Corrosion depth monitor, monitoring system and method for purified water and injection water pipeline

Abstract

The invention discloses a corrosion depth monitor, a corrosion depth monitoring system and a corrosion depth monitoring method for purified water and injection water pipelines. The monitor comprises a monitor shell, a monitor base frame, a power supply and communication interface, a sensor interface, a measurement mainboard and an antenna, the measurement mainboard is mounted in the monitor shell; the monitor bottom table and the monitor shell are connected and fixed through hexagonal screws, the monitor shell is sealed, and a sealing ring is arranged at the joint of the monitor bottom table and the monitor shell; the power supply and communication interface and the sensor interface are respectively connected with the measurement mainboard through an aviation plug; the antenna is arranged on the monitor shell and is connected with the measurement mainboard through a cable; a power supply and communication cable of an industrial field is connected to the power supply and communication interface through the power adapter, so that power supply and signal transmission of the corrosion depth monitor are realized; and the sensor interface is connected with the three-electrode sensor through the adaptive rod.

Description

Technical Field

[0001] The invention belongs to the technical field of corrosion monitoring, and relates to a corrosion depth monitor, a monitoring system and a method for purified water and water for injection pipelines. Background Art

[0002] Water for injection used in the pharmaceutical manufacturing process is the direct raw material for pharmaceutical manufacturing. The quality of purified water and water for injection is closely related to the quality of pharmaceutical production.

[0003] The material of the pipeline used in the water system of the pharmaceutical factory is mostly 316L high-quality austenitic stainless steel, which has the advantages of anti-oxidation and corrosion resistance. However, after the pipeline has been running for a period of time, a layer of red rust will appear on the inner wall of the pipeline, which can be partially removed by wiping, but cannot be completely wiped off.

[0004] The red rust in the water system pipelines of pharmaceutical factories can usually meet the heavy metal content limit requirements of various regulations and will not adversely affect the quality of purified water and water for injection. However, the red rust has the risk of falling off, which will cause the quality of pharmaceutical water to be contaminated by heavy metals. Therefore, pharmaceutical factories are required to take active measures to avoid and reduce the occurrence of this oxidative corrosion phenomenon in the equipment related to the water system of pharmaceutical factories.

[0005] Pharmaceutical factories usually use pickling and passivation methods to remove the red rust that has already occurred in the water system. In general, the water system of pharmaceutical factories is pickled and passivated at least once a year to eliminate the safety risks that may be caused by red rust. However, this blind and empirical regular pickling and passivation of pipelines may cause the red rust to remain in the pipeline for too long or even fall off due to untimely pickling, causing heavy metal pollution in the water quality of pharmaceutical water; on the contrary, if the pickling and passivation of pipelines is too frequent, the pharmaceutical factory needs to pay high fees, and the shutdown of water production equipment and sewage equipment during this period will also cause economic losses. At the same time, during the maintenance of the monitoring points, it is also necessary to pay high testing and verification fees, resulting in a large waste of resources and an increase in maintenance costs.

[0006] In summary, there is an urgent need for a corrosion depth monitoring instrument that can be used for purified water and water for injection pipelines, which can automatically and online monitor the corrosion status of the water system pipelines in pharmaceutical factories for a long time, and perform pickling and passivation maintenance treatments as needed, effectively reducing the probability of red rust and quality risks while saving maintenance costs. Summary of the invention

[0007] In order to solve the above technical problems, the purpose of the present invention is to provide a corrosion depth monitor, monitoring system and method for purified water and water for injection pipelines.

[0008] The present invention provides a corrosion depth monitor for purified water and water for injection pipelines, comprising: a monitor housing, a monitor base, a power supply and communication interface, a sensor interface, a measurement mainboard and an antenna;

[0009] The measuring mainboard is installed in the monitor housing; the monitor base and the monitor housing are connected and fixed by hexagonal screws, and the monitor housing is closed, and a sealing ring is provided at the connection between the monitor base and the monitor housing;

[0010] The power supply, communication interface and sensor interface are connected to the measurement main board via the aviation plug respectively; the antenna is installed on the monitor housing and connected to the measurement main board via a cable;

[0011] The power supply and communication cables at the industrial site are connected to the power supply and communication interface through a power adapter to realize power supply and signal transmission of the corrosion depth monitor; the sensor interface is connected to the three-electrode sensor through an adapter rod.

[0012] The present invention also provides a corrosion depth monitoring system for purified water and water for injection pipelines, comprising a monitoring device, a data processing server or an enterprise cloud server; the monitoring device adopts the above-mentioned corrosion depth monitoring instrument for purified water and water for injection pipelines; wherein the monitoring device is one or more sets, each set of monitoring devices is independently installed at a purified water or water for injection pipeline monitoring point in a pharmaceutical factory, and the corrosion monitoring data collected by the monitoring device is uploaded to a designated data processing server or enterprise cloud server via an RS485 bus or a GPRS data transmission module.

[0013] The present invention also provides a monitoring method using the above-mentioned corrosion depth monitor for purified water and water for injection pipelines, comprising the following steps:

[0014] Step 1: Measure the solution resistance. Use the signal source of the signal conditioning module to apply a step signal with an amplitude of f to the three-electrode sensor, and use the clock module to time the step time. At the instant of applying the step signal, the microcontroller controls the signal conditioning module to collect the feedback current I0 of the three-electrode sensor. The solution resistance R at this time u =f / I0;

[0015] Step 2: Adjust the compensation resistance value, and adjust the resistance value of the sliding rheostat in the signal conditioning module to the solution resistance value calculated in step 1, so as to reduce the error between the actual voltage value and the set voltage value of the polarization voltage signal and the weak polarization voltage signal applied to the working electrode;

[0016] Step 3: Measure the open circuit potential without applying polarization voltage. The microcontroller controls the signal conditioning module to collect the open circuit potential E0 of the three-electrode sensor.

[0017] Step 4: Apply polarization and measure polarization current. The microcontroller controls the signal source of the signal conditioning module to apply polarization to the three-electrode sensor. The polarization voltage signals are E0±5mV respectively. The microcontroller controls the signal conditioning module to collect the anode polarization current I of the three-electrode sensor. + and the cathodic polarization current I - ;

[0018] Step 5: Apply weak polarization and measure weak polarization current. The microcontroller controls the signal source of the signal conditioning module to apply weak polarization to the three-electrode sensor. The weak polarization voltage signals are E0±40mV respectively. The microcontroller controls the signal conditioning module to collect the anode weak polarization current I of the three-electrode sensor. a and cathode weak polarization current I c ;

[0019] Step 6: Calculate the corrosion rate and corrosion depth, and calculate the corrosion current density I using the linear polarization principle and the corrosion rate weak polarization measurement principle. corr , and then calculate the corrosion rate V mma And the corrosion depth H corr , the calculation formula is as follows:

[0020]

[0021]

[0022]

[0023]

[0024] Among them, ΔE1 is the polarization voltage value, and ΔE2 is the weak polarization voltage value;

[0025]

[0026] Where A is the atomic weight of the metal; n is the number of electrons gained or lost; F is the Faraday constant; ρ is the density of the electrode metal material;

[0027] The corrosion depth H is calculated using the current index relationship of the corrosion rate. corr , the calculation formula is as follows:

[0028] H corr =V mma ×(N_data n-1 +Internal)

[0029] Among them, N_data n-1 It is the total measurement time accumulated up to the last data, and Internal is the measurement interval of the current measurement;

[0030] Step 7: The corrosion data measurement process is completed, and the data is stored and transmitted to the enterprise cloud platform through the communication module.

[0031] The corrosion depth monitor, monitoring method and method of purified water and water for injection pipelines of the present invention have the following beneficial effects and advantages:

[0032] 1. The present invention sends an excitation signal to the three-electrode sensor through a signal conditioning module and receives a feedback signal. The microcontroller is based on corrosion electrochemical technology and the principle of weak polarization to calculate the corrosion rate of the medium on the pipeline and the equivalent corrosion depth according to the measured feedback signal. This can then provide an early warning of excessive corrosion thickness. In the field of actual industrial applications, it can guide the timing of pickling and passivation in pharmaceutical factories and evaluate the pickling and passivation effect of chemical solvents.

[0033] 2. Based on the weak polarization measurement principle of corrosion rate, the signal conditioning module of the present invention can measure the solution resistance in real time, and use it to set the resistance value of the sliding rheostat, and automatically realize voltage drop compensation. It reduces the deviation of polarization potential and weak polarization potential caused by uncompensated solution resistance. It greatly improves the measurement accuracy of corrosion rate and corrosion depth.

[0034] 3. The present invention provides a variety of data storage and transmission methods, including but not limited to remote GPRS data transmission, Beidou remote data transmission, RS232 / 485 data transmission, periodic data storage, local data reading and uploading, etc. The system has wide compatibility and stronger adaptability; it supports cloud platform technology and can realize seamless connection between the output signal of the monitor and the cloud platform. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a schematic diagram of the installation of the corrosion depth monitor for purified water and water for injection pipelines of the present invention;

[0036] Figure 2 It is a block diagram of the corrosion depth monitor for purified water and water for injection pipelines of the present invention;

[0037] Figure 3 It is the functional block diagram of the signal conditioning module;

[0038] Figure 4 It is a structural topological diagram of the corrosion depth monitoring system of the purified water and water for injection pipeline of the present invention;

[0039] Figure 5 The present invention is a flow chart of a method for monitoring the corrosion depth of purified water and water for injection pipelines. DETAILED DESCRIPTION

[0040] like Figure 1As shown, a corrosion depth monitor for purified water and water for injection pipelines of the present invention comprises: a monitor housing 102 , a monitor base 103 , a power supply and communication interface 105 , a sensor interface 106 , a measurement mainboard 104 and an antenna 101 .

[0041] The measuring mainboard 104 is installed in the monitor housing 102; the monitor base 103 is connected and fixed to the monitor housing 102 by hexagonal screws, and the monitor housing is closed, and a sealing ring is provided at the connection between the monitor base 103 and the monitor housing 102. The power supply and communication interface 105 and the sensor interface 106 are respectively connected to the measuring mainboard 104 through the aviation plug; the antenna 101 is installed on the monitor housing 102 and connected to the measuring mainboard 104 through a cable. The power supply and communication cable of the industrial site are connected to the power supply and communication interface 105 through the power adapter 4 to realize the power supply and signal transmission of the corrosion depth monitor 1. The sensor interface 106 is connected to the three-electrode sensor 3 through the adapter rod 2.

[0042] The three-electrode sensor 3 includes three sensor electrodes: a working electrode 301, an auxiliary electrode 302, and a reference electrode 303. The sensor electrode is connected to the electrode holder via a threaded column, and the contact surface is sealed with a sealing gasket end face. The working electrode 301, the auxiliary electrode 302, and the reference electrode 303 of the three-electrode sensor 3 are placed in the pipeline 5, and the three-electrode sensor 3 and the pipeline 5 are connected by a flange, fixed and clamped by a clamp, and a sealing ring is provided on the flange contact surface to ensure sealing.

[0043] The power supply and communication interface 105, the sensor interface 106, the aviation plugs at both ends of the adapter rod 2, and the interface aviation plugs of the three-electrode sensor 3 all use waterproof aviation plugs. After being firmly connected, their protection level reaches IP68 and can be used outdoors for a long time, meeting the requirements of long-term real-time monitoring on site. Figure 2 As shown, the measurement mainboard 104 includes: a microcontroller and a signal conditioning module, a self-test module, a power supply module, a storage module, a clock module, a communication module and a maintenance interface respectively connected to the microcontroller.

[0044] The output lead of the signal conditioning module is connected to the three-electrode sensor, and the feedback signal of the three-electrode sensor is connected to the input of the signal conditioning module. The microcontroller controls the signal conditioning module to output the polarization voltage signal and the weak polarization voltage signal and applies them to the three-electrode sensor. The feedback signal of the three-electrode sensor is processed and transformed by the signal conditioning module and transmitted to the microcontroller; the microcontroller calculates the corrosion rate and the rust depth according to the feedback signal and interacts with the storage module to realize the storage and reading of the monitoring data; the microcontroller uploads the calculated corrosion rate and rust depth to the data processing software of the data processing server or the enterprise cloud server via the GPRS or RS485 bus through the communication module, and compares the corrosion data with the rust depth warning value. If it exceeds the warning value, it means that the thickness of the red rust in the pipeline is about to exceed the standard, and an early warning is issued in the software to remind the user to perform rust removal. The microcontroller connects the computer to set the working parameters of the monitor through the maintenance interface; the microcontroller measures the three-electrode electrochemical equivalent circuit in the self-test module by controlling the signal conditioning module, and performs self-test on the signal conditioning module to ensure the accuracy of the signal conditioning module measurement.

[0045] like Figure 3 As shown, the signal conditioning module of the measurement mainboard 104 includes: a signal source, an analog-to-digital converter ADC, a first signal amplifier A1, a second signal amplifier A2, a third signal follower A3, a sliding resistor KRu, a gain unit, a filter unit and an adaptive gain control circuit.

[0046] The signal source receives the instruction of the microcontroller, and the excitation signal outputted by the signal source is connected to the in-phase end of the first signal amplifier A1. The output end of the first signal amplifier A1 is connected to the auxiliary electrode of the three-electrode sensor via the second resistor R2, and the in-phase end of the first signal amplifier A1 is connected to its output end via the first resistor R1. The feedback signal of the working electrode of the three-electrode sensor enters the input end of the analog-to-digital converter ADC via the second signal amplifier A2, the gain unit and the filter unit, and the output signal of the analog-to-digital converter ADC is connected to the microcontroller; the output end of the second signal amplifier A2 is connected to the in-phase end of the first signal amplifier A1 via a sliding rheostat; the output end of the second signal amplifier is connected to the working electrode of the three-electrode sensor via the third resistor R3. The feedback signal of the reference electrode of the three-electrode sensor is connected to the inverting end of the first signal amplifier A1 via the third signal follower A3. The microcontroller controls the adaptive gain control circuit to automatically control the gain change according to the measured signal value.

[0047] The excitation signal output by the signal source includes: a step signal, a polarization voltage signal and a weak polarization voltage signal. The polarization voltage signal is equal to E0±5mV, and the weak polarization voltage signal is equal to E0±40mV; E0 is the open circuit potential of the three-electrode sensor.

[0048] The microcontroller adopts STM32F103. The antenna adopts an outdoor AP high-gain 7dB Rogers waterproof antenna.

[0049] like Figure 4 As shown, a corrosion depth monitoring system for purified water and water for injection pipelines of the present invention includes a corrosion depth monitor, a data processing server or an enterprise cloud server; the corrosion depth monitor adopts the above-mentioned corrosion depth monitor for purified water and water for injection pipelines. The corrosion depth monitors are one or more sets, each set of corrosion depth monitors is independently installed at a monitoring point of purified water or water for injection pipelines in a pharmaceutical factory, and the corrosion monitoring data collected by the corrosion depth monitor is uploaded to a designated data processing server or enterprise cloud server via an RS485 bus or a GPRS data transmission module.

[0050] In this embodiment, the corrosion depth monitoring system includes N monitoring devices, each monitoring instrument collects the signal of a sensor, and each monitoring device can transmit data through GPRS wireless transmission or RS485 bus wired transmission. When the data transmission mode is wireless transmission, the monitoring device sends TCP / IP protocol data to the server through the GPRS wireless network. When the data transmission mode is RS485 bus wired transmission, the monitoring device transmits data to the server through a data converter.

[0051] During on-site installation, corrosion monitoring points are selected and monitoring devices are installed according to the actual needs of the industrial site. If the RS485 bus data transmission method is selected, data converters are arranged according to the distribution of monitoring points to realize data transmission between the monitoring device and the data converter, reduce on-site wiring costs, and solve the limitation on the number of monitoring points on a single bus. The data converter is connected to the data processing server through an Ethernet interface or a serial communication interface to realize the storage of corrosion monitoring data on the server. External network users or local area network users view or download data by accessing the data processing software installed and deployed on the data processing server or enterprise cloud server.

[0052] like Figure 5 As shown, a method for monitoring the corrosion depth of purified water and water for injection pipelines of the present invention comprises the following steps:

[0053] Step 1: Measure the solution resistance: Use the signal source of the signal conditioning module to apply a step signal to the three-electrode sensor 3, with an amplitude of 50mV, and use the clock module to time the step time to be 40ms. At the instant of applying the step signal, the microcontroller controls the signal conditioning module to collect the feedback current I0 of the three-electrode sensor 3. The solution resistance R at this time u =50 / I0.

[0054] Step 2: Adjust the compensation resistance value: adjust the resistance value of the sliding resistor KRu in the signal conditioning module to the solution resistance value calculated in step (1), thereby reducing the error between the actual voltage value and the set voltage value of the polarization voltage signal and the weak polarization voltage signal applied to the working electrode 301.

[0055] Step 3: Measure the open circuit potential: Without applying polarization voltage, the microcontroller controls the signal conditioning module to collect the open circuit potential E0 of the three-electrode sensor 3.

[0056] Step 4: Apply polarization and measure polarization current: The microcontroller controls the signal source of the signal conditioning module to apply polarization to the three-electrode sensor 3, and the polarization voltage signals are E0±5mV. The microcontroller controls the signal conditioning module to collect the anode polarization current I of the three-electrode sensor 3. + and the cathodic polarization current I - The polarization potential applied here can take different voltage values ​​according to the material and working conditions.

[0057] Step 5: Apply weak polarization and measure weak polarization current: The microcontroller controls the signal source of the signal conditioning module to apply weak polarization to the three-electrode sensor 3, and the weak polarization voltage signals are E0±40mV. The microcontroller controls the signal conditioning module to collect the anode weak polarization current I of the three-electrode sensor 3. a and cathode weak polarization current I c The weak polarization potential applied here can take different voltage values ​​according to the material and working conditions.

[0058] Step 6: Calculate the corrosion rate and corrosion depth: Calculate the corrosion current density I using the linear polarization principle and the weak polarization measurement principle of the corrosion rate. corr , and then calculate the corrosion rate V mma And the corrosion depth H corr , the calculation formula is as follows:

[0059]

[0060]

[0061]

[0062]

[0063] Among them, ΔE1 is the polarization voltage value, and ΔE2 is the weak polarization voltage value.

[0064]

[0065] Among them, A is the atomic weight of the metal; n is the number of electrons gained or lost; F is the Faraday constant; and ρ is the density of the electrode metal material.

[0066] The corrosion depth H is calculated using the current index relationship of the corrosion rate. corr , the calculation formula is as follows:

[0067] H corr =V mma ×(N_data n-1 +Internal)

[0068] Among them, N_data n-1 It is the total measurement time accumulated up to the last data, and Internal is the measurement interval of the current measurement.

[0069] Step 7: The corrosion data measurement process is completed, and the data is stored and transmitted to the enterprise cloud platform through the communication module.

[0070] After the corrosion data is transmitted to the data processing software installed on the data processing server or the enterprise cloud server by using the monitor 1 of the present invention, the corrosion data is compared with the rust depth warning value. If it exceeds the warning value, it means that the thickness of the red rust in the pipeline is about to exceed the standard, and an early warning is issued in the software to remind the user to perform rust removal operations.

[0071] The corrosion depth monitor for purified water and water for injection pipelines of the present invention can measure the solution resistance in real time and automatically realize the voltage drop compensation based on the weak polarization measurement principle of corrosion rate. The polarization potential and weak polarization potential deviation caused by the uncompensated solution resistance are reduced. The measurement accuracy of corrosion rate and corrosion depth is greatly improved. By measuring and calculating the corrosion rate of the pipeline by the medium and the equivalent corrosion depth, an early warning of excessive corrosion thickness is realized. In the field of actual industrial application, it can guide the pickling and passivation timing of pharmaceutical factories and evaluate the pickling and passivation effect of chemical solvents.

[0072] The present invention adopts high-precision analog signal source control technology and tiny signal measurement technology, and the accuracy of the measured polarization current and weak polarization current can reach nA level.

[0073] The use of 5G communication (technology) module can realize the remote transmission of measurement data to the data processing server or enterprise cloud server, and also supports RS232 / 485 wired data transmission method.

[0074] The corrosion depth monitor for purified water and water for injection pipelines of the present invention is not only suitable for measuring the corrosion depth of purified water and water for injection pipelines in pharmaceutical factories, but also suitable for measuring the corrosion depth of other pipelines with low-conductivity media.

[0075] The corrosion depth monitor for purified water and water for injection pipelines of the present invention is not limited to connecting to a three-electrode sensor and measuring the corrosion depth, but can also be connected to other two-electrode structure sensors and measure the corrosion depth through an electrochemical measurement method.

[0076] The above description is only a preferred embodiment of the present invention and is not intended to limit the concept of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A corrosion depth monitor for purified water and water for injection pipelines, characterized in that: include: Monitor housing, monitor base, power supply and communication interface, sensor interface, measurement mainboard and antenna; The measuring mainboard is installed in the monitor housing; the monitor base and the monitor housing are connected and fixed by hexagonal screws, and the monitor housing is closed, and a sealing ring is provided at the connection between the monitor base and the monitor housing; The power supply, communication interface and sensor interface are connected to the measurement main board via the aviation plug respectively; the antenna is installed on the monitor housing and connected to the measurement main board via a cable; The power supply and communication cables at the industrial site are connected to the power supply and communication interface through a power adapter to realize power supply and signal transmission of the corrosion depth monitor; the sensor interface is connected to the three-electrode sensor through an adapter rod.

2. The corrosion depth monitor for purified water and water for injection pipelines as claimed in claim 1, characterized in that: The measurement mainboard includes: a microcontroller and a signal conditioning module, a self-test module, a power supply module, a storage module, a clock module, a communication module and a maintenance interface respectively connected to the microcontroller; The output lead of the signal conditioning module is connected to the three-electrode sensor, the feedback signal of the three-electrode sensor is connected to the input of the signal conditioning module, the microcontroller controls the signal conditioning module to output a polarization voltage signal and a weak polarization voltage signal and applies them to the three-electrode sensor, and the feedback signal of the three-electrode sensor is processed and transformed by the signal conditioning module and transmitted to the microcontroller; the microcontroller calculates the corrosion rate and the rust depth according to the feedback signal and exchanges data with the storage module to realize the storage and reading of the monitoring data; the microcontroller uploads the calculated corrosion rate and rust depth to the data processing server or the enterprise cloud server via the GPRS or RS485 bus through the communication module; the microcontroller connects to the computer through the maintenance interface to set the working parameters of the monitor; the microcontroller controls the signal conditioning module to measure the three-electrode electrochemical equivalent circuit in the self-test module, and performs self-test on the signal conditioning module to ensure the accuracy of the measurement of the signal conditioning module.

3. The corrosion depth monitor for purified water and water for injection pipelines as claimed in claim 2, characterized in that: The signal conditioning module includes: a signal source, an analog-to-digital converter, a first signal amplifier, a second signal amplifier, a third signal follower, a sliding resistor, a gain unit, a filtering unit and an adaptive gain control circuit; The signal source receives instructions from the microcontroller, and the excitation signal output by the signal source is connected to the in-phase end of the first signal amplifier. The output end of the first signal amplifier is connected to the auxiliary electrode of the three-electrode sensor via the second resistor, and the in-phase end of the first signal amplifier is connected to its output end via the first resistor; the feedback signal of the working electrode of the three-electrode sensor enters the input end of the analog-to-digital converter ADC via the second signal amplifier, the gain unit and the filter unit, and the output signal of the analog-to-digital converter is connected to the microcontroller; the output end of the second signal amplifier is connected to the in-phase end of the first signal amplifier via a sliding rheostat; the output end of the second signal amplifier is connected to the working electrode of the three-electrode sensor via a third resistor; the feedback signal of the reference electrode of the three-electrode sensor is connected to the inverting end of the first signal amplifier via a third signal follower; the microcontroller controls the adaptive gain control circuit to automatically control the gain change according to the measurement signal value.

4. The corrosion depth monitor for purified water and water for injection pipelines as claimed in claim 3, characterized in that: The excitation signal output by the signal source includes: a step signal, a polarization voltage signal and a weak polarization voltage signal; the polarization voltage signal is equal to E0±5mV, and the weak polarization voltage signal is equal to E0±40mV; E0 is the open circuit potential of the three-electrode sensor.

5. The corrosion depth monitor for purified water and water for injection pipelines as claimed in claim 2, characterized in that: The microcontroller adopts STM32F103.

6. The corrosion depth monitor for purified water and water for injection pipelines according to claim 1, characterized in that: The antenna adopts an outdoor AP high-gain 7dB Rogers waterproof antenna.

7. The corrosion depth monitoring system for purified water and water for injection pipelines is characterized by: It comprises a monitoring device, a data processing server or an enterprise cloud server; the monitoring device adopts the corrosion depth monitor of the purified water and water for injection pipeline according to any one of claims 1 to 6; There are one or more monitoring devices, each of which is independently installed at the monitoring point of the purified water or injection water pipeline in the pharmaceutical factory. The corrosion monitoring data collected by the monitoring device is uploaded to the designated data processing server or enterprise cloud server through the RS485 bus or GPRS data transmission module.

8. A monitoring method for the corrosion depth of purified water and water for injection pipelines using the corrosion depth monitor of any one of claims 1 to 6, characterized in that: The steps include: Step 1: Measure the solution resistance. Use the signal source of the signal conditioning module to apply a step signal with an amplitude of f to the three-electrode sensor, and use the clock module to time the step time. At the instant of applying the step signal, the microcontroller controls the signal conditioning module to collect the feedback current I0 of the three-electrode sensor. The solution resistance R at this time u =f / I0; Step 2: Adjust the compensation resistance value, and adjust the resistance value of the sliding rheostat in the signal conditioning module to the solution resistance value calculated in step 1, so as to reduce the error between the actual voltage value and the set voltage value of the polarization voltage signal and the weak polarization voltage signal applied to the working electrode; Step 3: Measure the open circuit potential without applying polarization voltage. The microcontroller controls the signal conditioning module to collect the open circuit potential E0 of the three-electrode sensor. Step 4: Apply polarization and measure polarization current. The microcontroller controls the signal source of the signal conditioning module to apply polarization to the three-electrode sensor. The polarization voltage signals are E0±5mV respectively. The microcontroller controls the signal conditioning module to collect the anode polarization current I of the three-electrode sensor. + and the cathodic polarization current I - ; Step 5: Apply weak polarization and measure weak polarization current. The microcontroller controls the signal source of the signal conditioning module to apply weak polarization to the three-electrode sensor. The weak polarization voltage signals are E0±40mV respectively. The microcontroller controls the signal conditioning module to collect the anode weak polarization current I of the three-electrode sensor. a and cathode weak polarization current I c ; Step 6: Calculate the corrosion rate and corrosion depth, and calculate the corrosion current density I using the linear polarization principle and the corrosion rate weak polarization measurement principle. corr , and then calculate the corrosion rate V mma And the corrosion depth H corr , the calculation formula is as follows: Among them, ΔE1 is the polarization voltage value, and ΔE2 is the weak polarization voltage value; Where A is the atomic weight of the metal; n is the number of electrons gained or lost; F is the Faraday constant; ρ is the density of the electrode metal material; The corrosion depth H is calculated using the current index relationship of the corrosion rate. corr , the calculation formula is as follows: H corr =V mma ×(N_data n-1 +Internal) Among them, N_data n-1 It is the total measurement time accumulated up to the last data, and Internal is the measurement interval of the current measurement; Step 7: The corrosion data measurement process is completed, and the data is stored and transmitted to the enterprise cloud platform through the communication module.

9. The method for monitoring the corrosion depth of purified water and water for injection pipelines according to claim 8, characterized in that: The amplitude of the step signal applied in step 1 is 50 mV, and the step time is 40 milliseconds.

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