Corrosion Environment Monitoring System and Corrosion Environment Monitoring Method

Abstract

A laminate is prepared, comprising an insulating plate, a base metal film formed on the insulating plate, and a sensing metal film. The sensing metal film is formed on at least a portion of the base metal film and is more susceptible to corrosion by corrosive substances and has a lower resistivity than the base metal film. A corrosion environment monitoring sensor is configured with a frame containing the laminate, having an opening in the lateral direction, and having a gas channel for forming corrosive substances internally. The resistance between two points on the base metal film of the sensor is detected, and the type of corrosive substance is determined based on the change in resistance over time.

Description

Technical Field

[0001] This invention relates to a corrosive environment monitoring system and a corrosive environment monitoring method. Background Technology

[0002] In social infrastructure such as power systems, sewers, and factories, the shutdown of machinery due to malfunctions can impact social activities, thus requiring stable operation of these facilities. In particular, for facilities operating in highly corrosive environments, ensuring the corrosion resistance of both the facility itself and attached electronic equipment such as information and control systems is crucial.

[0003] Appropriate anti-corrosion measures have been implemented in electronic equipment attached to facilities expected to suffer corrosion damage, but the actual results are minimal. In facilities with inadequate anti-corrosion measures, new corrosion damage may occur. In such facilities, it is effective to measure and diagnose the local environment in order to implement appropriate anti-corrosion measures, and it is desirable to continuously monitor the corrosive environment using devices that monitor environmental corrosivity over a long period.

[0004] Previously, as a monitoring device for corrosive environments used in this purpose, the configuration described in Patent Document 1 has been proposed.

[0005] Patent Document 1 discloses a sensor for monitoring a corrosive environment, which includes a first thin-film metal that is not easily corroded by corrosive gases and a second thin-film metal that is easily corroded, within a frame having an opening on one side and sealing the side other than the opening.

[0006] In the technology described in Patent Document 1, an external voltage or current is applied to the first metal thin film of the sensor, and the resistance change corresponding to the corrosion status of the second thin film metal is measured, thereby obtaining the generation status of corrosive substances in the environment.

[0007] Existing technical documents

[0008] Patent documents

[0009] Patent Document 1: WO2017 / 061182 Summary of the Invention

[0010] The corrosion environment monitoring device using the sensor described in Patent Document 1 can predict the degree of corrosion risk of components in information equipment and control equipment installed at the location where the sensor is installed, based on the resistance change corresponding to the corrosion status of the second thin film metal.

[0011] However, in the existing sensors described in Patent Document 1, even if it is known that corrosion occurs in the local environment, it is difficult to detect the type of gas that causes the corrosion.

[0012] Previously, to detect the types of gases causing corrosion, it was necessary to bring the gases back from the local environment (site) and analyze them using specialized equipment. This resulted in problems such as the need for programmers with specialized skills for gas analysis and a lengthy diagnostic process. For example, when the plant being tested was located overseas, transporting and analyzing the gases could sometimes take up to a month.

[0013] Therefore, there is a desire to quickly identify the types of gases produced in sensor-equipped environments and diagnose the corrosion risks caused by these corrosive gases remotely and without requiring special skills. However, while bringing analytical equipment for corrosive gases to the local area to identify the gas types could lead to a more accurate diagnosis of corrosion risks, it is impossible to bring such equipment to all kinds of environments. Therefore, accurately diagnosing corrosion risks remotely, such as overseas, is extremely difficult.

[0014] The goal is to develop a corrosion environment monitoring system and methods that can not only monitor the corrosivity of the environment but also diagnose the types of gases involved.

[0015] To address the aforementioned issues, the configuration described in the claims may be employed, for example.

[0016] This invention includes several means for solving the aforementioned problems, but as one example, it comprises a corrosion environment monitoring system: a corrosion environment monitoring sensor having a laminate and a frame, the laminate having an insulating plate, a base metal film formed on the insulating plate, and a sensing metal film formed on at least a portion of the base metal film, the sensing metal film being made of a metal that is more easily corroded by corrosive substances and has a lower resistance value than the base metal film; the frame housing the laminate having an opening in the lateral direction and forming a gas channel for corrosive substances inside; a resistance measuring unit that detects the resistance between two points on the base metal film of the corrosion environment monitoring sensor; and a judgment unit that determines the type of corrosive substance based on the change in resistance over time measured by the resistance measuring unit.

[0017] Invention Effects

[0018] According to the present invention, it is possible to determine the type of corrosive substance in the environment where the corrosion environment monitoring sensor is installed from the data measured using the corrosion environment monitoring sensor.

[0019] Therefore, the analytical work previously required to determine the type of corrosive substances, and the special skills required for such analysis, are no longer needed, thus reducing the time and cost spent on determining the type of corrosive substances in the environment.

[0020] Other issues, structures, and effects will become clear from the following description of the implementation methods. Attached Figure Description

[0021] Figure 1 This is a diagram illustrating the overall configuration of a corrosion environment monitoring system according to an embodiment of the present invention.

[0022] Figure 2 This is a top view showing an example (Example 1) of the configuration of a corrosion environment monitoring sensor according to an embodiment of the present invention.

[0023] Figure 3 This is a cross-sectional view along line AA of an example (Example 1) illustrating the configuration of a corrosion environment monitoring sensor according to an embodiment of the present invention.

[0024] Figure 4 This is a cross-sectional view along line BB, illustrating an example (Example 1) of the configuration of a corrosion environment monitoring sensor according to an embodiment of the present invention.

[0025] Figure 5 This is a top view showing an example (Example 2) of the configuration of a corrosion environment monitoring sensor according to an embodiment of the present invention.

[0026] Figure 6 This is a cross-sectional view along line CC of an example (Example 2) illustrating the configuration of a corrosion environment monitoring sensor according to an embodiment of the present invention.

[0027] Figure 7 This is a cross-sectional view along line DD showing an example (Example 2) of the configuration of a corrosion environment monitoring sensor according to an embodiment of the present invention.

[0028] Figure 8 This is a diagram illustrating the principle of how the resistance of a corrosion environment monitoring sensor changes due to corrosion, according to one embodiment of the present invention.

[0029] Figure 9 This is a graph illustrating an example of how the resistance of a corrosion environment monitoring sensor varies with gas concentration, according to one embodiment of the present invention.

[0030] Figure 10 This is a graph illustrating an example of how the resistance of a corrosive environment monitoring sensor varies depending on the corrosive substance, according to one embodiment of the present invention.

[0031] Figure 11 This is a diagram illustrating an analytical example of the resistance of a corrosion environment monitoring sensor according to an embodiment of the present invention.

[0032] Figure 12 This is a flowchart illustrating an example of the processing flow of a corrosion environment monitoring system according to an embodiment of the present invention. Detailed Implementation

[0033] Hereinafter, an embodiment of the present invention (hereinafter referred to as "this example") will be described with reference to the accompanying drawings.

[0034] <System Composition>

[0035] Figure 1 This illustrates the overall structure of the corrosion environment monitoring system 100 in this example.

[0036] Figure 1 The example shown is the use of a corrosion environment monitoring system 100 to measure the environment within a factory where a plant facility 101 is installed. Specifically, the plant facility 101 is configured to operate under the control of a control device 102. Furthermore, a corrosion environment monitoring sensor 1 and a corrosion environment monitoring device 110 connected to the control device 102 are installed within the factory.

[0037] The corrosion environment monitoring device 110 and the control device 102 are connected to the monitoring center 120 via network N. The monitoring center 120 is equipped with a display device 121, which displays the monitoring status of the corrosion environment, which is the environment within the factory, and the operating status of the factory facilities 101.

[0038] The corrosion environment monitoring device 110 includes a resistance value measuring unit 111, a judgment unit 112, and a storage unit 113.

[0039] The resistance measurement unit 111 measures the resistance of the substrate metal thin film 2 disposed on the corrosive environment monitoring sensor 1. Figure 3 as well as Figure 4 The resistance value of the ) was measured.

[0040] The judgment unit 112 determines the condition of the corrosive environment and the type of gas that is a corrosive substance based on the change in resistance value measured by the resistance value measuring unit 111.

[0041] The storage unit 113 stores the changes in resistance values ​​measured by the resistance value measuring unit 111. In addition, the storage unit 113 also stores information indicating the relationship between the changes in resistance values ​​and the corrosion thickness.

[0042] Information that shows the relationship between the change in resistance value and the amount of corrosion is called calibration curve data. In this example, the information of the calibration curve is stored in the storage unit 113 for multiple corrosive substances.

[0043] In this way, information regarding the gas type and corrosive environment condition determined by the judgment unit 112 within the corrosion environment monitoring device 110 is stored in the storage unit 113. Furthermore, the information regarding the gas type and corrosive environment condition stored in the storage unit 113 is transmitted via network N to the monitoring center 120 and displayed on the display device 121 within the monitoring center 120. Additionally, the corrosion environment monitoring device 110 can also display the gas type and corrosive environment condition.

[0044] <Composition of Corrosive Environment Monitoring Sensors>

[0045] Figure 2 This is a top view illustrating the configuration of the corrosion environment monitoring sensor 1 in this example (Example 1). Figure 2 In the top view, the frame 6 on the upper side of the substrate 5 is shown with virtual lines.

[0046] Figure 3 It is along Figure 2 A cross-sectional view along line AA.

[0047] Figure 4 It is along Figure 2 A cross-sectional view of the BB line.

[0048] In the corrosion environment monitoring sensor 1, a base metal film 2 is disposed on a horizontally elongated substrate 5 with an insulating plate 4 in between, and a sensing metal film 3 is disposed over the entire area of ​​the base metal film 2 as a support member.

[0049] Corrosive gas 10 from Figure 2 The opening 7 on the left side of the horizontally elongated substrate 5 shown in the diagram flows into the corrosion environment monitoring sensor 1.

[0050] The base metal thin film 2 and the sensing metal thin film 3 are arranged in parallel along the long side of the substrate 5, and their ends near the opening 7 are connected together to form the character "コ".

[0051] The substrate metal film 2 is made of a material such as stainless steel or chromium that is less susceptible to corrosion than the inductive metal film 3 compared to the corrosive gas 10 present in the environment.

[0052] The sensing metal film 3 is made of a material such as silver, which is more easily corroded than the substrate metal film 2 compared to the corrosive gas 10.

[0053] The upper and lower surfaces of the substrate 5, which is equipped with the base metal thin film 2 and the sensing metal thin film 3, are covered by the frame 6. However, if... Figure 2 as well as Figure 4As shown, the structure is as follows: an opening 7 is formed at the left end of the frame 6, allowing corrosive gas 10 to flow into the gas channel 8 inside the corrosion environment monitoring sensor 1. That is, the sensing metal film 3 is exposed inside the gas channel 8.

[0054] In addition, corrosion environment monitoring sensor 1, such as Figure 4 As shown, the substrate 5 protrudes from the right end of the frame 6. Furthermore, lead-out electrodes 9 are connected to the right ends of the two parallel base metal thin films 2, and the terminals 9a and 9b at the front end of the lead-out electrodes 9 are disposed on the substrate 5 protruding from the frame 6.

[0055] Figure 1 The resistance measurement unit 111 of the corrosion environment monitoring device 110 shown measures the resistance between terminals 9a and 9b.

[0056] Figure 5 This is a top view showing another example (Example 2) of the configuration of the corrosion environment monitoring sensor 1 in this example. Figure 5 In the top view, with Figure 2 Similarly, the frame 6 on the upper side of the substrate 5 is represented by a virtual line.

[0057] Figure 6 It is along Figure 5 A cross-sectional view of the CC line.

[0058] Figure 7 It is along Figure 5 A cross-sectional view of the DD line.

[0059] exist Figures 5-7 In the case of the corrosion environment monitoring sensor 1 shown in Example 2, the base metal thin film 2 is formed in a "コ" shape on the substrate 5, separated by an insulating plate 4. Figures 2-4 The corrosive environment monitoring sensor 1 shown is the same.

[0060] Figures 5-7 The corrosion environment monitoring sensor 1 shown in Example 2 is... Figures 2-4 The difference between the corrosion environment monitoring sensor 1 shown in Example 1 is that the configuration of the sensing metal films 3a and 3b formed on the substrate metal film 2 is different.

[0061] That is, in Figures 5-7 In Example 2, two sensing metal films 3a and 3b are prepared, and these two sensing metal films 3a and 3b are disposed on two parallel substrate metal films 2, excluding the end near the opening 7. Therefore, as Figure 5 As shown, at the end near the opening 7, the base metal film 2 is exposed in the gas channel 8.

[0062] Figures 5-7Other components of the corrosion environment monitoring sensor 1 shown are similar to those of the other components shown. Figures 2-4 The corrosive environment monitoring sensor 1 shown is the same.

[0063] Figure 8 This shows how to make Example 1 ( Figures 2-4 Or Example 2 () Figures 5-7 The corrosion environment monitoring sensor 1 shown is in a state of being exposed to a corrosive environment, causing corrosion to develop over time, and the state of the change in resistance value measured by the resistance value measuring unit 111 of the corrosion environment monitoring device 110.

[0064] Figure 8 This diagram shows a front view of the corrosion status of a laminate consisting of a substrate metal film 2 and induction metal films 3 (3a, 3b) at times t0 before exposure, t1 after exposure, t2 after exposure, t3 after exposure, and t4 after exposure, and the relationship between exposure time and resistance value corresponding to the corrosion status. Here, the times t1 to t4 after exposure have the relationship t1 < t2 < t3 < t4.

[0065] Furthermore, in Example 1 ( Figures 2-4 Or Example 2 () Figures 5-7 In the sensor configuration, the substrate metal thin film 2 and the sensing metal thin film 3 (3a, 3b) are arranged in parallel in a "コ" shape, but... Figure 8 For the sake of simplicity, the substrate metal film 2 and the sensing metal film 3 are arranged in an I-shape in a straight line. Figure 8 The resistance values ​​shown in the curve were measured using the two ends of the type I substrate metal thin film 2.

[0066] Before exposure, neither the substrate metal film 2 nor the sensing metal film 3 was corroded.

[0067] The resistor R of the substrate metal thin film 2 BM1 and the resistance R of the sensing metal thin film 3 SM1 The resistance value of sensor 1, which is a parallel circuit, is used to represent the resistance value of the pre-exposed corrosive environment monitoring sensor.

[0068] Furthermore, the resistivity of the sensing metal is lower than that of the substrate metal, therefore the resistance value (resistance R) of the sensing metal thin film 3 is used. SM1 The value represents the resistance of sensor 1, which monitors the corrosive environment before exposure.

[0069] At time t1, after a certain period of exposure, corrosion products 31 begin to form on the upper surface of the sensing metal film 3 connected to the gas channel 8 due to the corrosive gas 10 present in the environment. The corrosive gas 10 invades from the opening 7 (left side) towards the depth side (right side) of the gas channel 8, therefore, the sensing metal film 3 begins to corrode from the opening 7 side where the concentration flux of the corrosive gas 10 is high.

[0070] At time t1 after exposure, only a layer of length L is formed at the left end of the sensing metal film 3. A The corrosion product 31 and the sensing metal film 3 also only remain on the left end.

[0071] If the length L of the corrosion product 31 is shown separately A The remaining length of the substrate metal film 2, to which no corrosion products 31 are formed, is then called the resistance R. BM2 and resistance R BM3 sum.

[0072] However, the resistance of the sensing metal thin film 3 is only present along the length L where corrosion products 31 are formed. A The portion becomes a different resistance value than before exposure. That is, the length L where corrosion products 31 form... A The portion becomes the resistor R SM2 The resistance R of corrosion product 31 CP2 The value after parallel connection. Therefore, as... Figure 8 As shown at time t1 after exposure, using resistor R BM2 Resistance R SM2 and resistance R CP2 Parallel resistors and resistor R BM3 and resistance R SM3 The parallel resistance is represented by the equivalent circuit after series connection, showing the resistance value at time t1 after exposure.

[0073] Furthermore, the resistance value of the corrosion environment monitoring sensor 1 at time t1 after exposure is determined based on the relationship between the resistivity of the substrate metal, the resistivity of the sensing metal, and the resistivity of the corrosion product 31, as shown by the dashed arrow on the equivalent circuit. Therefore, the resistance value of the corrosion environment monitoring sensor 1 at time t1 after exposure can approximate the resistance R of the sensing metal thin film 3. SM2 and resistance R SM3 The series circuit (series resistor). At time t1 after exposure, there is a sensing metal film 3 along the entire length, so the change in resistance value of the sensor chip relative to that before exposure is very small.

[0074] At time t2 after exposure, the corrosive gas 10 further penetrates from the opening 7 (left side) towards the depth side of the gas channel 8, and thus, the sensing metal film 3 is further corroded from the opening 7 where the concentration of corrosive gas 10 is high.

[0075] At time t2 after exposure, corrosion product 31 only forms with a length of L. B Corrosion product 31 reaches the lower surface of the sensing metal film 3 at the left end of the sensing metal film 3, and the sensing metal film 3 becomes a state in which it no longer remains at the left end of the sensing metal film 3.

[0076] If the same method is used as at time t1 after exposure, the resistance value of the corrosion environment monitoring sensor 1 at time t2 after exposure is equal to the resistance R of the substrate metal film 2. BM4 and resistance R BM5 The resistance R of the sensing metal thin film 3 SM4 and resistance R SM5 The resistance R of corrosion product 31 CP4 It is represented by the equivalent circuit.

[0077] Furthermore, the resistance value of the corrosion environment monitoring sensor 1 at time t2 after exposure becomes the combined resistance of the current flow path, based on the magnitude relationship between the resistivity of the base metal, the resistivity of the sensing metal, and the resistivity of the corrosion product 31, as shown by the dashed arrow on the equivalent circuit.

[0078] Therefore, the resistance value of the corrosion environment monitoring sensor 1 at time t2 after exposure can approximate the resistance R of the sensing metal thin film 3. SM4 and resistance R SM5 A series circuit (series resistor).

[0079] The resistance value of the corrosion environment monitoring sensor 1 at time t2 after exposure is slightly larger than that at time t1 after exposure, but the change in resistance value of the corrosion environment monitoring sensor 1 before exposure is still very small.

[0080] Using the time t2 after exposure as the dividing line, the resistance value of the corrosion environment monitoring sensor 1 changes significantly.

[0081] At exposure time t3, after a certain period of time has elapsed since exposure time t2, corrosive gas 10 further intrudes from opening 7 (left side) toward the depth side of gas channel 8. As a result, the sensing metal film 3 is further significantly corroded from opening 7, where the concentration and flux of corrosive gas 10 are high.

[0082] At time t3 after exposure, corrosion product 31 is formed over a certain length and the entire thickness of the induced metal film 3, and at a length of L. C The thickness of part of it has changed. This length L...C The length L of corrosion product 31 at time t2 after exposure B equal.

[0083] If the same method is used as at time t1 after exposure, the resistance value of the corrosion environment monitoring sensor 1 at time t3 after exposure is taken from the resistance of the substrate metal film 2. RBM6 Resistance R BM7 and resistance R BM8 The resistance R of the sensing metal thin film 3 SM7 and resistance R SM8 and the resistance R of corrosion product 31 CP6 and resistance R CP7 The equivalent circuit representation.

[0084] Furthermore, since the resistivity of the base metal, the resistivity of the sensing metal, and the resistivity of the corrosion product 31 are in the order that the resistivity of the corrosion product 31 > the resistivity of the base metal > the resistivity of the sensing metal, the resistance value of the corrosion environment monitoring sensor 1 at time t3 after exposure becomes the combined resistance of the current flow path, as indicated by the dashed arrow on the equivalent circuit.

[0085] That is, the resistance value of the corrosion environment monitoring sensor 1 at time t3 after exposure can approximate the resistance R of the substrate metal thin film 2. BM6 The resistance R of the sensing metal thin film 3 SM7 and resistance R SM8 A series circuit.

[0086] Therefore, the resistance value of the corrosion environment monitoring sensor 1 at time t3 after exposure changes significantly compared to the resistance value of the corrosion environment monitoring sensor 1 before exposure.

[0087] The resistance value of sensor 1 at time t4 after exposure to corrosion is measured using the resistance R of the substrate metal thin film 2. BM9 Resistance R BM10 and resistance R BM11 The resistance R of the sensing metal thin film 3 SM10 and resistance R SM11 The resistance R of corrosion product 31 CP9 and resistance R CP10 It is represented by the equivalent circuit.

[0088] Furthermore, the resistance value of the corrosion environment monitoring sensor 1 at time t4 after exposure, based on the magnitude relationship between the resistivity of the base metal, the resistivity of the sensing metal, and the resistivity of the corrosion product 31, becomes the combined resistance of the current flow path, as indicated by the dashed arrow on the equivalent circuit.

[0089] Therefore, the resistance value of the corrosion environment monitoring sensor 1 at time t4 after exposure can be approximated by the resistance R of the substrate metal film 2. BM9 and the resistance R of the sensing metal thin film 3 SM10 and resistance R SM11 A series circuit (series resistor).

[0090] At time t4 after exposure, corrosion product 31 is formed over a certain length and the entire thickness of the induced metal film 3, and over a length L D The thickness of part of it has changed. This length L... D The length L of corrosion product 31 at time t3 after exposure C equal.

[0091] The resistance value of the corrosion environment monitoring sensor 1 at time t4 after exposure, compared to the resistance value at time t3 after exposure, shows a relatively large change: the resistance value increases almost steadily per unit time (i.e., linearly). However, as will be discussed later... Figure 9 , Figure 10 As shown, the increase in resistance is linear when the exposure time is observed for a longer period.

[0092] <Changes in resistance based on gas concentration>

[0093] As in Figure 8 As explained in the text, the resistance value of the corrosion environment monitoring sensor 1 in this example is from the time it is placed in the corrosive environment until a certain period of time has elapsed. Figure 8 The resistance remains almost unchanged up to time t2 after exposure, and then gradually changes. In the following description, the period during which the resistance value remains almost unchanged is called the latency.

[0094] Figure 9 To compare the resistance change characteristics c1 and c2 when the types of gases causing corrosion are the same, but the concentrations of those gases differ. Here, silver is used as the sensing metal film 3 of the corrosion environment monitoring sensor 1, and the gases causing corrosion are H2S, S8, etc., which corrode silver.

[0095] exist Figure 9 In the diagram, resistance change characteristic c1 represents the state where the gas concentration is 1 (×1), and resistance change characteristic c2 ​​represents the state where the gas concentration is 2 (×2). Figure 9 The vertical axis represents the resistance value (Ω), and the horizontal axis represents time (h).

[0096] Here, the latency of the resistance change characteristic c1 when the gas concentration is 1 times is set as θ1, and the slope of the change in resistance after the latency time is set as α1. Similarly, the latency of the resistance change characteristic c2 ​​when the gas concentration is 2 times is set as θ2, and the slope of the change in resistance after the latency time is set as α2.

[0097] At this point, the latency times θ1 and θ2 reflect the gas concentration. That is, if the latency time θ1 for one time the gas concentration is set to 0.5 times, then it becomes the latency time θ2 for two times the gas concentration. The slopes α1 and α2 of the change in resistance value are also directly proportional to the gas concentration.

[0098] Therefore, even if the gas concentration changes, θ1×α1=θ2×α2 is the same value, becoming an inherent value for each gas type.

[0099] <Resistance variation based on gas type>

[0100] Figure 10 This shows how the resistance value changes depending on the type of gas. Figure 10 The vertical axis represents the resistance value (Ω), and the horizontal axis represents time (h).

[0101] exist Figure 10 The diagram shows the characteristics of gas H2S and gas S8. Here, θ represents the latency of the two gases, which differ in concentration in the air. H2S θ S8 Assuming they are equal, the slope α of the change in resistance after the latency period is considered. H2S α S8 The differences differ depending on the gas type H2S and gas type S8.

[0102] In this example, the type of gas (causative substance) that causes corrosion is identified by using θ×α, which is an inherent value for each type of gas, as the product of θ during the latency period and the slope α of the change in resistance after the latency period.

[0103] <Example based on actual analytical data of gas types>

[0104] Figure 11 Examples of changes in resistance values ​​analyzed in an environment containing gas g1, which contains corrosive substance S8, and examples of changes in resistance values ​​analyzed in an environment containing gas g2, which contains corrosive substance H2S, are shown. Figure 11 The vertical axis represents the resistance value (Ω), and the horizontal axis represents time (h).

[0105] exist Figure 11 In the example, in the case of gas g1 containing substance S8, the latency θS8 The slope α of the change in resistance after a latency period of 50 hours (time). S8 It is 0.7Ω / h.

[0106] On the other hand, in the presence of substance S H2S In the case of gas g2, the latency θ H2S The slope α of the change in resistance after a latency period of 10 hours. H2S It is 6Ω / h.

[0107] Thus, in the corrosive substances S8 and H2S, the slope α of the change in resistance value... H2S α S8 Unlike others, it can be determined based on the slope α. H2S α S8 and latency θ H2S θ S8 The multiplication value is used to distinguish between the two corrosive substances, S8 and H2S.

[0108] For example, when the judgment unit 112 of the corrosion environment monitoring device 110 identifies corrosion causative substance S8 and corrosion causative substance H2S, the slope α of the change in resistance value with respect to corrosion causative substance S8 is set. S8 and latency θ S8 The product value x1 and the slope α of the change in resistivity of the corrosive substance H2S H2S and latency θ H2S The threshold th1 is the value between the multiplication value x2 and the value between the two. Furthermore, the judgment unit 112 can determine whether the gas type contains corrosive substance S8 or corrosive substance H2S by comparing the multiplication value obtained from the measurement data with the threshold th1.

[0109] exist Figure 11 In the case of the gas g1 containing substance S8, the latency θ S8 For a time of 50 hours, the slope of the change in resistance is 0.7 Ω / h. Therefore, the product of gas g1 is 50 × 0.7 = 35. On the other hand, in the case of gas g2 containing SH2S, the latency θ... H2S The slope α of the change in resistance over 10 hours H2S The value is 6Ω / h, and the product of gas g2 is 10×6=60.

[0110] Therefore, by setting the threshold th1 to a value roughly between 35 and 60, it is possible to identify whether the corrosive substance contained in the gas is S8 or H2S.

[0111] <Processing of the Judgment Unit of the Corrosion Environment Monitoring Device>

[0112] Figure 12 This is a flowchart illustrating the judgment process of the judgment unit 112 of the corrosion environment monitoring device 110.

[0113] First, the resistance measurement unit 111 of the corrosion environment monitoring device 110 measures the resistance value of the corrosion environment monitoring sensor 1, and stores the measurement data and measurement time data in the storage unit 113 (step S11).

[0114] Then, the determination unit 112 determines whether the measurement data stored in the storage unit 113 is the initial measurement data of the corrosion environment monitoring sensor 1 set in a corrosive environment (step S12).

[0115] When it is determined in step S12 that the measurement data is the initial measurement data (step S12 determines that it is), the determination unit 112 monitors the measurement data until it can obtain the latency time θ when the resistance value hardly changes and the slope α of the change in resistance value after the latency time, and measures the corresponding latency time θ and the slope α of the change (step S13).

[0116] Next, the judgment unit 112 compares the product of the latency time θ and the slope α of the change with a preset threshold (step S14).

[0117] If the multiplication value is determined to be above a pre-set threshold in step S14 (step S14 determines that it is), the determination unit 112 determines that the gas contains H2S, a substance that causes corrosion (step S15).

[0118] In addition, if it is determined in step S14 that the multiplication value is lower than a preset threshold (step S14 determines no), the determination unit 112 determines that the gas contains a corrosive substance S8 (step S16).

[0119] Then, the judgment unit 112 performs a registration process and stores the data of the gas type determined in step S15 or S16 in the storage unit 113 (step S17).

[0120] Then, if it is determined in step S12 that the data is not the initial measurement data, that is, if the gas type has already been registered (step S12 determines no), the determination unit 112 determines whether the registered gas type is S8 or H2S (step S18). Similarly, after the gas type is registered in step S17, the gas type determination in step S18 is also performed.

[0121] In step S18, when the gas type is determined to be H2S (H2S in step S18), the determination unit 112 measures the change in resistance value ΔR (step S21). Then, the determination unit 112 obtains calibration curve data for gas type H2S from the storage unit 113 (step S22). This calibration curve data for gas type H2S is data showing the relationship between the change in resistance value and the corrosion thickness of the sensing metal thin film 3 in the case of gas type H2S.

[0122] Then, the judgment unit 112 calculates the corrosion thickness of the sensing metal thin film 3 based on the measured change in resistance value ΔR and the calibration curve data (step S23). Thus, the judgment unit 112 evaluates the corrosivity of the environment in which the corrosion environment monitoring sensor 1 is installed (step S24).

[0123] When the gas type is determined to be S8 in step S18 (S8 of step S18), the determination unit 112 measures the change in resistance value ΔR (step S31). Then, the determination unit 112 obtains calibration curve data for gas type S8 from the storage unit 113 (step S32). This calibration curve data for gas type S8 is data that shows the relationship between the change in resistance value and the corrosion thickness of the sensing metal thin film 3 under the condition of gas type S8.

[0124] Then, the judgment unit 112 calculates the corrosion thickness of the sensing metal thin film 3 based on the measured change in resistance value ΔR and the calibration curve data (step S33). Thus, the judgment unit 112 evaluates the corrosivity of the environment in which the corrosion environment monitoring sensor 1 is installed (step S34).

[0125] Furthermore, the judgment unit 112 within the corrosion environment monitoring device 110 can proceed up to the calculation of corrosion thickness in step S23 or S33, and an external information processing device that has acquired data on gas type and corrosion thickness will evaluate the corrosivity of the environment in which the corrosion environment monitoring sensor 1 is installed.

[0126] As explained above, the corrosion environment monitoring system 100 in this example can evaluate the corrosivity of the environment in which the corrosion environment monitoring sensor 1 is installed, and determine the type of corrosive substance. In particular, by determining the type of corrosive substance, an appropriate evaluation of the corrosive environment can be performed, accurately assessing the lifespan of equipment installed in the corresponding location affected by corrosion and the degree of corrosion resistance of the equipment. Furthermore, it has the following effect: when determining the type of corrosive substance, the accurate type of corrosive substance can be determined by using a latency time where the resistance changes almost continuously.

[0127] In addition, by using Figures 2-4 , Figures 5-7The corrosion environment monitoring sensor 1 shown is used for monitoring and can generate data in the corrosive environment. Figure 8 The corrosion-sensing metal films 3, 3a, and 3b described herein can effectively monitor the installation environment and identify corrosive substances. In particular, by employing a corrosion environment monitoring sensor 1 with the sensing metal films 3, 3a, and 3b and the substrate metal film 2 configured in a "コ" shape, a latency time with almost no change in resistance corresponding to the type of corrosive substance can be generated, and this appropriate latency time can be used to identify corrosive substances.

[0128] Moreover, such as Figures 5-7 As shown, by setting only the base metal film 2 exposed instead of the sensing metal films 3a and 3b on the opening 7 side of the corrosive environment monitoring sensor 1, the latency time when the resistance hardly changes can be calculated more accurately.

[0129] <Variation Example>

[0130] Furthermore, the present invention is not limited to the above-described embodiments, but includes various modifications. For example, the above-described embodiments are provided for ease of understanding of the present invention and are not limited to all the described configurations.

[0131] For example, in the above-described embodiments, hydrogen sulfide (H2S) and elemental sulfur (S8) were identified as the types of corrosive substances. However, the present invention can also be applied to environments where other corrosive substances are present.

[0132] Specifically, in addition to H2S and S8, it can also be applied to the detection of carbon sulfide (OCS), carbon disulfide (CS2), sulfur dioxide (SO2), etc. These gases—H2S, S8, OCS, CS2, and SO2—are all gases that corrode silver, and silver can be used as the sensing metal films 3, 3a, and 3b of the corrosion environment monitoring sensor 1. For example, in addition to detecting H2S and S8 as described in the above embodiment examples, it can also detect H2S and OCS.

[0133] In addition to volcanoes, hydrogen sulfide (H2S) is also produced in sewage and drainage. Elemental sulfur (S8) is produced as a gas emitted from rubber and adhesives. Carbon sulfide (OCS) and carbon disulfide (CS2) are produced as precursors to sulfuric acid aerosols generated by urban activities and as gases emitted from wallpaper and flooring.

[0134] In addition, such as Figure 1As shown, evaluating the corrosive environment within a factory equipped with control equipment 102 and factory facilities 101 is one example. This invention can be applied to evaluating corrosivity in various other environments. Specifically, in addition to manufacturing and transportation sites, this invention can be applied to evaluating corrosivity in various social infrastructures such as sewer systems.

[0135] Moreover, in Figure 1 In the corrosion environment monitoring system 100 shown, the corrosion environment monitoring device 110 is connected to the outside via a network to evaluate the corrosive environment. However, all processes up to the evaluation can also be performed within the corrosion environment monitoring device 110, which is connected to the corrosion environment monitoring sensor 1.

[0136] Alternatively, in a location where a corrosive environment monitoring sensor 1 is installed, only the resistance value can be measured, and an external judgment can be made based on the change in the resistance value.

[0137] In addition, regarding Figure 1 The corrosive environment monitoring device 110 shown can be constructed using dedicated hardware for monitoring and processing, or it can be constructed using a computer that performs calculations based on programs (software).

[0138] However, when using a computer to perform monitoring and processing, it is necessary to install a program on the computer to measure the resistance value of the corrosive environment monitoring sensor and to determine the type of corrosive substance from the time change of the resistance value.

[0139] In addition, Figure 1 The block diagram only shows the control lines and information lines required for the specifications; it is not necessary to show all control lines and information lines on the product. It is also possible to consider that almost all of them are actually interconnected. Additionally, in Figure 12 As shown in the flowchart, multiple processes can be performed simultaneously or the processing order can be changed within the scope that does not affect the processing result.

[0140] Explanation of reference numerals in the attached figures

[0141] 1 Corrosion environment monitoring sensor, 2 Substrate metal thin film, 3, 3a, 3b Sensing metal thin film, 4 Insulating plate, 5 Substrate, 6 Frame, 7 Opening, 8 Gas channel, 9 Lead-out electrode, 9a, 9b Terminal, 10 Corrosion gas, 31 Corrosion products, 100 Corrosion environment monitoring system, 101 Plant facilities, 102 Control equipment, 110 Corrosion environment monitoring device, 111 Resistance value measuring unit, 112 Judgment unit, 113 Storage unit, 120 Monitoring center, 121 Display device.

Claims

1. A corrosive environment monitoring system, comprising: A corrosive environment monitoring sensor has a laminate and a frame. The laminate has an insulating plate, a base metal film formed on the insulating plate, and a sensing metal film formed on at least a portion of the base metal film. The sensing metal film is made of a metal that is more susceptible to corrosion by corrosive substances and has a lower resistivity than the base metal film. The frame houses the laminate and has an opening in the lateral direction, forming a gas channel for the corrosive substances inside. The resistance measurement unit measures the resistance between two points on the substrate metal film of the corrosion environment monitoring sensor. as well as The judgment unit determines the type of corrosive substance based on the change in resistance over time measured by the resistance measurement unit. The determination unit determines the type of corrosive substance by comparing a calculated value obtained by multiplying the latency time when the resistance remains almost unchanged and the slope of the change in resistance per unit time after the latency time with a preset threshold.

2. The corrosion environment monitoring system according to claim 1, wherein, The judgment unit also acquires calibration curve data corresponding to the type of corrosive substance determined, which represents the relationship between the resistance change and the corrosion amount of the sensing metal film. Based on the calibration curve data and the resistance change measured by the resistance value measuring unit, the environment in which the corrosion environment monitoring sensor is installed is evaluated.

3. The corrosion environment monitoring system according to claim 1, wherein, The corrosion environment monitoring sensor has two parallel metal films arranged along the long side formed from the opening side of the frame towards the depth side of the gas channel. The ends of the two parallel metal films on the opening side are connected, and the terminals of the detection resistor are connected to the ends of the two parallel metal films on the depth side of the gas channel.

4. The corrosion environment monitoring system according to claim 3, wherein, The sensing metal film is not formed at the end of the two parallel base metal films on the opening side.

5. A method for monitoring a corrosive environment, comprising setting a corrosive environment monitoring sensor at a designated location to monitor the corrosive environment, wherein the corrosive environment monitoring sensor comprises: A laminate comprising an insulating plate, a base metal film formed on the insulating plate, and a sensing metal film formed on at least a portion of the base metal film, the sensing metal film being formed of a metal that is more susceptible to corrosion by corrosive substances and has a lower resistivity than the base metal film; and The frame, which houses the laminated body, has an opening in the lateral direction, forming a gas channel for the corrosive substance inside. The corrosive environment monitoring method includes the following processes: The resistance measurement unit measures the resistance between two points on the substrate metal film of the corrosion environment monitoring sensor; and the resistance measurement process is performed to detect the resistance between these two points. The judgment unit determines the type of corrosive substance based on the resistance change measured over time using the resistance value measurement process. In the judgment process, the judgment unit determines the type of corrosive substance by comparing a calculated value obtained by multiplying the latency time when the resistance is almost unchanged and the slope of the change in resistance per unit time after the latency time with a preset threshold.

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