Multi-channel corrosion measuring circuit and device for measuring corrosion of inner surface of metal steel pipe

Abstract

The utility model relates to the technical field of metal pipeline corrosion detection, and provides a multi-channel corrosion measuring circuit and a device for measuring corrosion of the inner surface of a metal steel pipe, the corrosion device comprises a shell and a corrosion sensor, the corrosion sensor is arranged in the shell, the corrosion sensor comprises a multi-channel corrosion measuring circuit, a first nickel sheet electrode and a second nickel sheet electrode, the multi-channel corrosion measuring circuit can provide a stable constant current source, and the micro resistance value between the steel pipe electrode matrixes can be efficiently and accurately detected through the micro potential difference between the four-stage cross measuring electrode matrixes. The corrosion condition of the inner surface of the steel pipe is obtained.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of metal pipeline corrosion detection, and particularly relates to a multi-channel corrosion measurement circuit and a device for measuring corrosion of an inner surface of a metal steel pipe. BACKGROUND

[0002] Steel pipes have high strength and good sealing performance, and can be applied to energy transportation pipelines such as oil and natural gas. However, during long-term use, the inner surfaces of these pipelines are exposed to various corrosive media, such as hydrogen sulfide (H2S), carbon dioxide (CO2), chloride ions (Cl - ) and dissolved oxygen (O2), which can cause corrosion inside the steel pipe, thereby affecting the performance of the material and the overall life of the pipeline.

[0003] To maintain the performance and life of the pipeline, the corrosion state of the inner surface of the steel pipe can be effectively detected, for example, by ultrasonic detection and magnetic flux leakage detection. Ultrasonic detection can be used to measure changes in the thickness of the steel pipe wall, thereby assessing the degree of corrosion. An ultrasonic probe emits high-frequency sound waves, and the thickness of the steel pipe wall is determined by receiving the reflected signals. Magnetic flux leakage detection generates a magnetic field inside the steel pipe. When there is a defect in the steel pipe wall, the magnetic field will leak, and an abnormal signal can be detected by a sensor.

[0004] However, ultrasonic detection requires a coupling agent to ensure effective transmission of ultrasonic waves, and the accuracy of the detection results can be affected in complex corrosion environments. Although magnetic flux leakage detection can detect corrosion defects on the surface of the pipeline, it has limited detection capability for internal corrosion, and has high requirements for the conditions of the pipeline surface, resulting in low detection accuracy. CONTENT OF THE INVENTION

[0005] The present application provides a multi-channel corrosion measurement circuit and a device for measuring corrosion of an inner surface of a metal steel pipe to solve the problem of low detection accuracy of the corrosion state.

[0006] In a first aspect, the present application provides a multi-channel corrosion measurement circuit, comprising: a basic measurement circuit;

[0007] The basic measurement circuit comprises:

[0008] The positive output end of the constant current source is connected with an electronic switch group;

[0009] The electronic switch group is connected with at least the input end of the first channel and the input end of the second channel;

[0010] The negative output end of the constant current source forms a loop with the positive output end of the constant current source;

[0011] The inductive positive terminal is connected with the positive terminal of the first channel and the positive terminal of the second channel through the electronic switch group.

[0012] The inductive negative terminal forms a loop with the inductive positive terminal.

[0013] The electronic switch group can selectively connect the first channel or the second channel, and the current passes through the selected channel and generates a voltage drop in the channel. The inductive positive terminal and the inductive negative terminal measure this voltage drop, so that the resistance of the channel can be calculated, and the corrosion of multiple channels can be accurately measured, thereby improving the accuracy of the measurement.

[0014] In some possible embodiments, the electronic switch group includes:

[0015] The first electronic switch has one end connected with the positive output terminal of the constant current source and the other end connected with the input terminal of the first channel and the input terminal of the second channel.

[0016] The second electronic switch has one end connected with the negative output terminal of the constant current source and the other end connected with the output terminal of the first channel and the output terminal of the second channel.

[0017] The third electronic switch has one end connected with the inductive positive terminal and the other end connected with the inductive positive terminal of the first channel and the inductive positive terminal of the second channel.

[0018] The fourth electronic switch has one end connected with the inductive negative terminal and the other end connected with the inductive negative terminal of the first channel and the inductive negative terminal of the second channel.

[0019] By introducing different electronic switches, the signal transmission between different channels can be more flexibly controlled, thereby realizing more complex multi-channel corrosion measurement tasks.

[0020] In some possible embodiments, the basic measurement circuit further includes an amplification circuit and a switch input circuit, and the basic measurement circuit is connected with the switch input circuit through the amplification circuit.

[0021] The switch input circuit includes a first transistor, a first input terminal, and a first ground terminal. The current passes through the first input terminal and the emitter of the first transistor to connect the first ground terminal.

[0022] When the external switch is closed, the current enters the switch input circuit through the input terminal and flows to the first ground terminal through the emitter of the first transistor. The state change of the transistor will produce a measurable signal change.

[0023] In some possible embodiments, the basic measurement circuit further includes an amplification circuit and a relay input circuit, and the basic measurement circuit is connected with the relay input circuit through the amplification circuit.

[0024] The relay input circuit comprises a relay, a second transistor, a second input end and a second ground end, when the relay input circuit works, the signal of the relay passes through the second transistor, and the current passes through the emitter of the transistor and is connected to the second ground end.

[0025] In some possible embodiments, the application further comprises an amplification circuit and a first output circuit, and the basic measurement circuit is connected to the amplification circuit and the first output circuit.

[0026] The first output circuit comprises a third transistor, a third input end, a third output end, a first common end and a third ground end.

[0027] The emitter of the third transistor is connected to the first common end, the collector of the third transistor is connected to the third output end, and when the input signal makes the third transistor conduct, a path is formed between the third output end and the first common end.

[0028] In some possible embodiments, the application further comprises an amplification circuit and a second output circuit, and the basic measurement circuit is connected to the amplification circuit and the second output circuit.

[0029] The second output circuit comprises a fourth transistor, a fourth input end, a fourth output end, a second common end and a fourth ground end.

[0030] The collector of the fourth transistor is connected to the fourth output end, and the emitter of the fourth transistor is connected to the second common end, and when the input signal makes the fourth transistor conduct, a positive current path is formed between the fourth output end and the second common end.

[0031] In a second aspect, the application provides a device for measuring the corrosion of the inner surface of a metal steel pipe, which comprises a shell and a corrosion sensor, wherein the corrosion sensor is arranged in the shell, and the corrosion sensor comprises a multi-channel corrosion measurement circuit, a first nickel sheet electrode and a second nickel sheet electrode.

[0032] One end of the first nickel sheet electrode is connected to a positive potential end of a first channel, and the other end of the first nickel sheet electrode is connected to a measured steel pipe.

[0033] One end of the second nickel sheet electrode is connected to a positive potential end of a second channel, and the other end of the second nickel sheet electrode is connected to the measured steel pipe.

[0034] The multi-channel corrosion measurement circuit can provide a stable constant current source, and through the measurement of the tiny potential difference between the electrode matrixes of the steel pipe, the tiny resistance value between the electrode matrixes of the steel pipe can be efficiently and accurately detected, and then the corrosion condition of the inner surface of the steel pipe can be obtained.

[0035] In some possible embodiments, a camera, a telescopic rod and a display screen are further included, the display screen is connected with the camera and the corrosion sensor, and the camera is connected with the shell through the telescopic rod.

[0036] From the above technical solutions, the application provides a multi-channel corrosion measurement circuit and a device for measuring corrosion of an inner surface of a metal steel pipe, the corrosion device comprising: a shell and a corrosion sensor, the corrosion sensor being arranged in the shell, the corrosion sensor comprising a multi-channel corrosion measurement circuit, a first nickel sheet electrode and a second nickel sheet electrode, the multi-channel corrosion measurement circuit can provide a stable constant current source, and through a small potential difference between the four-stage cross measurement electrode matrix, a small resistance value between the steel pipe electrode matrix can be efficiently and accurately detected, and then the corrosion condition of the inner surface of the steel pipe is obtained. BRIEF DESCRIPTION OF DRAWINGS

[0037] In order to more clearly illustrate the technical solutions of the application, the drawings needed in the embodiments will be briefly introduced as follows, and obviously, other drawings can also be obtained by those skilled in the art without creative labor on the premise of the drawings.

[0038] Figure 1 The basic measurement circuit schematic diagram provided for the embodiments of the application;

[0039] Figure 2 The switch input circuit schematic diagram provided for the embodiments of the application;

[0040] Figure 3 The relay input circuit schematic diagram provided for the embodiments of the application;

[0041] Figure 4 The first output circuit schematic diagram provided for the embodiments of the application;

[0042] Figure 5 The second output circuit schematic diagram provided for the embodiments of the application;

[0043] Figure 6 The structural diagram of the device for measuring corrosion of an inner surface of a metal steel pipe provided for the embodiments of the application.

[0044] ILLUSTRATIVE DESCRIPTION

[0045] Among them, 100-shell; 110-display screen; 200-first nickel sheet electrode; 300-second nickel sheet electrode. DETAILED DESCRIPTION

[0046] The embodiments will be described in detail below with reference to examples thereof as illustrated in the accompanying drawings. Descriptions of the embodiments in the following description will be presented with reference to the accompanying drawings, in which the same numbers represent the same or similar elements throughout the several drawings. The following description of embodiments is not representative of all possible embodiments consistent with the present application. Rather, it is merely an example of a system and method consistent with some aspects of the present application as detailed in the claims.

[0047] Ultrasonic testing can detect defects such as cracks, porosities, inclusions, etc. in materials by transmitting and receiving ultrasonic signals. Ultrasonic waves propagate in solid media require the medium to transfer energy. The acoustic impedance in air is very different from that of solid materials, which can cause most of the acoustic waves to reflect at the air-solid interface, and cannot effectively enter the material. Couplant is a liquid or gel used to fill the gap between the probe and the surface of the material being tested, reducing the air layer and improving the transmission efficiency of acoustic waves.

[0048] In a corrosive environment, the couplant can be contaminated by corrosion products, affecting its performance and leading to reduced acoustic wave transmission efficiency. Corrosion can cause the metal surface to become rough and uneven, affecting the uniform distribution of the couplant and in turn affecting the transmission and reception of ultrasonic waves. Oxides, rust, etc. produced by corrosion can form a layer of material on the surface of the material, which can affect the propagation of ultrasonic waves, leading to inaccurate test results. There may be more defects and inhomogeneities inside the material in a corrosive environment, causing the acoustic waves to attenuate more severely during propagation, affecting the detection depth and accuracy.

[0049] Magnetic flux leakage testing is a method that uses the characteristics of magnetic field propagation in materials to detect surface and near-surface defects. By detecting the leakage of the magnetic field, defects such as cracks and corrosion in the material can be found. Magnetic flux leakage testing mainly detects surface and near-surface defects, and has limited ability to detect internal corrosion. Internal corrosion can cause the thickness of the material to decrease, but magnetic flux leakage testing may not be able to effectively detect these internal defects. Magnetic flux leakage testing has high requirements for surface conditions, and the surface must be relatively flat and clean. Surface roughness, unevenness or the presence of a large amount of corrosion products caused by corrosion can affect the accuracy of the test results. Due to the limitations of surface conditions, magnetic flux leakage testing may not be able to provide high-precision test results in complex corrosion environments. Corrosion products and surface unevenness can cause irregular changes in the magnetic field, affecting the interpretation of the detection signal.

[0050] In summary, ultrasonic testing requires a couplant and has high requirements for surface conditions, and the corrosive environment can affect the distribution of the couplant and the transmission of acoustic waves. Magnetic flux leakage testing does not require a couplant, but has high requirements for surface conditions and limited ability to detect internal corrosion, resulting in low detection accuracy.

[0051] To solve the problem of low detection accuracy, such as Figure 1As shown, some embodiments of the present application provide a multi-channel corrosion measurement circuit, which includes a base measurement circuit, the base measurement circuit including a constant current source positive output (DRIVE+), a constant current source negative output (DRIVE-), a sensing positive terminal (SENSE+) and a sensing negative terminal (SENSE-).

[0052] The constant current source is a power supply that provides a stable current, the output current of which does not change with the load. In this circuit, the constant current source is used to provide a stable current to the channel to be measured. The constant current source positive output and the constant current source negative output provide positive and negative currents respectively, forming a loop.

[0053] The sensing positive terminal is connected to the positive potential terminal of the first channel and the positive potential terminal of the second channel through the electronic switch group, and the sensing positive terminal and the sensing negative terminal are used to measure the voltage change caused by corrosion and the like. Together with the positive output of the constant current source and the negative output of the constant current source, it forms a loop for detecting the voltage change generated when the current passes through the channel to be measured.

[0054] The constant current source positive output is connected to the electronic switch group, and the electronic switch group is connected to the input terminal of the first channel and the input terminal of the second channel. In some embodiments, the electronic switch group includes a first electronic switch, a second electronic switch, a third electronic switch and a fourth electronic switch.

[0055] One end of the first electronic switch is connected to the constant current source positive output, and the other end is connected to the input terminal of the first channel and the input terminal of the second channel; one end of the second electronic switch is connected to the constant current source negative output, and the other end is connected to the output terminal of the first channel and the output terminal of the second channel; one end of the third electronic switch is connected to the sensing positive terminal, and the other end is connected to the sensing positive terminal of the first channel and the sensing positive terminal of the second channel; one end of the fourth electronic switch is connected to the sensing negative terminal, and the other end is connected to the sensing negative terminal of the first channel and the sensing negative terminal of the second channel.

[0056] The electronic switch is a component of the electronic switch group, which is used to control the connection between the positive and negative outputs of the constant current source and the input / output terminals of different channels, as well as the connection between the sensing positive and negative terminals and the sensing positive and negative terminals of different channels. It can realize the switching between different channels, so as to allow the circuit to measure the corrosion of multiple channels in turn or simultaneously.

[0057] For example, the constant current source provides a stable current output, and the electronic switch group selectively connects the first channel or the second channel, the current passes through the selected channel, and a voltage drop is generated in the channel, for example due to resistance changes caused by corrosion and the like. The sensing positive terminal and the sensing negative terminal measure this voltage drop, so that the resistance parameter of the channel can be calculated.

[0058] By passing a constant current excitation current through the test specimen, the steel pipeline corrosion dynamic test analysis system software is used to measure the micro-resistance value at the same time, and the micro-resistance value field fingerprint coefficient can be calculated by the following formula:

[0059]

[0060] Wherein, R i (t x ) is the resistance of electrode pair i at t x , R i (t0) is the resistance of electrode pair i at t0, R ref (t x ) is the resistance of the reference electrode pair at t x , R ref (t0) is the resistance of the reference electrode pair at t0.

[0061] The micro-resistance value field fingerprint coefficient is a parameter in the field fingerprint technology, which can reflect the change of the resistance value of the outer surface of the pipeline, and is closely related to the corrosion state of the inner surface of the pipeline.

[0062] Based on the relationship between the resistance value and the thickness of the pipeline, the measured resistance value can be converted into the thickness information of the pipeline, and the residual thickness of the steel pipeline is calculated by the following formula:

[0063]

[0064] Wherein, WT(t0) is the original wall thickness of the test specimen, and FC is the micro-resistance value field fingerprint coefficient.

[0065] According to the measurement results, the residual thickness matrix of the steel pipeline is obtained, which can provide a comprehensive view of the corrosion morphology of the inner surface of the pipeline, and is used to evaluate the overall corrosion condition and the severity of local corrosion of the pipeline.

[0066] As Figure 2 shown, in some embodiments, it further includes an amplification circuit and a switch input circuit, the basic measurement circuit is connected to the switch input circuit through the amplification circuit, Figure 2 the integrated amplification circuit 3545 is used to amplify the input signal, and the amplification circuit is used to amplify the signal received from the switch input circuit, so that the basic measurement circuit can measure or process more accurately.

[0067] The switch input circuit includes a first transistor, a first input end (Input), and a first ground end (ISO_COM), and the current passes through the first input end and the emitter of the first transistor to connect the first ground end, wherein the first transistor is an NPN transistor, and the first transistor is used to control the flow of current. When the switch is closed, the first transistor allows the current to flow through its emitter to the first ground end, thereby changing the state of the circuit.

[0068] The first input terminal is the port where the switch input circuit connects to an external switch. When the external switch is closed, current is allowed to flow through the first input terminal into the circuit. The first ground terminal is a reference point in the circuit, connected to the power supply ground. In the switch input circuit, the first ground terminal provides a return path for the current.

[0069] When the external switch is closed, current flows through the first input terminal into the switch input circuit and then through the emitter of the first transistor to the first ground terminal. A change in the state of the first transistor, such as from cutoff to saturation, generates a measurable signal change, which is amplified by the amplifier circuit. The amplified signal is then transmitted to the basic measurement circuit, which can use it for further measurement or processing.

[0070] like Figure 3 As shown, in some embodiments, a relay input circuit is also included. The basic measurement circuit is connected to the relay input circuit via an amplifier circuit, which amplifies the signal from the relay input circuit so that the basic measurement circuit can process or measure the signal more accurately.

[0071] A relay is an electrical control device that activates its contact system (closing or opening) when the input value reaches a specified value, thereby controlling the on / off state of the circuit. In the relay input circuit, the relay provides the control signal. The relay input circuit is an interface circuit used to receive signals from external relays and convert them into signals recognizable internally. The relay input circuit includes: a relay, a second transistor, a second input terminal (Input), and a second ground terminal (ISO_COM). When the relay input circuit is operating, the relay signal passes through the second transistor, and the current flows through the transistor's emitter connected to the second ground terminal.

[0072] The second transistor is an NPN transistor, and like the first transistor, it is used to control the flow of current. When the relay operates, it changes the state of the second transistor, allowing or preventing current from flowing through the emitter of the second transistor to the second ground terminal. The second input terminal is the port connecting the relay input circuit to an external relay. When the external relay operates, it sends a signal to the internal circuit through the second input terminal.

[0073] When the external relay actuates, a signal is sent to the relay input circuit through the second input terminal. This signal is received by the second transistor, which then changes its state. The change in the transistor's state causes current to flow through its emitter to the second ground terminal, or it may prevent current flow. The amplifier circuit amplifies this current signal so that the basic measurement circuit can process or measure it more accurately. The basic measurement circuit then performs further measurements or processing based on the amplified signal.

[0074] As Figure 4 shown, in some embodiments, further comprising: an amplification circuit and a first output circuit, the base measurement circuit is connected through the amplification circuit and the first output circuit, in this embodiment, the amplification circuit is used to increase the amplitude or power of the signal, which can amplify the weak input signal to a level sufficient to drive the subsequent circuit, for amplifying the signal from the base measurement circuit.

[0075] The first output circuit is an interface circuit, which is used to convert the amplified signal into a form suitable for external devices or loads. The first output circuit includes a third transistor, a third input (Input), a third output (Output), a first common (Common), and a third ground (ISO_COM). The emitter of the third transistor is connected to the first common, and the collector of the third transistor is connected to the third output. When the input signal turns on the third transistor, a path is formed between the third output and the first common.

[0076] The third transistor is an NPN transistor, which is used to control the flow of current, and can change its conduction state according to the change of the input signal. The third input is a port of the first output circuit connected to the amplification circuit, which is used to receive the signal from the amplification circuit and transmit it to the third transistor. The third output is a port of the first output circuit connected to external loads such as relays, LED lights, etc. When the third transistor is turned on, the third output will provide a current path, allowing the external load to work. The first common is a reference point in the first output circuit, which is connected to the third ground or has a fixed potential. The first common provides a current return path for the third transistor. The third ground is a reference point in the circuit, which is connected to the ground of the power supply, and is used to provide a common return path for the current in the circuit, ensuring the stability and safety of the circuit.

[0077] For example, when the base measurement circuit detects a signal, it transmits the signal to the amplification circuit. After amplification, the signal is transmitted to the third input of the first output circuit. The third input receives the amplified signal and transmits it to the third transistor. When the amplitude of the input signal is large enough, the third transistor is turned on, and a path is formed between the collector and the emitter of the third transistor, allowing current to flow from the third output to the first common. The current path allows the external load to work, thereby realizing the output and control of the signal.

[0078] As Figure 5As shown, in some embodiments, the base measurement circuit is further connected to an amplification circuit and a second output circuit, the amplification circuit is used to amplify the signal from the base measurement circuit, and the second output circuit is an electronic interface used to convert the amplified signal into a form suitable for use by external devices.

[0079] The second output circuit includes a fourth transistor, a fourth input terminal (Input), a fourth output terminal (Output), a second common terminal (Common), and a fourth ground terminal (ISO_COM). The collector of the fourth transistor is connected to the fourth output terminal, and the emitter of the fourth transistor is connected to the second common terminal. When the fourth transistor is turned on by the input signal, a positive current path is formed between the fourth output terminal and the second common terminal. The fourth transistor is a PNP transistor used to control the flow of current, and is a semiconductor device that can change its conduction state according to changes in the input signal.

[0080] The fourth input terminal is a port connected to the amplification circuit, used to receive signals from the amplification circuit and pass them to the fourth transistor. The fourth output terminal is a port connected to the external load, which provides a positive current path when the fourth transistor is turned on, allowing the external load to work. The second common terminal is a reference point in the second output circuit, connected to the fourth ground terminal or having a fixed potential, and provides a current return path for the fourth transistor. The fourth ground terminal is a reference point in the circuit, connected to the ground of the power supply, and provides a common return path for the current in the circuit, ensuring the stability and safety of the circuit.

[0081] When the base measurement circuit detects a signal, it passes the signal to the amplification circuit, which amplifies the signal and passes it to the fourth input terminal of the second output circuit. The fourth input terminal receives the amplified signal and passes it to the fourth transistor. When the amplitude of the input signal is large enough, the fourth transistor is turned on, forming a positive current path between the collector and the emitter, allowing current to flow from the output terminal to the second common terminal. The positive current path allows the external load to work, thereby achieving signal output and control.

[0082] The single-chip microcomputer control and sampling system is responsible for data acquisition and processing. It controls the electronic switching circuit through the single-chip microcomputer, switches in real time, and improves the measurement accuracy.

[0083] Based on the above-mentioned multi-channel corrosion measurement circuit, see Figure 6The multi-channel corrosion measurement circuit is used to simultaneously measure the corrosion conditions of multiple channels, each channel corresponding to an electrode, and can measure the corrosion degree of different positions of the measured steel pipe. The corrosion sensor is arranged in the shell 100.

[0084] The corrosion sensor includes a multi-channel corrosion measurement circuit, a first nickel sheet electrode 200, and a second nickel sheet electrode 300. One end of the first nickel sheet electrode 200 is connected to the positive potential end of the first channel, and the other end of the first nickel sheet electrode 200 is connected to the measured steel pipe. One end of the second nickel sheet electrode 300 is connected to the positive potential end of the second channel, and the other end of the second nickel sheet electrode 300 is connected to the measured steel pipe. The first nickel sheet electrode 200 is an electrode in the corrosion sensor, used to contact the measured steel pipe and measure its corrosion condition, and the second nickel sheet electrode 300 is the same as the first nickel sheet electrode 200.

[0085] The first nickel sheet electrode 200 and the second nickel sheet electrode 300 are made of corrosion-resistant nickel material to ensure that they will not be damaged by corrosion during the measurement process. By simultaneously measuring the corrosion conditions of the two electrodes, the corrosion degrees of different positions can be compared, and the overall corrosion condition of the measured steel pipe can be more accurately evaluated.

[0086] The positive potential end is a port in the basic measurement circuit, used to provide a positive potential to the electrode. During the corrosion measurement process, the positive potential end applies a certain voltage to the electrode to excite the corrosion reaction and measure the current or potential change generated. The multi-channel corrosion measurement circuit applies a constant current excitation current to the first nickel sheet electrode 200 and the second nickel sheet electrode 300 respectively. Under the action of the constant current excitation, an electrochemical reaction occurs between the inner surface of the measured steel pipe and the nickel sheet electrode, producing a small resistance change. The steel pipe corrosion dynamic test analysis system software monitors and records these small resistance values in real time, and through specific algorithm processing, obtains key information such as corrosion rate and corrosion degree. Real-time monitoring of the inner surface corrosion of the metal steel pipe can be realized, and the accuracy and timeliness of the corrosion monitoring can be improved. Through multi-channel measurement, a wider area can be covered, and the comprehensiveness of the monitoring can be improved.

[0087] In some embodiments, the camera is connected to the shell 100 through a telescopic rod, and its position and angle of view can be adjusted to better observe the condition of the inner surface of the metal steel pipe. The display screen 110 is connected to the camera and the corrosion sensor, and can display the images captured by the camera and the data measured by the corrosion sensor in real time. The condition of the inner surface of the metal steel pipe can be observed through the display screen 110, and the measurement results of the corrosion sensor can be referred to for comprehensive evaluation of the corrosion condition.

[0088] The application provides a multi-channel corrosion measurement circuit and a device for measuring the inner surface corrosion of a metal steel pipe, the corrosion device comprising: a shell 100 and a corrosion sensor arranged in the shell 100, the corrosion sensor comprising a multi-channel corrosion measurement circuit, a first nickel sheet electrode 200 and a second nickel sheet electrode 300, the multi-channel corrosion measurement circuit can provide a stable constant current source, and through the tiny potential difference between the four-stage cross measurement electrode matrix, the tiny resistance value between the steel pipe electrode matrix can be efficiently and accurately detected, and then the corrosion condition of the inner surface of the steel pipe is obtained.

[0089] The similar parts among the embodiments provided in the application can be referred to each other, the specific embodiments provided above are only several examples under the general concept of the application, and do not constitute the limitation of the protection scope of the application. For those skilled in the art, any other embodiments extended according to the application scheme without creative labor are within the protection scope of the application.

Claims

1. A multi-channel corrosion measurement circuit, characterized by, include: Basic measurement circuit; The basic measurement circuit includes: An electronic switching assembly is connected to the positive output terminal of the constant current source. The electronic switching assembly is connected to at least the input terminal of the first channel and the input terminal of the second channel; The negative output terminal of the constant current source forms a circuit with the positive output terminal of the constant current source. The positive terminal of the sensing electrode is connected to the positive potential terminal of the first channel and the positive potential terminal of the second channel via the electronic switching group. The negative terminal of the sensor forms a circuit with the positive terminal of the sensor.

2. The multi-channel corrosion measurement circuit of claim 1, wherein, The electronic switching assembly includes: The first electronic switching switch has one end connected to the positive output terminal of the constant current source and the other end connected to the input terminal of the first channel and the input terminal of the second channel. The second electronic switching switch has one end connected to the negative output terminal of the constant current source, and the other end connected to the output terminal of the first channel and the output terminal of the second channel. The third electronic switching switch has one end connected to the positive sensing terminal and the other end connected to the first channel positive sensing terminal and the second channel positive sensing terminal. The fourth electronic switching switch has one end connected to the sensing negative terminal and the other end connected to the first channel sensing negative terminal and the second channel sensing negative terminal.

3. The multi-channel corrosion measurement circuit of claim 1, wherein, Also includes: An amplifier circuit and a switch input circuit are provided, wherein the basic measurement circuit is connected to the switch input circuit via the amplifier circuit. The switch input circuit includes: a first transistor, a first input terminal, and a first ground terminal. Current flows through the first input terminal and the emitter of the first transistor to the first ground terminal.

4. The multi-channel corrosion measurement circuit of claim 1, wherein, Also includes: An amplifier circuit and a relay input circuit are provided, wherein the basic measurement circuit is connected to the relay input circuit via the amplifier circuit. The relay input circuit includes a relay, a second transistor, a second input terminal, and a second ground terminal. When the relay input circuit is working, the signal of the relay passes through the second transistor, and the current passes through the emitter of the second transistor and is connected to the second ground terminal.

5. The multi-channel corrosion measurement circuit of claim 1, wherein, Also includes: An amplifier circuit and a first output circuit are provided, wherein the basic measurement circuit is connected to the first output circuit via the amplifier circuit. The first output circuit includes: a third transistor, a third input terminal, a third output terminal, a first common terminal, and a third ground terminal; The emitter of the third transistor is connected to the first common terminal, and the collector of the third transistor is connected to the third output terminal. When the input signal turns on the third transistor, a path is formed between the third output terminal and the first common terminal.

6. The multi-channel corrosion measurement circuit of claim 1, wherein, Also includes: An amplifier circuit and a second output circuit are provided, wherein the basic measurement circuit is connected to the second output circuit via the amplifier circuit. The second output circuit includes: a fourth transistor, a fourth input terminal, a fourth output terminal, a second common terminal, and a fourth ground terminal; The collector of the fourth transistor is connected to the fourth output terminal, and the emitter of the fourth transistor is connected to the second common terminal. When the input signal turns on the fourth transistor, the fourth output terminal and the second common terminal form a positive current path.

7. A device for measuring corrosion of an inner surface of a metal pipe, characterized by include: The housing and the corrosion sensor are disposed within the housing. The corrosion sensor includes the multi-channel corrosion measurement circuit, the first nickel electrode, and the second nickel electrode as described in any one of claims 1-6. One end of the first nickel sheet electrode is connected to the positive potential end of the first channel, and the other end of the first nickel sheet electrode is connected to the measured steel pipe; One end of the second nickel sheet electrode is connected to the positive potential end of the second channel, and the other end of the second nickel sheet electrode is connected to the measured steel pipe.

8. The apparatus for measuring the inner surface corrosion of a metal pipe according to claim 7, wherein Further comprising a camera, a telescopic rod and a display screen, the display screen is connected with the camera and the corrosion sensor, and the camera is connected with the shell through the telescopic rod.

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