WO2022258766A1

WO2022258766A1 - Method and device for detecting and locating moisture on moisture-carrying surfaces and/or in moisture-carrying layers

Info

Publication number: WO2022258766A1
Application number: PCT/EP2022/065724
Authority: WO
Inventors: Felix Moll; Dirk LIEDER
Original assignee: bygg AI GmbH
Priority date: 2021-06-11
Filing date: 2022-06-09
Publication date: 2022-12-15
Also published as: EP4352317A1; DE102021002979A1

Abstract

The invention relates to devices and methods for detecting and locating moisture on moisture-carrying surfaces (110) or in moisture-carrying layers of buildings or building structures, in particular roofs. For this purpose, sensor cables or sensor strips (120) having electrically insulated conductors are used, wherein the electrical insulation of the conductors is moisture-resistant. Moisture is detected by comparing measurement values obtained by the conductors of different sensor cables or sensor strips (120). The comparison additionally makes it possible to associate the detected moisture with the surroundings of a sensor cable or sensor strip (120) and thus to locate the moisture. Using electrically insulated conductors having moisture-resistant insulation allows not only safe operation but also reliable operation. In many cases, comparing the measurement values makes it possible to avoid complex determination of reference values. Weather-related or electromagnetic interferences are less significant. Accordingly, using the proposed devices and methods allows moisture to be easily and reliably detected and located.

Description

Method and device for detecting and locating moisture on moist-carrying surfaces and/or in moist-carrying layers

Description Field of the Invention

The invention relates to devices and methods for detecting and localizing moisture on moisture-carrying surfaces and/or in moisture-carrying layers, which belong, for example, to a flat, sloping or pitched roof. The invention is also suitable for detecting and locating leaks or accumulations of moisture in other parts of a building or a building structure, such as in concrete troughs, on masonry (e.g. under plaster) and facade cladding.

It is well known that buildings can be severely damaged by the ingress of water or moisture. The damage can usually be significantly reduced or even prevented if the penetrating water or moisture is detected early and appropriate countermeasures are taken. In many cases, however, the ingress of water or moisture is difficult to detect. Many parts of the building, especially roofs, are poorly visible. In addition, the corresponding leaks, cracks or leaks are often very small and inconspicuous or even hidden or covered by other building structures. In addition, water or moisture often spreads unnoticed along moisture-carrying (surface) surfaces and/or in moisture-carrying layers, eg along water pipes, underlays or vapor barriers. It then only becomes obvious in one place (e.g. through the formation of droplets, damp stains, detachment of plaster, mold formation and/or rot) that is far away from the actual damaged area or the leak. A corresponding repair therefore requires a complex search for the actual damaged area or the leak in many cases.

State of the art

A large number of solutions are found in the prior art for early detection of leaks and accumulations of moisture in or on buildings. One obvious approach is to identify moisture or water based on its ability to conduct electricity. In the published specifications DE 42 39495 A1, WO 91/10889 A1, US Pat , EP 3 168589 B1 and US Pat Resistance measured between the conductors In US 2007/0046481 A1 time domain reflectometry is used to detect such a short circuit, in US 10,078,030 B2 the capacitance of electrical conductors. For the formation of a short circuit, the relevant devices must have exposed or electrically non-insulated conductors that can come into contact with moisture or water. However, these do not only represent a security problem or require appropriate protective measures. They are also exposed to their environment without protection, become dirty and are subject to corrosion. This is particularly problematic when monitoring building structures. Building structures tend to be very durable and vulnerable to damage and moisture ingress, especially at the end of their intended lifespan. A different approach is therefore taken in the published application WO 2019 046961 A1. A conductive plastic is used here, which absorbs liquid on contact and loses its conductive properties in the process. The resulting one electrical resistance is used to detect a leak. However, the process is not reversible. In addition, such a plastic can also decompose - especially over a long period of time - due to other influences, such as, for example, due to UV radiation or the influence of atmospheric humidity.

A further alternative for creating a short circuit is presented in US Pat. No. 5,159,276 A, in which a coaxial cable with a moisture-permeable coating is described. If the cable comes into contact with moisture, this penetrates the cable, changing the capacitance of the cable accordingly. In this way it can be determined that the cable has come into contact with moisture. However, a more precise localization of the moisture is not possible. In addition, moisture can only be detected if enough moisture penetrates the cable. A false alarm due to other causes of a change in capacitance of the cable cannot be ruled out.

The published application US 2015/0259923 A1 proposes the use of glass fibers, with moisture being detected on the basis of temperature fluctuations and mechanical stresses associated with the moisture. However, such indirect detection of moisture is prone to error in many cases, particularly under roofing where temperature changes and mechanical stresses can be traced back to a variety of causes, such as day-night cycles or fluctuations in solar radiation caused by clouds.

The comprehensive use of moisture sensors is similarly complex, as is described, for example, in the utility model DE 20 2018005538 Ul. Since each sensor can only detect moisture at a certain point or in its vicinity, a complete monitoring of building structures is not only expensive in many cases, but also very complex.

task The object of the invention is to simplify the detection and localization of moisture on moisture-carrying surfaces and/or in moisture-carrying layers and to make it more reliable and safer.

solution

This object is solved by the subject matter of the independent claims. Advantageous developments of the subject matter of the independent claims are characterized in the dependent claims. The wording of all claims is hereby made part of the content of this description by reference.

The use of the singular is not intended to exclude the plural, which also applies vice versa, unless otherwise disclosed.

Individual process steps are described in more detail below. In a preferred variant of the invention, the steps are carried out in the specified order. However, the steps do not necessarily have to be carried out in the order given, and the method to be described can also have further steps that are not mentioned.

A method for detecting and locating moisture on a moisture-conducting surface and/or in a moisture-conducting layer with a plurality of sensor cables and/or strips positioned on the moisture-conducting surface and/or in the moisture-conducting layer is proposed to solve the task . To this end, each sensor cable and/or sensor strip comprises at least one electrically insulated conductor, with the electrical insulation of the at least one electrically insulated conductor being moisture-resistant. The procedure includes the following steps:

performing a first measurement using at least one electrically isolated conductor of a first sensor cable and/or ribbon of the plurality of sensor cables and/or ribbons; performing a second measurement using at least one electrically isolated conductor of a second sensor cable and/or ribbon of the plurality of sensor cables and/or ribbons;

comparing the readings of the first and second measurements;

Checking by comparing the measured values of the first and second measurement whether moisture is present on the moisture-carrying surface and/or in the moisture-carrying layer; and

Issue a message if the check shows that there is moisture on the moisture-carrying surface and/or in the moisture-carrying layer.

Moisture is detected by comparing the readings from the first and second measurements. The measured value of the first measurement represents a reference value for the second measurement and vice versa. In this way, interference that affects both sensor cables/strips in the same way cannot lead to a false alarm. These include seasonal or weather-related temperature fluctuations, fluctuations in humidity or electromagnetic influences, but also measurement inaccuracies or measurement errors. In this way, the occurrence of moisture can not only be reliably detected, but also assigned to the area surrounding the corresponding sensor cable and/or sensor strip and localized in this way. By comparing the measured values, it is generally not necessary to determine absolute values which, if exceeded or fallen below, indicate the presence of moisture. In many cases, determining these values is very time-consuming and highly dependent on the building structure to be monitored and its surroundings. In contrast to this, the proposed method enables an almost automatic adaptation to the individual circumstances of the building structure to be monitored or its surroundings.

Influences that affect the first sensor cable and/or ribbon more than the second, for example due to electrical installations or radiators, can also be taken into account. For example, when installing the Multiple sensor cables and / or tapes recorded one or more measured values or the comparison of this or these measured values and included in the comparison of the measured values of the first and the second measurement. The recording can also include several measured values that were measured at different times, for example distributed over one day or several days. By calibrating the method in this way, changes in the readings due to the presence of moisture can be distinguished from changes due to influences affecting the first and second sensor cables and/or ribbons differently, but not with the ingress of moisture keep in touch. Such a calibration can also take place later, for example at the beginning of the heating season, once a year or every six months or whenever there is a change in the building structure to be monitored or its surroundings.

The reliability of the method can be increased if more than two sensor cables and/or tapes are used and/or the sensor cables are positioned in such a way that moisture penetrating at one point affects only one or at least as few sensor cables and/or tapes as possible . In extreme cases, e.g. if the roof covering is torn away over a large area during a storm, it is usually not possible to prevent penetrating moisture from affecting several or even all sensor cables and/or strips. However, this extreme case does not represent a relevant application of the method.

The first and second measurements can be carried out simultaneously or almost simultaneously or one after the other, it also being possible for the second measurement to be carried out at an earlier point in time than the first measurement. The comparison of the measured values shows whether a property in the vicinity of the at least one electrically isolated conductor of the first sensor cable has changed in the same way as a property in the vicinity of the at least one electrically isolated conductor of the second sensor cable and/or tape. The proposed method is based on the use of electrically insulated conductors for the detection and localization of moisture, the electrical insulation of the conductors being moisture-resistant. This not only allows the method to be carried out safely, but also to be carried out repeatedly over a longer period of time, since the conductors are not exposed but are protected from environmental influences, in particular from corrosion.

The first/second measurement is carried out using at least one electrically insulated conductor of the first/second sensor cable and/or band, i.e. the conductor is electrically contacted and an electrical voltage and/or an electrical current is applied. The at least one electrically insulated conductor of a sensor cable and/or sensor strip thus forms the element with the aid of which moisture in the vicinity of the sensor cable and/or sensor strip is detected. The at least one electrically insulated conductor preferably extends essentially over the entire length of the sensor cable and/or sensor band. A sensor cable and/or ribbon can also consist of only one electrically insulated conductor. A sensor cable and/or tape can comprise a moisture-resistant, electrically insulating carrier tape on which electrical conductor tracks are arranged next to one another. The conductor tracks are additionally surrounded by a moisture-resistant, electrically insulating layer. The conductor tracks can be made of copper or aluminum, for example.

The sensor cables and/or strips are preferably positioned on the moisture-carrying surface and/or in the moisture-carrying layer such that the moisture-carrying surface and/or the moisture-carrying layer is divided into different segments by the sensor cables and/or strips and each segment at least a sensor cable and/or ribbon can be assigned. The segments are formed by the preferred direction for the propagation of moisture on the moisture-carrying surface and/or in the moisture-carrying layer and the length of the sensor cables and/or strips. The length of the sensor cables and/or sensor strips is preferably selected in such a way that a good signal-to-noise ratio can be assumed. They preferably have a predetermined length ranging between 50 cm and 10 m,

1 m and 5 m or 2 m and 4 m. This makes it easier to compare the measured values of the first and second measurement and thus enables the method to be configured more reliably. This applies in particular if the specified lengths are selected in such a way that the measured values can be assigned to the specified lengths of the sensor cables and/or strips (e.g. via signal propagation times, capacities, etc.). However, sensor cables and/or tapes of different lengths can also be used in order to divide the moisture-carrying surface and/or the moisture-carrying layer as completely as possible into (preferably non-overlapping) segments, which must be taken into account when comparing the measured values. The segments formed with the sensor cables and/or strips can thus also be adapted to the structural conditions of the building structure to be monitored, e.g. to the position of a dormer window or a chimney, which represent particularly critical points for the ingress of moisture. The sensitivity and resolution of the method can be improved by choosing shorter sensor cables and/or tapes. In many cases, the longer a sensor cable and/or tape, the lower the effect of a certain amount of water on the cable or tape. In addition, longer sensor cables and/or ribbons absorb more external interference. With a suitable choice of sensor bands, an almost complete monitoring of the moisture-carrying surface and/or layer can be achieved.

The first and second measurements do not necessarily have to be the same measured variables. Different variables can also be determined, which can be converted accordingly when comparing the measured values or set in relation to one another in order to be able to compare the values.

The comparison can also consist in the measured values being compared with earlier measured values and only the relative change in the measured values being compared. If, for example, the measured value of the first measurement deviates from a previous one determined mean value for the measured values of the first measurement, for example by more than 10%, moisture can be recognized by whether the measured value of the second measurement shows a similar deviation from a previously determined mean value for the measured values of the second measurement or not.

The comparison of the readings is used to check whether there is moisture in the vicinity of one of the sensor cables and/or straps. If the test determines that there is moisture in the vicinity of one of the sensor cables and/or straps, a corresponding message is issued. A message can also be issued if the test is negative, i.e. if no moisture is detected. The message can include an acoustic or optical (warning) signal, an entry in a corresponding file or a message that is transmitted to a service provider via the Internet.

The process is preferably repeated at regular intervals, for example every five minutes, every hour or once a day. But it can also be done as needed. The implementation can also be linked to specific weather events, e.g. the occurrence of rain or storms.

The proposed procedure may also include the following steps:

providing the plurality of sensor cables and/or ribbons; and positioning the plurality of sensor cables and/or ribbons on the moisture-bearing surface and/or in the moisture-bearing layer.

The plurality of sensor cables and/or ribbons may include at least one sensor cable and/or ribbon having a plurality of electrically insulated conductors whose electrical insulation is moisture resistant.

Additional electrically insulated conductors not only increase the reliability of the sensor cable and/or tape. They also enable verification of the measurements carried out and thus a reduction in measurement errors. They can also be used for other tasks, such as voltage or energy supply or data transmission. Thus, additional lines to Contacting the sensor cables and/or strips or for carrying out measurements or for contacting other measuring equipment is eliminated or saved.

The at least one sensor cable and/or sensor strip with the plurality of electrically insulated conductors can also be designed as a flat cable or FFC cable or round cable.

Ribbon cables, FFC cables or round cables are usually inexpensive and can be easily laid in flats and/or in layers. Such a sensor cable and/or ribbon designed as a ribbon cable or FFC cable preferably has 2 to 50 electrically insulated conductors (wires) arranged next to one another, particularly preferably 4 to 20 or 6 to 16 or 10 to 12 electrically insulated conductors arranged next to one another. Round cables can have the same number of conductors as a ribbon cable or FFC cable, but the conductors are gathered into a round cross-section. In many versions, the electrically insulated conductors of a flat ribbon cable, FFC cable or round cable are identical or at least almost identical, so that in many cases it does not matter in which orientation the cables are installed. This facilitates the assembly of the sensor cables and/or straps.

At least one sensor cable and/or sensor tape of the plurality of sensor cables and/or sensor tapes can be attached to the moisture-conducting surface and/or in the moisture-conducting layer with an adhesive.

The use of adhesives, preferably adhesive tapes, not only makes it easy to lay the sensor cables and/or tapes, but also reduces sources of interference and errors caused by metal fasteners such as nails, staples or staples. A double-sided adhesive tape is preferably used. An adhesive tape with an acylate-based adhesive has proven particularly effective under roof coverings, among other things because of its holding power and durability in a temperature range from 120 °C to -25 °C or even -40 °C. All sensor cables and/or sensor tapes are preferably attached to the moisture-carrying surface and/or in the moisture-carrying layer using adhesive tapes. Typically, suitable adhesive tapes have a thickness of 1 to 3 mm.

At least one sensor cable and/or strap of the plurality of sensor cables and/or straps can be positioned in such a way that moisture spreading on the moisture-conducting surface and/or in the moisture-conducting layer collects on the at least one sensor cable and/or strap and/or or propagates along the at least one sensor cable and/or ribbon. At least one sensor cable and/or strap of the plurality of sensor cables and/or straps can also have means for absorbing moisture.

This can be achieved, for example, on a moisture-carrying surface by attaching the sensor cable and/or sensor tape to the moisture-carrying surface with adhesive tape, with the sensor cable or sensor tape protruding beyond the adhesive tape on at least one side and this side perpendicular to the preferred direction of propagation of moisture on the moisture-carrying surface. If moisture now spreads along the moisture-conducting surface, the moisture collects in the gap formed by the sensor cable and/or tape, the adhesive tape and the moisture-conducting surface. In addition, the moisture is guided along the sensor cable and/or band.

With the help of typical adhesive tapes, which have a thickness of 1 to 3 mm, the capillary effect can also be used to additionally bind the moisture to the sensor cable and/or tape and to guide it along it.

In addition to forming such a gap or such a water pocket, the at least one sensor cable and/or sensor strip can also have additional means for absorbing moisture. For this purpose, for example, an absorbent flocking or a foam (rubber) or a water-storing cover can be used. By collecting or damming moisture on the sensor cable and/or ribbon and/or directing the moisture along the sensor cable and/or ribbon, the reliability of the method can be improved. First, it keeps moisture near the sensor cable and/or strap for a longer period of time. On the other hand, the wetting of the sensor cable and/or tape with moisture increases, which usually leads to a significantly more pronounced measurement signal.

The at least one sensor cable and/or tape positioned in such a way that moisture spreading on the moisture-carrying surface and/or in the moisture-carrying layer collects at one point on the at least one sensor cable and/or tape and/or flows along the at least one sensor cable and/or tape, may include first and second electrically insulated conductors and may be configured and arranged such that the first conductor is closer to where moisture collects and/or travels along the at least one sensor cable and/or tape, as the second electrically insulated conductor. The electrical insulation of the first and second conductors is also resistant to moisture.

The detection of moisture can be further improved or made more reliable by comparing measured values that are measured with the first and second conductors. Finally, the sensor cable is designed and arranged in such a way that any moisture that may be present affects the first conductor more than the second. In this way, interference can be filtered out that may not be detectable when comparing measured values obtained with conductors of different sensor cables and/or strips.

In the first and/or second measurement, the capacitance of the at least one electrically insulated conductor of the first and/or second sensor cable and/or band can be measured. The first and/or second measurement can also be a time domain reflectometry measurement on the at least one electrically isolated Be conductors of the first and / or second sensor cable and / or tape. Furthermore, the first and/or second measurement can represent a frequency domain reflectometry measurement on the at least one electrically isolated conductor of the first and/or second sensor cable and/or ribbon.

The capacitance can be determined, for example, using a reference conductor that is part of the measuring device used for the measurement or is part of the first and/or second sensor cable and/or band. It can be determined using the charge that can be transferred to the conductor of the first and/or second sensor cable and/or ribbon at a given voltage. It can also be determined using the time required to deposit a given charge across a resistor on the conductor. Several charging cycles in a row can also be used for this purpose. In addition, the capacitance can be determined using an oscillating circuit formed by the capacitance of the conductor (and its reference conductor) and an inductance.

The location or localization of the moisture can be further improved if an electrically insulated conductor of at least one sensor cable and/or sensor strip of the plurality of sensor cables and/or sensor strips is provided with a separation point. Such a separation point represents an interruption in the electrical contact between the sections of the electrical conductor that are located on opposite sides of the separation point.

In this way, moisture can not only be assigned to the environment of a sensor cable and/or sensor strip, but it can also be determined on which side of the separation point the moisture is located.

At least one sensor cable and/or ribbon of the plurality of sensor cables and/or ribbons may also include at least one electrical conductor that is not insulated. With the help of such non-insulated electrical conductors, more Measurements are carried out to improve or check the detection and localization of moisture.

The object is also achieved by an evaluation unit for a plurality of sensor cables and/or sensor strips, which is set up to carry out one of the proposed methods as soon as it is connected to the plurality of sensor cables and/or sensor strips.

The evaluation unit can be connected directly to each sensor cable and/or strip (star topology). However, it can also be connected to the sensor cables and/or strips using a data bus (ring topology). The connection may be through a data line or wireless, with each sensor cable and/or ribbon having a respective sub-unit connected thereto with means for performing the appropriate measurements and communication. Hybrids of the connection models just presented are also conceivable.

The evaluation unit can also have means for storing the collected data or the data and computer programs required for the evaluation and implementation of the method. Furthermore, the evaluation unit can be equipped with means for communicating with the Internet in order to enable remote monitoring of the corresponding building structure. In addition, a service port can be provided with which the evaluation unit can be controlled or initialized and, if necessary, recorded data, e.g. about the measured values, comparisons, tests and reports, can be read out.

The object is also achieved by a method for detecting and localizing moisture on a moisture-carrying surface and/or in a moisture-carrying layer with at least one sensor cable and/or sensor strip; each sensor cable and/or ribbon having a plurality of electrically insulated conductors; wherein the electrical insulations of the electrically insulated conductors are moisture resistant; wherein the at least one sensor cable and/or ribbon is positioned on the moisture-carrying surface and/or in the moisture-carrying layer; the method comprising the following steps:

performing a first measurement using a first electrically isolated conductor of the sensor cable and/or ribbon;

performing a second measurement using at least one second electrically isolated conductor of the sensor cable and/or ribbon;

comparing the readings of the first and second measurements;

Checking by comparing the measured values of the first and second measurement whether moisture is present on the moisture-carrying surface and/or in the moisture-carrying layer;

According to a further embodiment of the method, at least one sensor cable and/or sensor strip of the plurality of sensor cables and/or sensor strips can have means for absorbing moisture, the sensor cable or sensor strip comprising in particular an adhesive tape for attaching the sensor cable to the moisture-conducting layer , wherein the sensor cable or sensor tape protrudes in particular at least on one side beyond the adhesive tape and this side is laid transversely to the preferred direction of propagation of moisture on the moisture-carrying surface.

According to a further embodiment of the method, the at least one sensor cable and/or sensor tape, which is positioned in such a way that moisture spreading on the moisture-carrying surface and/or in the moisture-carrying layer, can be attached to the at least one sensor cable and/or sensor tape at one point collects and/or propagates along the at least one sensor cable and/or ribbon, have a first and a second electrically insulated conductor and/or at least one sensor cable and/or ribbon of the plurality of sensor cables and/or ribbons means for receiving have moisture and configured and arranged such that the first conductor is closer to where moisture collects and/or travels along the at least one sensor cable and/or ribbon than the second electrically isolated conductor, wherein the electrical Insulation of the first and second electrically insulated conductor is moisture resistant.

The object is also achieved by a connecting element that has an evaluation unit as has already been described above. The connecting element is also designed in such a way that at least two sensor cables and/or sensor strips of the plurality of sensor cables and/or sensor strips can be connected to one another with the aid of the connecting element.

Accordingly, the connecting element not only establishes the electrical contact between the evaluation unit and at least two sensor cables and/or sensor strips, but also connects them mechanically. The mechanical connection can be non-positive and/or positive and/or via a plug-in connection. In this way, additional lines for contacting the sensor cables and/or strips can be omitted or at least their number can be reduced. In addition, the signal propagation times for carrying out the first and second measurement can be shortened, which increases the quality of the measurement and the data transmission.

The object is also achieved by a system with a plurality of evaluation units and/or connection elements, the plurality of evaluation units and/or connection elements being set up to carry out one of the proposed methods as soon as the plurality of evaluation units and/or connection elements with the plurality of sensor cables and/or straps.

As already described above, a connecting element is distinguished in that at least two sensor cables and/or sensor strips of the plurality of sensor cables and/or sensor strips can be mechanically connected to one another with the aid of the connecting element. One of the evaluation units and/or one of the connection elements can take on a leading role, whereas the other evaluation units and/or connection elements are set up only for carrying out the first and/or second measurement. This leading role can be assigned dynamically or as needed, which increases reliability and simplifies the installation or assembly of the system. The leading unit can, for example, also be set up to control the other evaluation units and/or the connecting elements in order to force a restart or reset, if necessary, and/or to monitor or reduce the energy consumption of the system.

At least one evaluation unit and/or one connection element of the system with a plurality of evaluation units and/or connection elements can have an additional connection for further sensors and/or a voltage or energy supply and/or for communication.

Such a connection can be used, for example, to operate the at least one evaluation unit and/or the at least one connecting element with a self-sufficient energy supply, e.g. from a photovoltaic system. This means that a broader range of possible applications is available. In addition, reliability can be increased. In many cases, one connection to the power supply is sufficient. The corresponding unit can then be set up to supply energy to the other units of the plurality of evaluation units and/or connecting elements, for example via corresponding lines which may already be available due to the connected sensor cables and/or sensor strips.

The connection of additional sensors, such as microphones, gas sensors, rain sensors, etc. also enables other tasks to be performed (detection of fire or pest infestation, which can also lead to leaks) and the inclusion of additional data in the detection and localization of moisture the moisture-carrying surface and/or in the moisture-carrying layer. The monitoring of the building structure can thus be improved.

The evaluation units and/or connecting elements can also be connected to one another via such a connection, so that they can communicate with one another. However, the evaluation units and/or connecting elements can also be equipped with appropriate radio units for such communication.

At least one evaluation unit and/or at least one connection element of the plurality of evaluation units and/or connection elements can have means for protection against electrostatic discharges.

The means for protecting against electrostatic discharges can include protective diodes, for example. In this way, electrostatic discharges can be avoided and the system can be operated more safely.

At least one evaluation unit and/or one connection element of the plurality of evaluation units and/or connection elements can have an inverter.

In this case, the inverter is preferably used to carry out the first and/or second measurement. By using one or more inverters, interference signals can be filtered out when carrying out the first and/or second measurement. The use of an inverter thus enables measurements that are not only more precisely defined by filtering out interference signals, but can also be better compared with one another.

At least one evaluation unit and/or one connection element of the plurality of evaluation units and/or connection elements can be set up to detect whether it has been connected to a sensor cable and/or sensor strip of the plurality of sensor cables and/or sensor strips. This simplifies in particular the commissioning of the system. The operation of the system or the commissioning can also be simplified if at least one evaluation unit and/or at least one connection element of the plurality of evaluation units and/or connection elements is set up to detect whether another evaluation unit or another connection element of the plurality of evaluation units and /or connecting elements is connected to a sensor cable and/or strap of the plurality of sensor cables and/or straps. In addition, the reliability of the system can thus be improved.

The system can also be set up in such a way that, when at least one sensor cable and/or strap of the plurality of sensor cables and/or straps is connected to two units of the plurality of evaluation units and/or connecting elements, the first or second measurement is taken at the be able to run at least one sensor cable and/or strap through the two units and compare the results of the measurements with each other. In this way, measurement results can not only be verified, but measurement inaccuracies/errors can also be compensated for and the reliability of the system improved.

The system can also be set up in such a way that it can execute one of the proposed methods if the evaluation units and/or connecting elements of the plurality of evaluating units and/or connecting elements and the sensor cables and/or straps of the plurality of sensor cables and/or straps alternate are arranged one behind the other. Such a serial connection of the sensor cables and/or sensor strips to the evaluation units and/or connecting elements simplifies the installation of the system.

The object is also achieved by a computer program comprising instructions that cause one of the evaluation units just described, one of the just described connecting elements or a system of evaluation units or connecting elements that performs the method steps of one of the proposed methods.

A computer-readable medium on which the computer program just described is stored also solves the problem.

Further details and features result from the following description of preferred exemplary embodiments in conjunction with the figures. The respective features can be implemented individually or in combination with one another. The options for solving the task are not limited to the exemplary embodiments. For example, range information always includes all - not mentioned - intermediate values and all conceivable sub-intervals.

The exemplary embodiments are shown schematically in the figures. The same reference numerals in the individual figures designate elements that are the same or have the same function or that correspond to one another in terms of their functions. In detail shows:

1 shows part of a moisture-conducting surface of a sloping roof with a system of connecting elements which is connected to a plurality of sensor strips;

2 shows a flow chart of a method according to the invention;

3 shows a connecting element to which two sensor bands are connected; FIG. 4 shows a section of a sensor strip which shows the functions with which the electrically insulated conductors of the sensor strip are assigned;

5a shows a cross section of an inclined moisture-carrying surface to which a sensor tape is stuck with a double-sided adhesive tape; and FIG. 5b shows the cross-section shown in FIG. 5a, with moisture remaining between the sensor band and the moisture-carrying surface. 1 shows part 100 of a moisture-conducting surface 110 of a sloping roof with rafters 114. The moisture-conducting surface 110 is formed by an underlay membrane that is attached to the underside of the rafters 114. The roof is equipped with a moisture detection and localization system. The system includes connecting elements 130 which are connected to one another with sensor bands 120 . The connecting elements 130 and the sensor bands 120 are positioned on the moisture-carrying surface and arranged alternately one behind the other. In this case, the connecting elements 130 are attached laterally to the rafters 114 . The sensor bands 120 are designed as multi-core ribbon cables.

The sensor bands 120 are positioned on the moisture-conducting surface 110 in such a way that the moisture-conducting surface 110 is divided into different segments. The individual segments correspond to the areas between the rafters 114, i.e. the segments or the areas to be monitored with the individual sensor strips 120 are adapted to the individual conditions of this part 100 of the roof. Exactly one sensor band 120 can thus be assigned to each segment. If moisture is detected using the system, the corresponding damage or leak between the rafters 114 can be located or identified. be localized, between which the sensor band 120 is located, with which the moisture was detected. Accordingly, in order to repair the damaged area, it is not necessary to check the entire roof for damaged areas or leaks, but only the corresponding area between the rafters 114 .

The positioning of the sensor bands 120 on the moisture-conducting surface 110 and the connecting elements 130 on the sides of the rafters 114 selected in this embodiment allows the moisture-conducting surface 110 to be monitored almost without gaps. This exploits the fact that moisture tends to spread in one direction due to the effect of gravity, namely in the direction of the eaves or away from the ridge of the roof. Accordingly, the sensor bands 120 is positioned in the vicinity of the eaves in order to be able to monitor as large an area of the area 110 as possible with the system of connecting elements 130 and the plurality of sensor bands 120 .

The connectors 130 are attached to the sides of the rafters because moisture prefers not to spread along the side surfaces of the rafters 114, but rather runs down them. However, the connecting elements 130 could also have been positioned at other points on the moisture-conducting surface 130. In order to be able to locate moisture penetrating into the roof even more precisely, further connecting elements could be positioned in the middle between two rafters 114, with the length of the sensor strips 120 being adjusted accordingly and, if necessary, further means for detecting moisture spreading on the surface 110 to route the fasteners around. Alternatively, some of the electrically insulated conductors of the sensor bands 120 could also be provided with separation points, which would have to be taken into account accordingly when detecting and localizing moisture.

The sensor bands 120 have a plurality of electrically insulated conductors whose electrical insulation is moisture-resistant. A part of the electrical conductors is used for the measurements required to carry out the method. The other part of the conductors is used to supply voltage or energy to the connecting elements 130 and for the connecting elements 130 to communicate with one another.

In this exemplary embodiment, the connecting elements 130 have an evaluation unit for carrying out one of the proposed methods for detecting and locating moisture, i.e. each connecting element 130 can use the sensor strips 120 connected to it to determine whether moisture is spreading in the segments connected to the connected sensor strips 120 assigned. One of the connecting elements 130 assumes a leading role, namely the connecting element 130, which is connected directly to the house connection connected to the power supply (this element not being part of the part 100 of the roof shown in Fig. 1). The leading connector 130 communicates with the other connectors 130 and supplies them with power. The communication mainly includes the exchange of messages, namely whether a connection element has detected moisture in a segment and which segment it is. The leader 130 stores these messages in non-volatile memory. It also has a connection to the Internet (alternatively, other communication networks can also be used) and thus also sends the incoming messages to a server. The server is used to remotely monitor the roof.

The connectors perform the process of detecting and locating moisture at regular intervals. The length of the intervals can be controlled by the lead unit 130 and adjusted as needed, e.g., to save energy. A command can also be sent to the leading unit 130 via the Internet connection, which causes the connecting elements 130 to carry out the method for detecting and locating moisture at a specific point in time, e.g. to check the tightness of the roof during or after a heavy rain event check over.

In other embodiments, the connecting elements 130, in particular those that represent a leading unit, can be connected to a power supply that is independent of the mains power supply, for example in the form of a rechargeable battery or a photovoltaic system. Furthermore, connection elements 130 can additionally have a radio modem for wireless data transmission for communication with other connection elements 130 . In this way, a message can also be output wirelessly. A non-volatile memory or a service port are also additional elements of a connection element 130 with which the reliability and flexibility of a system according to the invention can be improved. 2 shows a flow chart of an embodiment of a method 200 for detecting and locating moisture according to the invention. The method 200 is performed by the connection elements 130 . It starts with step 210 in which a first measurement is carried out using an electrically insulated conductor of a sensor band 120 which is connected to the connection element 130 . The capacitance of the electrically isolated conductor is determined using another electrically isolated conductor of the sensor band 120 as a reference conductor. In step 220, a measurement is carried out using an electrically isolated conductor of the sensor band 120 which is connected to the connecting element 130 on the other side . The capacitance of the conductor is again determined, with another conductor of the same sensor band 120 serving as a reference conductor. In step 230, the results of the measurements or the measured values are compared. Since the capacitance of the conductors is measured in both cases and the conductors are basically the same in terms of design and length, the measured values can be directly compared with one another. However, the values are not directly compared with each other. They are first compared with measured values that were determined beforehand and stored in a memory of the connection element 130 . In this way, it is determined whether the capacitance has changed and, if so, how large the deviation is. Finally, the deviations are compared. By comparing the deviations, step 240 checks whether there is moisture due to a leak. If both deviations are of the same magnitude, either because there are no deviations or because an increase in humidity was measured with both sensor bands due to increased humidity, it is recognized that there is no humidity due to a leak. However, if the deviations are significantly different, moisture is detected and assigned to the corresponding sensor band 120 or segment. If moisture due to a leak is detected in this way, in step 250 a message is issued. In a further expansion stage of the method, the connecting elements 130 can mutually exchange their measured values and these can be included in the comparison 230 of FIG Include readings and the 240 test. This exchange can also be limited to the leading unit 130, in which case the measured values exchanged can also be stored for documentation purposes and for later evaluation.

3 shows part 300 of a system with a plurality of connecting elements 330. Part 300 comprises a connecting element 330 to which two sensor strips 320 with electrically insulated conductors 322 are connected. The sensor bands 320 are connected to the connecting element 330 with the aid of plug connections 340 . The plug connections 340 are designed as IDE plug connections. They create a non-positive and positive connection as well as the electrical contact of the connecting element 330 with the electrical conductors 322 of the sensor strips 320.

IDE connectors are not only cheap to buy. They also enable easy assembly.

The sensor strips 320 are designed as ribbon cables or IDE cables. Such ribbon cables are also inexpensive and easy to assemble. They also have moisture-resistant insulation on their electrical conductors.

To protect the contacts, the plug connections 340 can be fitted with a protective cap or sealed with adhesive tape.

4 shows a detail 400 of a sensor strip 420. The sensor strip 420 is a ribbon cable with 12 electrically insulated conductors 422 to 433. In the detail 400 the electrically insulated conductors 422 to 433 are arranged next to one another.

The sensor band 420 is part of a system that can be used to detect and locate moisture. The conductors 422 to 433 are assigned different functions. Conductors 422, 423, 424, 431, 432 and 433 are used for measurements. Conductors 425 and 430 are ground connections. The conductors 427 and 428 will used for the voltage or energy supply. Conductors 427 and 428 are used for serial communication

5A shows a cross section 500 of an inclined moisture-carrying surface 510. A sensor strip 520 is attached to the moisture-carrying surface 510 using double-sided adhesive tape 550. FIG. The double-sided adhesive tape 550 and the sensor tape 520 are arranged in such a way that there is a gap 560 between the sensor tape 520 and the moisture-conducting surface 510 . The sensor band 520 has twelve electrically isolated conductors, in particular the conductors 522, 524, 531 and 533, and an electrical insulation 570. The conductors 522, 524, 531 and 533 are used for measurements for the detection and localization of moisture. Electrical insulation 570 encompasses the electrical conductors of sensor band 520 and is moisture resistant. The gap 560 is formed by the position of the adhesive tape 550 and the sensor tape 520 in such a way that the conductor 522 is closer to the gap 560 than the conductor 524.

5B shows cross-section 500 after moisture has propagated along moisture-conducting surface 510 and collected in gap 560. FIG. The collected moisture 580 affects the sensor band 522 more than the sensor band 524, which can be used to improve one of the proposed methods for detecting and locating moisture.

Electrical contact glossary

An electrical contact represents a contact between two electrical conductors or electrically conductive objects. Two electrical conductors or electrically conductive objects are in electrical contact with one another if current can flow through the contact area almost unhindered, i.e. the contact area represents a negligible resistance. Electrical contacts can be detachable, e.g. switching or sliding contacts. They can also be non-detachable, e.g. with soldered, welded, pressed, crimped, riveted, wrapped or glued connections of electrical conductors or electrically conductive ones objects. moisture-carrying surface or layer

A moisture-bearing surface or layer is a surface or layer on or in which moisture, moisture or water can spread.

humidity

Moisture or humidity describes the presence of water in or on a material (e.g. textiles) or substance or in a gas or air (humidity) or in a room (e.g. in the basement of a building). Strong moisture is also referred to as wetness. Moisture can occur in buildings, for example, due to condensation or leaks. Moisture or moisture can also be understood as meaning the content of other liquids, for example benzene or electrically conductive fluids.

Moisture resistant electrical insulation

Moisture-resistant electrical insulation is electrical insulation that, when exposed to moisture, retains its electrical insulation properties, even over a long period of time. In the case of moisture-resistant electrical insulation, individual atoms/molecules can get into or through the material diffuse through the material, but the amount is not sufficient to make any appreciable electrical contact of the insulated body with the moisture. In this way, the insulated body is protected against corresponding damage or impairments such as corrosion or short circuits.

ribbon cable

A ribbon cable is a multi-wire cable in which the wires are not bundled in a circle in a round insulating tube, but run parallel to one another. Ribbon cables are primarily used to connect electronic assemblies, e.g. in computers. They usually represent two- or multi-pole signal or data lines.

Flexible flat cable or FFC cable

A flexible flat cable or FFC cable is an electrical cable that is both flat and flexible, with flat conductors or traces. Flexible flat lines or FFC cables are often extremely thin. They are preferably used in high-density electronic applications such as laptops or in mobile phones.

Frequency Domain Reflectometry (FDR)

Frequency domain reflectometry is a method for determining and analyzing run lengths and reflection characteristics of sinusoidal excitations of electrical conductors or conductor tracks. The conductor or the conductor track is excited with sinusoidal signals at different frequencies and both phase and amplitude information of the reflected signals is collected. Frequency domain reflectometry does not work like time domain reflectometry (TDR) with time-resolved but frequency-resolved data. This makes it possible, for example, to determine precisely how much water is on the conductor or the conductor track or at how many points. However, due to the different type of excitation (sinusoidal excitation instead of a pulse), frequency domain reflectometry does not offer the same spatial resolution as time domain reflectometry (TDR). inverters

In digital technology, an inverter is a gate with an input and an output and corresponds to the logical “not”. The output returns a 1 if a 0 is present at the input and a 0 if a 1 is present at the input. An inverter thus supplies the negation of the signal present at the input. The inverter also delivers the corresponding negation if the signal at the input does not exactly correspond to a 1 or a 0 or is noisy, i.e. independent of the quality of the input signal and without the deviations being reflected in the output signal. Inverters are therefore often used to process input signals or to filter interference signals.

capacitance (electrical capacity)

Capacitance or electrical capacity is a physical quantity from the field of electrostatics, electronics and electrical engineering. The electrical capacitance between two electrically conductive bodies that are insulated from one another is equal to the ratio of the amount of charge stored on these conductors to the electrical voltage that prevails between them. The capacitance is determined, among other things, by the dielectric constant of the insulating medium and the surroundings of the conductive bodies and the geometry of the bodies (in particular the distance between the bodies).

The electrical capacitance of a conductor or a conductor track is understood to mean the capacitance of the conductor or the conductor track in relation to a reference or a reference conductor. This reference or reference conductor can be ground, or another conductor or trace.

In many practical applications, the electrical capacity is determined using charging and discharging times or cycles. For this purpose, for example, a voltage can be applied to the conductor or the conductive body and the resulting current as a function of the time that flows into the conductor or between the conductive bodies. The electrical capacity is measured in units of the electrical resistance that the measured current has to overcome. A measurement circuit known, among other things, as a "charge counter" can also be used. The measuring circuit consists of a voltage source, which generates a step function, and an evaluation circuit, which includes an integrator, for example, which measures the charge required to charge the conductor or the conductive body. conductors arranged side by side

Side-by-side conductors are conductors that are spaced apart by a distance that is substantially constant (but may vary within certain limits). Conductors arranged next to one another thus generally have courses which are offset from one another but are otherwise very similar to one another. This includes a parallel arrangement of the conductors, in which the conductors run in a straight line or linear. However, the course of the ladder can also have bends, bends or kinks. The curvatures, bends or kinks of the individual conductors are offset from one another in such a way that the distance between the conductors is essentially constant (but can vary within certain limits).

Time-domain reflectometry (TDR, Time-Domain-Reflectometry)f Time-domain reflectometry is a method for determining and analyzing run lengths and reflection characteristics of current or voltage pulses in electrical conductors or conductor tracks. The procedure is also known in German-speaking countries under the term cable radar. It is used in industry and science, among other things, to determine or identify line lengths or line breaks. A current or voltage pulse with a high edge steepness is fed in at one end of the line or conductor track. Any change in the characteristic of the wave impedance of the line or the trace leads to distortions, reflections and splitting of the pulse. The reflected portions of the pulse can be evaluated at the same point at which the current or voltage pulse was applied. Reference sign

100 Part of a moisture-bearing surface

110 moist leading surface

114 rafters

120 sensor band

130 fastener

200 procedures

210 first measurement

220 second measurement

230 Comparison of the measured values

240 Check using the comparison 230

250 Issuing a message

300 Part of a system connected to a plurality of sensor bands

320 sensor band

330 fastener

340 connector

400 Section of a sensor band 420 sensor band

422 electrically insulated conductor

423 electrically insulated conductor

424 electrically insulated conductor

425 electrically insulated conductor

426 electrically insulated conductor

427 electrically insulated conductor

428 electrically insulated conductor

429 electrically insulated conductor 430 electrically insulated conductor

431 electrically insulated conductor

432 electrically insulated conductor

433 electrically insulated conductor

500 cross section

510 moist-carrying surface

520 sensor band

522 electrically insulated conductor

524 electrically insulated conductor

531 electrically insulated conductor

533 electrically insulated conductor

550 tape

560 gap

565 collected moisture 570 insulation

literature cited patent literature cited

DE 42 39495 A1 WO 91/10889 A1 US 5,081,422 A EP 2 339 314 A1 JP S541 33 196 A US 2009 173143 A1 US 12/0313652 A1 US 7,652,481 B2 EP 3 168 589 B1 US 10,078,030 B2

US 2007/0046481 A1 WO 2019046961 A1 US 5, 159, 276 A US 2015/0259923 A1 DE 20 2018005538 Ul

Claims

P atentClaims

1. Method (200) for detecting and locating moisture on a moisture-conducting surface (110; 510) and/or in a moisture-conducting layer with a plurality of sensor cables and/or tapes (120; 320; 420; 520); each sensor cable and/or ribbon (120; 320; 420; 520) comprising at least one electrically insulated conductor (422, 423, 424, 431, 432, 433; 522, 524, 531, 533); wherein the electrical insulation (570) of the at least one electrically isolated conductor (422, 423, 424, 431, 432, 433; 522, 524, 531, 533) is moisture resistant; wherein the sensor cables and/or straps (120; 320; 420; 520) are positioned on the moisture-conducting surface (110; 510) and/or in the moisture-conducting layer; the method (200) comprising the steps of:

Performing a first measurement (210) using at least one electrically isolated conductor (422, 423, 424, 431, 432, 433; 522, 524, 531, 533) of a first sensor cable and/or ribbon (120; 320; 420; 520 ) the plurality of sensor cables and/or ribbons (120; 320; 420; 520);

Carrying out a second measurement (220) using at least one electrically isolated conductor (422, 423, 424, 431, 432, 433; 522, 524, 531, 533) of a second sensor cable and/or band (120; 320; 420; 520 ) the plurality of sensor cables and/or ribbons (120; 320; 420; 520);

comparing the readings (230) of the first and second measurements;

checking, by comparing the measured values (240) of the first and second measurement, whether moisture is present on the moisture-carrying surface (110; 510) and/or in the moisture-carrying layer; Outputting a message (250) if the check shows that moisture is present on the moisture-carrying surface (110; 510) and/or in the moisture-carrying layer.

2. The method (200) according to any one of the preceding claims, characterized in that at least one sensor cable and / or tape (120; 320; 420; 520) of the plurality of sensor cables and / or tapes (120; 320) means for receiving exhibits moisture, with the sensor cable or strip in particular comprising an adhesive tape for attaching the sensor cable to the moisture-conducting layer, the sensor cable or strip in particular protruding beyond the adhesive tape on at least one side and this side transverse to the preferred direction of propagation of moisture on the moisture-carrying surface is laid.

3. Method (200) according to the immediately preceding claim, characterized in that the at least one sensor cable and/or sensor strip (120; 320; 420; 520) which is positioned in such a way that on the moisture-conducting surface (110; 510 ) and/or moisture spreading in the moisture-carrying layer collects on the at least one sensor cable and/or strip (120; 320; 420; 520) at one point (560) and/or collects along the at least one sensor cable and/or strip (120; 320; 420; 520), a first (522) and a second electrically insulated conductor (524), and/or at least one sensor cable and/or ribbon (120; 320; 420; 520) of the plurality of Sensor cables and/or straps (120; 320) has means for absorbing moisture and is designed and arranged in such a way that the first conductor (522) is closer to the point (560) where the moisture collects and/or itself along the at least one sensor cable and/or ribbon (120; 320; 420; 520) as the second electrically insulated conductor (524), wherein the electrical insulation (570) of the first (522) and second electrically insulated conductor (524 ) is moisture resistant.

4. The method (200) according to any one of the preceding claims, characterized in that in the first and/or second measurement the capacitance of the at least one electrically insulated conductor (422, 423, 424, 431, 432, 433; 522, 524, 531 , 533) of the first and/or second sensor cable and/or band (120; 320; 420; 520); and/or the first and/or second measurement is a time domain reflectometry measurement on the at least one electrically isolated conductor (422, 423, 424, 431, 432, 433; 522, 524, 531, 533) of the first and/or second sensor cable and/or - band (120; 320; 420; 520); and/or the first and/or second measurement

Frequency domain reflectometry measurement on the at least one electrically isolated conductor (422, 423, 424, 431, 432, 433; 522, 524, 531, 533) of the first and/or second sensor cable and/or ribbon (120; 320; 420; 520) represents.

5. Method (200) according to one of the preceding claims, characterized in that an electrically insulated conductor (422, 423, 424, 431, 432, 433; 522, 524, 531, 533) of at least one sensor cable and/or sensor strip ( 120; 320; 420; 520) of the plurality of sensor cables and/or ribbons (120; 320; 420; 520) has a point of separation, the point of separation being an interruption in the electrical contact between the sections of the electrically insulated conductor (422, 423, 424, 431, 432, 433; 522, 524, 531, 533) located on opposite sides of the separation point.

6. The method (200) according to any one of the preceding claims, characterized in that at least one sensor cable and / or band (120; 320; 420; 520) of the plurality of sensor cables and / or bands (120; 320) at least one electrical Head has, which is not insulated.

7. Method (200) for detecting and locating moisture on a moisture-conducting surface (110; 510) and/or in a moisture-conducting layer with at least one sensor cable and/or strip (120; 320; 420; 520); each sensor cable and/or ribbon (120; 320; 420; 520) comprising a plurality of electrically insulated conductors (422, 423, 424, 431, 432, 433; 522, 524, 531, 533); wherein the electrical insulations (570) of the electrically insulated conductors (422,

423, 424, 431, 432, 433; 522, 524, 531, 533) are moisture resistant; wherein the at least one sensor cable and/or tape (120; 320; 420; 520) is positioned on the moisture-conducting surface (110; 510) and/or in the moisture-conducting layer; the method (200) comprising the steps of:

performing a first measurement (210) using a first electrically isolated conductor (422, 423, 424, 431, 432, 433; 522, 524, 531, 533) of the sensor cable and/or ribbon (120; 320; 420; 520) ;

Performing a second measurement (220) using at least a second electrically isolated conductor (422, 423, 424, 431, 432, 433; 522, 524, 531, 533) of the sensor cable and/or ribbon (120; 320; 420; 520 );

comparing the readings (230) of the first and second measurements;

8. evaluation unit for a plurality of sensor cables and / or strips (120; 320; 420; 520), wherein the evaluation unit is set up to perform a method (200) according to any one of the preceding claims 1 to 6 as soon as it is with the plurality by sensor cables and/or ribbons (120; 320; 420; 520).

9. Connecting element (130; 330), which has an evaluation unit according to the directly preceding claim, wherein the connecting element (130; 330) is designed in such a way that, with the aid of the connecting element (130; 330), at least two sensor cables and/or sensor strips (120 ; 320; 420; 520) of the plurality of sensor cables and/or ribbons (120; 320; 420; 520) can be connected to one another.

10. System with a plurality of evaluation units and/or connection elements (130; 330), wherein the plurality of evaluation units and/or connection elements (130; 330) is set up to carry out a method (200) according to one of claims 1 to 6, as soon as the plurality of evaluation units and/or connecting elements (130; 330) is connected to the plurality of sensor cables and/or sensor strips (120; 320; 420; 520).

11. System according to claim 10, characterized in that at least one evaluation unit and/or at least one connecting element (130; 330) of the plurality of evaluation units and/or connecting elements (130; 330) is set up to recognize whether another evaluation unit or a other connecting element (130; 330) of plurality of evaluation units and/or connecting elements (130; 330) is connected to a sensor cable and/or strap (120; 320; 420; 520) of the plurality of sensor cables and/or straps (120; 320; 420; 520).

12. System according to any one of the preceding claims 10 to 11, characterized in that the system is set up such that, if at least one sensor cable and / or tape (120; 320; 420; 520) of the plurality of sensor cables and / or - Bands (120; 320; 420; 520) are connected to two units of the plurality of evaluation units and/or connecting elements (130; 330), the first or second measurement on the at least one sensor cable and/or band (120; 320; 420; 520) with the two units and can compare the results of the measurements with each other.

13. System according to one of the preceding claims 10 to 12, characterized in that the system is set up in such a way that it can carry out a method (200) according to one of claims 1 to 9 if the evaluation units and/or connecting elements (130; 330 ) of the plurality of evaluation units and/or connecting elements (130; 330) and the sensor cables and/or straps (120; 320; 420; 520) of the plurality of sensor cables and/or straps (120; 320; 420; 520) alternately are arranged one behind the other.

14. A computer program comprising instructions which cause an evaluation unit according to claim 8 or a connecting element (130; 330) according to claim 9 or a system according to one of claims 10 to 13 to carry out the method steps of a method (200) according to one of claims 1 to 6 executes.

15. Computer-readable medium on which the computer program according to claim 14 is stored.