Liquid sensor and damage detection device and method thereof

Abstract

The present disclosure relates to the field of sensor technology. A liquid sensor damage detection device is used for a liquid sensor with a sealed cavity. The liquid sensor damage detection device includes an external electrode, an internal electrode, a diagnostic circuit, and a control circuit. The internal electrode and the external electrode are both electrically connected to the diagnostic circuit. The external electrode is disposed outside the cavity. The internal electrode, the diagnostic circuit, and the control circuit are disposed inside the cavity. The diagnostic circuit diagnoses whether the liquid sensor is damaged based on the diagnostic signal between the external electrode and the internal electrode. The control circuit is connected to the diagnostic circuit to turn on the diagnostic circuit, and turns off the diagnostic circuit after the diagnosis is completed. This technical solution will not always keep the diagnostic circuit discharging to the outside, attracting strong electricity into the external electrode, and the liquid sensor damage detection device will have higher stability and lifespan.

Description

Technical Field

[0001] The present disclosure relates to the field of sensor technology, and in particular to a liquid sensor and a damage detection device and method thereof. Background Art

[0002] A liquid sensor is an electronic sensor that can measure the physical or chemical properties of a liquid. It can convert the physical or chemical properties of a liquid into electrical signals, such as dissolved oxygen and pH in water.

[0003] Because liquid sensors are often deployed in outdoor environments, where aquatic organisms or debris can impact the sensors, they are susceptible to damage, particularly the membranes used for selective filtration. Damage to the sensor's housing or membrane allows liquid to enter the sensor cavity, where the reaction electrode is located, causing measurement results to deviate significantly from normal values.

[0004] In the prior art, in order to detect damage to the sensor housing or diaphragm, an external electrode is set on the outside of the liquid sensor cavity and an internal electrode is set inside the liquid sensor cavity. By real-time detecting changes in the resistance value and voltage divider value between the external electrode and the internal electrode, it is determined whether the housing is damaged.

[0005] However, this detection method requires the installation of external electrodes, which are connected to the internal circuit board. Liquid sensors placed in the wild environment are often interfered by strong electricity. Strong electricity can easily enter the internal circuit board through the external electrodes, causing the internal circuit board to be burned, resulting in low stability and life of the liquid sensor. Summary of the Invention

[0006] In order to solve the above technical problems or at least partially solve the above technical problems, the present disclosure provides a liquid sensor damage detection device and a liquid sensor, which have higher stability and lifespan.

[0007] In a first aspect, the present disclosure provides a liquid sensor damage detection device for a liquid sensor having a sealed cavity, the liquid sensor damage detection device comprising an internal electrode, an external electrode, a diagnostic circuit, and a control circuit;

[0008] The external electrode is arranged outside the cavity of the liquid sensor;

[0009] The internal electrodes, diagnostic circuit and control circuit are arranged inside the cavity of the liquid sensor;

[0010] wherein the internal electrode and the external electrode are both electrically connected to the diagnostic circuit;

[0011] The diagnostic circuit sends a diagnostic signal to the outside through the external electrode and receives the diagnostic signal through the internal electrode, and the diagnostic circuit diagnoses whether the liquid sensor is damaged based on the diagnostic signal between the external electrode and the internal electrode;

[0012] The control circuit is connected to the diagnosis circuit to turn on the diagnosis circuit and to turn off the diagnosis circuit after the diagnosis circuit completes diagnosis.

[0013] Optionally, the liquid sensor damage detection device further includes an isolation circuit for coupling and isolating the external electrode and the diagnostic circuit, and the external electrode is electrically connected to the diagnostic circuit via the isolation circuit.

[0014] Optionally, the isolation circuit includes a coupling capacitor, and the external electrode is electrically connected to the diagnostic circuit via the coupling capacitor.

[0015] Optionally, the liquid sensor damage detection device further includes a strong current protection circuit, which is electrically connected to the external electrode so as to conduct the external strong current to an external lead-out portion when the external strong current enters the external electrode.

[0016] Optionally, the high-current protection circuit includes a transient diode, the lead-out part includes a ground wire, the first end of the transient diode is connected to an external electrode, and the second end of the transient diode is connected to the ground wire, so that the external electrode is grounded to lead out the external high current when the external high current enters the external electrode.

[0017] Optionally, the diagnostic signal includes a resistance value, a voltage division value, or an electrical signal, and the diagnostic circuit compares the detected resistance value between the external electrode and the internal electrode with a preset resistance threshold range, or compares the voltage division value between the external electrode and the internal electrode with a preset voltage division threshold range, or compares the electrical signal received by the internal electrode with the electrical signal sent by the external electrode to obtain an electrical signal transmission integrity rate;

[0018] If the resistance value is within the resistance threshold range, the shell is determined to be damaged; or if the voltage division value is within the voltage division threshold range, the shell is determined to be damaged; or if the electrical signal transmission integrity rate is within the preset integrity rate range, the shell is determined to be damaged.

[0019] Optionally, the diagnostic circuit includes an excitation circuit and a signal receiving and analysis circuit, the excitation circuit is connected to an external electrode, and when the control circuit turns on the diagnostic circuit, the excitation circuit sends a diagnostic signal to the outside through the external electrode; the signal receiving and analysis circuit is electrically connected to the internal electrode and the external electrode to detect the diagnostic signal.

[0020] Optionally, the liquid sensor damage detection device further includes a remote communication unit, which is connected to a diagnostic circuit. The diagnostic circuit diagnoses that the liquid sensor is damaged and generates a damage signal. The remote communication unit receives the damage signal and sends the damage signal to an external server.

[0021] In a second aspect, the present disclosure provides a liquid sensor, comprising a liquid sensor damage detection device, a shell and a penetration device as described in any one of the first aspects, wherein the penetration device and the shell form a closed cavity, the internal electrodes, diagnostic circuit and control circuit are arranged in the cavity, and at least part of the external electrodes are arranged outside the shell.

[0022] In a third aspect, the present disclosure provides a method for detecting damage to a liquid sensor, using any of the sensor damage detection devices described in the first aspect, wherein the control unit controls the diagnostic circuit to be turned on according to a preset signal;

[0023] The diagnostic circuit detects the resistance value, voltage division value or electrical signal between the internal electrode and the external electrode;

[0024] The diagnostic circuit compares the detected resistance value between the external electrode and the internal electrode with a preset resistance threshold range, or compares the voltage divided value between the external electrode and the internal electrode with a preset voltage divided threshold range, or compares the electrical signal received by the internal electrode with the electrical signal sent by the external electrode to obtain an electrical signal transmission integrity rate;

[0025] If the resistance value is within the resistance threshold range, or the divided voltage value is within the divided voltage threshold range, or the electrical signal transmission integrity rate is within a preset integrity rate range, the diagnostic circuit determines that the liquid sensor is damaged and issues a damage signal;

[0026] The control unit controls the diagnosis circuit to be closed.

[0027] The technical solution provided by the embodiments of the present disclosure has the following advantages over the prior art:

[0028] The present disclosure provides a liquid sensor damage detection device, wherein the diagnostic circuit is activated or deactivated by a control circuit. When liquid sensor damage detection is required, the control circuit activates the diagnostic circuit, causing it to send a diagnostic signal via an external electrode, detect the resistance value or voltage divider between the external electrode and the internal electrode, and then determine whether the liquid sensor is damaged based on the resistance value or voltage divider between the external electrode and the internal electrode. The control circuit then deactivates the diagnostic circuit after the detection is complete.

[0029] Compared to the prior art, the liquid sensor provided by the present disclosure activates its diagnostic circuit only when testing is required. This means that the connection between the diagnostic circuit and the external electrode is established only during diagnosis. Therefore, compared to the prior art, the present technical solution does not constantly maintain the diagnostic circuit transmitting diagnostic signals to the outside via the external electrode. In other words, the external electrode is not constantly electrically connected to the diagnostic circuit. In high-voltage environments such as lightning strikes, the external electrode does not discharge electricity to the outside, thereby attracting high-voltage electricity such as lightning to the external electrode. The present disclosure provides a liquid sensor damage detection device and its liquid sensor, offering enhanced stability and lifespan. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a schematic structural diagram of the liquid sensor damage detection device according to the first embodiment of the present disclosure;

[0031] Figure 2 This is a flow chart of the method for detecting damage to a liquid sensor according to the first embodiment of the present disclosure;

[0032] Figure 3 This is a schematic structural diagram of the liquid sensor damage detection device according to the second embodiment of the present disclosure;

[0033] Figure 4 This is another structural schematic diagram of the liquid sensor damage detection device according to the second embodiment of the present disclosure;

[0034] Figure 5 This is a partial structural diagram of the liquid sensor described in Example 3 of the present disclosure.

[0035] Among them, 1. Liquid sensor damage detection device; 11. External electrode; 12. Internal electrode; 13. Diagnostic circuit; 131. Signal receiving and analysis circuit; 132. Excitation circuit; 14. Control circuit; 15. Isolation circuit; 16. High-voltage protection circuit; 17. Remote communication unit; 18. Derivation unit;

[0036] 2. Shell;

[0037] 3. Infiltration device;

[0038] 4. Cavity. DETAILED DESCRIPTION

[0039] In order to more clearly understand the above-mentioned objectives, features and advantages of the present disclosure, the scheme of the present disclosure will be further described below. It should be noted that the embodiments of the present disclosure and the features therein can be combined with each other in the absence of conflict.

[0040] In the following description, many specific details are set forth to facilitate a full understanding of the present disclosure, but the present disclosure may also be implemented in other ways different from those described herein; it is obvious that the embodiments in the specification are only part of the embodiments of the present disclosure, rather than all of the embodiments.

[0041] Example 1:

[0042] Figure 1 This is a schematic diagram of the structure of the liquid sensor damage detection device according to the first embodiment of the present disclosure. Figure 1 As shown, the liquid sensor damage monitoring device described in the present disclosure includes an external electrode 11, an internal electrode 12, a diagnostic circuit 13 and a control circuit 14.

[0043] The liquid sensor damage detection device 1 is installed in a liquid sensor. A liquid sensor is an electronic sensor that can measure the physical or chemical properties of a liquid, converting these properties into electrical signals, such as dissolved oxygen or pH. For example, a dissolved oxygen sensor is a type of liquid sensor. The dissolved oxygen sensor uses an oxygen-permeable membrane in the permeation device and an outer shell 2 to form a sealed chamber 4 that isolates the liquid. This sealed chamber 4 allows for the free exchange of oxygen with the outside world through the oxygen-permeable membrane.

[0044] The liquid sensor damage detection device 1 is used in the liquid sensor having a sealed cavity 4 for isolating the liquid.

[0045] like Figure 1 As shown, the external electrode 11 is disposed outside the cavity 4 of the liquid sensor; the internal electrode 12, diagnostic circuit 13, and control circuit 14 are disposed inside the cavity 4 of the liquid sensor; wherein the internal electrode 12 and the external electrode 11 are both electrically connected to the diagnostic circuit 13. The diagnostic circuit 13 transmits diagnostic signals to the outside through the external electrode 11 and receives the diagnostic signals through the internal electrode 12. The diagnostic circuit 13 diagnoses whether the liquid sensor is damaged based on the diagnostic signals between the external electrode 11 and the internal electrode 12. Specifically, the diagnostic circuit 13 is used to detect the resistance value, voltage divider value, or electrical signal between the external electrode 11 and the internal electrode 12, wherein the electrical signal includes a current signal and a voltage signal.

[0046] The diagnostic circuit 13 compares the detected resistance value between the external electrode 11 and the internal electrode 12 with a preset resistance threshold range, or compares the voltage division value between the external electrode 11 and the internal electrode 12 with a preset voltage division threshold range; or compares the electrical signal received by the internal electrode 12 with the electrical signal sent by the external electrode 11 to obtain the electrical signal transmission integrity rate between the external electrode 11 and the internal electrode 12;

[0047] If the resistance value is within the resistance threshold range, or the divided voltage value is within the divided voltage threshold range, or the electrical signal transmission integrity rate is within a preset integrity rate range, the diagnostic circuit 13 determines that the liquid sensor is damaged and issues a damage signal;

[0048] For example, in this embodiment, since the internal electrode 12 and the external electrode 11 are respectively provided inside and outside the cavity 4 that isolates the liquid, the resistance value between the internal electrode 12 and the external electrode 11 should be close to the resistance value of air. If the liquid sensor is damaged, liquid will enter the cavity 4, and the resistance value between the internal electrode 12 and the external electrode 11 will be close to the resistance value of the liquid entering the cavity 4. If the preset resistance threshold range is set to the resistance value of the liquid, when the diagnostic circuit 13 determines that the resistance value between the external electrode 11 and the internal electrode 12 is within the preset resistance threshold range, it indicates that liquid has entered the cavity 4, and further deduces that the liquid sensor is damaged. The diagnostic circuit 13 can therefore determine that the liquid sensor is damaged and issue a damage signal.

[0049] Based on the same principle, in other embodiments, the preset resistance threshold range is set to the resistance of air. When the diagnostic circuit 13 determines that the resistance value between the external electrode 11 and the internal electrode 12 is within the preset resistance threshold range, liquid has not entered the cavity 4, and it is thus deduced that the liquid sensor is not damaged. If the diagnostic circuit 13 determines that the resistance value between the external electrode 11 and the internal electrode 12 is not within the preset resistance threshold range, it can be deduced that liquid has entered the cavity 4, thereby causing the resistance values ​​of the internal electrode 12 and the external electrode 11 to change. Therefore, the diagnostic circuit 13 can determine that the liquid sensor is damaged and issue a damage signal.

[0050] In other embodiments, since the internal electrode 12 and the external electrode 11 are respectively disposed inside and outside the cavity 4 that isolates the liquid, the resistance between the internal electrode 12 and the external electrode 11 should be close to the resistance of air. Therefore, the internal electrode 12 and the external electrode 11 cannot conduct electricity. Therefore, the voltage divider between the external electrode 11 and the internal electrode 12 should be close to the voltage output by the external electrode 11 to the outside. If the liquid sensor is damaged, liquid will enter the cavity 4, that is, the circuit between the internal electrode 12 and the external electrode 11 is conductive, and the detected voltage divider will also be pulled down to a constant value. The range of the voltage divider value can be obtained through experimentation. The voltage divider value range is set as a voltage divider threshold range. When the diagnostic circuit 13 determines that the voltage divider value between the external electrode 11 and the internal electrode 12 is within the preset voltage divider threshold range, it indicates that liquid has entered the cavity 4, and thus deduce that the liquid sensor is damaged. The diagnostic circuit 13 can therefore determine that the liquid sensor is damaged and issue a damage signal.

[0051] Similarly, in other embodiments, when the liquid sensor is damaged, liquid will enter the cavity 4, that is, at this time the circuit between the internal electrode 12 and the external electrode 11 is connected. The electrical signal emitted by the external electrode 11 will be completely received by the internal electrode 12. By comparing the electrical signal emitted by the external electrode 11 with the electrical signal received by the internal electrode 12, the electrical signal transmission integrity rate between the external electrode 11 and the internal electrode 12 can be determined. If the electrical signal transmission integrity rate is within the preset integrity rate range, it means that the internal electrode 12 has relatively completely received the electrical signal emitted by the external electrode 11, indicating that liquid has entered the cavity 4, and it can be deduced that the liquid sensor is damaged. The diagnostic circuit 13 can therefore determine that the liquid sensor is damaged and issue a damage signal.

[0052] The control circuit 14 is connected to the diagnostic circuit 13 to turn on the diagnostic circuit 13. The diagnostic circuit has a switch for controlling the electrical connection between the diagnostic circuit and the external electrode. When the diagnostic circuit 13 is turned off, the switch controlling the electrical connection between the diagnostic circuit and the external electrode will also be turned off. When the diagnostic circuit 13 is turned on, the switch controlling the electrical connection between the diagnostic circuit and the external electrode will also be turned on. The control circuit 14 can turn on the diagnostic circuit 13 according to a preset signal. The preset signal is a timing signal sent by a timer inside the diagnostic circuit at intervals. For example, the timer sends a timing signal as a preset signal every 5 minutes to start the diagnostic circuit 13. Figure 2 As shown, the process of the liquid sensor damage detection method includes:

[0053] S1: The control circuit 14 starts the diagnostic circuit 13, so that the diagnostic circuit 13 starts its diagnostic process;

[0054] S2: The diagnostic circuit 13 detects the resistance value, voltage division value or electrical signal between the external electrode 11 and the internal electrode 12;

[0055] S3: The diagnostic circuit 13 compares the resistance value with a preset resistance threshold range, or compares the voltage division value with a preset voltage division threshold, or compares the electrical signal received by the internal electrode 12 with the electrical signal sent by the external electrode 11 to obtain the electrical signal transmission integrity rate between the external electrode 11 and the internal electrode 12;

[0056] S4: The diagnostic circuit 13 determines whether the liquid sensor is damaged;

[0057] S5: The control circuit 14 turns off the diagnosis circuit 13 after the diagnosis circuit 13 completes the diagnosis process.

[0058] Compared with the prior art, the present technical solution controls the diagnostic circuit 13 to turn on through the control circuit 14, and quickly turns off the diagnostic circuit 13 after the diagnostic circuit 13 completes a diagnostic process. This approach can reduce the external strong electricity that enters the diagnostic circuit 13 through the external electrode 11 and damages the diagnostic circuit 13. The external strong electricity refers to a strong electricity that occurs occasionally in the liquid environment where the liquid sensor is located. For example, when the liquid sensor is arranged in a pond, it may be struck by lightning during a thunderstorm. The diagnostic circuit 13 in the prior art always maintains an electrical connection with the external electrode 11. The applicant found that the external electrode 11 in the prior art is always in a discharge state, and therefore will attract external strong electricity to enter the external electrode 11, which will cause the diagnostic circuit 13 electrically connected thereto to be burned.

[0059] The liquid sensor damage detection device 1 proposed in this disclosure activates the diagnostic circuit 13 only when a diagnosis is needed. The diagnostic process is very brief, typically taking approximately 50 milliseconds. After the diagnostic process is complete, the control circuit 14 quickly shuts down the diagnostic circuit 13. This prevents strong external electricity from entering the external electrode 11 and potentially damaging the diagnostic circuit 13. This improves the stability and lifespan of the liquid sensor damage detection device 1.

[0060] Example 2:

[0061] Figure 3 This is a schematic diagram of the structure of the liquid sensor damage detection device according to the second embodiment of the present disclosure. Figure 3 As shown, based on the liquid sensor damage detection device 1 provided in Example 1, the liquid sensor damage detection device 1 provided in the embodiment of the present disclosure further includes an isolation circuit 15, a high-voltage protection circuit 16 and a remote communication unit 17.

[0062] The external electrode 11 is electrically connected to the diagnostic circuit 13 via an isolation circuit 15. In this embodiment, the coupling circuit includes a coupling capacitor, one end of which is connected to the diagnostic circuit 13, and the other end of which is connected to the external electrode 11.

[0063] The liquid sensor damage detection device 1 described in the disclosed embodiment utilizes a coupling capacitor disposed between the external electrode 11 and the diagnostic circuit 13, thereby achieving both isolation and coupling between the external electrode 11 and the diagnostic circuit 13. Because the coupling capacitor prevents high-voltage currents from entering weak-voltage systems, it further prevents external high-voltage currents from entering the diagnostic system through the external electrode 11. In other embodiments, the coupling capacitor can be replaced with a transformer or an optocoupler.

[0064] Optionally, the liquid sensor damage detection device 1 further includes a high-current protection circuit 16 electrically connected to the external electrode 11 to conduct strong external current when it enters the external electrode 11. In this embodiment, the high-current protection circuit 16 includes a transient diode, with a first end connected to the external electrode 11 and a second end connected to ground. This allows the external electrode 11 to be grounded and conduct the strong external current when it enters the external electrode 11. A transient voltage suppressor (TVS) is a high-performance diode-type protection device. When a TVS diode is subjected to a high-energy reverse transient, it can reduce the high impedance between its two poles to a low impedance at a rate of 10 to the negative 12th power of seconds, allowing the strong external current to be conducted through the transient diode to the ground, further preventing the strong external current from entering the diagnostic circuit 13 through the external electrode 11. In other embodiments, the transient diode can be replaced with a varistor.

[0065] The liquid sensor damage detection device 1 further includes a remote communication unit 17 , which is connected to the diagnostic circuit 13 to receive a damage signal from the diagnostic circuit 13 and send the damage signal to an external server.

[0066] Figure 4 This is another structural diagram of the liquid sensor damage detection device according to the second embodiment of the present disclosure. Figure 4 As shown, the diagnostic circuit 13 includes an excitation circuit 132 and a signal receiving and analyzing circuit 131. The excitation circuit 132 is connected to the external electrode 11. When the control circuit 14 turns on the diagnostic circuit 13, the excitation circuit 132 sends a diagnostic signal to the outside through the external electrode 11. The signal receiving and analyzing circuit 131 is electrically connected to the internal electrode 12 and the external electrode 11, respectively, to detect the resistance value or voltage divider value between the external electrode 11 and the internal electrode 12.

[0067] In this embodiment, the excitation circuit 132 is a voltage source. If the liquid sensor is damaged, the voltage sent through the external electrode 11 will be received by the internal electrode 12, so that the voltage sent by the external electrode 11 will be attenuated. The degree of attenuation depends on the impedance of the water body and the degree of damage of the fragments, and is transmitted back to the signal receiving and analysis circuit 131 through the external electrode 11 itself through the isolation capacitor.

[0068] The signal analysis circuit can determine whether the liquid sensor is damaged based on whether the voltage division value between the external electrode 11 and the internal electrode 12 is within a preset voltage division value threshold.

[0069] Example 3:

[0070] Figure 5 This is a schematic diagram of the structure of the liquid sensor described in the third embodiment of the present disclosure. Figure 5 As shown, the liquid sensor includes the liquid sensor damage detection device 1 described in any one of Examples 1 and 2, as well as a housing 2 and a permeation device 3. The permeation device 3 and the housing 2 form a sealed cavity 4 that isolates liquid. The sensor damage detection device is disposed within the cavity 4, and an external electrode 11 is disposed outside the housing 2 through the cavity 4.

[0071] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or device comprising the element.

[0072] The foregoing description is intended only to provide specific embodiments of the present disclosure, intended to enable those skilled in the art to understand and implement the present disclosure. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present disclosure. Therefore, the present disclosure is not intended to be limited to the embodiments described herein, but rather to be construed in the broadest manner consistent with the principles and novel features disclosed herein.

Claims

1. A liquid sensor damage detection device for a liquid sensor having a sealed cavity, characterized in that: The liquid sensor damage detection device includes an internal electrode, an external electrode, a diagnostic circuit, and a control circuit; The external electrode is arranged outside the cavity of the liquid sensor; The internal electrodes, diagnostic circuit and control circuit are arranged inside the cavity of the liquid sensor; wherein the internal electrode and the external electrode are both electrically connected to the diagnostic circuit; The diagnostic circuit sends a diagnostic signal to the outside through the external electrode and receives the diagnostic signal through the internal electrode, and the diagnostic circuit diagnoses whether the liquid sensor is damaged based on the diagnostic signal between the external electrode and the internal electrode; The control circuit is connected to the diagnosis circuit to turn on the diagnosis circuit and to turn off the diagnosis circuit after the diagnosis circuit completes diagnosis.

2. A liquid sensor damage detection device according to claim 1, characterized in that: The liquid sensor damage detection device further includes an isolation circuit for coupling and isolating the external electrode and the diagnostic circuit, wherein the external electrode is electrically connected to the diagnostic circuit via the isolation circuit.

3. A liquid sensor damage detection device according to claim 2, characterized in that: The isolation circuit includes a coupling capacitor, and the external electrode is electrically connected to the diagnosis circuit via the coupling capacitor.

4. The liquid sensor damage detection device according to claim 1, characterized in that: The liquid sensor damage detection device further includes a strong current protection circuit, which is electrically connected to the external electrode so as to conduct the external strong current to an external lead-out portion when the external strong current enters the external electrode.

5. The liquid sensor damage detection device according to claim 4, characterized in that: The strong current protection circuit includes a transient diode, the lead-out portion includes a ground wire, a first end of the transient diode is connected to an external electrode, and a second end of the transient diode is connected to the ground wire, so that when external strong current enters the external electrode, the external electrode is grounded to lead out the external strong current.

6. The liquid sensor damage detection device according to claim 1, characterized in that: The diagnostic signal includes a resistance value, a voltage division value, or an electrical signal. The diagnostic circuit compares the detected resistance value between the external electrode and the internal electrode with a preset resistance threshold range, or compares the voltage division value between the external electrode and the internal electrode with a preset voltage division threshold range, or compares the electrical signal received by the internal electrode with the electrical signal sent by the external electrode to obtain an electrical signal transmission integrity rate. If the resistance value is within the resistance threshold range, the liquid sensor is determined to be damaged; or if the partial pressure value is within the partial pressure threshold range, the liquid sensor is determined to be damaged; or if the electrical signal transmission integrity rate is within the preset integrity rate range, the liquid sensor is determined to be damaged.

7. The liquid sensor damage detection device according to claim 1, characterized in that: The diagnostic circuit includes an excitation circuit and a signal receiving and analyzing circuit. The excitation circuit is connected to an external electrode. When the control circuit turns on the diagnostic circuit, the excitation circuit sends a diagnostic signal to the outside through the external electrode. The signal receiving and analyzing circuit is electrically connected to the internal electrode and the external electrode to detect the diagnostic signal.

8. The liquid sensor damage detection device according to claim 1, characterized in that: The liquid sensor damage detection device further includes a remote communication unit, which is connected to a diagnostic circuit. The diagnostic circuit diagnoses damage to the liquid sensor and generates a damage signal. The remote communication unit receives the damage signal and sends the damage signal to an external server.

9. Liquid sensor, characterized in that It comprises the liquid sensor damage detection device, a shell and a penetration device according to any one of claims 1 to 8, wherein the penetration device and the shell form a closed cavity, the internal electrodes, diagnostic circuit and control circuit are arranged in the cavity, and at least part of the external electrodes are arranged outside the shell.

10. A method for detecting damage to a liquid sensor, characterized in that: Using the sensor damage detection device according to any one of claims 1 to 8, the control circuit controls the diagnostic circuit to turn on according to a preset signal; The diagnostic circuit detects the resistance value, voltage division value or electrical signal between the internal electrode and the external electrode; The diagnostic circuit compares the detected resistance value between the external electrode and the internal electrode with a preset resistance threshold range, or compares the voltage divided value between the external electrode and the internal electrode with a preset voltage divided threshold range, or compares the electrical signal received by the internal electrode with the electrical signal sent by the external electrode to obtain an electrical signal transmission integrity rate; If the resistance value is within the resistance threshold range, or the divided voltage value is within the divided voltage threshold range, or the electrical signal transmission integrity rate is within a preset integrity rate range, the diagnostic circuit determines that the liquid sensor is damaged and issues a damage signal; The control circuit controls the diagnosis circuit to be turned off.

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