Atmosphere corrosion sensor

Abstract

An atmospheric corrosion sensor for detecting corrosion of an electrical device, comprising at least two atmospheric corrosion sensing structures (Rs1, Rs2, Rs3), the at least two atmospheric corrosion sensing structures (Rs1, Rs2, Rs3) being placed on at least one insulating corrosion sensor substrate, where the corrosion sensing structures are capable of entering a corrosive atmosphere. The atmospheric corrosion sensing structures (Rs1, Rs2, Rs3) have the same spatial size, and each of the atmospheric corrosion sensing structures (Rs1, Rs2, Rs3) comprises a corrodible material of a different composition.

Description

Technical Field

[0001] The object of the present invention is an atmosphere corrosion sensor for detecting corrosion of electrical equipment due to corrosive gases. The sensor can be used for various types of electrical equipment susceptible to atmosphere corrosion. In particular, the sensor is intended for use in electrical equipment used in the most aggressive corrosive environments that may be present in the power distribution industry, chemical production plants, aircraft, automobile manufacturing, transportation infrastructure, offshore structures and the construction industry. Background Art

[0002] Atmospheric corrosion is the electrochemical degradation process of materials exposed to corrosive atmospheres. The susceptibility of materials to atmospheric corrosion depends on many factors, the most important of which are as follows: type and structure of material, presence of water, composition of atmosphere, humidity, ambient temperature. Particularly susceptible to atmospheric corrosion are metals and their alloys, such as copper, aluminum, iron, zinc, nickel, silver, steel, brass, etc. The most aggressive corrosive environments may be found in the power distribution industry, chemical production plants, aircraft, automobile manufacturing, transportation infrastructure, offshore structures and the construction industry. These atmospheres are usually rich in many corrosive substances, such as, for example, chlorides, phosphates, nitrates, sulfates, carbonates, sulfur oxides, nitrogen oxides, carbon dioxide, hydrogen sulfide, which together with moisture and oxygen may cause severe metal corrosion.

[0003] Different electronic and electrical equipment are used in each of these environments, and because they are composed of various metals and alloys, they are particularly susceptible to damage due to atmospheric corrosion. The increasing complexity and reliability requirements of electronic equipment and components make atmospheric corrosion a significant issue. Therefore, atmospheric corrosion monitoring can help predict the service life of electronic and electrical equipment in a specific environment and plan service and maintenance actions to prevent fatal failures and equipment downtime.

[0004] Many corrosion sensors use thin metal films to detect atmospheric corrosion. The corrosive substances in the atmosphere react with the metal surface, causing corrosion to advance into the depth of the film, thereby consuming the metal and increasing resistance until continuity is broken. The time required to destroy the metal film depends on its thickness and a number of environmental conditions, such as the concentration of corrosive substances in the atmosphere, humidity, and temperature. Under stable environmental conditions, the thicker the film, the longer it takes to destroy electrical continuity.

[0005] In the prior art, corrosion sensors are known. For example, document US8723534B2 discloses a corrosion sensor, which includes a plurality of metal strips with different thicknesses. A first metal strip with the smallest thickness is first used to provide sensitive corrosion detection. After the leaking portion of the first metal strip is consumed, a second metal strip with a second smallest thickness can be used to continue to provide sensitive corrosion detection using the remaining non-corroded portion of the second metal strip. When the leaking portion of the thinner metal strip cannot be used due to complete corrosion and the non-corroded leaking portion of the thicker metal strip becomes thin enough to provide sensitive corrosion detection, multiple metal strips can be used in sequence.

[0006] Patent US8390306B2 discloses an atmospheric corrosion sensor. Its corrosion sensor is based on a metal film resistor. The corrosion sensor includes a group of multiple metal films with gradually increasing widths. The metal film is located on a non-conductive material. The operation of the corrosion sensor is such that the resistance of each metal film is measured. Its resistance depends on its spatial size. Therefore, atmospheric corrosion affects the spatial size of the metal film and changes its resistance. When the width of the metal film changes from metal to non-conductive oxide due to corrosion, the resistance changes due to the reduction of the conductive path. When the corrosive gas in the atmosphere in which the sensor operates attacks the metal of the metal film and converts it into a non-conductive oxide, the width is reduced, thereby increasing the resistance of the metal film. The operation of the corrosion sensor is optimized to work at a relatively low corrosion rate, where corrosion products are formed at a rate of about 30 nanometers per month or less. The corrosion sensor is designed to be used indoors. Therefore, when a certain level of corrosion is detected via the sensor response, the internal atmosphere can be adjusted accordingly. In this solution, a reference sensor element can also be used, which is substantially not susceptible to corrosion caused by the atmosphere.

[0007] Patent application US200230134944A1 discloses a corrosion environment monitoring device, including a laminated body, the laminated body including an insulating plate, a base metal film and a sensing metal film, the base metal film is formed on the insulating plate and is resistant to corrosion by corrosive substances, the sensing metal film is formed on the base metal film and is susceptible to corrosion by corrosive substances. The corrosion environment monitoring also includes a shell for accommodating the laminated body, the shell includes an opening portion along the side surface direction, and a gas channel for corrosive substances is formed inside, wherein the sensing metal film is formed in a local area on the base metal film.

[0008] To evaluate the corrosion rate of electronic devices, a variety of methods are used, however, four of these methods appear to be the most popular.

[0009] One of these methods is based on the optical evaluation of the corrodible surface affected by the corrosion process. It can be based on optoelectronic components such as photodiodes and phototransistors. However, these simple solutions are very sensitive to dirt, dust and light conditions (i.e. daylight vs. artificial lighting), while more advanced solutions based on picture recognition (cameras and image processing units) are not widely used because their size and cost can be very high, limiting their use to protecting only the most important and valuable assets.

[0010] Another approach is based on electrochemical corrosion measurement, where very small values ​​of potential, anodic current and cathodic current are monitored. This approach requires the use of specific electrodes and extremely accurate monitoring circuits, which increases the cost and size of this solution.

[0011] Yet another approach is based on the continuous monitoring of some physical parameters of corrosion sensors made of corrodible materials to assess the progress of the corrosion process, for example, the monitoring of the change in the resistance of a metal strip. In the continuous method, a single metal film of a predetermined thickness is used, and its resistance is measured so that the corrosion process can be monitored continuously in time. Sometimes, another anti-corrosion metal film is also used to compensate for temperature changes and other environmental factors that are not directly related to corrosion. This method requires high-quality measuring equipment to detect small changes in parameter values ​​and is very sensitive to environmental conditions (such as temperature and humidity). In addition, in order to detect trends within the device (when using a stand-alone solution that is not connected to a more advanced system), it may be necessary to store the measurement data over time and compare them. All these requirements will increase the cost of the measuring equipment that can meet the required functions with reasonable sensitivity. Therefore, the total cost of the solution and its size may still be too high to place it as an additional functional block in many products.

[0012] The fourth method, known as the discrete method, is based on detecting the moment when the corrosion process causes the continuity of the corrosion sensor to be interrupted. This detection circuit is extremely low cost and small in size, however, the disadvantage of using this solution is limited information about the progression of corrosion - it can only indicate the threshold point at which the continuity is broken and does not provide information about the progression of corrosion over time.

[0013] To enhance the capabilities of the fourth solution, multiple sensing elements can be used based on detecting loss of connection. However, it is crucial to ensure that they are damaged by the corrosion process at different times so that information about the loss of connection in subsequent sensing elements can be obtained and, based on the sequence, the corrosion progression of the protected device can be evaluated. The drawback of the discrete approach is the need to use metal films of different thicknesses, which increases manufacturing costs and limits the choice of available technologies.

[0014] It is an object of the present invention to provide a low cost corrosion sensor that provides comprehensive information about the atmospheric corrosion rate of electrical equipment operating in a corrosive environment. Summary of the invention

[0015] This object is achieved by a device according to claim 1 .

[0016] An atmosphere corrosion sensor for detecting corrosion of electrical equipment includes at least two atmosphere corrosion sensing structures, which are placed on at least one insulating corrosion sensor substrate, wherein the corrosion sensing structures can enter the corrosive atmosphere. The atmosphere corrosion sensing structures have the same spatial dimensions, and each of the atmosphere corrosion sensing structures includes a corrodible material of different composition.

[0017] Due to the corrosion process, the continuity of the corrosion sensing structure will be damaged after a period of time, which depends on the composition of the corrodible material of the corrosion sensing structure. Since the composition of the corrodible material in each corrosion sensing structure is different, the time when the continuity is damaged is also different. By monitoring the status of all corrosion sensing structures, it is possible to detect how many of them have been affected by corrosion, and based on this information, it is possible to evaluate the corrosion rate that has affected the equipment monitored by the sensor.

[0018] In one preferred implementation of the preferred implementation of the present invention, each of the atmospheric corrosion sensing structures includes a corrodible material of the same chemical composition at a different concentration.

[0019] The atmospheric corrosion sensor includes at least two corrosion sensing structures of the same spatial size, but they have different concentrations of corrodible materials within the same volume. Due to this difference, the time required to produce discontinuity in each of the corrosion sensing structures due to the corrosion process is different. Since multiple corrosion sensing structures are used, each of these structures will corrode (lose its continuity - lose its internal connection) at a different time. By evaluating the state of each of these corrosion sensing structures (which means by knowing whether the internal connection exists), the severity of the corrosive environment in which the atmospheric corrosion sensor operates can be evaluated. This information can also be used to estimate the corrosion rate of assets operating in the same environment as the atmospheric corrosion sensor, thereby predicting the time when it reaches the end of its operating life due to the corrosion process, planning maintenance actions in advance, and reducing the cost of unplanned service actions taken due to unexpected failures.

[0020] In another preferred implementation of the present invention, each of the atmosphere corrosion sensing structures includes corrodible materials of different chemical compositions.

[0021] The atmospheric corrosion sensor comprises at least two corrosion sensing structures, each of which comprises a corrodible material of a different chemical composition, i.e., a different metal or a different alloy. Due to the corrosion process, the continuity of a single corrosion sensing structure may be damaged after a period of time, depending on the chemical composition of the corrodible material of the corrosion sensing structure. Since the type of corrodible material in each of the corrosion sensing structures is different, the time at which its continuity is damaged is also different. By monitoring the status of all corrosion sensing structures, it is possible to detect how many of them have been affected by corrosion, and based on this information, an assessment can be made of the corrosion rate that has affected the equipment monitored by the sensor.

[0022] Preferably, the corrodible material is a corrodible metal or metal alloy, in particular copper, aluminum, iron, zinc, nickel, silver, steel or brass.

[0023] Preferably, the corrosion sensing structure is made in the form of a thin film.

[0024] Preferably, each of the corrosion sensing structures is connected in series to a resistive component, respectively. In this case, the resistive component is embedded as a part of the atmospheric corrosion sensor.

[0025] The object of the present invention also includes a group of the atmosphere corrosion sensors and an electrical device for corrosion detection, which includes at least one atmosphere corrosion sensor or at least one group of atmosphere corrosion sensors.

[0026] Advantages of the invention

[0027] Atmospheric corrosion sensors allow multiple threshold levels to be set as required for a single sensor that includes multiple corrosion sensing structures. Due to the different chemical compositions of the corrodible materials, the time required to destroy the continuity of each corrosion sensing structure is also different. Atmospheric corrosion allows for the assessment of when the corrosion rate reaches some threshold indicated by the moment when the internal connection of the sensing element is lost.

[0028] The atmospheric corrosion sensor according to the present invention allows estimation of the corrosion rate of electronic and electrical equipment operating in the same environment as the corrosion sensor.

[0029] Furthermore, the atmosphere corrosion sensor according to the present invention allows the service life of electronic and electrical equipment in a specific environment to be predicted, and service and maintenance actions to be planned in advance to prevent fatal failures and equipment downtime, and reduce the cost of unplanned service actions due to unexpected failures.

[0030] Furthermore, the atmosphere corrosion sensor according to the present invention is small in size, easy to implement in monitored electronic and electrical equipment, and has low production cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The object of the present invention is illustrated in the embodiment shown in the accompanying drawings, wherein

[0032] Figure 1 An atmospheric corrosion sensor implemented as part of a resistive voltage divider connected to a high potential according to the present invention is presented;

[0033] Figure 2 An atmospheric corrosion sensor implemented as part of a resistive voltage divider connected to a low potential according to the present invention is presented;

[0034] Figure 3 An atmospheric corrosion sensor placed between an output in a high state and an input with a pull-down according to the present invention is presented;

[0035] Figure 4 An atmospheric corrosion sensor placed between an output in a low state and an input with a pull-up according to the present invention is presented;

[0036] Figure 5 An atmospheric corrosion sensor placed between a single output in a high state and an input with a pull-down is presented according to the present invention;

[0037] Figure 6 An atmospheric corrosion sensor placed between a single output in a low state and an input with a pull-up according to the present invention is presented;

[0038] Figure 7 An atmospheric corrosion sensor placed between a high potential and an input with a pull-down according to the present invention is presented;

[0039] Figure 8 An atmospheric corrosion sensor placed between a low potential and an input with a pull-up according to the invention is presented;

[0040] Fig. 9 An oscillator feedback network including an atmospheric corrosion sensor according to the present invention is presented;

[0041] Fig.10 An example of a Schmitt inverter-based RC oscillator including an atmospheric corrosion sensor according to the present invention is presented;

[0042] Fig.11 Presents example output frequency changes due to corrosion of a corrosion sensing structure of an atmospheric corrosion sensor according to the present invention incorporating a Schmidt inverter based RC oscillator;

[0043] Fig.12 An example of a logic inverter-based Colpitts oscillator including an atmospheric corrosion sensor according to the present invention is presented;

[0044] Fig.13 Presents example output frequency changes due to corrosion of the corrosion sensing structure of an atmospheric corrosion sensor according to the present invention incorporating a logic inverter-based Colpitts oscillator;

[0045] Fig.14 An example of an LM555-based oscillator with output frequency as a function of the resistance of the corrosion sensing structure of the atmospheric corrosion sensor according to the present invention in parallel with R1 is presented;

[0046] Fig.15 An example of an LM555-based oscillator with output frequency as a function of the resistance of the corrosion sensing structure of the atmospheric corrosion sensor according to the present invention in parallel with R2 is presented;

[0047] Fig.16 An example of a circuit of a current source controlled by the resistance of a corrosion sensing structure of an atmospheric corrosion sensor according to the present invention is presented;

[0048] Fig.17 Another example of a circuit of a current source controlled by the resistance of the corrosion sensing structure of the atmospheric corrosion sensor according to the present invention is presented;

[0049] Fig.18 A scheme of a measuring system with a distributed atmosphere corrosion sensor and a common measuring unit according to the invention is presented;

[0050] Fig.19 A scheme of a measuring system with a distributed atmospheric corrosion sensor according to the invention and a common measuring unit capable of demodulating signals from different sources is presented;

[0051] Fig. 20 An example of a circuit for a current sink that outputs current as a function of the resistance of a corrosion sensing structure of an atmospheric corrosion sensor according to the present invention is presented;

[0052] Fig.21 An example of a circuit of a current source that outputs current as a function of the resistance of a corrosion sensing structure of an atmospheric corrosion sensor according to the present invention is presented;

[0053] Fig. 22 An example of a narrow bandpass filter whose center frequency is controlled by an atmospheric corrosion sensor according to the present invention is presented;

[0054] Fig.23 A measuring circuit based on a filter of a corrosion sensor according to the invention is presented;

[0055] Fig.24 An example of a narrow bandpass filter having a very high quality factor and a center frequency controlled by a corrosive atmosphere corrosion sensor according to the present invention is presented;

[0056] Fig.25 A scheme of a measuring system with distributed narrowband filters and a common measuring unit controlled by an atmospheric corrosion sensor according to the invention is presented;

[0057] Fig.26 A narrow bandpass filter is presented with a center frequency as a function of the resistance of the corrosion sensing structure of the atmospheric corrosion sensor according to the present invention;

[0058] Fig. 27 A narrow bandpass filter with a very high quality factor and a center frequency as a function of the resistance of the corrosion sensing structure of the atmospheric corrosion sensor according to the present invention is presented. DETAILED DESCRIPTION

[0059] Example 1

[0060] Figure 1 An example circuit according to the present invention comprising a resistor divider of an atmospheric corrosion sensor 1 connected to a high potential is shown.

[0061] An atmosphere corrosion sensor 1 for detecting corrosion of electrical equipment includes three atmosphere corrosion sensing structures Rs1, Rs2, Rs3 in the form of thin films, which are placed on an insulating corrosion sensor substrate. However, other structures of the corrosion sensing structure 2 are also possible, for example, a metal plate. The corrosion sensing structures Rs1, Rs2, Rs3 can enter a corrosive environment. The atmosphere corrosion sensing structures Rs1, Rs2, Rs3 have the same spatial dimensions, however, each of the atmosphere corrosion sensing structures Rs1, Rs2, Rs3 includes a copper alloy with a different copper concentration. In other embodiments, the corrosion sensing structure may include other corrodible metal alloys, in particular alloys of aluminum, iron, zinc, nickel, silver, tin (preferably steel and brass).

[0062] Since the copper concentration in each of the corrosion sensing structures Rs1, Rs2, Rs3 is different, the time required for discontinuity to occur in each of them due to the corrosion process is also different. Each of them will lose continuity (internal connection) at a different time, and by evaluating the state of each of the corrosion sensing structures Rs1, Rs2, Rs3 (which means by knowing whether the internal connection exists), the severity of the corrosive environment in which the corrosion sensor operates can be evaluated. This information can also be used to estimate the corrosion rate of assets operating in the same environment as corrosion sensor 1, allowing the prediction of the time when it will reach the end of its operating life due to the corrosion process, planning maintenance actions in advance, and reducing the cost of unplanned service actions due to unexpected failures.

[0063] In this example, each of the corrosion sensing structures Rs1 , Rs2 , Rs3 acts as a resistor of smaller value.

[0064] If the resistance of the corrosion sensing structure Rs1, Rs2, Rs3 in each of the branches is much smaller than the resistance of the resistance component R1, R2, R3 connected to the low potential, and the corrosion sensing structure Rs1, Rs2, Rs3 is not affected by corrosion, the voltage at the output of the voltage divider is close to the high potential. Once the continuity of the corrosion sensing structure Rs1, Rs2, Rs3 is lost, the resistors R1, R2, R3 connected to the low potential cause the monitoring block to recognize the low state on its input, thereby detecting damage to the corresponding corrosion sensing structure located in its branch. Knowing the status of all branches, the corrosion rate of the protected equipment can be evaluated.

[0065] Information about each of the inputs to the monitoring block can be combined, for example, as a single digital word where each bit provides information about a corresponding input - this allows information compression while enabling easy assessment of the state of each of the corrosion sensing structures and the state of a combination of them, which corresponds to the progression of corrosion on each of the corrosion sensing structures and can be converted into information about corrosion rates reaching multiple thresholds.

[0066] In other embodiments of the atmosphere corrosion sensor 1 according to the present invention, the resistance components R1, R2, R3 (eg, resistors) may be connected in series with the corresponding corrosion sensing structures Rs1, Rs2, Rs3 and embedded in the atmosphere corrosion sensor.

[0067] Example 2

[0068] The difference of the atmosphere corrosion sensor 1 for detecting corrosion of electrical equipment as described in Example 1 is that each of the atmosphere corrosion sensing structures Rs1, Rs2, and Rs3 includes a different corrodible material. The corrosion sensing structure Rs1 is made of silver, Rs2 is made of copper, and Rs3 is made of tin. In other embodiments, other combinations of corrodible materials can be used, in particular corrodible metals, metal alloys, preferably aluminum, iron, zinc, nickel, silver, steel or brass.

[0069] If the resistor divider ( Figure 1) The resistance of the corrosion sensing structure Rs1, Rs2, Rs3 in each branch of the circuit of the present invention is much smaller than the resistance of the resistance component R1, R2, R3 connected to the low potential, and the corrosion sensing structure Rs1, Rs2, Rs3 is not affected by corrosion, then the voltage at the output of the resistor divider is close to the high potential. Once the continuity of the corrosion sensing structure Rs1, Rs2, Rs3 is lost, the resistors R1, R2, R3 connected to the low potential will cause the monitoring block to recognize the low state on its input, thereby detecting the damage of the corresponding corrosion sensing structure located in its branch. Knowing the status of all branches, the corrosion rate of the protected equipment can be evaluated.

[0070] Because the chemical composition in each of the corrosion sensing structures Rs1, Rs2, Rs3 is different, the time required for discontinuity to occur in each of them due to the corrosion process is also different. Each of them will lose continuity (internal connection) at a different time, and by evaluating the state of each of the corrosion sensing structures Rs1, Rs2, Rs3 (which means by knowing whether the internal connection exists), the severity of the corrosive environment in which the corrosion sensor operates can be evaluated. This information can also be used to estimate the corrosion rate of assets operating in the same environment as corrosion sensor 1, thus allowing the prediction of the time when it will reach the end of its operating life due to the corrosion process, planning maintenance actions in advance, and reducing the cost of unplanned service actions due to unexpected failures.

[0071] Information about each of the inputs to the monitoring block can be combined, for example, as a single digital word where each bit provides information about a corresponding input - this allows information compression while enabling easy assessment of the state of each of the corrosion sensing structures and the state of a combination of them, which corresponds to the progression of corrosion on each of the corrosion sensing structures and can be converted into information about corrosion rates reaching multiple thresholds.

[0072] In other embodiments of the atmosphere corrosion sensor 1 according to the present invention, the resistance components R1, R2, R3 (eg, resistors) may be connected in series with the corresponding corrosion sensing structures Rs1, Rs2, Rs3 and embedded in the atmosphere corrosion sensor.

[0073] Example 3

[0074] Figure 2 An example circuit including a resistor divider connected to a lower potential of an atmosphere corrosion sensor 1 according to the present invention is shown. The atmosphere corrosion sensor 1 for detecting corrosion of electrical equipment includes three atmosphere corrosion sensing structures Rs1, Rs2, Rs3 as described in Embodiment 1 or 2.

[0075] In this example, the corrosion sensing structures Rs1, Rs2, Rs3 are connected to a lower potential, while the resistive components R1, R2, R3 of each resistor divider segment are connected to a high potential. If the resistance of the corrosion sensing structures Rs1, Rs2, Rs3 is much smaller than the resistance of the resistors R1, R2, R3 connected to a high potential, the monitoring block can first see a low state on its input, and once the corrosion sensing components Rs1, Rs2, Rs3 are affected by corrosion and lose their internal connections, the monitoring device will enter a high state on the corresponding input, thereby recognizing that the corresponding corrosion sensing structures Rs1, Rs2, Rs3 have been damaged due to corrosion. Knowing the status of all branches, it is possible to assess the severity of the corrosive environment in which the corrosion sensor operates; this information can also be used to estimate the corrosion rate of assets operating in the same environment as the corrosion sensor, thereby predicting the time when it will reach the end of its operating life due to the corrosion process, planning maintenance actions in advance, and reducing the cost of unplanned service actions due to unexpected failures.

[0076] Information about each of the inputs to the monitoring block can be combined, for example, as a single digital word where each bit provides information about a corresponding input - this allows information compression while enabling easy assessment of the state of each of the corrosion sensing structures and the state of a combination of them, which corresponds to the progression of corrosion on each of the corrosion sensing structures and can be converted into information about corrosion rates reaching multiple thresholds.

[0077] Example 4

[0078] Figure 3 An example circuit is shown, which includes an atmosphere corrosion sensor 1 for detecting corrosion of electrical equipment. The atmosphere corrosion sensor 1 includes three atmosphere corrosion sensing structures Rs1, Rs2, and Rs3 as described in Example 1 or 2.

[0079] The corrosion sensing structures Rs1, Rs2, Rs3 of the atmosphere corrosion sensor 1 according to the present invention are connected between the dedicated output and input of the monitoring block. The output of the monitoring block has a default high state, and the input is equipped with an internal pull-down circuit (i.e., a resistor or a transistor). As long as the corrosion sensing structures Rs1, Rs2, Rs3 maintain continuity internally, the state on the input is high, and once the continuity of the corrosion sensing structures Rs1, Rs2, Rs3 is broken due to corrosion, it switches to a low state.

[0080] Knowing the status of all inputs allows the severity of the corrosive environment in which the corrosion sensor operates to be assessed; this information can also be used to estimate the corrosion rate of assets operating in the same environment as the corrosion sensor, thereby predicting when they will reach the end of their operating life due to the corrosion process, planning maintenance actions in advance, and reducing the cost of unplanned service actions due to unexpected failures.

[0081] Information about each of the inputs to the monitoring block can be combined, for example, as a single digital word where each bit provides information about a corresponding input - this allows information compression while enabling easy assessment of the state of each of the corrosion sensing structures and the state of a combination of them, which corresponds to the progression of corrosion on each of the corrosion sensing structures and can be converted into information about corrosion rates reaching multiple thresholds.

[0082] Example 5

[0083] Figure 4 An example circuit is shown, which includes an atmosphere corrosion sensor 1 for detecting corrosion of electrical equipment. The atmosphere corrosion sensor 1 includes three atmosphere corrosion sensing structures Rs1, Rs2, and Rs3 as described in Example 1 or 2.

[0084] The corrosion sensing structures Rs1, Rs2, Rs3 of the atmosphere corrosion sensor 1 according to the present invention are connected between the dedicated output and input of the monitoring block. The output of the monitoring block has a default low state, and the input is equipped with an internal pull-up circuit. As long as the corrosion sensing structures Rs1, Rs2, Rs3 maintain continuity internally, the state on the input will be low, and once the continuity of the corrosion sensing structures Rs1, Rs2, Rs3 is broken due to corrosion, it will switch to a high state.

[0085] Knowing the status of all inputs allows the severity of the corrosive environment in which the corrosion sensor operates to be assessed; this information can also be used to estimate the corrosion rate of assets operating in the same environment as the corrosion sensor, thereby predicting when they will reach the end of their operating life due to the corrosion process, planning maintenance actions in advance, and reducing the cost of unplanned service actions due to unexpected failures.

[0086] Information about each of the inputs to the monitoring block can be combined, for example, as a single digital word where each bit provides information about a corresponding input - this allows information compression while enabling easy assessment of the state of each of the corrosion sensing structures and the state of a combination of them, which corresponds to the progression of corrosion on each of the corrosion sensing structures and can be converted into information about corrosion rates reaching multiple thresholds.

[0087] Example 6

[0088] Figure 5 An example circuit is shown, which includes an atmosphere corrosion sensor 1 for detecting corrosion of electrical equipment. The atmosphere corrosion sensor 1 includes three atmosphere corrosion sensing structures Rs1, Rs2, and Rs3 as described in Example 1 or 2.

[0089] The corrosion sensing structures Rs1, Rs2, Rs3 of the atmosphere corrosion sensor 1 according to the present invention are connected between the common output and the dedicated input of the monitoring block. The output of the monitoring block has a default high state, and the input is equipped with an internal pull-down circuit. As long as the corrosion sensing structures Rs1, Rs2, Rs3 maintain continuity internally, the state on the input will be high, and once the continuity of the corrosion sensing structures Rs1, Rs2, Rs3 is destroyed due to corrosion, it will switch to a low state.

[0090] Knowing the status of all inputs allows the severity of the corrosive environment in which the corrosion sensor operates to be assessed; this information can also be used to estimate the corrosion rate of assets operating in the same environment as the corrosion sensor, thereby predicting when they will reach the end of their operating life due to the corrosion process, planning maintenance actions in advance, and reducing the cost of unplanned service actions due to unexpected failures.

[0091] Information about each of the inputs to the monitoring block can be combined, for example, as a single digital word where each bit provides information about a corresponding input - this allows information compression while enabling easy assessment of the state of each of the corrosion sensing structures and the state of a combination of them, which corresponds to the progression of corrosion on each of the corrosion sensing structures and can be converted into information about corrosion rates reaching multiple thresholds.

[0092] Example 7

[0093] Figure 6 An example circuit is shown, which includes an atmosphere corrosion sensor 1 for detecting corrosion of electrical equipment. The atmosphere corrosion sensor 1 includes three atmosphere corrosion sensing structures Rs1, Rs2, and Rs3 as described in Example 1 or 2.

[0094] The corrosion sensing structures Rs1, Rs2, Rs3 of the atmosphere corrosion sensor 1 according to the present invention are connected between the common output and the dedicated input of the monitoring block. The output of the monitoring block has a default low state, and the input is equipped with an internal pull-up circuit. As long as the corrosion sensing structures Rs1, Rs2, Rs3 maintain continuity internally, the state on the input will be low, and once the continuity of the corrosion sensing structures Rs1, Rs2, Rs3 is destroyed due to corrosion, it will switch to a high state.

[0095] Knowing the status of all inputs allows the severity of the corrosive environment in which the corrosion sensor operates to be assessed; this information can also be used to estimate the corrosion rate of assets operating in the same environment as the corrosion sensor, thereby predicting when they will reach the end of their operating life due to the corrosion process, planning maintenance actions in advance, and reducing the cost of unplanned service actions due to unexpected failures.

[0096] Information about each of the inputs to the monitoring block can be combined, for example, as a single digital word where each bit provides information about a corresponding input - this allows information compression while enabling easy assessment of the state of each of the corrosion sensing structures and the state of a combination of them, which corresponds to the progression of corrosion on each of the corrosion sensing structures and can be converted into information about corrosion rates reaching multiple thresholds.

[0097] Example 8

[0098] Figure 7 An example circuit is shown, which includes an atmosphere corrosion sensor 1 for detecting corrosion of electrical equipment. The atmosphere corrosion sensor 1 includes three atmosphere corrosion sensing structures Rs1, Rs2, and Rs3 as described in Example 1 or 2.

[0099] The corrosion sensing structures Rs1, Rs2, Rs3 of the atmospheric corrosion sensor 1 according to the present invention are connected between a stable high potential and a dedicated input of the monitoring block, wherein the input is equipped with an internal pull-down circuit. As long as the corrosion sensing structures Rs1, Rs2, Rs3 maintain continuity internally, the state on the input will be high, and once the continuity of the corrosion sensing structures Rs1, Rs2, Rs3 is broken due to corrosion, it will switch to a low state.

[0100] Knowing the status of all inputs allows the severity of the corrosive environment in which the corrosion sensor operates to be assessed; this information can also be used to estimate the corrosion rate of assets operating in the same environment as the corrosion sensor, thereby predicting when they will reach the end of their operating life due to the corrosion process, planning maintenance actions in advance, and reducing the cost of unplanned service actions due to unexpected failures.

[0101] Information about each of the inputs to the monitoring block can be combined, for example, as a single digital word where each bit provides information about a corresponding input - this allows information compression while enabling easy assessment of the state of each of the corrosion sensing structures and the state of a combination of them, which corresponds to the progression of corrosion on each of the corrosion sensing structures and can be converted into information about corrosion rates reaching multiple thresholds.

[0102] Example 9

[0103] Figure 8 An example circuit is shown, which includes an atmosphere corrosion sensor 1 for detecting corrosion of electrical equipment. The atmosphere corrosion sensor 1 includes three atmosphere corrosion sensing structures Rs1, Rs2, and Rs3 as described in Example 1 or 2.

[0104] The corrosion sensing structures Rs1, Rs2, Rs3 of the atmosphere corrosion sensor 1 according to the present invention are connected between a stable low potential and a dedicated input of the monitoring block, wherein the input is equipped with an internal pull-up circuit. As long as the corrosion sensing structures Rs1, Rs2, Rs3 maintain continuity internally, the state on the input will be low, and once the continuity of the corrosion sensing structures Rs1, Rs2, Rs3 is broken due to corrosion, it will switch to a high state.

[0105] Knowing the status of all inputs allows the severity of the corrosive environment in which the corrosion sensor operates to be assessed; this information can also be used to estimate the corrosion rate of assets operating in the same environment as the corrosion sensor, thereby predicting when they will reach the end of their operating life due to the corrosion process, planning maintenance actions in advance, and reducing the cost of unplanned service actions due to unexpected failures.

[0106] Information about each of the inputs to the monitoring block can be combined, for example, as a single digital word where each bit provides information about a corresponding input - this allows information compression while enabling easy assessment of the state of each of the corrosion sensing structures and the state of a combination of them, which corresponds to the progression of corrosion on each of the corrosion sensing structures and can be converted into information about corrosion rates reaching multiple thresholds.

[0107] Example 10

[0108] An oscillator circuit for corrosion detection includes an atmosphere corrosion sensor 1 for detecting corrosion of electrical equipment. The atmosphere corrosion sensor 1 includes a plurality of corrosion sensing structures as described in Embodiment 1 or 2. Fig. 9 Marked as F n The corrosion sensing structure is connected to multiple reactive components (R-resistor, C-capacitor, L-inductor) of the oscillator circuit and forms part of the oscillator feedback network.

[0109] The corrosion sensing structure F of the atmosphere corrosion sensor 1 n Once the corrosion sensing structure F is exposed to a corrosive atmosphere, the reactive components are disconnected from the oscillator circuit. n The electrical continuity of the oscillator is destroyed due to corrosion, and the output frequency f owill change because the topology of its feedback network will also change.

[0110] First, all corrosion sensing structures F n Both provide electrical continuity, so they can be represented by a short circuit. Due to the corrosion process, the structures will degrade until their continuity is broken. In this case, they can be represented by an open circuit. The corrosion sensing structures have the same spatial dimensions but different compositions of the corrodible material, so the time required to destroy each structure due to corrosion is also different.

[0111] Two implementations of an oscillator including an atmospheric corrosion sensor 1 are proposed, wherein the corrosion sensing structure is composed of Figures 9 to 13 The fuse symbol F in the diagram represents.

[0112] First is the well-known RC oscillator based on a single Schmitt trigger inverter gate, such as Fig.10 It uses a single resistor R and multiple capacitors in the feedback network. Capacitor C0 is permanently connected to the inverter input and when the corrosion sensing structures F1, F2, F3, ..., F n When the electrical continuity of capacitors C1, C2, C3, ..., C n Will also be cut off.

[0113] The output frequency of the oscillator is f o This can be calculated using the following formulas [1], [2]:

[0114]

[0115] C=C0+δ1C1+δ2C2+δ3C3+…+δ n C n [2]

[0116]

[0117] Where: Vc c is the supply voltage of the Schmitt inverter, V T- and V T+ are the negative going input threshold voltage and the positive going input threshold voltage.

[0118] Since the output frequency f o It is inversely proportional to the feedback capacitance, so once the fuse starts cutting out the capacitor, it will gradually increase. Fig.11 An example output frequency change over time due to corrosion of the sensing structure is depicted. Assuming capacitors C0, ..., C nhave the same value. The output frequency is an indicator of ongoing corrosion and can be measured by a frequency counter, which is easily implemented in most programmable logic devices and microcontrollers used today.

[0119] The second implementation is an example of a well-known Colpitts oscillator based on the gates of logic inverters, such as Fig.12 The feedback network includes two capacitors C1 and C2, which are connected to the input and output of the gate, respectively. The path between the input and output of the gate is closed by a number of inductors connected in series. Inductor L0 is permanently connected, while inductors L1, L2, L3, ..., L n By corrosion sensing structures F1, F2, F3, ..., F n Once the corrosion sensing structure F i If it is destroyed, the inductance of Li will be added to the total feedback inductance of the oscillator.

[0120] The output frequency of the oscillator is f o This can be calculated using the following formulas [3], [4]:

[0121]

[0122] L=L0+δ1L1+δ2L2+δ3L3+…+δ n L n [4]

[0123]

[0124] Since the output frequency is inversely proportional to the square root of the feedback inductance, once the fuse F i As the inductance starts to increase, the output frequency will gradually decrease. Fig.13 Depicts an example output frequency change over time due to corrosion of the sensing structure. Assuming L0, ..., L n Same as the previous implementation example, the output frequency f o is an indicator of ongoing corrosion and can be measured by a frequency counter, which is easily implemented in most programmable logic devices and microcontrollers used today.

[0125] Embodiment 11

[0126] An oscillator circuit for corrosion detection of an integrated circuit with an LM555 timer includes an atmosphere corrosion sensor 1 as described in Embodiment 1 or 2, wherein the atmosphere corrosion sensor 1 includes a plurality of corrosion sensing structures.

[0127] Two implementations of an oscillator of an integrated circuit including an atmospheric corrosion sensor 1 with an LM555 timer are proposed, wherein the corrosion sensing structures Rs1 to RsN are composed of Figure 14 to Figure 15 Fuse symbol F1......F N express.

[0128] according to Fig.14 The first implementation presented, with multiple resistors R P1 To R PN The corrosion sensing structure F1 of the atmosphere corrosion sensor 1 connected in series N The arrangement is connected in parallel with the resistor R1.

[0129] The equivalent resistance is given by the following formula [5]:

[0130]

[0131] The output frequency of the oscillator is f o It can be calculated as follows[6]:

[0132]

[0133] It can be seen that the output frequency f is inversely proportional to the equivalent resistance R1' o It will gradually decrease as corrosion progresses.

[0134] according to Fig.15 The second implementation of the embodiment 11 is presented, with the resistor R P1 ......R PN Corrosion sensing structures F1......F connected in series N The arrangement is connected in parallel with resistor R2. The equivalent resistance is given by the following formula [7]:

[0135]

[0136] The output frequency of the oscillator is f o It can be calculated as follows[8]:

[0137]

[0138] It can be seen that the output frequency f is inversely proportional to the equivalent resistance R2' o It will gradually decrease as corrosion progresses.

[0139] Example 12

[0140] A circuit of a current source includes a sensing element R_sens in the form of an atmosphere corrosion sensor 1, wherein the atmosphere corrosion sensor 1 includes a plurality of corrosion sensing structures as described in Embodiment 1 or 2.

[0141] The corrosion sensing structure of the sensing element R_sens controls the current I_set of the current source. The resistance of the corrosion element R_sens is used to set the value of the current source I_set, so the current at the output of the source changes with the resistance of the sensing element R_sens. The changed resistance is reflected in the change of the output current of the current source controlled by the corrosion sensing structure.

[0142] An additional resistor R_limit may be used in series with the sensing element R_sens so that the current can be limited to a reasonable value even if the resistance of the sensing element R_sens is very small.

[0143] Two implementations of this circuit are proposed.

[0144] Fig.16 The first implementation presented in discloses a circuit with a fixed power supply Vdd and a fixed value of the control voltage Vin.

[0145] The output current value I_set can be calculated using the following formula [9]:

[0146]

[0147] The voltage output Vout across the load resistor R_load can also be calculated using the following formula

[10] :

[0148]

[0149] Fig.17 Another example of an implementation is presented.

[0150] The output current value I_set can be calculated using the following formula

[11] :

[0151]

[0152] The voltage output Vout across the load resistor R_load can also be calculated using the following formula

[12] :

[0153]

[0154] Furthermore, since the output signal of the current source is not affected by the length of the wire, it is possible to combine many such circuits including a current source in the form of the sensing element R_sens of the atmosphere corrosion sensor 1 with a single measurement unit (e.g., a measurement card accepting a signal range of 4 mA to 20 mA) capable of measuring the current generated by a single source. In this way, a measurement system with distributed sensors and a common measurement unit can be constructed, such as Fig.18 shown.

[0155] Furthermore, such a circuit including a current source in the form of a sensing element R_sens of the atmospheric corrosion sensor 1 can be connected together and a modulation is applied to each Vin signal with a different carrier frequency. In this case, the measurement unit can demodulate and extract the corrosion data from the combined signal, so there is no need to use a source selection module such as Fig.19 shown.

[0156] Example 13

[0157] This embodiment relates to a current sink circuit, including the atmosphere corrosion sensor 1 according to embodiment 1 or 2. The corrosion sensing structures Rs1 to RsN of the atmosphere corrosion sensor 1 are as follows: Fig. 20 The form of the resistor presented. Emitter resistor R E connected in parallel with the arrangement of corrosion sensing structures Rs1 to RsN, which are arranged with fixed resistors R P1 ......R PN Series connection.

[0158] In this case, the corrosion sensing structures Rs1 to RsN of the atmosphere corrosion sensor 1 are intended to function as electronic fuses that show a very low resistance in an initial state and a very high resistance after being corroded.

[0159] The equivalent resistance of the network can be expressed by the following formula

[13] :

[0160]

[0161] Output current I OUT This can be calculated using the following formula

[14] :

[0162]

[0163] Where: V REF It is the voltage reference of the current source and can set the initial current as needed.

[0164] With the equivalent resistance R E The inversely proportional output current will gradually decrease as corrosion progresses.

[0165] Embodiment 14

[0166] This embodiment relates to a current source circuit, including the atmosphere corrosion sensor 1 according to embodiment 1 or 2. Fig.21 Presented are corrosion sensing structures Rs1 to RsN of an atmospheric corrosion sensor 1 in the form of resistors. Econnected in parallel with the arrangement of corrosion sensing structures Rs1 to RsN, which are arranged with fixed resistors R P1 ......R PN Series connection.

[0167] In this case, the corrosion sensing structures Rs1 to RsN of the atmosphere corrosion sensor 1 are intended to function as electronic fuses that show a very low resistance in an initial state and a very high resistance after being corroded.

[0168] The equivalent resistance of the network can be expressed by the following formula

[15] :

[0169]

[0170] Output current I OUT This can be calculated using the following formula

[16] :

[0171]

[0172] Where: V REF It is the voltage reference of the current source and can set the initial current as needed.

[0173] With the equivalent resistance R E The inversely proportional output current will gradually decrease as corrosion progresses.

[0174] Embodiment 15

[0175] The present embodiment relates to a narrow band pass filter, comprising an atmosphere corrosion sensor 1 as described in Embodiment 1 or 2. The corrosion sensing structure is used to control the center frequency of the narrow band pass filter. The resistance of the corrosion sensing structure is used to set the center frequency of the narrow band pass filter. Therefore, the center frequency of the filter changes due to the change of the resistance of the atmosphere corrosion sensor 1.

[0176] Fig. 22 A multi-feedback narrow bandpass filter is presented. The corrosion sensing structure of the atmosphere corrosion sensor 1 (in Fig. 22 In the figure, Rs is represented as Rs) and is connected in series with R2.

[0177] The center frequency is given by the following formula

[17] :

[0178]

[0179] The sensing element can also be connected in series with R1 or R5, and then the above equations should be changed appropriately.

[0180] In order to check the center frequency of the narrow bandpass filter controlled by the corrosion sensor 1, signals of various frequencies must be generated and passed through the filter. The control unit, knowing the transmission frequency and amplitude of the signal received by the detector, can calculate the change in the resistance of the sensing element and, on this basis, provide information about the progress of corrosion. Fig.23 A measurement circuit for a filter based corrosion sensor 1 is presented.

[0181] like Fig. 22 The quality factor of a single-stage filter such as the one presented is usually below 20, so its passband may be too wide. To make the filter characteristics narrower, it can be modified by adding a second operational amplifier, such as Fig.24 As shown, this can increase the quality factor (Q) to several hundred, thereby enabling narrower bandwidths.

[0182] Furthermore, it is also possible to combine many filter-based sensors with a single measurement unit that can measure the frequency response of a single filter. This allows the construction of measurement systems with distributed sensors and a common measurement unit, such as Fig.25 shown.

[0183] Example 16

[0184] This embodiment relates to a narrow band pass filter, comprising the atmosphere corrosion sensor 1 according to embodiment 1 or 2. Corrosion sensing structure R of atmosphere corrosion S1 ......R SN Present Fig.26 The resistor R S1 ......R SN The narrow bandpass filter circuit includes a corrosion sensing structure R S1 ......R SN The arrangement connects the resistor R2 in parallel, the corrosion sensing structure R S1 ......R SN The arrangement of fixed resistors R P1 ......R PN Series connection.

[0185] In this case, the corrosion sensing structure R S1 ......R SN Intended to act as an electronic fuse that exhibits a very low resistance in its initial state and a very high resistance after being corroded.

[0186] The equivalent resistance of the network can be expressed by the following formula

[18] :

[0187]

[0188] The center frequency of the filter is f o It is given by the following equation

[19] :

[0189]

[0190] Depends on the center frequency f of R2' o It will gradually decrease as corrosion progresses.

[0191] Similar corrosion sensing structure networks can also be incorporated into high quality factor narrow bandpass filter circuits to obtain narrower frequency responses, such as Fig. 27 The center frequency of the filter depends on the equivalent resistance of the corrosion sensing structure network and will gradually change as the corrosion progresses.

Claims

1. An atmosphere corrosion sensor (1) for detecting corrosion of electrical equipment, the atmosphere corrosion sensor (1) comprising at least two atmosphere corrosion sensing structures (Rs1, Rs2, Rs3), at least two of the atmosphere corrosion sensing structures (Rs1, Rs2, Rs3) being placed on at least one insulating corrosion sensor substrate, wherein the corrosion sensing structures (Rs1, Rs2, Rs3) are capable of entering a corrosive atmosphere, and characterized in that: The atmosphere corrosion sensing structures (Rs1, Rs2, Rs3) have the same spatial size, and each of the atmosphere corrosion sensing structures (Rs1, Rs2, Rs3) includes a corrodible material of a different composition.

2. The atmosphere corrosion sensor (1) according to claim 1, characterized in that: Each of the atmosphere corrosion sensing structures ( Rs1 , Rs2 , Rs3 ) includes a corrodible material of the same chemical composition at a different concentration.

3. The atmosphere corrosion sensor (1) according to claim 1, characterized in that: Each of the atmosphere corrosion sensing structures ( Rs1 , Rs2 , Rs3 ) includes corrodible materials of different chemical compositions.

4. The atmosphere corrosion sensor according to any one of the preceding claims, characterized in that Corrodible materials are corrodible metals or metal alloys, in particular copper, aluminum, iron, zinc, nickel, silver, tin, steel or brass.

5. The atmosphere corrosion sensor according to any one of the preceding claims, characterized in that The corrosion sensing structures (Rs1, Rs2, Rs3) are made in thin film form.

6. The atmosphere corrosion sensor according to any one of the preceding claims, characterized in that Each of the corrosion sensing structures (Rs1, Rs2, Rs3) is connected in series with a resistance component (R1, R2, R3), respectively.

7. A set of atmospheric corrosion sensors (1) according to any one of claims 1 to 6.

8. An electrical device for corrosion detection, comprising at least one of the following: an atmosphere corrosion sensor (1) according to any one of claims 1 to 6 or at least one group of atmosphere corrosion sensors (1) according to claim 7.

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