An in - well tubing corrosion real - time on - line probe monitoring device

Abstract

An in-well tubing corrosion real-time online probe monitoring device, comprising a monitoring unit, a PCB board unit, a ground computer processing system, a heat-insulating outer shell, and an armored cable. The monitoring unit includes a ball screw, and a lead screw vertical moving body is fixed on the outer periphery of the ball screw. The lead screw vertical moving body has two layers of baffles perpendicular to the ball screw, and a corrosion probe mounting table is connected to the bottom. A rotary support block is installed on the inner side of the bottom of the heat-insulating outer shell, and two layers of rotary protection shells are fixedly connected thereto. The end of the upper layer extends between the two layers of baffles, and the movement of the baffles can drive the movement of the upper layer and simultaneously drive the rotation of the rotary support block. The two parts of the lower layer can be exposed or closed to wrap the corrosion probe mounting table along with the rotation of the rotary support block. The present invention provides a protection device for the corrosion probe assembly, preventing premature corrosion during the downhole process, capable of directionally monitoring the corrosion degree of tubing at any depth, realizing continuous data acquisition and storage, and achieving the function of online transmission.

Description

Technical Field

[0001] The present invention relates to the technical field of on-line corrosion monitoring, and particularly to a real-time on-line probe monitoring device for downhole tubing corrosion. Background Art

[0002] During the oilfield exploitation process, the downhole corrosion of oil and water well tubing has become increasingly serious. To ensure the normal development and production of the oilfield and avoid the perforation and fracture of downhole tubing, it is necessary to monitor the downhole tubing corrosion in real time.

[0003] At present, traditional downhole tubing corrosion monitoring mostly adopts the coupon method and is monitored based on the weight loss method. For example, a downhole production tubing corrosion rate tester disclosed in Chinese Patent Document with the application number 201220556299.5 monitors the corrosion conditions of the inner and outer walls of the tubing by using the methods of inner coupon and outer coupon. However, the corrosion condition of the tubing can only be determined by measuring after taking out the coupon, and it cannot reflect the downhole corrosion state in real time.

[0004] Existing downhole corrosion monitoring also mostly adopts the resistance probe method. A patent with the application number 201010176251.7 discloses a scheme for on-line corrosion monitoring of oil and gas pipelines using the resistance probe technology. Utilizing the characteristic that the cross-sectional area of a metal wire or sheet decreases due to corrosion and the resistance value increases, the metal corrosion amount and corrosion rate are obtained by measuring the resistance increment. However, the measured resistance is directly exposed to the corrosion environment inside the pipeline and is only suitable for long-term corrosion monitoring.

[0005] A composite probe for on-line monitoring of downhole tubing corrosion proposed in Chinese Patent Document with the application number 201410722531.1 calculates the corrosion allowance of the downhole tubing by collecting the terminal voltages of the reference element and the sensing element of the resistance probe, and obtains the instantaneous corrosion rate of the downhole tubing by applying sine wave signals with different frequency points to the working electrode. Although this invention can measure the instantaneous corrosion rate, the pipeline is extremely long, the signal is unstable, it is prone to deviation, the structure is complex and inconvenient to install, it is not easy to repair when a fault occurs, and all the tubing needs to be taken out for inspection and repair, resulting in high maintenance costs. Summary of the Invention

[0006] In order to solve the problems in the prior art such as the inability to reflect the downhole corrosion state in real time, unstable signal, prone to deviation, and complex structure, the present invention provides a real-time on-line probe monitoring device for downhole tubing corrosion.

[0007] The technical solution of the present invention is as follows:

[0008] An in - well tubing corrosion real - time online probe monitoring device, characterized in that it includes a monitoring unit, a PCB board unit, a ground computer processing system, a heat - insulating shell, and an armored cable. The heat - insulating shell is of a cylindrical structure, with an upper heat - insulating sealing cover fixed at the top. The monitoring unit and the PCB board unit are located inside the heat - insulating shell. The inside of the armored cable's outer shell wraps a steel wire rope and a composite cable. The ground end of the composite cable is connected to the ground computer processing system, and the bottom end is connected to the PCB board unit;

[0009] The monitoring unit includes a motor control cable and a top corrosion probe cable led out from the PCB board unit, a servo motor connected to the motor control cable. The servo motor is connected to a ball screw below. A screw vertical moving body is fixed on the outer circumference of the ball screw. The screw vertical moving body has two layers of baffles perpendicular to the ball screw. The bottom of the screw vertical moving body is connected to a corrosion probe mounting table. The bottom of the corrosion probe mounting table has the corrosion probe assembly connected to the top corrosion probe cable;

[0010] A rotating support block is installed on the inner side of the bottom of the heat - insulating shell. Two layers of rotating protective shells are fixedly connected to the rotating support block. Each layer includes two opposite parts. The end of the upper layer extends between the two layers of baffles, and the movement of the baffle can drive the movement of the upper layer and simultaneously drive the rotation of the rotating support block. The two parts of the lower layer can be exposed or closed to wrap the corrosion probe mounting table along with the rotation of the rotating support block.

[0011] Preferably, the servo motor is installed on a heat - insulating sealing plate covering the cross - section of the cylindrical structure. The heat - insulating sealing plate has through - holes for passing through the top corrosion probe cable and the ball screw.

[0012] Further preferably, the bottom of the servo motor is connected to the ball screw through a coupling. A rolling ball bearing is arranged at the connecting rod passing through the through - hole of the heat - insulating sealing plate between the coupling and the servo motor.

[0013] Preferably, the rotating protective shell is made of heat - insulating material. A rubber sealing strip is installed at the bottom where the two parts of the lower layer contact when closed.

[0014] Preferably, the top of the corrosion probe mounting table is flat and the bottom is a downward - convex arc surface. The top of the mounting table has a mounting table top heat - insulating sealing cover, and the side and bottom are mounting table bottom heat - insulating sealing shells. The bottom corrosion probe cable has a cable block at the place passing through the mounting table top heat - insulating sealing cover, which is divided into several corrosion probe sub - cables and then connected to several corrosion probe assemblies. The corrosion probe assemblies pass through the mounting table bottom heat - insulating sealing shell.

[0015] Further preferably, three groups of the corrosion probe assemblies 25 are evenly distributed at the bottom of the corrosion probe mounting table.

[0016] Preferably, the corrosion probe assembly includes a corrosion probe positive cable, a corrosion probe negative cable, a cable joint mounting block, a corrosion probe top insulation seal, a corrosion probe housing, a corrosion probe, a housing hole, a corrosion probe mounting block, a welding block, a corrosion probe bottom connecting piece, and a corrosion probe bottom metal seal. The corrosion probe positive cable is fixedly connected to the corrosion probe mounting block. The corrosion probe mounting block is a metal conductor. The material of the corrosion probe is the same as that of the oil pipe. The top is fixedly connected to the corrosion probe mounting block through the welding block, and the bottom is connected to the corrosion probe bottom metal seal through the corrosion probe bottom connecting piece. The bottom of the corrosion probe housing is connected to the corrosion probe bottom metal seal by a thread, and the top is connected to the corrosion probe negative cable through the cable joint mounting block.

[0017] Preferably, the PCB board unit includes a single-chip microcomputer, a voltage regulator, an A / D converter, a Flash memory, a control clock, and a bidirectional constant current source. The single-chip microcomputer is connected to the voltage regulator. The A / D converter is a multi-channel A / D converter and is connected to the corrosion probe in the monitoring unit. The control clock 46 is connected to the single-chip microcomputer.

[0018] The technical effects of the present invention are as follows:

[0019] The present invention discloses a real-time online probe monitoring device for downhole oil pipe corrosion, which includes a monitoring unit, a PCB board unit, a ground computer processing station, a heat insulation housing, an upper heat insulation seal cover, an armored cable, a steel wire rope, and a composite cable. The composite cable is composed of multiple lines to achieve the functions of conducting electricity and transmitting data, and is connected to the PCB board unit at the bottom. The ground computer processing station can receive and process data through the composite cable, and then obtain the corrosion rate of the oil pipe. The A / D converter is a multi-channel A / D converter and is connected to the corrosion probe in the monitoring unit for receiving and transmitting electrical signals. When in use, all components of the device are assembled on the ground. At this time, the rotary protection shell is in a closed state. The armored cable is wound around a pulley and installed on the ground computer processing station. The corrosion probe monitoring device is lowered to a fixed depth in the oil pipe through computer control. The ground computer processing system is operated to energize the corrosion probe monitoring device, and the servo motor is controlled to work, driving the lead screw vertical moving body to move downward, thereby driving the rotary protection shell to rotate around the rotary protection block, so that the corrosion probe assembly is exposed to the corrosion environment.

[0020] Compared with the prior art, the present invention provides a protection device for the corrosion probe assembly to prevent premature corrosion during downhole operation and enable directional monitoring of the corrosion degree of tubing at any depth; three groups of corrosion probe assemblies are provided, and the average value of the measured corrosion rate results is taken to make the measurement results more accurate; continuous data acquisition, storage and online transmission functions can be realized.

[0021] Specifically, the advantages of the present invention are as follows:

[0022] 1. A real-time online probe monitoring device for downhole tubing corrosion is designed, and a protection device for the corrosion probe assembly is provided to prevent premature corrosion during downhole operation and enable directional monitoring of the corrosion degree of tubing at any depth.

[0023] 2. Three groups of corrosion probe assemblies are provided in the present invention, and the average value of the measured corrosion rate results is taken to make the measurement results more accurate.

[0024] 3. The present invention can realize continuous data acquisition, storage and online transmission functions.

[0025] 4. All downhole components of the present invention are made of high-temperature resistant materials, which can withstand a temperature of 140 degrees Celsius and a high pressure of 60 MPa. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic structural diagram of the corrosion monitoring device of the present invention.

[0027] Figure 2 It is a schematic working diagram of the monitoring unit of the present invention.

[0028] Figure 3 It is a schematic internal structure diagram of the corrosion probe mounting table of the present invention.

[0029] Figure 4 It is a schematic structural diagram of the corrosion probe assembly of the present invention.

[0030] Figure 5 It is a schematic working diagram of the present invention.

[0031] Figure 6 It is a schematic circuit principle diagram of the present invention.

[0032] The reference numerals in the drawings are listed as follows:

[0033] 1. Monitoring unit, 2. Heat-insulating housing, 3. PCB board unit, 4. Upper heat-insulating sealing cover, 5. Armored cable, 6. Steel wire rope, 7. Composite cable, 8. Motor control cable, 9. Top corrosion probe cable, 10. Servo motor, 11. Heat-insulating sealing plate, 12. Vertical moving body of lead screw, 13. Rotating support block, 14. Rotating protective housing, 15. Corrosion probe mounting table, 16. Rolling ball bearing, 17. Coupling, 18. Ball screw, 19. Rubber sealing strip, 20. Upper heat-insulating sealing cover of mounting table top, 21. Bottom corrosion probe cable, 22. Cable block, 23. Corrosion probe sub-cable, 24. Lower heat-insulating sealing housing of mounting table, 25. Corrosion probe assembly, 26. Positive cable of corrosion probe, 27. Negative cable of corrosion probe, 28. Cable joint mounting block, 29. Top insulating seal of corrosion probe, 30. Corrosion probe housing, 31. Corrosion probe, 32. Housing hole, 33. Corrosion probe mounting block, 34. Welding block, 35. Bottom connecting part of corrosion probe, 36. Bottom metal seal of corrosion probe, 37. Corrosion probe monitoring device, 38. Oil pipe, 39. Pulley support frame, 40. Ground computer processing table, 41. Single-chip microcomputer, 42. Voltage stabilizer, 43. External power supply, 44. Flash memory, 45. A / D converter, 46. Control clock, 47. Bidirectional constant current source. Detailed implementation manners

[0034] For a better understanding of the present invention, the present invention will be further explained below in conjunction with specific embodiments.

[0035] Embodiment 1

[0036] As Figure 1 and Figure 5 As shown in FIGS. 1 and [FIGURE NUMBER NOT PROVIDED IN THE ORIGINAL, SO CAN'T BE TRANSLATED ACCURATELY], an on-line probe monitoring device for real-time corrosion of downhole oil pipes in this embodiment includes a monitoring unit 1, a PCB board unit 3, a ground computer processing system, i.e., a ground computer processing table 40, a heat-insulating housing 2, an upper heat-insulating sealing cover 4, an armored cable 5, a steel wire rope 6, and a composite cable 7. The heat-insulating housing 2 is in a cylindrical tubular structure, and is fixedly connected to the upper heat-insulating sealing cover 4 at the top, ensuring that the monitoring device can work in the high-temperature environment at the bottom of the well. The monitoring unit 1 and the PCB board unit 3 are located inside the heat-insulating housing 2. The outer shell of the armored cable 5 is made of high-temperature resistant material, and internally wraps the steel wire rope 6 and the composite cable 7. The composite cable 7 is composed of multiple lines, and can realize the functions of conducting electricity and transmitting data, and is connected to the PCB board unit 3 at the bottom. The ground computer processing table 40 can receive and process data through the composite cable 7, and then obtain the corrosion rate of the oil pipe.

[0037] As shown in 1 and Figure 6As shown, the PCB board unit 3 includes a single-chip microcomputer 41, a voltage regulator 42, an A / D converter 45, a Flash memory 44, a control clock 46, and a bidirectional constant current source 47. The single-chip microcomputer 41 is connected to the voltage regulator 42, and the voltage regulator 42 provides power. The A / D converter 45 is a multi-channel A / D converter, which is connected to the corrosion probe in the monitoring unit 41 and is used to receive and transmit electrical signals. The control clock 46 is connected to the single-chip microcomputer 41 and can periodically control the start and stop of the single-chip microcomputer 41.

[0038] As Figure 2 and Figure 3As shown, the monitoring unit 1 includes a motor control cable 8, a top corrosion probe cable 9, a servo motor 10, a heat insulation and sealing plate 11, a lead screw vertical moving body 12, a rotating support block 13, a rotating protective shell 14, a corrosion probe mounting table 15, a rolling ball bearing 16, a coupling 17, a ball screw 18, a rubber sealing strip 19, a heat insulation and sealing cover 20 for the top of the mounting table, a bottom corrosion probe cable 21, a cable block 22, a corrosion probe sub-cable 23, and a heat insulation and sealing shell 24 for the bottom of the mounting table. Specifically, the monitoring unit 1 includes a servo motor that leads out the motor control cable 8 and the top corrosion probe cable 9 from the PCB board unit 3. The servo motor 10 is connected to the motor control cable 8 and is connected to the ball screw 18 below. The outer circumference of the ball screw 18 is fixed with a lead screw vertical moving body 12. The lead screw vertical moving body 12 has two layers of baffles perpendicular to the ball screw 18. The bottom of the lead screw vertical moving body 12 is connected to a corrosion probe mounting table 24. The bottom of the corrosion probe mounting table 24 has a corrosion probe assembly 25 connected to the top corrosion probe cable 9. The servo motor 10 is installed on the heat insulation and sealing plate 11 covering the cross-section of the cylindrical structure and is connected to the ball screw 18 through the coupling 17 at the bottom. The heat insulation and sealing plate 11 has through holes for passing through the top corrosion probe cable 9 and the ball screw 18. A rolling ball bearing is provided at the connecting rod passing through the through hole of the heat insulation and sealing plate 11 between the coupling 17 and the servo motor 10. A rotating support block 13 is installed on the inner side of the bottom of the heat insulation outer shell 2. Two layers of rotating protective shells 14 are fixedly connected to the rotating support block 13. Each layer includes two opposite parts. The end of the upper layer extends between the two layers of baffles, and the movement of the baffle can drive the movement of the upper layer and simultaneously drive the rotation of the rotating support block 13. The two parts of the lower layer can be exposed or closed to wrap the corrosion probe mounting table 15 as the rotating support block 13 rotates. That is, the ball screw 18 is connected in cooperation with the lead screw vertical moving body 12. The rotation of the servo motor 10 drives the lead screw vertical moving body 12 to move up and down, and then drives the rotation of the rotating protective shell 14 to achieve opening and closing. The rotating protective shell 14 is made of heat insulation material and is preferably semicircular in shape. A circle of the rubber sealing strip 19 is installed at the bottom, which can achieve sealing and heat insulation when closed. The bottom of the lead screw vertical moving body 12 is fixedly connected to the corrosion probe mounting table 15. The corrosion probe mounting table 15 is in the shape of a frustum of a cone plus a spherical bottom, and three groups of the corrosion probe assemblies 25 are evenly distributed at the bottom.

[0039] As Figure 4As shown in the figure, the corrosion probe assembly 25 includes a corrosion probe positive cable 26, a corrosion probe negative cable 27, a cable joint mounting block 28, a corrosion probe top insulation seal 29, a corrosion probe housing 30, a corrosion probe 31, a housing hole 32, a corrosion probe mounting block 33, a welding block 34, a corrosion probe bottom connecting piece 35, and a corrosion probe bottom metal seal 36. The corrosion probe positive cable 26 is fixedly connected to the corrosion probe mounting block 33, and the corrosion probe mounting block 33 is a metal conductor. The material of the corrosion probe 31 is the same as that of the oil pipe. The top is fixedly connected to the corrosion probe mounting block 33 through the welding block 34, and the bottom is connected to the corrosion probe bottom metal seal 36 through the corrosion probe bottom connecting piece 35. The bottom of the corrosion probe housing 30 is threadedly connected to the corrosion probe bottom metal seal 36, and the top is connected to the corrosion probe negative cable 27 through the cable joint mounting block 28.

[0040] When the present invention is in use, as Figure 5 shown in the figure, all components of the present device are assembled on the ground. At this time, the rotary protective shell 14 is in a closed state. The armored cable 5 is wound around a pulley and installed on the ground computer processing table 40. The corrosion probe monitoring device 37 is lowered to a fixed depth in the oil pipe through computer control. The ground computer processing table 40 is operated to energize the corrosion probe monitoring device 37, and the servo motor 10 is controlled to work, driving the lead screw vertical moving body 12 to move downward, thereby driving the rotary protective shell 14 to rotate around the rotary protection block 13, so that the corrosion probe assembly 25 is exposed to the corrosion environment.

[0041] In the monitoring corrosion environment of this embodiment, which is a gas phase, the bidirectional constant current source 47 can directly supply current to the monitoring unit 1. The signal is transmitted back to the single-chip microcomputer 41 through the A / D converter, and after being processed by the single-chip microcomputer 41, it is stored in the Flash memory 44. In addition, the electrical signal continues to be transmitted to the ground computer processing table 40 through the composite cable 7, and the corrosion rate of the oil pipe in the gas phase environment is obtained after computer processing. After the monitoring is completed, the servo motor 10 can be restarted through the single-chip microcomputer 41 to close the rotary protective shell 14 and perform device recovery.

[0042] It should be further elaborated that during the real-time monitoring process, the control clock 46 can perform timed control of the single-chip microcomputer operation, so manual real-time operation is not required. After the monitoring is completed, the Flash memory 44 is taken out, the stored data is analyzed, and the obtained corrosion rate of the oil pipe is compared with the corrosion rate of the oil pipe directly transmitted to the ground computer processing table 40 to prevent errors caused during data transmission and ensure the accuracy of the monitoring results.

[0043] In addition, nine high-temperature resistant wires are included in the bottom corrosion probe cable 21, and three high-temperature resistant wires are wrapped in each of the corrosion probe sub-cables 23. There are three groups in total, which are respectively connected to the three groups of corrosion probe assemblies 25. During operation, the bidirectional constant current source 47 transmits a current signal to the monitoring unit 1, which flows through the corrosion probe positive cable 26, the corrosion probe mounting block 33, the welding block 34, the corrosion probe 31, the corrosion probe bottom connecting piece 35, the corrosion probe bottom metal seal 36, the corrosion probe housing 30, the cable joint mounting block 28, and finally is transmitted back to the A / D converter 45 through the corrosion probe negative cable 26 for processing.

[0044] Embodiment 2

[0045] In this embodiment, the monitored corrosion environment is a liquid phase or a liquid-solid mixed phase. Different from Embodiment 1, before the bidirectional constant current source 47 transmits current to the monitoring unit 1, the servo motor 10 needs to be started to close the rotating protective shell 14 and then the current is transmitted for corrosion monitoring.

[0046] Although the embodiments of the present invention have been described above, they are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention should be included in the protection scope of the present invention. The above shows and describes the basic principles, main features, and advantages of the present invention. Therefore, the above is only the embodiment of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification is only the principle of the present invention. Without departing from the spirit and scope of the present invention, the present invention also includes various equivalent changes and improvements, and these changes and improvements will all fall within the scope of the present invention claimed. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. An in - well tubing corrosion real - time on - line probe monitoring device, characterized in that It includes a monitoring unit, a PCB board unit, a ground computer processing system, a heat-insulating shell, and an armored cable. The heat-insulating shell is of a cylindrical structure, with an upper heat-insulating sealing cover fixed at the top. The monitoring unit and the PCB board unit are located inside the heat-insulating shell. Inside the outer shell of the armored cable, a steel wire rope and a composite cable are wrapped. The ground end of the composite cable is connected to the ground computer processing system, and the bottom end is connected to the PCB board unit; The monitoring unit includes a motor control cable and a top corrosion probe cable led out from the PCB board unit, a servo motor connected to the motor control cable. Below the servo motor, a ball screw is connected. A screw vertical moving body is fixed on the outer periphery of the ball screw. The screw vertical moving body has two layers of baffles perpendicular to the ball screw. At the bottom of the screw vertical moving body, a corrosion probe mounting table is connected. At the bottom of the corrosion probe mounting table, there is the corrosion probe assembly connected to the top corrosion probe cable; At the inner side of the bottom of the heat-insulating shell, a rotating support block is installed. Two layers of rotating protection shells are fixedly connected to the rotating support block. Each layer includes two opposite parts. The end of the upper layer extends between the two layers of baffles, and the movement of the baffle can drive the movement of the upper layer and at the same time drive the rotation of the rotating support block. The two parts of the lower layer can be exposed or closed to wrap the corrosion probe mounting table along with the rotation of the rotating support block; The servo motor is installed on a heat-insulating sealing plate covering the cross-section of the cylindrical structure. The heat-insulating sealing plate has through holes for passing through the top corrosion probe cable and the ball screw; The rotating protection shell is made of heat-insulating material. At the bottom where the two parts of the lower layer are in contact when closed, a rubber sealing strip is installed in a circle; The top of the corrosion probe mounting table is flat, and the bottom is a downwardly convex arc surface. The top is the top heat-insulating sealing cover of the mounting table. The side and the bottom are the bottom heat-insulating sealing shell of the mounting table. At the place where the bottom corrosion probe cable passes through the top heat-insulating sealing cover of the mounting table, there is a cable partition block, which is divided into several corrosion probe sub-cables and then connected to several corrosion probe assemblies. The corrosion probe assemblies pass through the bottom heat-insulating sealing shell of the mounting table; Three groups of the corrosion probe assemblies are evenly distributed at the bottom of the corrosion probe mounting table; The ball screw is connected to the screw vertical moving body in a matching manner. The rotation of the servo motor drives the screw vertical moving body to move up and down, and then drives the rotation of the rotating protection shell to realize opening and closing.

2. The device according to claim 1, characterized in that The bottom of the servo motor is connected to the ball screw through a coupling. At the connecting rod passing through the through hole of the heat-insulating sealing plate between the coupling and the servo motor, a rolling ball bearing is provided.

3. The device according to claim 1, characterized in that The corrosion probe assembly includes a corrosion probe positive electrode cable, a corrosion probe negative electrode cable, a cable joint mounting block, a corrosion probe top insulation seal, a corrosion probe housing, a corrosion probe, a housing hole, a corrosion probe mounting block, a welding block, a corrosion probe bottom connecting piece, and a corrosion probe bottom metal seal. The corrosion probe positive electrode cable is fixedly connected to the corrosion probe mounting block. The corrosion probe mounting block is a metal conductor. The corrosion probe material is the same as the tubing material. The top is fixedly connected to the corrosion probe mounting block through the welding block. The bottom is connected to the corrosion probe bottom metal seal through the corrosion probe bottom connecting piece. The bottom of the corrosion probe housing is connected to the corrosion probe bottom metal seal by a thread. The top is connected to the corrosion probe negative electrode cable through the cable joint mounting block.

4. The device according to claim 1, wherein The PCB board unit includes a single-chip microcomputer, a voltage regulator, an A / D converter, a Flash memory, a control clock, and a bidirectional constant current source. The single-chip microcomputer is connected to the voltage regulator. The A / D converter is a multi-channel A / D converter and is connected to the corrosion probe in the monitoring unit. The control clock (46) is connected to the single-chip microcomputer.

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