is, for example, colorless, it may also be sufficient to detect only state 162, which indicates that a corresponding humidity limit value has been reached or exceeded.

[0040] Fig. 2a shows a schematic block diagram of a humidity monitoring system 2001 according to an embodiment, which includes a humidity sensor 201, which can be coupled, for example, to a reader 25, wherein a so-called backscatter coupling 24 between an antenna 26 of a transponder 28 connected to the humidity sensor 10 and an antenna 32 of the reader 25 is shown as an example. The reader 25 can be configured in a known manner to enable a signal 34 for displaying and / or evaluating the information content received from the transponder 28 and provided by the humidity sensor 10.

[0041] Fig. Figure 2b shows a schematic block diagram of a humidity monitoring system 2002 according to a further embodiment, in which the transponder technology for transmitting the sensor data to the reader 25 is implemented via an inductive coupling 36, which can be achieved by appropriately designing an antenna 26' of a transponder 28' and an antenna 32' of the reader 25. Thus, interaction with a wireless signal can occur. In both embodiments of the Fig. 2a and the Fig. 2b, the information device can be designed as a transmission device to provide wireless communication for remote retrieval. Other or additional elements for wireless communication can be readily employed.

[0042] In other words, Fig. 2a an embodiment with a backscatter transponder with humidity sensor and Fig. 2b an inductively coupled transponder with humidity sensors.

[0043] Fig. 3 shows a schematic representation of the moisture-sensitive element 12 in the first state 161 and in the second state 162. Due to the transition to the second state 162, a color of the moisture-sensitive element 12 has changed from a transparent state or a first color to the color of state 162, which can be easily detected by optical detection systems. Silica gel readily enables such behavior. In combinatorial or alternative embodiments, the moisture-sensitive element can also execute a change between the first state 161 and the second state 162 such that, alternatively or in addition to a change in the resistance value or the electrical conductance, another electrical property is permanently changed, such as an electrical capacitance, an electrical inductance, an electrical magnetic field strength, or the like.

[0044] Fig. Figure 4 shows a schematic block diagram of a system 400 for humidity monitoring according to one embodiment. In this embodiment, the humidity-sensitive element is designed to permanently change color under the influence of humidity, as is the case in connection with the Fig. 1 and the Fig. 3. This means that state 161 is associated with a first color or a colorless state, and state 162 is associated with a second color different from the colorless state or the first color.

[0045] The information device is designed as a transmission device 38, for example in the form of the transponder 28 or 28' including the associated antenna, although other concepts can also be implemented to provide wireless communication for remote interrogation in order to transmit the state 161 and / or the state 162. It should be noted at this point that embodiments are directed toward transmitting the respective state that prevails in the humidity-sensitive element 12, for example, during communication with the reader 25. Since the humidity-sensitive element 12 permanently changes its state when a certain threshold value is reached or exceeded, this can provide information that an inadmissible humidity level was reached at some point in the past, even if the humidity-sensitive element 12 is currently in a dry environment, which also enables the evaluation of a history.In an exemplary binary embodiment, meaning that the humidity-sensitive element 12 has either the first state or the second state, the transmission or possibility of transmission of only one of the two states can also obtain a sufficient level of information, since the absence of a corresponding signal or information can then be interpreted as a different state. For example, it may be sufficient to actively determine only whether the humidity threshold has been reached or exceeded, thus obtaining state 162, for example, in order to output or receive an alarm in the signal 34. Alternatively or additionally, it is also possible to transmit the first state 161, for example, to indicate that everything is OK and a predetermined state has not been left.

[0046] A humidity sensor 40 according to an embodiment, which can be used in the humidity-monitoring system 400 and which has the transmission device 38, can have a light source 42 configured to emit a first light 44 to illuminate the humidity-sensitive element 12. The humidity sensor 40 can include a receiving element 46 configured to receive a second light 48 reflected or transmitted by the humidity-sensitive element 12, wherein the second light 48, while the first light 44 remains constant, changes due to a transition of the humidity-sensitive element 12 into the second state 162. This means that upon continuous or repeated illumination of the humidity-sensitive element 12 with the light 44 of the light source 42, the transition to the state 162 due to the light 48 can be detected with or at the receiving element 46.For example, the light source 42 may comprise a light-emitting diode or a laser or the like, while the receiving element 46 may, for example, comprise a photoreceiver or the like.

[0047] The transmission device 38 is configured to output a wireless signal, for example, by means of the backscatter coupling 24 and / or the inductive coupling 36 or other transmission methods, based on a difference between the light 44 and the light 48. For example, the transmission device 38 may have a corresponding evaluation circuit that derives the second state 162 based on knowledge of a desired state expected in the first state 161 and a deviation therefrom.

[0048] Optionally, a color filter 521 and / or a color filter 522 can be arranged between the light source 42 and the humidity-sensitive element 12 or between the humidity-sensitive element 12 and the receiving element 46. Corresponding color filters can be configured to provide color filtering that is matched to the color 44 or the color 48, respectively. This enables a corresponding color filter 521 and / or 522 to focus the light signal 44 or 48, respectively, on a color that is well or highly absorbed by one of the two states of the humidity-sensitive element 12 and is absorbed to a low or as low a degree as possible by the other state.

[0049] Accordingly, the light source 42 can be configured to emit the light 44 in a color spectrum that is matched to the color 44 or 48. For example, the humidity-sensitive element 12, which reflects or transmits the light 44, can also act as a color filter. The color of the light 44 can be selected such that it is well absorbed in one state of the humidity-sensitive element 12 and as little as possible in the other state, which enables a robust detection option via a signal amplitude in a receiver signal 54 of the receiver element 46, which is also comparable in terms of good and robustness to a control signal 56 of the light source 42.

[0050] The humidity sensor 40 may include an evaluation circuit 58 coupled to the receiving element 46 and possibly also to the light source 42, for example, to receive the received signal 54 and provide the control signal 56. The receiving element 46 may be configured to output the signal 54 based on the light 48. The evaluation circuit 58 may be configured to evaluate the received signal 54 to determine whether the humidity-sensitive element 12 is in state 161 or state 162 in order to obtain a result signal 62, which is provided to the transmission device 38.

[0051] The transmission device 38, the light source 42, the reception element 46, the evaluation circuit 58, and the humidity-sensitive element 12 can form a common module, for example, an integrated circuit having a predefined area in which the humidity-sensitive element 12 is arranged. Such a module can be used in a simple manner for data transmission to the reader 25 in order to monitor the humidity of a device or a corresponding object to be monitored and to transmit and / or remotely evaluate the monitoring result, i.e., to perform an evaluation using a distance-permitting device.

[0052] In the illustrated embodiment of the humidity sensor 40, the changing state can thus be monitored by means of a simple sensor device based on illumination.

[0053] In other words, a gel with a color indicator can be introduced into the sensor system. The sensor system comprises a light-emitting diode, a photoreceiver, and an evaluation circuit that detects the color change. The result can then be read wirelessly via an electronic system (e.g., a transponder). The change in the gel upon reaching its moisture saturation, for example, from colorless to orange (equivalently for other color changes), can lead to a decrease or increase in the photocurrent in the receiver circuit. The selection of specific colored LEDs or the additional use of color filters can improve or optimize the evaluation. This eliminates the need for an additional, expensive moisture sensor circuit. This simplifies moisture detection.Furthermore, the dedicated humidity circuits avoided in the embodiments described herein have the problem that they immediately saturate when directly measuring the breath. With the approaches presented in the embodiments described herein, however, short-term humidity pulses, such as those resulting from respiration, are eliminated by the slow absorption of moisture into the gel. In one embodiment, the transponder, light-emitting diode, light receiver, evaluation circuit, and gel are combined in a single component (module or circuit).

[0054] Fig. Figure 5 shows a schematic block diagram of a system 500 for humidity monitoring according to another embodiment. Reference is made here, by way of example, to a disposable article 55, which is shown in the form of a face covering or face mask. A humidity sensor 50 according to one embodiment is configured such that the humidity-sensitive element 12 is the same as or comparable to the embodiments of Fig. 1, Fig. 3 and / or 4 is designed to permanently change color under the influence of moisture, wherein the first state 161 is associated with a first color or a colorless state and the second state 162 is associated with a second color, as described in connection with the silica gel. An information device 64 of the moisture sensor 50 is designed to display a position on the moisture sensor 50 at which the state 161 and / or the state 162 can be optically detected for remote retrieval. The information device comprises, for example, a bar code or a QR code. An implementation as a QR code is shown as an example, wherein the moisture-sensitive element 12 is arranged in an interior region of the QR code.Based on reference markings and further information, for example, a corresponding inner area of ​​the QR code can be displayed in order to evaluate the moisture-sensitive element 12 with regard to a color obtained therefrom.

[0055] As an alternative to a QR code, other information may also be provided which indicates a position of the moisture-sensitive element 12 with respect to the evaluated information, as is the case in connection with the Fig. 6 is explained.

[0056] The system 500 further comprises a device 57 configured to evaluate a corresponding state of the humidity sensor 50 or the humidity-sensitive element 12. The device 57 comprises, for example, a camera configured, for example, as an area camera, for example, using known image capture techniques. Alternatively, however, laser-based scanning or line-scan cameras can also be used. The camera 66 or a selected alternative is configured to capture an object area in order to obtain image information 68 of the object area. The object area can, for example, be a specific distance in a corridor, a passageway, an access, a lock, for example in a hospital or a medical area, or any other area in which the humidity sensor 50 is expected, for example, a lock through which transport goods are moved.The device 57 further comprises an evaluation device 72, for example comprising a microcontroller, a processor device, CPU, a field-programmable gate array (FPGA), or the like, which is designed to perform programmable computing operations. The evaluation device 72 is designed to evaluate the image information 68 for reference information. The reference information indicates the presence and position of sensor information from the humidity sensor. The presence can be determined, for example, by recognizing and / or decoding the information device 46, such as a barcode or QR code. In other words, recognizing the code can be understood as an instruction to also evaluate the humidity-sensitive element 12, or the color one. Thus, the evaluation device 72 can know where, relative to the information device 64, the evaluation is to take place.As an example of the QR code, an interior region of the code can be used, which is easily recognizable via the reference markings in the corners of the QR code. Any other position can also be implemented alternatively or additionally. The evaluation device 72 can be configured to evaluate the image information 68 at the displayed position with respect to the sensor information and to output an evaluation result 47 based on the sensor information. For this purpose, any optical, haptic, and / or acoustic output devices can be part of the device 57, so that the result can be output based on images, sounds, and / or haptic feedback, such as vibrations.

[0057] In other words, particular attention can be paid to low costs when monitoring mass-produced items with low manufacturing costs. The reading device and evaluation, on the other hand, can be designed to be more complex and cost-intensive. Little to minimal effort can be required on the object to be monitored, such as a disposable item such as a type of mask, if it only contains the gel, the moisture-sensitive element for the color change. In this case, the reading device, such as device 57, can have a camera that detects and evaluates the color change. The position of the gel on the object to be monitored can be marked with a unique marker for image analysis. The marker can be, for example, a printed barcode or QR code.An image analysis extracts information from the data, such as reduced information such as only the humidity information from the color change, which can make it possible to forego saving images, so that in exemplary embodiments, images are not saved. Fig. Figure 5 shows a concept for evaluating the color change using imaging.

[0058] Fig. 6 shows a schematic block diagram of a positioning of the moisture-sensitive element 12 with respect to the information device 64. In an evaluating system, it may be known in advance and / or encoded in the information device 64 how a relative positioning 76 or a displacement with respect to the information device 64 occurs along one, two, or more directions, such as x, y. This can be done explicitly, for example, by selecting a center in the QR code, but can also be done implicitly, for example, by image displacement operations directed at the information device 64 or by using a position of the information device 64 to check its surroundings for the presence of the moisture-sensitive element 12.

[0059] Fig. 7a and Fig. 7b shows a schematic block diagram of a system 700 for evaluating a humidity sensor 70 according to one embodiment. The components of the system 700, with the exception of the humidity sensor 70, can be based on known concepts, such as those used in retail for detecting anti-theft tags. For example, a coil of a transmitter circuit 78 can be coupled to a coil of a receiver circuit 82, wherein a measuring device 84 can be provided to detect a signal amplitude based on an alternating electromagnetic field that extends from the transmitter coil 78 to the receiver circuit 82. The presence of an electrical resonant circuit, for example with the humidity sensor 70, can lead to a reduced signal amplitude in the measuring device 84.

[0060] Embodiments are based on this effect in that the first state and the second state are associated with whether or not the humidity sensor 70 provides a corresponding electrical capacitance and / or inductance or, in combination, a resonant frequency of an oscillating circuit. For this purpose, it was recognized according to the invention that the humidity-sensitive element 12 can be designed in such a way that, under the influence of the moisture 14, it permanently changes an electrical conductivity in order to provide a first electrical conductivity in the first state and to provide a second electrical conductivity that is different therefrom in the second state. The electrical conductivity can be associated with an electrical capacitance, inductance or an oscillating circuit.form a part thereof, so that in one of the states a first electrical capacitance value, inductance value and / or resonant frequency is obtained and in the second state a different value is obtained, which can be associated, for example, with a first electrically conductive state and a second electrically conductive state. The electrically conductive states here denote, for example, conductive / non-conductive and / or a change between two preferably significantly different ohmic resistance values. Thus, for example, in one state a relevant or effective electrical capacitance value, inductance value or resonant frequency can be obtained and in the other no such value, or vice versa and / or two different values ​​of the electrical capacitance, inductance or resonant frequency can be obtained.

[0061] This allows the humidity sensor 70 to be configured such that, after being exposed to a corresponding amount of moisture according to the system design, it produces a reduced or increased signal amplitude at the measuring device 84 compared to the previous state, as will be explained in detail below.

[0062] In other words, anti-theft tags are used in retail. These consist only of a coil and a capacitor without any active components and can therefore be manufactured very cost-effectively. This radio frequency process utilizes induction effects. Fig. 7a and Fig. 7b shows a schematic layout of a control gate. In the situation according to Fig. 7a there is no security label in the lock, in the situation according to Fig. 7b, such a tag is located between the transmitting circuit and the receiving circuit. The generator in the transmitting circuit generates an alternating current that flows through the transmitting coil. This creates an alternating electromagnetic field. The alternating field induces an alternating voltage in the receiving circuit, which can be registered as a comparatively large signal. If the security tag is now placed between the transmitting and receiving coils, the deflection in the detection device of the receiving circuit becomes smaller. The security tag, with its coil and its capacitance, forms an oscillating circuit that resonates at the frequency of the generator. The alternating current through the coil of the transmitting circuit generates an alternating magnetic field, which also permeates the coil in the receiving circuit. This alternating magnetic field induces a voltage in the receiving coil, which can be registered with a detection device.If the tag, with its closed conductor loops, now passes between the transmitting and receiving coils, a current is induced in the tag's conductor loops. According to Lenz's law, this current is directed in such a way that it seeks to inhibit its source. This means that the magnetic field generated by the induced current is directed opposite to the magnetic field of the transmitting coil. This also reduces the magnetic field passing through the receiving coil, and the received signal becomes smaller. Using a suitable electronic circuit, an alarm can be triggered due to the drop in the received signal. If the tag's oscillating circuit is interrupted, it will no longer be detected in the RF gate.

[0063] In other words, the Fig. 7a and Fig. 7b shows a highly simplified functional principle of an RF lock.

[0064] So in the Fig. 8a-c schematic representation of a conductor track 861 in the first state 161 and a conductor track 862 in the second state 162, into which the conductor track 861 changes under the influence of the moisture 14.

[0065] According to Fig. 8a, the conductor track 861 has a first ohmic resistance value R1, which transitions into a larger or smaller ohmic resistance value R2 of the conductor track 862, wherein the ohmic resistance values ​​preferably lie between at least 20%, at least 50%, or at least 100% of the resistance value R1. For example, a reduction or increase in a conductor cross-section under the influence of moisture 14 can cause the resistance change.

[0066] According to Fig. 8b, the conductor track 861 is an interrupted conductor track, which is also the case with a resistance value of infinity of the conductor track 861 according to Fig. 8a. In state 162, the conductor track 862 has a closed state, which can also be understood as a short circuit, and thus a significantly reduced ohmic resistance value.

[0067] In the Fig. 8c is a Fig. 8b shows complementary behavior, in which state 161 of track 861 is a closed state and state 162 of track 862 is an open state.

[0068] The conductor track 861 or 862 can be part of an electrical capacitance or capacitor, an inductance or coil or a resonant circuit or a supply line thereof, which can also result in an activation / deactivation of the electrical capacitance, inductance or the resonant circuit.

[0069] A corresponding example is for the humidity sensor 70 in the Fig. 9a and Fig. 9b, which corresponds to the design of the conductor track 86 according to the Fig. 8c. For example, a capacitor (C) 88 is connected in series with a coil (L) 92, whereby the corresponding LC resonant circuit is closed using conductor track 86. The conductor track can be arranged at any location and / or another series resonant circuit or parallel resonant circuit can be implemented.

[0070] The conductor track 86 has, for example, a section 86A that is formed from moisture-soluble material 94 or uses the moisture-soluble material 94 as a carrier material. For example, wax materials are known that dissolve under the influence of moisture, which in Fig. 9b. Here, the moisture-soluble material 94 is dissolved and has thus removed at least the section 96A from the conductor track 86 to obtain the state 862. Remaining components 86B and / or 86C can enable simple connection, but are optional for the functionality of the conductor track 86 as a limit value sensor. This means that the moisture-sensitive element 12 can be formed so as to be soluble at least in part under the influence of the moisture 14 and, for example, provide a carrier element for an electrical conductor track 86A. The carrier element 94 can be designed to dissolve upon the occurrence of the moisture 14 beyond a predefined amount set up in the carrier element, and thus to at least partially remove an electrical conductor track in order to change the electrical conductivity, for example to interrupt it. This can also interrupt the oscillating circuit, which can, for example, lead to the state according to Fig. 7a can lead.

[0071] A complementary implementation is possible in that the moisture-sensitive element 12 is formed soluble under the influence of the moisture 14 and a first state is an undissolved, electrically insulating state and in the second state an at least partially dissolved and electrically conductive state is present, so that in the second state the electrical conductivity is present, in order then to use the state according to Fig. 7b. Based on the system design, the state can be determined according to Fig. 7a or the condition according to Fig. 7b can be interpreted as a condition in which the humidity sensor was exposed to a corresponding amount of moisture. Both the moisture-soluble material 94 of the Fig. 9a and Fig. 9b as well as the moisture-soluble material for producing the electrical conductivity can be designed in consistency and / or quantity such that it is adapted to a tolerable amount of moisture.

[0072] According to the Fig. 9a and Fig. 9b, an oscillating circuit can thus be interrupted by a limit value sensor that reacts to humidity. With a limit value sensor, a direct change in the electrical properties occurs when a certain humidity saturation is reached, e.g. an electrical conductor that interrupts the flow of current when a certain humidity saturation is reached. This allows cost-effective RF humidity detection to be implemented, which can, for example, be integrated into a mouth and nose mask in order to be able to make statements about its continued usability. In a further exemplary embodiment, the humidity detection is implemented in such a way that the oscillating circuit is closed when the humidity increases. For this purpose, strips with dried salts or gels are used, for example. The moisture dissolves the salts or gels.Gels and can ensure that a current can flow in the resonant circuit, for example, by the information device comprising an electrical resonant circuit that is passive and comprises an electrical inductance and an electrical capacitance. A resonance property of this resonant circuit can vary depending on the first state and the second state, as is also the case for the embodiments of the . Fig. 9a and Fig. 9b is valid. The salts dissolved by the liquid may themselves be electrically conductive, so that a dissolved form of the material can then provide part of the conductive path, for example corresponding to section 86A.

[0073] In embodiments, the information device may comprise an electrical resonant circuit configured to interact with a wireless signal, as described in connection with the Fig. 2a and Fig. 2b is described by way of example. The moisture-sensitive element 12 can be part of the resonant circuit. Such a resonant circuit can have a first resonant frequency in the first state 161 and a second, different resonant frequency in the second state 162. Alternatively, the resonant circuit can have a resonant frequency in one of the two states and be inoperable in the other state, for example, by the resonant circuit being open in the corresponding state.

[0074] In other words, the Fig. 9a / 9b an RF label with a limit sensor for moisture detection. In Fig. 9a shows a dry state with a closed oscillating circuit. In Fig. 9b shows a wet state (irreversible) with an interrupted oscillating circuit.

[0075] As explained above, the moisture can be moisture contained in a tissue, in particular resulting from atmospheric humidity or respiratory humidity.

[0076] Embodiments are designed such that the moisture-sensitive element 12 is brought into effective connection with the corresponding material to be monitored.

[0077] This will be described using an exemplary embodiment of what constitutes a disposable article. Reference is made to the design of the disposable article 55 as a face covering or mouth-nose covering. Here, it is desirable for the moisture-sensitive element 12 to detect the condition of the mask or disposable article 55. For this purpose, the moisture-sensitive element 12 is connected to the material of the mask.

[0078] Embodiments provide that the disposable article has a moisture barrier configured to partially shield the humidity sensor, to shield contact with moisture from a first direction, and to enable contact with moisture from a second direction. With reference to the disposable article 55, the moisture barrier can, for example, be arranged such that direct impingement of the breathing air is prevented, while, for example, lateral or sideward diffusion of moisture from the fabric of the mask is enabled.

[0079] Plastic materials, for example, can be provided as a moisture barrier. According to one embodiment, the moisture barrier is formed at least partially from the moisture-sensitive element 12. If this is formed, for example, at least partially from silica gel, this gel can act as a type of low-pass filter and ensure a gel barrier from the direction of exhaled air, so that moisture, for example, does not directly impinge on a sensor element. This can lead to a corresponding time constant and thus wear time, for example, if the disposable article 55 is not formed using an optically detectable barcode or QR code, but, for example, in accordance with the moisture sensor 40 and / or 70 or other implementations in which additional electronics are provided.

[0080] This means that the first shielded direction can be the wearer's airway direction and the second direction can be different from this.

[0081] Further embodiments relate, for example, to devices for monitoring the transport of goods with a moisture sensor according to the embodiments described herein. These can be arranged, for example, as a so-called label on individual articles or packaging units thereof.

[0082] With further reference to the Fig. 5, the device 57 is explained in more detail below. The device 57 comprises the evaluation device 72. According to exemplary embodiments, this can be designed to evaluate the image information at the position displayed by the information device 64 for a predefined color associated with a state of the humidity sensor obtained under the influence of moisture on the humidity sensor. Furthermore, the evaluation device 72 can output an evaluation result to indicate that a level of moisture acting on the humidity sensor has reached or exceeded a humidity threshold. This combination highlights a particular advantage of the present invention. For example, any color can be assumed for certain articles to be monitored.Mouth and nose coverings, for example, can be of any color, so errors can occur during optical image evaluations if there is color overlap with the moisture-sensitive element 12. By indicating at which position an evaluation should be performed, the probability of such an error can be reduced or even avoided.

[0083] The corresponding reference information indicating the position may include a barcode or a QR code or other information sources.

[0084] In the example of a QR code, the evaluation device 72 can be designed to evaluate an inner area of ​​the QR code for the predefined color, as is the case, for example, in Fig. 5. As mentioned, the areas, including the interior, can be easily identified due to position markers arranged in the corners of the QR code.

[0085] Fig. 10 shows a schematic flow diagram of a method 1000 according to an embodiment. A step 1010 comprises combining a humidity-sensitive element, which is configured to permanently transition from a first state to a second state under the influence of moisture, with an information device, which is configured to provide wireless communication for remote interrogation, to wirelessly transmit at least one of the first state and the second state; or to indicate a position on the humidity sensor at which at least one of the first state and the second state is optically detectable for remote interrogation.

[0086] The method 1000 may be applied to provide a remote humidity sensor.

[0087] Fig.11 shows a schematic flow diagram of a method 1100 according to an embodiment, such as can be used, for example, to evaluate the state of a humidity sensor, for example, using device 57. Method 1100 can also be carried out with computer support. In a step 1110, an object region is detected in order to obtain image information of the object region. In a step 1120, the image information is evaluated for reference information indicating the presence and position of sensor information of the humidity sensor. In a step 1130, the image information at the displayed position is evaluated for the sensor information.

[0088] In a step 1140, an evaluation result based on the sensor information is output.

[0089] The embodiments described herein can be used in a wide variety of applications, including disposable items such as mouth and nose coverings / protective masks. This is particularly relevant due to the shortage of reliable protective masks for employees in hospitals and care settings. If the mask becomes damp, it must be changed. However, it is unclear how quickly this happens. Effective protection depends not only on the filtration properties of the material used. It is known that as the moisture content in the material increases, the protective effect (filter efficiency) decreases. Moisture and body heat also promote increasing microbial contamination on the wearer's side. The mask must be changed as soon as it becomes completely damp, as this poses the risk of an infection bridge between the wearer and the environment.This applies to efficient masks for self-protection (such as FFP2 masks), but even more so to the simpler versions for protecting others. For example, when coughing or sneezing, droplets can be projected from the outer surface of the moist mask into the environment. Examples of implementations address this issue by determining the moisture content in the filter material in order to individually optimize the wearing time of the mask. This can prevent the mask from being worn for too long and losing its effectiveness. On the other hand, unnecessary, premature mask changes are avoided, which leads to significant cost savings in hospitals or similar facilities. The moisture content can be evaluated automatically, for example by only issuing a new mask when it is used up, or by denying access to protected areas when a mask is used up.

[0090] Embodiments thus relate to monitoring systems that enable automated evaluation of humidity sensors, for example, on masks. Such a system comprises a humidity sensor, optionally attached to an object to be monitored, such as a mask or a transport container, and an evaluation device or device for remotely interrogating the sensor, which may include, for example, and tailored to the implementation of the humidity sensor to be monitored, the known reading device 25, the known combination of transmitting coil 78 and receiving coil 82, and / or the inventive implementation of the device 57. It should be noted that a plurality of humidity sensors can be monitored simultaneously and / or sequentially.

[0091] Although some aspects have been described in connection with a device, it is understood that these aspects also represent a description of the corresponding method, so that a block or component of a device can also be understood as a corresponding method step or as a feature of a method step. Similarly, aspects described in connection with or as a method step also represent a description of a corresponding block, detail, or feature of a corresponding device.

[0092] Depending on specific implementation requirements, embodiments of the invention may be implemented in hardware or software. The implementation may be performed using a digital storage medium, such as a floppy disk, a DVD, a Blu-ray Disc, a CD, a ROM, a PROM, an EPROM, an EEPROM, or a FLASH memory, a hard disk, or other magnetic or optical storage device storing electronically readable control signals that can interact or cooperate with a programmable computer system to perform the respective method. Therefore, the digital storage medium may be computer-readable.Some embodiments according to the invention thus comprise a data carrier having electronically readable control signals capable of interacting with a programmable computer system such that one of the methods described herein is carried out.

[0093] In general, embodiments of the present invention can be implemented as a computer program product with a program code, wherein the program code is effective to perform one of the methods when the computer program product is run on a computer. The program code can also be stored, for example, on a machine-readable medium.

[0094] Other embodiments include the computer program for performing one of the methods described herein, wherein the computer program is stored on a machine-readable carrier.

[0095] In other words, one embodiment of the method according to the invention is thus a computer program comprising program code for performing one of the methods described herein when the computer program is run on a computer. Another embodiment of the method according to the invention is thus a data carrier (or a digital storage medium or a computer-readable medium) on which the computer program for performing one of the methods described herein is recorded.

[0096] A further embodiment of the method according to the invention is thus a data stream or a sequence of signals that represents the computer program for carrying out one of the methods described herein. The data stream or the sequence of signals can be configured, for example, to be transferred via a data communication connection, for example, via the Internet.

[0097] A further embodiment comprises a processing device, for example a computer or a programmable logic device, which is configured or adapted to carry out one of the methods described herein.

[0098] A further embodiment comprises a computer on which the computer program for performing one of the methods described herein is installed.

[0099] In some embodiments, a programmable logic device (e.g., a field-programmable gate array, an FPGA) may be used to perform some or all of the functionalities of the methods described herein. In some embodiments, a field-programmable gate array may interact with a microprocessor to perform any of the methods described herein. In general, in some embodiments, the methods are performed by any hardware device. This may be general-purpose hardware such as a computer processor (CPU) or method-specific hardware such as an ASIC.

[0100] The above-described embodiments are merely illustrative of the principles of the present invention. It is understood that modifications and variations of the arrangements and details described herein will be apparent to others skilled in the art. Therefore, it is intended that the invention be limited only by the scope of the following claims and not by the specific details presented in the description and explanation of the embodiments herein.

Claims

[1] Face covering including: a humidity sensor with: a moisture-sensitive element (12) which is designed to permanently change from a first state (161) to a second state (162) under the influence of moisture (14); and with an information device (18) configured to provide wireless communication for remote retrieval, to wirelessly transmit at least one of the first state (161) and the second state (162); or to display a position on the humidity sensor at which at least one of the first state (161) and the second state (162) is optically detectable for remote retrieval. [2] The face covering of claim 1, comprising a moisture barrier configured to partially shield the moisture sensor to shield contact with moisture (14) from a first direction and to allow contact with moisture (14) from a second direction. [3] A face covering according to claim 2, wherein the moisture-sensitive element (12) at least partially provides the moisture barrier. [4] A face covering according to claim 2 or 3, wherein the first direction at least partially coincides with a respiratory direction of a wearer of the face covering; and the second direction is different therefrom. [5] A face covering according to any one of claims 1 to 4, wherein the moisture-sensitive element (12) of the moisture sensor is configured to permanently change color under the action of the moisture (14), the first state being associated with a first color or a colorless state; and the second state being associated with a second color. [6] A face covering according to claim 5, wherein the humidity sensitive element (12) of the humidity sensor comprises a silica gel. [7] Face covering according to one of claims 1 to 4, wherein the moisture-sensitive element (12) of the moisture sensor is designed to permanently change an electrical conductivity under the action of the moisture (14) in order to provide a first electrical conductivity in the first state (161) and to provide a second electrical conductivity different therefrom in the second state (162). [8] A face covering according to claim 7, wherein the first state is an electrically non-conductive state and the second state is an electrically conductive state; or wherein the first state is an electrically conductive state and the second state is an electrically non-conductive state. [9] Face covering according to one of claims 1 to 4, wherein the moisture-sensitive element (12) of the moisture sensor is designed to permanently change color under the influence of the moisture (14), wherein the first state is associated with a first color or a colorless state; and the second state is associated with a second color; wherein the information device (18) of the moisture sensor is designed as a transmission device to provide wireless communication for remote retrieval in order to wirelessly transmit at least one of the first state (161) and the second state (162). [10] A face covering according to claim 9, wherein the humidity sensitive element (12) of the humidity sensor comprises a silica gel. [11] The face covering according to claim 9 or 10, wherein the humidity sensor comprises: a light source configured to emit a first light to illuminate the humidity-sensitive element (12); and a receiving element configured to receive a second light reflected or transmitted by the humidity-sensitive element (12), which second light, while the first light remains constant, is variable due to a transition of the humidity-sensitive element (12) to the second state (162); and wherein the transmitting device is configured to output a wireless signal based on a difference between the first light and the second light. [12] A face covering according to claim 11, wherein the transmission device of the humidity sensor comprises a transponder. [13] A face covering according to claim 11 or 12, wherein the humidity sensor comprises: an evaluation circuit coupled to the receiving element; wherein the receiving element is configured to output a signal based on the second light, wherein the evaluation circuit is configured to evaluate the received signal to determine whether the moisture-sensitive element (12) is in the first state (161) or the second state (162) in order to obtain a result signal; and to provide the result signal to the transmission device. [14] Face covering according to claim 13, wherein the transmission device, the light source, the receiving element, the evaluation circuit and the moisture-sensitive element (12) of the moisture sensor form a common module. [15] A face covering according to any one of claims 11 to 14, wherein the light source of the humidity sensor is configured to emit the first light in a color spectrum that is matched to the first color or the second color. [16] A face covering according to any one of claims 11 to 15, wherein the humidity sensor further comprises a color filter disposed between the light source and the humidity-sensitive element (12) or between the humidity-sensitive element (12) and the receiving element, and configured to provide color filtering matched to the first color or the second color. [17] Face covering according to one of claims 1 to 4, wherein the moisture-sensitive element (12) of the moisture sensor is designed to permanently change color under the influence of the moisture (14), wherein the first state is associated with a first color or a colorless state; and the second state is associated with a second color; wherein the information device (18) is designed to indicate a position on the moisture sensor at which at least one of the first state (161) and the second state (162) is optically detectable for remote retrieval. [18] A face covering according to claim 17, wherein the humidity sensitive element (12) of the humidity sensor comprises a silica gel. [19] A face covering according to claim 17 or 18, wherein the information device (18) of the humidity sensor comprises a bar code or a QR code. [20] Device according to claim 19, wherein the information device (18) comprises a QR code; wherein the humidity-sensitive element (12) is arranged in an inner region of the QR code. [21] Face covering according to one of claims 1 to 4, wherein the moisture-sensitive element (12) of the moisture sensor is designed to permanently change an electrical conductivity under the action of the moisture (14) in order to provide a first electrical conductivity in the first state (161) and to provide a second electrical conductivity different therefrom in the second state (162). [22] A face covering according to claim 21, wherein the first state is an electrically non-conductive state and the second state is an electrically conductive state; or wherein the first state is an electrically conductive state and the second state is an electrically non-conductive state. [23] Face covering according to claim 21 or 22, wherein the moisture-sensitive element (12) of the moisture sensor is formed so as to be soluble under the influence of the moisture (14) and provides a carrier element for an electrical conductor track; wherein the carrier element is designed to detach upon the occurrence of the moisture (14) beyond a predefined amount established in the carrier element and thus to at least partially remove the electrical conductor track; in order to change the electrical conductivity. [24] Face covering according to one of claims 21 to 23, wherein the moisture-sensitive element (12) of the moisture sensor is formed to be soluble under the influence of the moisture (14); wherein in the first state (161) an undissolved, electrically insulating state is present and in the second state (162) an at least partially dissolved and electrically conductive state is present; in order to change the electrical conductivity. [25] A face covering according to any one of claims 21 to 24, wherein the information device (18) of the humidity sensor comprises an electrical resonant circuit which is passive and formed comprising an electrical inductance and an electrical capacitance; and has a resonance characteristic which is variable depending on the first state (161) and the second state (162). [26] A face covering according to any one of claims 21 to 25, wherein the information device (18) of the humidity sensor comprises an electrical resonant circuit configured to interact with a wireless signal; wherein the humidity-sensitive element (12) is part of the resonant circuit; wherein the resonant circuit has a first resonant frequency in the first state (161) and a second, different resonant frequency in the second state (162); or has a resonant frequency in one of the states and is inoperable in the other state. [27] A face covering according to claim 26, wherein the electrical resonant circuit is passive and comprises an electrical inductance and an electrical capacitance. [28] Face covering according to one of the preceding claims, wherein the moisture (14) is moisture contained in a fabric, in particular resulting from atmospheric humidity or respiratory humidity. [29] Humidity sensor for remote query with: a moisture-sensitive element (12) which is designed to permanently transition from a first state (161) to a second state (162) under the influence of moisture (14); an information device (18) configured to provide wireless communication for remote retrieval, to wirelessly transmit at least one of the first state (161) and the second state (162); or to display a position on the humidity sensor at which at least one of the first state (161) and the second state (162) is optically detectable for remote retrieval; wherein the humidity-sensitive element (12) is designed to permanently change color under the influence of moisture (14), wherein the first state is associated with a first color or a colorless state; and the second state is associated with a second color; wherein the information device (18) is designed as a transmission device to provide wireless communication for remote retrieval in order to wirelessly transmit at least one of the first state (161) and the second state (162); wherein the humidity sensor has a light source designed to emit a first light to illuminate the humidity-sensitive element (12);and a receiving element configured to receive a second light reflected or transmitted by the humidity-sensitive element (12), which second light, while the first light remains constant, is variable due to a transition of the humidity-sensitive element (12) into the second state (162); and wherein the transmitting device is configured to output a wireless signal based on a difference between the first light and the second light; or; wherein the humidity-sensitive element (12) is designed to permanently change color under the influence of the moisture (14), wherein the first state is associated with a first color or a colorless state; and the second state is associated with a second color; wherein the information device (18) is designed to indicate a position on the humidity sensor at which at least one of the first state (161) and the second state (162) is optically detectable for remote retrieval; wherein the information device (18) comprises a barcode or a QR code; or wherein the moisture-sensitive element (12) is designed to permanently change an electrical conductivity under the influence of the moisture (14) in order to provide a first electrical conductivity in the first state (161) and to provide a different second electrical conductivity in the second state (162); wherein the first state is an electrically non-conductive state and the second state is an electrically conductive state; or wherein the first state is an electrically conductive state and the second state is an electrically non-conductive state. [30] Device for monitoring the transport of goods with a moisture sensor according to claim 29. [31] Monitoring system with: a face covering according to any one of claims 1 to 28; or a humidity sensor according to claim 29; a device for remotely querying the humidity sensor. [32] Device designed to evaluate a state of a moisture sensor on a face covering, having the following features: a camera configured to capture an object area to obtain image information of the object area; an evaluation device configured to evaluate the image information for reference information indicating the presence and position of sensor information of the humidity sensor; wherein the evaluation device is configured to evaluate the image information at the displayed position with respect to the sensor information; and to output an evaluation result based on the sensor information. [33] Device according to claim 32, wherein the evaluation device is designed to evaluate the image information at the displayed position for a predefined color associated with a state of the humidity sensor obtained under the action of moisture (14) on the humidity sensor; and to output the evaluation result to indicate that a level of moisture (14) acting on the humidity sensor has reached or exceeded a humidity threshold. [34] Device according to claim 32 or 33, wherein the reference information comprises a bar code or a QR code. [35] Device according to claim 34, wherein the reference information comprises a QR code; wherein the evaluation device is designed to evaluate an inner region of the QR code for the predefined color. [36] A method for providing a face covering with a humidity sensor for remote sensing, comprising the following steps: Combining (1010) the face covering with a moisture-sensitive element configured to permanently transition from a first state to a second state under the influence of moisture; with an information device configured to provide wireless communication for remote retrieval, to wirelessly transmit at least one of the first state and the second state; or to indicate a position on the moisture sensor at which at least one of the first state and the second state is optically detectable for remote retrieval. [37] Method for evaluating a state of a humidity sensor, comprising the following steps: detecting (1110) an object area on a face covering to obtain image information of the object area; Evaluating (1120) the image information for reference information indicating the presence and a position of sensor information of the humidity sensor; Evaluating (1130) the image information at the displayed position with respect to the sensor information; and Outputting (1140) an evaluation result based on the sensor information. [38] A computer program comprising a program code for carrying out the method according to claim 37 when the program runs on a computer.

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