Sensor connection bridge, sensor coupon, corrosion measurement device for monitoring airborne corrosivity, bridge holder, airborne corrosivity monitoring system and monitoring method

Abstract

The present invention also provides a sensor-connection bridge (1) configured for use in conjunction with a corrosion measurement device (20) for monitoring airborne corrosivity, the sensor-connection bridge comprising at least one connector assembly (3a, 3b, 4a, 4b) configured to enable electrical connection between the measurement device (20) and at least one sensor coupon (30a, 30b) inserted into the sensor-connection bridge, and a computer-readable memory comprising information related to sensor bridge identification. The present invention also provides a sensor coupon (30) adapted for use in conjunction with the sensor bridge (1), a corrosion measurement device (20) for monitoring airborne corrosivity, a passive sensor-connection bridge holder (41) for offline corrosivity determination, a monitoring system (21) for monitoring airborne corrosivity at one or more different locations, and a method of monitoring airborne corrosivity at one or more different locations using the monitoring system (21).

Description

[Technical Field]

[0001] The present disclosure relates to airborne corrosivity monitoring and apparatus therefor, more particularly to a sensor-connecting bridge configured for use in conjunction with a corrosion measurement device for airborne corrosivity monitoring, a sensor coupon adapted for use in conjunction with a sensor bridge, a corrosion measurement device for airborne corrosivity monitoring, a passive sensor-connecting bridge holder, a monitoring system for monitoring airborne corrosivity at one or more different locations, and a method of monitoring airborne corrosivity at one or more different locations using a monitoring system as defined in the introduction to the independent claims. [Background technology]

[0002] Corrosivity is a term that describes the ability of an environment to produce corrosion on metal surfaces. Any corrosion investigation that aims to expose a sample or measurement device in a field environment attempts to assess the corrosivity or corrosion damage of a particular object.

[0003] Important applications where corrosivity measurements are crucial include communication / data transfer facilities, industrial process control equipment, sensitive products, and cultural heritage sites. The challenge is that the atmospheric corrosivity of an environment depends on a complex interaction between the contaminants present in the everyday environment as well as the temperature and relative humidity.

[0004] Corrosivity at a location is not easy to measure because corrosivity levels cannot be assumed to be equal, even within a small area. Corrosivity varies with the moisture level on surfaces, which depends on relative humidity, which in turn depends on temperature. In outdoor environments, temperature and humidity fluctuations can be large, resulting in condensation over the course of a day. Similar problems can arise in indoor locations, which can vary at different heights, especially if the room contains equipment with fans to dissipate heat and circulate air.

[0005] Besides temperature and humidity, a contaminant is required for corrosion to occur. This can simply be oxygen in the air, or one of the many common pollutants present in urban and industrial areas, such as sulfur dioxide, nitrogen dioxide, or hydrogen sulfide. Airborne particulates that can deposit on surfaces can contain corrosive contaminants, for example, in the form of salts. All of these contaminants present outdoors can enter indoor locations, and indoor sources such as organic acids and aldehydes can add to outdoor sources.

[0006] In both outdoor environments where it is desired to evaluate corrosivity, and in indoor environments, e.g., air-conditioned rooms, it is important to be able to select an appropriate measurement location to obtain the desired information. It is also important to select an appropriate method for evaluating corrosivity. Many techniques have been proposed in research and practical work, all with their own advantages and disadvantages. Several standards for corrosivity and environmental parameters are also available, such as ISO 11844, ISO 9223, ISO 9226, and ISO 9225, ANSI / ISA-71.04-2013, and ASTM B825-02(2008).

[0007] Widely used in many environments, ANSI / ISA-71.04-2013 was originally developed to identify corrosion on metal connectors in telephone switches. Today, it is used in everything from museums and other cultural heritage facilities to server halls.

[0008] This standard uses copper and silver solid metal coupons as sensor surfaces that are exposed in an environment for a nominal period of 30 days after the thickness of the corrosion products has been determined ex-site by laboratory procedures. The thickness values ​​are then converted to a classification scale of levels G1, G2, G3, and GX, with G1 being the least severe and GX being the most severe. Even if methods exist for recalculating for exposures shorter or longer than 30 days, the methods are time-consuming, and severity levels are only available after ex-site laboratory procedures.

[0009] These shortcomings have resulted in the development of several different instruments that attempt to determine on-site values ​​that can be correlated with classifications from G1 to GX without removing the sensor surface and continuing the measurement. Even if these instruments have been in use for a long time, there are still many improvements that can be made.

[0010] The present disclosure seeks to provide an improved approach to monitoring airborne corrosivity that is flexible, cost-effective, and easy to use. Summary of the Invention

[0011] It is an object of the present disclosure to mitigate, alleviate or eliminate one or more of the deficiencies and drawbacks in the prior art identified above and to solve at least the problems set forth above. According to a first aspect, there is provided a sensor connection bridge configured for use in association with a corrosion measurement device for monitoring airborne corrosivity, the sensor connection bridge comprising: at least one connector assembly configured to enable electrical connection between the measurement device and at least one sensor coupon inserted into the sensor connection bridge; and a computer readable memory comprising information relating to the sensor bridge identification.

[0012] The at least one connector assembly may include a first connector portion configured to connect the sensor connection bridge to a connector in the measurement device. The at least one connector assembly may include a second connector portion including a sensor coupon receiving slot configured to receive a connection end of a sensor coupon. The sensor preferably includes two connector assemblies arranged in parallel to allow two sensor coupons to be inserted into the sensor connection bridge.

[0013] The at least one connector assembly may be at least partially disposed within the casing, and a sensor coupon protector plate may be disposed on the casing preferably adjacent the sensor coupon receiving slot, the protector plate suitably configured to shield and protect the active front face of the sensor coupon when inserted into the sensor connection bridge. One or more ventilation openings adapted to allow air circulation may be provided in the protector plate or in the sensor connection bridge.

[0014] According to a second aspect of the present disclosure, a sensor coupon adapted for use in conjunction with the sensor bridge of the first aspect described above is provided, comprising a non-conductive substrate and a metal track applied to the substrate, the sensor coupon having a connection end at a first edge of the substrate, the metal track applied to the substrate comprising at least one elongated metal track having an elongated, curved, or wavy shape, and at least two ends with a connection region located at the first edge of the substrate. The substrate preferably has a surface roughness of 5 to 600 angstroms. Advantageously, the entire metal film track, including the connection region, is applied by a thin-film technique, and the application technique for the metal film track is preferably the same along its entire length, including the connection region. Most preferably, the metal track is applied by sputtering or evaporation, or a combination thereof. The metal track suitably comprises at least one M-shaped portion, preferably two or more M-shaped portions. To generate a flat and uniform top surface of the metal track that enables a reproducible corrosion reaction, the underlying substrate surface must be similarly smooth. The substrate preferably has a surface roughness of 5 to 600 angstroms.

[0015] A first portion of the metal film track may suitably be covered by a protective layer that is impervious to corrosive substances, while at least one second portion thereof is uncovered so that it may be exposed to corrosive substances during use. The active sensor surface suitably comprises a metal that is susceptible to corrosion, preferably copper or silver. The substrate further includes a grip area where no metal track is used, preferably located at a second end of the substrate opposite the first connecting end of the substrate. The coupon suitably has a width dimension parallel to the first edge and a length dimension perpendicular to the first edge, with W:L being 0.7 to 1.3, preferably 0.8 to 1.2, most preferably 0.9 to 1.1. The substrate may be made of glass, alumina, or silicon.

[0016] According to a third aspect of the present disclosure, there is provided a sensor connection bridge arrangement comprising a sensor connection bridge according to the first aspect and at least one sensor coupon according to the second aspect inserted into at least one connector.

[0017] According to a fourth aspect of the present disclosure, there is provided a corrosion measurement device for monitoring airborne corrosivity configured to receive and connect to the sensor-connection bridge of the first aspect, the measurement device comprising: at least one connector configured to enable electrical connection between the measurement device and the sensor-connection bridge; electronic circuitry enabling determination of the resistance of a metal track of at least one sensor coupon carried by the sensor-connection bridge; and an electronic circuitry comprising an interface configured to retrieve sensor bridge identification information from a memory in the sensor-connection bridge. The corrosion measurement device may comprise electronic circuitry enabling determination of the resistance of the metal track of the sensor coupon by applying a current or voltage to the metal track. The corrosion measurement device may further comprise a bridge-receiving recess configured to receive and accommodate the sensor bridge and any sensor coupons carried by the sensor-connection bridge, the at least one connector being accessible from the recess. The bridge-receiving recess may suitably be located at the bottom end of the front face of the device when positioned in the upright position, and the front and bottom may be open, and the rear, side, and top walls may be closed, the rear wall suitably configured to extend beyond any sensor coupons carried by the sensor-connecting bridge, and the side walls extending beyond the front of the sensor coupon when the sensor bridge carrying the sensor coupon is received within the recess. Further, the corrosion measurement device comprises a microprocessor configured to derive corrosivity information based on determining a difference in resistance of the uncovered metal track versus the covered track of the sensor coupon. The corrosion measurement device may also comprise a display having a graphical user interface. Preferably, the corrosion measurement device comprises a communications unit arranged to transmit the corrosivity information to a cloud-based user communications interface.

[0018] According to a fifth aspect, there is provided a passive sensor-connection bridge holder for offline corrosivity determination configured to receive and accommodate the sensor-connection bridge of the first aspect and any sensor coupons carried by the sensor-connection bridge, the holder comprising a bridge-receiving recess configured to receive and accommodate the sensor bridge and any sensor coupons carried by the sensor-connection bridge. The bridge-receiving recess may be located at a bottom end of a front face of the holder when held in an upright position, the front and bottom may be open, and the rear, side, and top walls are closed, the rear wall configured to extend beyond any sensor coupons carried by the sensor-connection bridge, and the side walls extend beyond the front of the sensor coupons when the sensor bridge carrying the sensor coupons is received in the recess.

[0019] According to a sixth aspect, there is provided a monitoring system for monitoring airborne corrosivity at one or more different locations, the system comprising a monitoring device according to the second aspect, one or more sensor-connected bridges according to the first aspect, a set of sensor coupons according to the second aspect, and optionally one or more passive sensor bridge holders according to the fifth aspect configured to accommodate the sensor-connected bridge arrangement during time periods between active measurement occasions.

[0020] According to a seventh aspect, there is provided a method of monitoring airborne corrosivity at one or more different locations using the monitoring system of the sixth aspect, comprising the steps of: 1. inserting fresh sensor coupons according to the second aspect into one or more sensor-connected bridges according to the first aspect to form one or more sensor-connected bridge arrangements according to the third aspect; 2. calibrating the sensor-connected bridge arrangement by determining resistance in the fresh sensor coupons using a corrosion measurement device according to the fourth aspect; 3. placing the sensor-connected bridge arrangement in a desired location; 4. after a predetermined period of time, bringing the corrosion measurement device to the location where the sensor-connected bridge arrangement is present or bringing the sensor-connected bridge arrangement to the corrosion measurement device; 5. inserting the sensor-connected bridge into the corrosion measurement device and determining corrosion of the sensor coupons; and 6. returning the sensor-connected bridge arrangement to its previous desired location to continue measuring in step 3.

[0021] The effects and features of the second to seventh aspects are largely similar to those described above in connection with the first aspect. The embodiments described with respect to the first aspect are largely compatible with the second to seventh aspects. The present disclosure will become apparent from the following detailed description. The detailed description and specific examples disclose preferred embodiments of the present disclosure by way of example only. Those skilled in the art will understand from the guidance in the detailed description that changes and modifications can be made within the scope of the present disclosure. Therefore, it will be understood that the disclosure disclosed herein is not limited to the specific component parts of the described devices or the specific steps of the described methods, as such may vary. It will also be understood that the terms used herein are not intended to describe only specific embodiments, but are not intended to be limiting. It should be noted that, as used in this specification and the appended claims, the articles “a,” “an,” “the,” and “said” are intended to mean that there is one or more elements, unless the context clearly indicates otherwise. Furthermore, the words “comprising,” “including,” “containing,” and similar phrases do not exclude other elements or steps.

[0022] (Detailed explanation) The main improvement of the present disclosure is to enable both online and offline measurements while avoiding damage and measurement errors due to connecting and disconnecting sensors.

[0023] Another feature, a demand for any modern measuring device, is to offer multiple communication methods. This includes having a clear and easy to understand graphical user interface, GUI, on the unit itself, while also providing the possibility to connect to remote computers, supervisory systems, building management systems, BMS, and various cloud services.

[0024] Since standards and all methods determine the thickness of corrosion products, it is inevitable that the sensor surface will wear away and therefore need to be replaced. It is therefore important that the sensor be reliable, have tight tolerances, and be able to be made at an affordable cost to the user.

[0025] By controlling the immediate space around the sensing surface, the airflow over the sensor surface can be controlled to eliminate anomalies caused by personnel and equipment as well as sudden air movement due to direct contact with the sensor surface.

[0026] The sensor-connection bridge is configured for use in conjunction with a corrosion measurement device for monitoring airborne corrosivity. The sensor-connection bridge comprises at least one connector assembly configured to enable electrical connection between the measurement device and at least one sensor coupon inserted into the sensor-connection bridge, and a computer-readable memory comprising information related to sensor bridge identification. The sensor-connection bridge forms a sensor-connection bridge arrangement when at least one, preferably two, sensor coupons are inserted into the sensor-connection bridge. The sensor-connection bridge can be used for active (real-time) online measurements by maintaining the sensor-connection bridge in association with the measurement device, but most preferably can also be used for passive offline measurements by using a dedicated passive holder and transporting the sensor-connection bridge to the measurement device (or vice versa) and placing it elsewhere, connecting it to the online system at a desired time in a "plug-and-play" arrangement. The use of sensor-connection bridges also allows for the combination of multiple sensor-connection bridges with one or a small number of measurement devices. The sensor-connection bridge can also facilitate handling of sensor coupons during measurements, as the coupons are held by the bridge and do not need to be touched by a user or operator. Furthermore, by removing the entire bridge and leaving the sensor coupon in place, damage and measurement errors resulting from connecting and disconnecting the sensor are avoided. This allows for lower robustness requirements for the sensor coupon, keeping costs for the sensor coupon lower. In particular, the connection area on the sensor coupon does not need to be as resistant to wear as in applications where a sensor bridge is not used.

[0027] A computer-readable memory with information regarding sensor bridge identification can tie measured data to a specific sensor-connected bridge, thereby eliminating the need to provide identification information on the sensor coupons, further keeping costs for the sensor coupons low.

[0028] A sensor coupon intended for use in connection with a sensor bridge comprises a substrate and a metal track applied to the substrate. Connection areas are included at the ends of the elongated metal track. Sensor coupons are described in more detail below. It should be understood that any number of sensors can be used simultaneously with a sensor bridge, and that the sensor bridge is designed according to the desired number of sensor coupons by providing the bridge with an appropriate number of sensor coupon receiving slots. A preferred setup may include two sensor coupons with active sensor tracks made of different materials. The description below may refer to both a "sensor coupon" or "sensor coupons." This should be interpreted as one or more sensor coupons unless explicitly indicated.

[0029] The at least one connector assembly preferably includes a first connector portion configured to connect the sensor connection bridge to a connector in the measuring device, and a second connector portion having a sensor coupon receiving slot configured to receive the connection end of a sensor coupon.

[0030] The first connector portion may be in the form of a carrier substrate, for example made of a glass fiber-containing sheet material, to which conductive traces, for example of copper, are applied. The conductive traces are suitably arranged to establish electrical contact with electrical circuit elements in a measuring device in association with which the sensor connection bridge is to be used. The first connector portion may thus function as an interface for communication with the measuring device. A computer-readable memory comprising sensor bridge identification information may also be carried by or included in the first connector portion.

[0031] The second connector portion may be in the form of a connector housing having a sensor coupon receiving slot, and spring-loaded contact members may be disposed within the connector housing so as to make electrical contact with contact or connection areas on the sensor coupon when the sensor coupon is inserted into the slot and to hold the sensor coupon in place even when the sensor connection bridge is oriented so that the sensor coupon faces downward without any other support member or element. A plurality of pins may be disposed on the exterior of the connector housing, typically on the side opposite the sensor coupon receiving slot. The pins may suitably be arranged to be inserted into through-holes disposed in a carrier substrate of the first connector portion to establish electrical contact between the spring-loaded contact members of the second connector portion and the conductive traces of the first connector portion.

[0032] The sensor connection bridge may include two connector assemblies arranged side by side so that two sensor coupons can be inserted into the sensor connection bridge. When more than one connector assembly is included, a carrier substrate having a separate set of conductive traces for each coupon-receiving connector housing can be integrated.

[0033] The at least one connector assembly may suitably be at least partially disposed within a casing, typically made of a plastic material. The casing may be of two-part construction, with a rear part including a through opening through which the first connector part may extend rearward or upward to provide access to the outside of the casing, and a front part that may include a handle for convenient handling of the sensor-connection bridge. The two parts of the casing may be joined by screws or snap fasteners.

[0034] The sensor-connection bridge may further include a sensor coupon protection plate disposed on the casing adjacent the sensor coupon receiving slot, typically in the front portion of a two-part casing. The protection plate is configured to shield and protect the active front surface of the sensor coupon when the coupon is inserted into the sensor-connection bridge and to function as a front boundary of the sensor coupon space defined by the protection plate and the bridge receiving recess. Therefore, the protection plate suitably has at least the same size as the opening of the bridge receiving recess and thus extends in width and length to form a protective surface at least as large as, and preferably larger than, the sensor coupon. The protection plate is suitably disposed on the bridge casing such that there is a distance of preferably approximately 0.2 to 1.5 cm between the protection plate and the surface of the sensor coupon. The protection plate suitably has one or more through openings that allow air circulation around the sensor coupon within the sensor coupon space to maintain a uniform temperature within the sensor coupon space and the same as that within the environment being measured. Ventilation openings may also be provided within the casing of the sensor-connection bridge. The sensor coupon space is advantageous because it provides more control over airflow, temperature, and humidity in the immediate vicinity of the sensor surface, is less susceptible to air movement due to passing personnel or airflow from equipment, and avoids direct contact. By controlling the immediate space around the sensing surface, the airflow over the sensor surface can be controlled to eliminate anomalies due to sudden air movement and direct contact with the sensor surface by personnel and equipment.

[0035] The sensor coupons are disposable parts that are consumed and need to be replaced after a certain measurement period. They are then detached from the sensor-connecting bridge and discarded or recycled. The sensor-connecting bridge can be reused with a new set of sensor coupons. The sensor coupons are protected during measurement by the sensor-connecting bridge, preferably in combination with a receiving recess in the measuring device (for active measurements) or by a passive sensor bridge holder for passive measurements, as described below.

[0036] The computer readable memory comprising information regarding the sensor bridge identification may be, for example, a read-only memory configured to contain sensor bridge identification data, such as an electrically erasable programmable read-only memory (EEPROM).

[0037] The sensor coupon, adapted for use in conjunction with the sensor connection bridge, comprises an insulating substrate and a thin metal track applied to the substrate. The original resistance of the metal track is preferably 1 to 10 ohms, more preferably 4 to 5 ohms, with an optimized thickness-area relationship to provide the desired sensitivity for corrosion product thickness measurement. When airborne contaminants corrode the metal, a corrosion product film forms on top of the thin metal track, reducing the track's cross-sectional area. This metal loss and corrosion product accumulation can then be registered as an increase in electrical resistance. As previously mentioned, sensor coupons are disposable parts of corrosion measurement equipment and must be replaced after a period of time. Therefore, it is important to keep the manufacturing costs of sensor coupons at an acceptable level. Part of the track or another metal track can be covered by a contamination prevention barrier to serve as a means of temperature compensation for electrical resistance measurements.

[0038] The sensor coupon comprises at least one elongated, thin metal track applied to the substrate, with at least one connection end at a first end of the substrate near the substrate edge. The metal track or pattern is applied in a wavy, preferably M-shaped, pattern, including an end with a connection area located at the first edge of the substrate, with first and second ends, both located at the connection end of the substrate. Since gold does not form an oxide layer on its surface, the connection area can be most advantageously covered with a gold surface sputtered on top of the metal of the metal track, e.g., copper or silver, to ensure a good contact area toward the connector of the sensor connection bridge.

[0039] The M-shaped pattern preferably has a layout in which each M-section is created by a track including a straight section that rotates six 90-degree turns to form an "M." The middle section of the "M" can be folded back 30-70% of the height of the "M." Preferably, there are at least two "M"s on one sensor coupon, connected by a bridge portion between adjacent "M" legs. The end portion including the connection region is suitably located at the end of the M-leg. Furthermore, an additional leg can be provided, having a connection to one of the M-legs and a connection region at its end. For example, the connection region on the M-leg can be used for applying current or voltage, and the connection region on the additional leg can be used for measuring resistance.

[0040] The substrate is an electrically non-conductive substrate, such as a ceramic or glass substrate, or a glass laminate or glass fiber composite board. The substrate should have a surface roughness of 5 to 600 angstroms, preferably 5 to 100 angstroms, more preferably 5 to 50 angstroms, to keep the original surface of the metal track as flat as possible, ensuring a uniform buildup of corrosion product layers during sensor use and thereby improving the reliability of corrosion measurements.

[0041] Because the cross-sectional resistance is the parameter measured by the measuring device, theoretical models for resistive corrosion sensor measurements are based on the assumption that the accumulation of corrosion products is perfectly uniform, and therefore the reduction in the available pure metal cross-sectional area of ​​the metal track is perfectly uniform. Additionally, the corrosion process at the top of the corroding metal surface is also significantly affected and can be accelerated by any unevenness present due to initial surface roughness. This effect is particularly pronounced when the applied sensor metal film track has a very low thickness, especially when the metal track is applied using thin-film technology, since the applied thin metal film advances along the surface of the substrate. Suitable substrates can be obtained, for example, by polishing the surface of a glass sheet material to the desired surface roughness of 5 to 600 angstroms. Other methods can also be used. Unpolished glass typically has an average surface roughness of approximately 350 nm.

[0042] The metal film tracks are thin-film tracks, preferably applied by thin-film techniques, such as PVD metal deposition or sputtering, to provide a thin metal layer, resulting in a highly sensitive sensor. Most preferably, the entire metal track, including the connection area, is fabricated using the same application technique. The metal tracks may have a thickness of preferably 400 to 1000 nm. At the lower end of the thickness interval, sensor sensitivity is increased, but the metal track thickness is still sufficient to provide a reasonably long sensor life. At the upper end of the interval, the sensor can be used in more corrosive environments. As mentioned above, thin metal tracks require a very smooth substrate surface. The metal track thickness is preferably 400 to 800 nm, more preferably 500 to 600 nm, to ensure high sensor sensitivity and sufficient service life. The metal tracks preferably have a width of 1.7 to 2.3 mm. By providing the metal tracks with the aforementioned M-shaped layout and selecting the metal track thickness and width within the specified ranges, the metal tracks can be relatively short while still maintaining a preferred original resistance of 1 to 10 ohms. This allows the sensor metal track to fit onto a very small section of the sensor coupon substrate, requiring less metal to obtain the sheet, which is important in reducing the cost of the sensor coupon, as both the substrate material and especially the sensor metal are expensive materials. Additionally, the distance between adjacent edges of the wavy metal track is preferably 0.7-3 mm, thereby making the metal track more compact and surface-effective, while being large enough to avoid the risk of short circuits when water droplets build up due to condensation, which can bridge between adjacent portions of the metal track.

[0043] Therefore, by matching the length-to-height ratio of the sensor coupon to the overall length-to-height ratio of the substrate material, the number of sensors can be optimized, improving production speed and reducing scrap and manufacturing costs. This can be achieved if the shape of the membrane track can be adapted to the most advantageous length-to-height ratio of the sensors. Advantageously, the sensor coupon has a width dimension (W) parallel to the first edge (34) and a length dimension (L) perpendicular to the first edge, with W:L being 0.7 to 1.3, preferably 0.8 to 1.2, and most preferably 0.9 to 1.1. The substrate material blank from which the sensor coupon substrate is made usually has a roughly square shape and typically measures approximately 114 x 114 mm. Therefore, using the selected preferred M-shape of the metal track and the selected dimensions of the sensor coupon, most of the substrate material blank can be used, reducing waste and therefore leading to more cost-effective sensor coupon production. An appropriate size can be obtained when the sensor coupon length L is approximately 2.5 to 4.0 cm. Additionally, the width of the sensor coupon may suitably be approximately 25-40mm, preferably 30-38mm, to match the size of standard off-the-shelf connectors, which are often approximately 31mm wide.

[0044] As previously mentioned, a contact area is provided on the end of the sensor coupon and is adapted to be inserted into a measurement device.

[0045] Known sensors of the aforementioned type, i.e. in the form of thin metal tracks applied to a substrate, are generally made to withstand wear when inserted into a measuring device, so as to allow repeated insertion and removal into and from the contact means of the corrosion measuring device. This can be obtained, for example, by forming the connection area of ​​the metal track by thin-film technology, or by combining a thick-film technology layer on top of a thin-film technology layer, or by applying a separate wear-resistant conductive coating in the connection area. In many previously known cases, the entire sensor metal track, including the connection area, is made by thick-film technology and etching.

[0046] Within the scope of the present invention, connection areas applied solely by thin-film technology and having a thickness within the same spacing as the sensor metal tracks described above have been found to be sufficiently durable when used with the sensor connection bridge described herein. The contact areas may be slightly scratched when inserted into the connector portion of the sensor connection bridge, but can still provide sufficient electrical contact to obtain suitable corrosion measurements. Therefore, the otherwise commonly required complicated step of applying a thick-film technology layer over the connection areas is not necessary, which means that the sensor coupons can be made easier and therefore cheaper to manufacture.

[0047] The substrate further includes a grip area, preferably located at a second end of the substrate opposite the first connection end of the substrate, where no metal tracks are used. The grip area preferably has a size of 8-15 mm along the length of the sensor coupon and a width corresponding to approximately half the width of the sensor coupon. The grip area is preferably marked with printed text (e.g., "touch here only") or a pattern. The grip area allows the user to easily hold the sensor coupon for insertion into the sensor connection bridge without the risk of accidentally touching the sensitive sensor tracks, which could affect resistance and therefore compromise corrosion measurements.

[0048] Preferably, a first portion of the metal film track is covered by a protective layer that is impervious to corrosive substances and thus serves as a reference portion, while a second portion of the metal film track is left uncovered to allow exposure to corrosive substances during use and serves as a measurement or sensing portion. The protective layer or coating may preferably be a polyester film and may preferably be transparent. The resulting measurement and reference portions of the sensor will suitably have the same shape and size and are typically connected by a bridge portion, with the protective layer or coating covering half of the bridge portion. The protective layer or coating preferably extends substantially completely to the substrate edge at the second end of the substrate. When a gripping region is included in the sensor coupon, it is preferably positioned and marked in the open area between the covered reference portion and the substrate edge at the second end of the substrate, and is therefore also covered by the protective layer or coating, thereby further reducing the risk of contamination of the sensor metal film track.

[0049] During the measurement, the sensing part is exposed to air and is intended to corrode. The reference part is covered with a coating that functions as temperature compensation. When the sensing part corrodes, the cross-sectional area for conducting current is greatly reduced, and the metal consumption can be directly measured by measuring the increase in resistance. As described on page 2 of T. Prosek et al., 18th International Corrosion Congress 2011, Paper 436, "Application of automated corrosion sensors for real-time monitoring in atmospheres polluted with organic acids," by assuming that the conductivity of the pattern is proportional to the remaining thickness of the metal pattern and that corrosion products do not contribute to the conductivity, the corrosion depth Δh of a metal sensor can be calculated according to the following formula:

[0050]

number

[0051] In the above equation, h ref i is the initial reference pattern thickness, R A is the resistance of the active uncovered part of the metal track, R P is the resistance of the passive covered part of the metal track, R A i is the initial resistance of the active uncovered part of the metal track, R P i is the initial resistance of the passive covered part of the metal track.

[0052] The metal tracks of the sensor coupons are preferably made of copper or silver metal. Preferably, two coupons with different active sensor surfaces are used simultaneously. Most preferably, a sensor coupon with a copper sensor pattern is used together with a sensor coupon with a silver sensor pattern. The parameter measured is the actual metal loss of the sample, and therefore has a direct correlation to corrosivity, regardless of assumptions.

[0053] A corrosion measurement device for monitoring airborne corrosivity in association with which a sensor-connection bridge is to be used is a device configured to receive and connect to the sensor-connection bridge as described above. The measurement device includes at least one connector configured to enable electrical connection between the measurement device and the sensor-connection bridge, electronic circuitry that enables determining the resistance of the active sensor surface of at least one sensor coupon held by the sensor-connection bridge, and an electronic circuitry with an interface, e.g., an I2C interface, configured to retrieve sensor bridge identification information from a memory within the sensor bridge. The measurement device can be battery-powered, independently operable, and easily transportable to various locations.

[0054] The electronic circuitry enables the determination of the resistance of the active sensor surface of the sensor coupon by applying a current or voltage to the active sensor surface, and suitably includes measurement and control circuitry and other components known in the art. Furthermore, the measurement device may include a microprocessor configured to retrieve corrosivity information based on the determined resistance of the active sensor surface, and may also include a communications unit with a transmitter arranged to transmit the corrosivity information to a cloud-based user communications interface. The measurement device may also include sensors for measuring the temperature, relative humidity, and differential / absolute pressure of the environment under test. The measurement device may suitably include a memory containing software for storing data, performing calculations, and comparing readings to relevant standards, such as ANSI / ISA-71.04-2013.

[0055] The at least one connector configured to enable an electrical connection between the measuring device and the sensor-connection bridge may be in the form of a connector housing having a contact-receiving slot, and the spring-loaded contact members may be arranged inside the connector housing such that when inserted into the slot, they make electrical contact with the extension of the first connector part of the sensor-connection bridge and hold the first connector part in position, so that the sensor-connection bridge is securely attached to the measuring device when the extension of the first connector part is inserted into the connector of the measuring device.

[0056] The measuring device comprises a main printed circuit board containing the electronic circuitry required for the resistance measurement, and preferably also comprises a display with a graphical user interface. The components of the measuring device are preferably held within a casing which may typically be of a plastic material.

[0057] The measuring device may further include a bridge-receiving recess configured to receive and accommodate the sensor bridge, which may have a shape corresponding to the shape of the sensor-connecting bridge. The recess is suitably formed in the casing of the measuring device and may, for example, have a substantially rectangular parallelepiped shape, open on two sides and closed on three sides, thus providing protection for the sensor coupon during measurement. The measuring device may typically be oriented during use such that the recess for receiving the sensor-connecting bridge is located at the bottom of the front part of the device and has its open face facing forward and downward. The bridge-receiving recess can thereby protect the sensor coupon from the rear and sides, and a protective plate attachable to the sensor-connecting bridge can protect the sensor coupon from the front. In this way, the bridge-receiving recess, together with the protective plate, can form a sensor coupon-accommodating space. The bridge-receiving recess is configured to protect the rear and edge faces of at least one sensor coupon and, together with the protective plate, defines the boundary of the sensor coupon space, allowing air communication between the open bottom section and one or more openings in the upper part of the sensor coupon space adapted to allow air circulation, while simultaneously protecting the sensor coupon space and controlling access of contaminated air to the sensor coupon surface.

[0058] At least one measuring device connector is suitably located in the recess at a position corresponding to the extending connector portion of the sensor connection bridge.

[0059] As described above, the described sensor-connecting bridge and measurement device may be included in a monitoring system for monitoring airborne corrosivity at one or more different locations. The system may also include a passive sensor-connecting bridge holder for offline corrosivity determination configured to receive and accommodate the sensor-connecting bridge and any sensor coupons carried by the sensor-connecting bridge. The holder suitably includes a bridge-receiving recess configured to receive and accommodate the sensor bridge and any sensor coupons carried by the sensor-connecting bridge. Preferably, the bridge-receiving recess may be located at a bottom end of the front face of the holder when held in an upright position, with the front and bottom open, and the rear, side, and top walls closed, the rear wall configured to extend beyond any sensor coupons carried by the sensor-connecting bridge, and the side walls extending beyond the front of the sensor coupons when the sensor bridge-carrying sensor coupons are accommodated in the recess. The passive sensor bridge holder for offline corrosivity determination has a bridge-receiving recess and a protective plate for defining the boundary of the sensor coupon space, allowing air communication between the open bottom section and one or more openings in the upper part of the sensor coupon space adapted to allow air circulation, while simultaneously protecting the sensor coupon space and controlling access of contaminated air to the sensor coupon surface. Optionally, the system can include one or more passive sensor-connected bridge holders configured to accommodate the sensor-connected bridge arrangement during time periods between active measurement occasions. The system suitably includes a communication device including a transmitter for transmitting information to a remote receiver.

[0060] The measurement device is preferably arranged to transmit corrosivity information, and preferably also one or more of room temperature, relative humidity, differential / absolute pressure, and sensor life information. The transmitted corrosivity information may then be converted to a classification value of G1, G2, G3, or GX, preferably according to ANSI / ISA-71.04-2013.

[0061] For example, the information may be transmitted to a mobile phone, tablet, etc. via short-range wireless technology such as Bluetooth. The information may also be transmitted to a remote user network via wired or wireless communication.

[0062] The information may be transmitted via wired or wireless communication to one or more building management systems (BMS) that control the HVAC system, or may also be transmitted directly to the heating, cooling, or ventilation units, such that the building management systems (BMS) that control the HVAC system and the heating, cooling, or ventilation units can be included in the monitoring system to adjust the environment within a particular location based on the corrosivity information obtained by the corrosion measurement devices.

[0063] The monitoring may be used in a method of monitoring airborne corrosivity at one or more different locations, including the steps of inserting fresh sensor coupons into one or more sensor-connected bridges to form one or more sensor-connected bridge arrangements, calibrating the one or more sensor-connected bridge arrangements by determining the resistance in the fresh sensor coupons using a corrosion measurement device, placing the one or more sensor-connected bridge arrangements in one or more desired locations, and after a predetermined period of time, transporting the corrosion measurement device to the location where the sensor-connected bridge arrangement is located or transporting the sensor-connected bridge arrangement to the corrosion measurement device, inserting the sensor-connected bridge into the corrosion measurement device and determining corrosion of the sensor coupons, and returning the one or more sensor-connected bridge arrangements to their previous desired location or locations to continue measurements.

[0064] The above objects and additional objects, features, and advantages of the present disclosure will be more fully understood by reference to the following illustrative and non-limiting detailed description of exemplary embodiments of the present disclosure when taken in conjunction with the accompanying drawings. [Brief explanation of the drawings]

[0065] [Figure 1] 1 is a schematic diagram of a sensor connection bridge with a sensor coupon according to the present invention; [Figure 2] 1 is a perspective view of a sensor connection bridge with a sensor coupon and a sensor coupon protector according to the present invention; [Figure 3] 1 is a perspective exploded view that shows a schematic representation of a sensor connection bridge with a two-part casing and two connector assemblies according to the present invention; FIG. [Figure 4] 1 is a front view of a schematic representation of a corrosion measurement device including a display, a bridge receiving recess, two connectors, and a disconnected sensor bridge in accordance with the present invention; [Figure 5] 1 is a perspective view that shows a schematic representation of a corrosion measurement device with a connected (attached) sensor bridge according to the present invention; [Figure 6] 1 is a front view showing a schematic representation of a corrosion measurement device according to the present invention, comprising a bridge-receiving recess with two connectors and two ledges intended to guide and secure the sensor bridge when mounted; FIG. [Figure 7] 1 is a schematic diagram illustrating a monitoring system according to the present disclosure including a passive holder; [Figure 8] 1 is a schematic diagram showing a sensor coupon according to the present invention, comprising a substrate, an elongated metal track having a wave-like shape, and several connection areas located on a first edge of the substrate. [Figure 9] 1 is a schematic diagram showing a sensor coupon according to the present invention, comprising a substrate, an elongated metal track with a wave-like shape, and several connection areas, wherein sections of the metal track are covered by a layer that is impermeable to corrosive substances. [Figure 10] 1 is a block diagram that schematically illustrates a method for monitoring airborne corrosivity at one or more different locations in accordance with the present invention. [Figure 11]FIG. 1 is a schematic diagram illustrating various forms of communication between a system for monitoring airborne corrosivity and a display device, a storage or logging device, a cloud service, and a unit for removing airborne contamination that may be controlled based on the corrosivity information. DETAILED DESCRIPTION OF THE INVENTION

[0066] Illustrative Embodiments The present disclosure will now be described with reference to the accompanying drawings, in which preferred exemplary embodiments of the present disclosure are shown. However, the present disclosure may be embodied in other forms and should not be construed as limited to the embodiments disclosed herein. The disclosed embodiments are provided so that the scope of the present disclosure will be fully conveyed to those skilled in the art.

[0067] Figures 1 to 3 show a sensor connection bridge according to the present invention. In Figure 1, a sensor coupon is inserted into the connection bridge. Figure 3 is an exploded view showing how the connector assembly is comprised of first and second connector portions.

[0068] A first aspect of the present disclosure shows a sensor connection bridge 1 configured to be used in association with a corrosion measurement device 20 for monitoring airborne corrosivity, the sensor connection bridge comprising at least one connector assembly 3a, 3b, 4a, 4b configured to enable electrical connection between the measurement device 20 and at least one sensor coupon 30a, 30b inserted into the sensor connection bridge, and a computer-readable memory comprising information relating to sensor bridge identification.

[0069] In the example shown in FIG. 3 , the at least one connector assembly includes a first connector portion 3a, 4a configured to connect the sensor-connection bridge 1 to connectors 23a, 23b in the measurement device 20 and a second connector portion 4a, 4b with sensor coupon receiving slots 2a, 2b configured to receive the connection ends 33 of the sensor coupons 30a, 30b. FIG. 3 is an exploded view illustrating how the connector assembly can include the first and second connector portions. As shown in the figure, the sensor includes two parallel-arranged connector assemblies 3a, 3b, 4a, 4b to allow the two sensor coupons 30a, 30b to be inserted into the sensor-connection bridge. The at least one connector assembly 3a, 3b, 4a, 4b is at least partially disposed within a casing 5, and a sensor coupon protection plate 6 is disposed on the casing adjacent the sensor coupon receiving slots 2a, 2b. The protection plate 6 is configured to shield and protect the active front faces of the sensor coupons when inserted into the sensor-connection bridge. FIG. 2 shows how the protective plate 6 is included in the sensor connection bridge.

[0070] As shown in FIG. 2, one or more ventilation openings 7 adapted to allow air circulation are provided in the protective plate 6 or in the sensor connection bridge.

[0071] 8 and 9 illustrate a second embodiment of the present disclosure, showing a sensor coupon comprising a non-conductive substrate 31 adapted for use in connection with the sensor bridge 1 of the first embodiment and a metal track 32 applied to the substrate, the sensor coupon having a connection end 33 at a first edge 34 of the substrate, and the metal track applied to the substrate comprising at least one elongated metal track having an elongated, curved, or wavy shape and including at least two ends 35a-c, 35a'-c' with connection regions 36a-c, 36a'-c' located at the first edge 34 of the substrate. As previously mentioned, the entire metal film track is applied by thin-film technology, and the application technique for the metal film track is the same along its entire length, including the connection region, and the metal track may be applied by sputtering or evaporation, or a combination thereof. FIG. 9 illustrates the connection region to which a gold layer is applied to protect the connection region from corrosion.

[0072] 8 and 9 show how a metal track can include at least one M-shaped portion, preferably two or more. The M-shaped pattern preferably has a layout in which each M-shaped portion is created by a track including a straight section that rotates six times 90 degrees to form an "M." The middle section of the "M" can be folded back 30-70% of the height of the "M." Preferably, there are at least two "M"s on one sensor coupon, connected by a bridge portion between adjacent "M" legs. The end portion including the connection region is suitably located at the end of the M-leg. Furthermore, an additional leg can be provided, having a connection to one of the M-legs and a connection region at its end. For example, the connection region on the M-leg can be used for applying current or voltage, and the connection region on the additional leg can be used for measuring resistance. A first portion 37 of the metal film track is covered by a protective layer 38 that is impervious to corrosive substances, while a second portion 39 of at least one of the metal film tracks is left uncovered to allow exposure to corrosive substances during use. The active sensor surface comprises a metal that is prone to corrosion, preferably copper or silver.

[0073] As shown in Figure 9, the substrate may include a grip region 49 where no metal tracks are used, preferably located at a second end of the substrate opposite the first connecting end 33 of the substrate. In the example shown, the protective layer 38 extends to the second end 48 of the substrate. The sensor coupon preferably has a width dimension W parallel to the first edge 34 and a length dimension L perpendicular to the first edge, with W:L being 0.7 to 1.3, preferably 0.8 to 1.2, and most preferably 0.9 to 1.1. The substrate may comprise glass, alumina, or silicon.

[0074] A sensor connection bridge arrangement comprising a sensor connection bridge and two sensor coupons 30a, 30b is also shown in Figures 1-2.

[0075] 4-6 illustrate a corrosion measurement device for monitoring airborne corrosivity configured to receive and connect to a sensor-connecting bridge 1, as described above. FIG. 5 illustrates a sensor-connecting bridge mounted in a recess 24 of the corrosion measurement device. FIG. 5 illustrates a corrosion measurement device without a sensor-connecting bridge; in this example, ledges are provided on each side of the recess to facilitate fitting the sensor-connecting bridge within the recess. In the illustrated example, the measurement device includes two connectors 23a, 23b configured to enable electrical connection between the measurement device 20 and the sensor-connecting bridge 1, an electronic circuit (not shown) capable of determining the resistance of the metal tracks of at least one sensor coupon 30a, 30b held by the sensor-connecting bridge 1, and an electronic circuit (not shown) with an interface configured to retrieve sensor bridge identification information from a memory in the sensor-connecting bridge. The corrosion measurement device includes an electronic circuit (not shown) capable of determining the resistance of the metal tracks of the sensor coupon by applying a current or voltage to the metal tracks.

[0076] The corrosion measurement device includes a bridge-receiving recess 24 configured to receive and accommodate the sensor bridge 1 and any sensor coupons carried by the sensor-connecting bridge, with at least one connector 23 a, 23 b accessible through the recess. The bridge-receiving recess 24 is located at a bottom end on the front surface 22 of the device when positioned in an upright position, with the front and bottom open, and a rear wall 26, side walls 27 a, b, and top wall 27 c closed, with the rear wall 26 configured to extend beyond any sensor coupons carried by the sensor-connecting bridge 1, and the side walls extending beyond the front of the sensor coupons when the sensor bridge carrying the sensor coupons is accommodated within the recess.

[0077] The corrosion comprises a microprocessor configured to derive corrosivity information based on a determination of a difference in resistance of the uncovered metal track versus the covered track of the sensor coupon. The corrosion comprises a display 25 having a graphical user interface GUI. The corrosion comprises a communications unit arranged to transmit the corrosivity information to a cloud-based user communications interface.

[0078] 7 shows a passive sensor-connecting bridge holder of the present disclosure for offline corrosivity determination configured to receive and accommodate the first embodiment of the sensor-connecting bridge 1 and any sensor coupons carried by the sensor-connecting bridge, the holder including a bridge-receiving recess 44 configured to receive and accommodate the sensor bridge 1 and any sensor coupons carried by the sensor-connecting bridge. The bridge-receiving recess 44 is located at the bottom end of the front surface 42 of the holder 41 when held in an upright position, with the front and bottom open, and the rear wall 46, side walls 47 a, b, and top wall 47 c closed, with the rear wall 46 configured to extend beyond any sensor coupons carried by the sensor-connecting bridge 1, and the side walls extending beyond the front of the sensor coupons when the sensor bridge carrying the sensor coupons is accommodated within the recess.

[0079] Figure 7 shows a second embodiment of a monitoring system for monitoring airborne corrosivity at one or more different locations, the system comprising a monitoring device 20, two sensor-connected bridges 1a, 1b, a set of sensor coupons (not shown), and a passive sensor bridge holder 41 configured to accommodate the sensor-connected bridge arrangement during time periods between active measurement occasions.

[0080] A seventh aspect of the present disclosure, as shown in FIG. 10 , is a method of monitoring airborne corrosivity at one or more different locations using a monitoring system, compressing the steps of the sixth aspect and including step 901 of inserting fresh sensor coupons 30 a, 30 b into one or more sensor-connected bridges 1 to form one or more sensor-connected bridge arrangements; step 902 of calibrating the sensor-connected bridge arrangement by determining resistance in the fresh sensor coupons using a corrosion measurement device 20; step 903 of placing the sensor-connected bridge arrangement in a desired location; and after a predetermined period of time, step 904 a of transporting the corrosion measurement device 20 to the location where the sensor-connected bridge arrangement is located or step 904 b of transporting the sensor-connected bridge arrangement to the corrosion measurement device 20; step 905 of inserting the sensor-connected bridge into the corrosion measurement device and determining corrosion of the sensor coupon; and step 906 of returning the sensor-connected bridge arrangement to its previous desired location to continue measurements.

[0081] FIG. 11 shows a schematic diagram of how the monitoring system transmits data to various locations.

[0082] Those skilled in the art will understand that the present disclosure is not limited to the preferred embodiments described above. Moreover, those skilled in the art will understand that modifications and variations are possible within the scope of the appended claims. Furthermore, variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed disclosure, from a study of the drawings, the disclosure, and the appended claims.

Claims

1. A sensor connection bridge (1) configured for use in conjunction with a corrosion measurement device (20) for monitoring airborne corrosivity, comprising: at least one connector assembly (3a, 3b, 4a, 4b) configured to enable an electrical connection between the measuring device (20) and at least one sensor coupon (30a, 30b) inserted into the sensor connection bridge; a computer readable memory comprising information relating to the sensor bridge identification; A sensor connection bridge comprising:

2. 2. The sensor-connection bridge of claim 1, wherein the at least one connector assembly includes a first connector portion (3a, 4a) configured to connect the sensor-connection bridge (1) to a connector (23a, 23b) in the measuring device (20).

3. 3. The sensor connection bridge of claim 1, wherein the at least one connector assembly includes a second connector portion (4a, 4b) having a sensor coupon receiving slot (2a, 2b) configured to receive a connection end (33) of a sensor coupon (30a, 30b).

4. 4. A sensor-connection bridge according to claim 1, comprising two connector assemblies (3a, 3b, 4a, 4b) arranged in parallel, allowing two sensor coupons (30a, 30b) to be inserted into the sensor-connection bridge.

5. the at least one connector assembly (3a, 3b, 4a, 4b) is at least partially disposed within a casing (5), and a sensor coupon protector (6) is disposed on the casing adjacent to one or more of the sensor coupon receiving slots (2a, 2b); 5. The sensor connection bridge according to claim 1, wherein the protective plate (6) is configured to shield and protect the active front face of one or more of the sensor coupons when inserted into the sensor connection bridge.

6. The sensor-connecting bridge of claim 6 , wherein one or more ventilation openings adapted to allow air circulation are provided in the protective plate or in the sensor-connecting bridge.

7. A sensor coupon (30) adapted for use in connection with the sensor bridge (1) of any one of claims 1 to 6, comprising: It comprises a non-conductive substrate (31) and metal tracks (32) applied onto said substrate, the sensor coupon has a connecting end (33) at a first edge (34) of the substrate; the metal track applied to the substrate comprises at least one elongated metal track having an elongated, curved or wavy shape, and includes at least two ends (35a-c, 35a'-c') with connection areas (36a-c, 36a'-c') located at a first edge (34) of the substrate; the substrate has a surface roughness of 5 to 600 angstroms; A sensor coupon, wherein the entire metal film track including the connection area is applied by thin film technology.

8. The sensor coupon of claim 7, wherein the metal film track has a thickness of 400 to 1000 nm.

9. The sensor coupon of claim 8 , wherein the metal tracks are applied by sputtering or evaporation or a combination thereof.

10. 10. The sensor coupon according to any one of claims 7 to 9, wherein the metal track comprises at least one M-shaped portion, preferably two or more M-shaped portions.

11. 11. A sensor coupon according to any one of claims 7 to 10, wherein a first portion (37) of the metal film track is covered by a protective layer (38) that is impermeable to corrosive substances, and at least a second portion (39) thereof is uncovered so that it may be exposed to corrosive substances during use.

12. The sensor coupon of claim 7 , wherein the active sensor surface comprises a metal that is prone to corrosion, preferably copper or silver.

13. 13. A sensor coupon according to any one of claims 7 to 12, wherein the substrate includes a grip area (49) in which no metal tracks are used, preferably located at a second end of the substrate opposite the first connection end (33) of the substrate.

14. the coupon has a width dimension (W) parallel to the first edge (34) and a length dimension (L) perpendicular to the first edge; The sensor coupon of any one of claims 7 to 13, wherein W:L is between 0.7 and 1.3, preferably between 0.8 and 1.2, most preferably between 0.9 and 1.

1.

15. The sensor coupon of claim 7 , wherein the substrate comprises glass, alumina, or silicon.

16. A sensor connection bridge (1) according to claims 1 to 6, at least one sensor coupon (30) according to claims 7 to 15 inserted into said at least one connector (3a, 3b, 4a, 4b); 1. A sensor connection bridge arrangement comprising:

17. two sensor coupons (30a, 30b); the first sensor coupon has a metal track comprising a first metal; the second sensor coupon has a metal track comprising a second metal; 17. A sensor connection bridge arrangement according to claim 16, wherein the first and second metals are different, preferably copper and silver, respectively.

18. A corrosion measuring device (20) for monitoring airborne corrosivity, configured to receive and connect to a sensor connection bridge (1) according to any one of claims 1 to 6, comprising: at least one connector (23a, 23b) configured to enable an electrical connection between the measuring device (20) and the sensor connection bridge (1); an electronic circuit that allows the determination of the resistance of the metal tracks of at least one sensor coupon (30a, 30b) carried by said sensor connection bridge (1); an electronic circuit comprising an interface configured to retrieve sensor bridge identification information from the memory in the sensor connection bridge; A corrosion measurement device comprising:

19. 20. The corrosion measurement device of claim 18, comprising electronic circuitry that enables determining the resistance of one or more of the metal tracks of one or more of the sensor coupons by applying a current or voltage to one or more of the metal tracks.

20. a bridge receiving recess (24) configured to receive and accommodate the sensor bridge (1) and any sensor coupons carried by the sensor connecting bridge; 20. The corrosion measurement device of claim 18 or 19, wherein the at least one connector (23a, 23b) is accessible from the recess.

21. the bridge receiving recess (24) is located at the bottom end of the front face (22) of the device when positioned in an upright position, the front and bottom faces are open, and the rear wall (26), side walls (27a, b) and top wall (27c) are closed; the rear wall (26) is configured to extend beyond any sensor coupons carried by the sensor connection bridge (1); 21. The corrosion measurement device of claim 20, wherein the sidewall extends beyond a front of the sensor coupon when a sensor bridge carrying the sensor coupon is received within the recess.

22. 22. The corrosion measurement device of claim 18, further comprising a microprocessor configured to derive corrosivity information based on the determination of the difference in resistance of uncovered metal tracks versus covered tracks of a sensor coupon.

23. 23. The corrosion measurement device of any one of claims 18 to 22, further comprising a display (25) having a graphical user interface (GUI).

24. 21. The corrosion measurement device of any one of claims 15 to 20, further comprising a communication unit arranged to transmit corrosivity information to a cloud-based user communication interface.

25. 7. A passive sensor-connecting bridge holder (41) for offline corrosivity determination configured to receive and accommodate a sensor-connecting bridge (1) according to any one of claims 1 to 6 and any sensor coupons carried by said sensor-connecting bridge, comprising: A passive sensor-connecting bridge holder, wherein the holder comprises a bridge-receiving recess (44) configured to receive and accommodate the sensor bridge (1) and any sensor coupons carried by the sensor-connecting bridge.

26. the bridge receiving recess (44) is located at the bottom end of the front face (42) of the holder (41) when held in an upright position, the front and bottom faces are open, and the rear wall (46), side walls (47a, b) and top wall (47c) are closed; the rear wall (46) is configured to extend beyond any sensor coupons carried by the sensor connection bridge (1); 26. The bridge holder of claim 25, wherein the sidewall extends beyond a front of a sensor coupon carrying a sensor bridge when the sensor coupon is received within the recess.

27. A monitoring system (21) for monitoring airborne corrosivity at one or more different locations, comprising: A measuring device (20) according to any one of claims 18 to 24, One or more sensor-connecting bridges (1a, 1b) according to any one of claims 1 to 6, A set of sensor coupons according to any one of claims 7 to 12; Optionally, one or more passive sensor bridge holders (41) according to claims 25-26 configured to accommodate the sensor connection bridge arrangement during the time periods between active measurement occasions; A monitoring system comprising:

28. 28. A method for monitoring airborne corrosivity at one or more different locations using the monitoring system (21) of claim 27, comprising the steps of: 1) inserting (901) fresh sensor coupons (30a, 30b) according to any one of claims 7 to 12 into one or more sensor-connecting bridges (1) according to any one of claims 1 to 6 to form one or more sensor-connecting bridge arrangements according to claims 16 or 17; 2) calibrating (902) the one or more sensor connection bridge arrangements by determining resistance within the fresh sensor coupons using a corrosion measurement device (20) according to any one of claims 18 to 24; 3) placing one or more of said sensor connection bridge arrangements in one or more desired locations (903); 4) after a predetermined period of time, bringing the corrosion measurement device (20) to the location where the sensor-connected bridge arrangement is located (904a) or bringing the sensor-connected bridge arrangement to the corrosion measurement device (20) (904b); 5) inserting the sensor connection bridge into the corrosion measurement device and determining the corrosion of the sensor coupon (905); 6) returning one or more of the sensor connection bridge arrangements to their previous desired location(s) to continue the measurements in step 3 (906); A method comprising:

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