Corrosion early warning monitor based on impedance transformation technology
Technical Field
The invention relates to a corrosion early warning monitoring technology, in particular to a corrosion early warning monitor based on an impedance transformation technology.
Background
The corrosion refers to that metal is exposed in the atmosphere and contacts with oxygen, moisture and other impurities to generate chemical or electrochemical reaction, so that discoloration or corrosion is caused, and corrosion products which can be observed by naked eyes are generated. Such as metal oxides, hydroxides, etc., the corrosion product of which is rust, commonly referred to as rust or rust.
According to incomplete statistics, economic losses of various industries in China caused by corrosion reach hundreds of billions of yuan each year. In order to reduce economic loss caused by corrosion, metal materials are subjected to rust prevention treatment. Common rust prevention methods can be classified into three major categories: the first, changing the internal organization of the metal. For example: various corrosion-resistant alloys are manufactured, and chromium, nickel and the like are added into common steel to manufacture stainless steel; the second major category, surface treatment processes. For example: coating, galvanizing, nickel plating, heat treatment (carburizing, nitriding, etc.), chemical surface treatment (phosphating, passivation, blackening, soda-boiling, etc.), various coatings (dacromet, spray molding, encapsulation, vapor deposition, etc.); the third category, isolation, is to treat the corrosive medium to reduce the contact area between the corrosive medium and the metal surface; for example: antirust packaging (antirust oil, dry sealing, gas phase antirust, water-based antirust agent, cutting fluid and the like).
At present, almost all the application process of the anti-corrosion technology is to implement method research into field application through laboratory evaluation.
The corrosion of metal components or products in a strict sense is closely related to environmental factors, the treatment state of metal surfaces, whether the base material contains inclusions and the like, and from the development process of the corrosion, the metal components or products are subjected to the processes of germination, rusty spots and the like. At present, a stable and reliable rust dynamic monitoring and early warning technology aiming at the metal product packaging and sealing environment, the weapon equipment storage environment and the logistics environment does not exist. There is no commercial product for monitoring the corrosion state and the corrosion degree of metal products and weapons in real time.
At present, the existing metal corrosion monitoring methods and sensors, such as chinese patents CN101865815B, CN100424497C, CN105842148A, etc., are all designed for monitoring the corrosion degree of steel bars in concrete environments such as bridges, etc., and are not suitable for monitoring the metal corrosion condition in a package-sealing microenvironment, and even can not realize the diagnosis and early warning of the rust-proof package state. There is no mature product and commercial application case in China, abroad
At present, the corrosion detection is mainly manual inspection, the working strength is high, quantification cannot be realized, the efficiency is low, and the post-repair cost is high; the known detection means mainly comprises a detection rod, belongs to qualitative detection and cannot realize accurate quantification and early warning. Under the condition of great change of temperature and humidity, the antirust package has the protection aging and antirust capacity on equipment, especially in the transportation and storage process. At present, in the aspect of the rust state early warning online monitoring technology, no relevant mature products and commercial application cases exist in China, abroad and abroad.
Disclosure of Invention
The invention provides a high-precision and high-stability corrosion early warning monitor based on an impedance transformation technology, aiming at the current situation of the metal corrosion degree monitoring technology in the prior art, especially the defects of high difficulty in manufacturing a sensor, inconvenience in replacing a test piece, low testing precision of an impedance transformation circuit of the monitor, large data error and the like in the implementation process of the corrosion degree monitoring technology.
In order to solve the technical problems, the invention adopts the technical scheme that:
the invention relates to a rust early warning monitor based on an impedance transformation technology, which comprises a rust sensor, a temperature/humidity sensor, a central processing unit, a signal acquisition module, a signal conditioning module, a state display module, a communication module and a power supply module, wherein the central processing unit is connected with the signal acquisition module through the signal conditioning module, an outgoing line of the signal conditioning module applies an alternating current signal to the rust sensor, the input end of the signal acquisition module is connected with the rust sensor and the temperature/humidity sensor, and an output signal of the signal acquisition module is processed and transformed by an analog/digital converter in the signal conditioning module and then enters the central processing unit.
The central processing unit is also provided with a maintenance interface which receives the encrypted data from the enterprise cloud platform to complete the setting of the working parameters of the monitor.
The signal conditioning module comprises a logic control module, a digital frequency synthesizer, an analog-to-digital converter, a first signal amplifier and a second signal amplifier, wherein the digital frequency synthesizer receives an instruction of the central processing unit through the logic control module, outputs an alternating current excitation signal, is output by the first amplifier and is applied to the measuring test piece and the compensating test piece through a second resistor; the feedback signal enters the input end of the analog-to-digital converter through the second signal amplifier, the gain unit and the filtering unit; the analog-to-digital converter outputs digital signals, and after the digital signals are converted by the DFT unit, the digital signals extract measurement data and are input to the central processing unit through the logic control module.
The corrosion sensor comprises a measuring test piece, a compensating test piece and a first connecting contact pin, a second connecting contact pin and a corrosion sensor body, wherein the measuring test piece is of a snake-shaped structure and is contacted with an environment to be measured; the compensation test piece is a sealing structure, is adhered to the bottom of the measurement test piece and is sealed by epoxy resin sealing materials to be isolated from the environment to be measured; the second connecting pin is led out from the measuring test piece and is connected to the second resistor through a lead, and the first connecting pin is led out from the compensating test piece and is simultaneously connected to the third resistor and the reverse input end of the second operational amplifier.
The device is characterized by also comprising a temperature/humidity sensor which is arranged in the corrosion sensor, and the signal of the temperature/humidity sensor is connected with the central processing unit through the signal acquisition module and the signal conditioning module.
And the GPRS communication interface is also provided, and the communication module is controlled by the central processing unit.
The invention comprises a host circuit, a box body, a battery compartment, a data interface, an embedded corrosion sensor, a temperature/humidity sensor and a battery compartment sealing plug, wherein the host circuit is arranged in the box body and is provided with a circuit cover plate; one end of the circuit cover plate is connected with the host circuit through a lead; the circuit cover plate is provided with a jack, the bottom of the surface of the upper cover is provided with a contact pin, and the contact pin is inserted into the jack so that the circuit cover plate is electrically connected with the surface of the upper cover; the battery compartment is arranged on one side of the box body.
The invention has the following beneficial effects and advantages:
1. according to the invention, the continuous frequency scanning technology is adopted to realize the measurement of the corrosion early warning data of the metal in the corrosion medium, and the result shows that the accuracy and the stability of the corrosion data measurement are improved by adopting a novel measurement technology and a hardware module; by using the optimized continuous frequency scanning technology, the anti-interference capability of the instrument is improved, the power consumption of the whole instrument is reduced, the requirements of testing and evaluating the corrosion degree of the environments such as industrial environment, natural environment, logistics storage and the like can be met, and the instrument can be used as an instrument for rapidly evaluating the effect of the vapor phase corrosion inhibitor in a laboratory.
2. Compared with the similar functional instruments, the invention has small volume, light weight and convenient use and carrying; possess the condition of using in high corrosion risk occasions such as equipment storage and transportation, realize the early warning to environment corrosion state, through corrosion state monitoring, data analysis, go on the early warning to corrosion emergence point prejudgement, support cloud platform technique simultaneously, can realize corrosion monitor output signal and cloud platform seamless connection.
3. The continuous frequency scanning technology and the impedance transformation unit (integrated in the signal conditioning module) adopted by the invention have the characteristics of high integration level, high speed and low power consumption; the signal application and the data processing are automatically and continuously completed, so that the continuous collection of the corrosion signals is ensured, and the device has the characteristics of accurate measurement and good signal integrity.
4. The invention provides a plurality of data transmission modes, such as remote GPRS data transmission, Beidou remote data transmission, regular storage, local reading and uploading and the like, and has the advantages of wide compatibility and stronger adaptability.
5. The invention provides a solution for a special application scene, which adopts a state indicator lamp alarming mode under the condition of no data remote transmission; meanwhile, a hand-copy device is designed, and data acquisition in a non-destructive state is realized through a wireless communication technology; the hand-held device has a wireless transmission function, and when the conditions allow, data are uploaded to the system platform.
Drawings
FIG. 1 is a functional block diagram of a corrosion degree monitor according to the present invention;
FIG. 2 is a functional block diagram of a signal conditioning module according to the present invention;
FIG. 3A is a structural diagram of a corrosion sensor of the present invention;
FIG. 3B is a structural diagram of a corrosion sensor according to the present invention;
FIG. 4 is a flow chart of the monitor of the present invention;
FIG. 5 is a graph of impedance versus corrosion for an embodiment of the present invention;
FIG. 6 is a schematic structural diagram of each component of the monitor according to the embodiment of the present invention.
Wherein, 1 is the power supply battery, 2 is the battery compartment, 3 is data interface, 4 is the host computer circuit, 5 is the circuit apron, 6 is the corrosion sensor, 7 is temperature \ humidity transducer, 8 is the sealing plug, 9 corrosion monitor casing, 14 is the measurement test block, 15 is the compensation test block, 16 first connecting pin, 17 second connecting pin.
Detailed Description
The invention is further elucidated with reference to the accompanying drawings.
As shown in fig. 1, the corrosion early warning monitor based on the impedance transformation technology of the present invention includes a corrosion sensor, a temperature/humidity sensor, a central processing unit, a signal acquisition module, a signal conditioning module, a state display module, a communication module, and a power supply module. The central processing unit is connected with the signal acquisition module through the signal conditioning module, an outgoing line of the signal conditioning module applies an alternating current signal to the corrosion sensor, the input end of the signal acquisition module is connected with the corrosion sensor and the temperature/humidity sensor, and an output signal of the signal acquisition module enters the central processing unit after being processed and converted by an analog-to-digital converter (ADC) in the signal conditioning module.
The central processing unit is also provided with a maintenance interface which receives the encrypted data from the enterprise cloud platform to complete the setting of the working parameters of the monitor; the invention also has a temperature/humidity sensor which is arranged in the rust sensor, the signal of the temperature/humidity sensor is connected with the central processing unit through the signal acquisition module and the signal conditioning module, and the temperature measurement range is as follows: -40 to 120 ℃, temperature resolution: 0.1 ℃, humidity measurement range: 0-100%, humidity resolution: . + -. 1.8% RH. And the GPRS communication interface is also provided, and the communication module is controlled by the central processing unit.
As shown in fig. 2, the signal conditioning module includes a logic control module, a digital frequency synthesizer (DDS), an 8-channel analog-to-digital converter (ADC), and a first and a second signal amplifiers a1 and a2, wherein the DDS receives an instruction from the cpu through the logic control module, outputs an ac excitation signal, is outputted from the first amplifier a1, and is applied to the measurement test piece 14 and the compensation test piece 15 through the second resistor R2; the feedback signal enters the input end of the 8-channel analog-to-digital converter through the second signal amplifier A2, the gain unit and the filtering unit; the 8-channel analog-to-digital converter outputs digital signals, which are converted by the DFT unit, and then the digital signals are extracted and input to the central processing unit through the logic control module.
As shown in fig. 3A to 3B, the corrosion sensor 1 includes a measurement strip 14, a compensation strip 15, and first to second connection pins 16 to 17, wherein the measurement strip 14 has a serpentine structure and contacts with an environment to be measured; the compensation test piece 15 is also of a snake-shaped structure, is adhered to the bottom of the measurement test piece 14, is sealed by epoxy resin sealing materials, and is isolated from the environment to be measured and the measurement test piece to play a role in temperature compensation; the second connecting pin 17 is led out from the measurement test strip 14 and connected to the second resistor R2 through a conducting wire, and the first connecting pin 16 is led out from the compensation test strip 15 and connected to the third resistor R3 and the inverting input terminal of the second operational amplifier a 2.
The invention provides a high-precision and high-stability corrosion degree early warning monitor by adopting a high-precision signal source manufacturing technology, an impedance transformation technology, a weak signal extraction technology and a low-power consumption technology and combining a high-speed MCU technology.
In the invention, the central processing unit is connected with the signal acquisition module through the signal conditioning module, and the signal conditioning module passes through the second resistor R and the third resistor R2、R3The lead wires at two ends apply alternating current signals to the rust sensors 1, and the signals of the sensors are amplified by the signal acquisition module and then enter the central processing unit through an analog-to-digital converter (ADC) of the signal conditioning module.
And the data processing software running in the central processing unit reads the measurement data stored by the enterprise cloud platform through the Internet to complete the analysis and processing of the measurement data. The data processing software also completes the setting of the working parameters of the monitor through the monitor maintenance interface. The specific functions are shown in figure 1.
As shown in fig. 4, the monitor has a working flow chart, and after the monitor is powered on and initialized, parameters such as temperature, humidity, corrosion degree and the like are measured. After the analog signal is amplified by the signal acquisition module and impedance conversion is completed by the signal conditioning module, the current corrosion degree is indicated by the indicator lamp of the state display module according to different corrosion degrees of the corrosion sensor measuring test piece 14.
When the green-colored indicator light is on,indicates that the metal surface is intact and has no rust (Z)t≤Z0);
When the yellow indicator light is lighted, the metal surface is basically intact, the rusting risk is increased, and measures (Z) are required to be taken0≤Zt≤Z1);
When the red indicator light is lighted, indicating that the metal surface is rusted, the protective or remedial measures (Z) need to be taken immediatelyt≥Z1);
According to the measurement result, the corrosion degree is graded, the monitor stores corrosion risk data, and normal data (without corrosion) are not stored. The measured data is controlled by the central processing unit and transmitted to the enterprise cloud platform through the communication module, meanwhile, the measured data is stored in an internal storage of the instrument for backup, and the data storage capacity is not lower than 30000 groups.
As shown in fig. 5, which is a graph of impedance versus corrosion degree according to an embodiment of the present invention, a corrosion sensor (containing a test piece, made of 20# carbon steel) is placed in a beaker, heated with distilled water, taken out after rusting to a certain degree, dried, measured for its resistance value, averaged three times for each measurement, and compared with non-corroded data, and 50 sets of data are continuously collected for each experiment, for four experiments. It can be seen from the experimental results that the resistance variation (Δ R) of the test piece increases in a cumulative manner as the degree of corrosion increases. Specific values are given in the following table:
serial number
|
Number of data sets
|
Proportion of rusted area (%)
|
Specimen impedance change Δ R: (mu. omega)
|
1
|
0~50
|
0
|
0
|
2
|
50~100
|
10~15
|
50±5%
|
3
|
100~175
|
15~25
|
150±5%
|
4
|
175~225
|
25~35
|
200±5% |
As shown in fig. 6, which is a schematic structural diagram of each component of the monitor according to the embodiment of the present invention, the mechanical structure includes a host circuit 4, a box 9, a battery compartment 2, a data interface 3, an embedded corrosion sensor 6, a temperature \ humidity sensor 7, and a battery compartment sealing plug 8, wherein the host circuit 4 is disposed in the box 9, the host circuit 4 has a circuit cover plate 5, and the corrosion sensor 6 and the temperature \ humidity sensor 7 are mounted on the surface of the upper cover and fastened to the box 9; one end of the circuit cover plate 5 is connected with the host circuit 4 through a lead. The circuit cover plate 5 is provided with a connector (in a jack form), the bottom of the upper cover surface (the bottom of the structure where the pins 6 and 7 are located) is provided with a contact pin, and the contact pin and the jack are used for connecting the circuit cover plate 5 and the bottom of the upper cover surface. The battery compartment 2 is arranged on one side of the box body 9.
The invention adopts the continuous frequency scanning technology and the impedance transformation technology to finish frequency scanning and impedance value output, thereby realizing the measurement of metal corrosion degree data and the output of early warning state.
By adopting the 5G communication (technology) module and the low-power-consumption power supply module, the power consumption of the whole machine is reduced while data remote transmission and industrial Internet of things access are realized, the requirements of corrosion degree testing and evaluation of environments such as industrial environment, natural environment, logistics storage and the like can be met, and the power supply module can also be used as an instrument for rapidly evaluating the effect of the gas-phase corrosion inhibitor in a laboratory.