A method and system for detecting water shortage in electric steamer

Abstract

The present invention discloses a method for detecting water shortage in an electric steamer, which collects the capacitance value C of a water pipe built into the electric steamer body when it is filled with pure water. 1 , and the capacitance value C in the anhydrous state 0 ; Start the water pump and collect the capacitance value C of the built-in water pipe in real time t , and record the maximum capacitance value C' of the built-in water pipe t , according to C t With C 1 , C' t and C 0 The relationship between the water tank and the water pump is used to determine whether the water tank is short of water; if so, the water pump stops, indicating that the water tank is short of water; otherwise, there is water in the water tank, and water continues to be pumped, and the capacitance value C of the built-in water pipe at this moment is recorded. t , and then according to C t With C 1 , C” t and C 0 The relationship between the inner and outer surfaces of the water pipe determines whether there are bubbles in the built-in water pipe. If so, the water pump stops, indicating that the water tank is short of water; otherwise, it indicates that there is water in the water tank and continues to pump water. The invention also discloses a water shortage detection system for an electric steamer. The detection method and system of the invention can protect the water pump by quickly determining whether the water tank is short of water.

Description

Technical Field

[0001] The invention belongs to the technical field of electric steamer water level detection, and in particular relates to an electric steamer water shortage detection method and a detection system. Background Art

[0002] In the home appliance industry, electric steamers are becoming more and more popular. In order to ensure that the evaporator does not dry-burn, water level detection devices are generally installed. Currently, the more commonly used water level detection methods are: reed switch detection method, Hall element detection method, electrode liquid level detection method, etc.

[0003] The reed switch detection method is that its water level sensor consists of a reed switch, a float, a pulley and a permanent magnet. When the float moves up and down due to the rise and fall of the liquid level, the permanent magnet will be driven up and down through the pulley and the rope. When the permanent magnet moves to the set position of the reed switch, the normally open contact in the reed switch is connected under the action of the permanent magnet's magnetic field. When the permanent magnet moves away, the contact is released. The water level can be determined based on the connection and disconnection of the reed switch contacts.

[0004] The Hall element detection method is to install the Hall element outside the container and support the permanent magnet on the float. As the liquid level changes, the magnetic induction intensity of the magnetic field acting on the Hall device changes, so that the liquid level can be measured.

[0005] The electrode-type liquid level detection method uses the principle of water conductivity. It uses at least two electrodes (usually one on top and the other on the bottom) and uses water as a conductor. When the water covers both electrodes at the same time, the circuit is turned on. When the water leaves at least one electrode, the electrode that leaves is disconnected from the other electrodes. The water level is determined by the on-off circuit.

[0006] The existing detection methods can only determine whether the water tank has water or no water, but cannot quickly determine whether the water tank is short of water, which causes the water pump to run idle for a long time. Summary of the invention

[0007] The purpose of the present invention is to provide a method for detecting water shortage in an electric steamer, so as to solve the problem that the existing detection method cannot quickly determine that the water tank is short of water, which causes the water pump to run idle for a long time and reduces the service life of the water pump.

[0008] Another object of the present invention is to provide a detection system using the above-mentioned electric steamer water shortage detection method.

[0009] In order to solve the above problems, the technical solutions adopted are:

[0010] A method for detecting water shortage in an electric steamer, collecting a capacitance value C1 of a built-in water pipe of the electric steamer body when it is filled with pure water, and a capacitance value C0 when it is dry;

[0011] Start the water pump and collect the capacitance value C of the built-in water pipe in real time t , and record the maximum capacitance value C' of the built-in water pipe t , according to the capacitance value C t With capacitance value C1, maximum capacitance value C' t The relationship between the capacitance value C0 and the water tank determines whether there is water shortage. If so, the water pump stops, indicating that the water tank is short of water. Otherwise, there is water in the water tank, and the pumping continues, and the capacitance value C of the built-in water pipe is recorded at this moment. t , and then according to the capacitance value C t With capacitance value C1, capacitance value C" t The relationship between the capacitance value C0 determines whether there are bubbles in the built-in water pipe. If so, the water pump stops, indicating that the water tank is short of water; otherwise, it indicates that there is water in the water tank and continues to pump water.

[0012] Preferably, according to the capacitance value C t With capacitance value C1, maximum capacitance value C' t The relationship between the capacitance value C0 and the water tank is used to determine whether the water tank is short of water, including:

[0013] When the capacitance C t and the maximum capacitance C' t The difference is less than the threshold value, and the capacitance value C t When it is greater than 1 / 2 of the capacitance value (C1-C0), it means there is water in the water tank, and the pumping continues; otherwise, it means there is no water in the water tank.

[0014] Preferably, according to the capacitance value C t With capacitance value C1, capacitance value C" t The relationship between the capacitance value C0 and the built-in water pipe is used to determine whether there are bubbles in the built-in water pipe. Specifically:

[0015] When the capacitance value C appears at least three times t Less than 1 / 3 of the capacitance value (C" t -C0) or capacitance C t When it is less than 1 / 2 of the capacitance value (C1–C0), it means there are bubbles in the built-in water pipe and the water pump stops, indicating that the water tank is short of water; otherwise, it means there is water in the water tank and pumping continues.

[0016] A detection system using the above-mentioned electric steamer water shortage detection method comprises an electric steamer body, a control module and a capacitance detection module; the control module and the capacitance detection module are both arranged in the electric steamer body, the control module is electrically connected to the capacitance detection module, and the capacitance detection module is arranged on the built-in water pipe of the electric steamer body to realize the detection of the water pipe capacitance.

[0017] Preferably, the control module includes a capacitance measurement integrated circuit, a standard reference capacitor and a zero reference capacitor; one end of the standard reference capacitor and the zero reference capacitor are electrically connected to the capacitance measurement integrated circuit respectively, and the other end is grounded; the capacitance detection module is electrically connected to the capacitance measurement integrated circuit.

[0018] Preferably, the capacitance detection module comprises a first measuring electrode and a second measuring electrode; the first measuring electrode and the second measuring electrode are respectively arranged at intervals on the outer side wall of the water pipe to measure the capacitance of the water pipe.

[0019] Preferably, the first measuring electrode is grounded, and the second measuring electrode is electrically connected to a capacitance measuring integrated circuit.

[0020] Preferably, the first measuring electrode and the second measuring electrode are both arc-shaped metal electrodes.

[0021] Preferably, the first measuring electrode and the second measuring electrode are both snap-fitted onto the outer side wall of the water pipe.

[0022] Compared with the prior art, the present invention has the following beneficial effects by adopting the above technical solution:

[0023] The method for detecting water shortage in an electric steamer of the present invention firstly detects the water shortage in an electric steamer by measuring the capacitance value C t With capacitance value C1, maximum capacitance value C' t The relationship between the capacitance value C0 determines whether the water tank is short of water, and then the capacitance value C t With capacitance value C1, capacitance value C" t The relationship between the capacitance value C0 and the capacitance value C1 can be used to determine whether there are bubbles in the built-in water pipe; that is, the detection method of the present invention can quickly determine whether the water tank is short of water based on whether there are bubbles in the built-in water pipe, effectively avoiding the idling of the water pump and being beneficial to protecting the water pump; in addition, the present invention uses the capacitance value C1 of the built-in water pipe when it is full of pure water as a reference capacitance value, which can prevent drift from being misjudged as water in the water tank and reduce the risk of misjudgment.

[0024] The electric steamer water shortage detection system of the present invention can quickly determine whether there are bubbles in the water pipe by real-time detection of the capacitance value in the water pipe, and further quickly determine whether the built-in water tank of the electric steamer body is in a water shortage state, thereby avoiding the problem of long-term idling of the water pump due to the inability to quickly determine the water shortage, which is beneficial to protecting the water pump and increasing the service life of the water pump. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic flow chart of a method for detecting water shortage in an electric steamer provided in Embodiment 1 of the present invention;

[0026] Figure 2is a structural schematic diagram of a water shortage detection system for an electric steamer provided in Embodiment 2 of the present invention;

[0027] Figure 3 Schematic diagram of the positional relationship between a built-in water pipe and a capacitance detection module in a water shortage detection system for an electric steamer provided in Embodiment 2 of the present invention;

[0028] In the figure: 1. control module; 2. capacitance detection module; 3. built-in water pipe; 11. capacitance measurement integrated circuit; 12. standard reference capacitor; 13. zero reference capacitor; 21. first measurement electrode; 22. second measurement electrode. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0030] Embodiment 1 of the present invention provides a method for detecting water shortage in an electric steamer, such as Figure 1 As shown, it includes the following steps:

[0031] S1, collect the capacitance value C1 of the built-in water pipe of the electric steamer body when it is full of pure water, and the capacitance value C0 when it is dry;

[0032] S2, start the water pump and collect the capacitance value C of the built-in water pipe in real time t , and record the maximum capacitance value C' of the built-in water pipe t , according to the capacitance value C t With capacitance value C1, maximum capacitance value C' t The relationship between the capacitance value C0 and the water tank determines whether there is water shortage. If so, the water pump stops, indicating that the water tank is short of water. Otherwise, there is water in the water tank, and the pumping continues, and the capacitance value C of the built-in water pipe is recorded at this moment. t ;

[0033] S3, according to the capacitance value C t With capacitance value C1, capacitance value C" t The relationship between the capacitance value C0 determines whether there are bubbles in the built-in water pipe. If so, the water pump stops, indicating that the water tank is short of water; otherwise, it indicates that there is water in the water tank and continues to pump water;

[0034] Preferably, within the time threshold range, according to the capacitance value C t With capacitance value C1, maximum capacitance value C' t The relationship between the capacitance value C0 and the water tank is used to determine whether the water tank is short of water. The judgment conditions can be:

[0035] Within the time threshold range, when the capacitance C t and the maximum capacitance C't The difference is less than the threshold value, and the capacitance value C t When it is greater than 1 / 2 of the capacitance value (C1-C0), it means there is water in the water tank, so continue to pump water and record the capacitance value C of the built-in water pipe at this moment. t ; Otherwise it means the water tank is short of water;

[0036] Preferably, within the time threshold range, according to the capacitance value C t With capacitance value C1, capacitance value C" t The relationship between the capacitance value C0 and the built-in water pipe is used to determine whether there are bubbles. The judgment conditions can be:

[0037] When the capacitance value C appears at least three times within the time threshold range t Less than 1 / 3 of the capacitance value (C" t -C0) or capacitance C t When it is less than 1 / 2 of the capacitance value (C1–C0), it means there are bubbles in the built-in water pipe, the water pump stops, and it indicates that the water tank is short of water; otherwise, it means there is water in the water tank and the pumping continues;

[0038] Preferably, within the time threshold range, when the capacitance value C t Less than 1 / 3 of the capacitance value (C" t -C0) or capacitance C t When it is less than 1 / 2 of the capacitance value (C1–C0), it means there are bubbles in the built-in water pipe, the water pump stops, and it indicates that the water tank is short of water; otherwise, it means there is water in the water tank and the pumping continues;

[0039] The capacitance value C1 of the built-in water pipe when it is full of pure water is used as a reference capacitor because in actual use, the built-in water pipe usually contains tap water, and the threshold values ​​of tap water and pure water (the fluctuation range of the capacitance value when the built-in water pipe is full of water) are different, which prevents drift from being misjudged as a water state.

[0040] The reasons for making the above judgment within the time threshold range are:

[0041] There are three states of the water tank: with water, lack of water and no water. The water tank with water state can be further divided into two types. One is that there is more water in the water tank, that is, after the water pump is started, the water content in the water tank can ensure the normal operation of the water pump. The other is that the water tank is in a critical state of with water and lack of water, that is, after the water pump is started, although there is water in the water tank, the water content in the water tank is insufficient. After a short period of work of the water pump, the water tank directly changes from a water state to a water-lack state.

[0042] When there is more water in the water tank, the water pump is started for the first time. At this time, there is water in the built-in water pipe, and usually there is also air. When there is air in the built-in water pipe, after the water pump is started, there will be a short bubble state in the built-in water pipe, and then there will be water in the built-in water pipe without air, and the water pump will operate normally.

[0043] When the water tank is in a critical state of having water or lacking water, when the water pump is started for the first time, there is still water in the built-in water pipe, which usually contains air; after the water pump is started, the built-in water pipe is in a state of bubbles due to the presence of air; and because the water tank does not have enough water to fill the built-in water pipe, bubbles continue to form in the built-in water pipe until the water tank is out of water. In this case, if the water pump cannot be stopped in time, the water pump will continue to run when the water tank is in a critical state of having water or lacking water, and can only be stopped when the water tank is out of water, which causes the water pump to run idle for a long time and reduces its service life.

[0044] In order to solve the problem of the water pump running idle for a long time when the water tank is in a critical state of having water or lacking water, this embodiment stipulates that when judging whether there is water in the water tank, it is necessary to perform it within a time threshold range; this time threshold value is taken as a reference to the time period when there is a short bubble state in the built-in water pipe when there is more water in the water tank; so that the water tank is short of water after the bubble appears. If the running time of the water pump exceeds this time threshold when judging whether there is water in the water tank, the capacitance value C is still not met. t and the maximum capacitance C' t The difference is less than the threshold value, and the capacitance value C t If the capacitance is greater than 1 / 2 (C1-C0), the water pump will stop running directly, which effectively solves the problem of long-term idling of the water pump when the water tank is in a critical state of water or water shortage, thereby increasing the service life of the water pump.

[0045] When the water tank is short of water, the water pump is started for the first time. At this time, the built-in water pipe is in a state of residual water and air. After the water pump is started, the built-in water pipe is in a state of containing bubbles. If the time threshold is not specified, then this bubble state will continue until the water tank is out of water, and the water pump will stop running, which will cause the water pump to run idle for a long time and reduce the service life of the water pump. If the time threshold is specified, then after exceeding this time threshold, the water pump will stop directly, effectively avoiding the water pump from running idle and increasing the service life of the water pump.

[0046] The time threshold range in the present embodiment is preferably 1s to 3s; because when there is more water in the water tank, the time period in which the built-in water pipe has a short bubble state is usually 1s to 3s. If the built-in water pipe is still in a bubble state after exceeding this time period of 1s to 3s, then no matter whether the water tank is in a water shortage state or in a critical state before starting the water pump, the water tank is in a water shortage state at this time. Therefore, the time threshold is preferably 1s to 3s, which can quickly determine whether the water tank is short of water and avoid idling of the water pump.

[0047] It should also be noted that if the capacitance value C of the built-in water pipe t When it is equal to the capacitance value C0 of the built-in water pipe in the water-free state (obtained by testing the built-in water pipe before leaving the factory), it means that the water tank is in a water-free state.

[0048] The specific process of electric steamer water shortage detection is as follows:

[0049] Collect the capacitance value C1 of the built-in water pipe of the electric steamer body when it is filled with pure water;

[0050] Start the water pump and collect the capacitance value C of the built-in water pipe in real time t , and record the maximum capacitance value C' of the built-in water pipe t If within 1s to 3s, when the capacitance C t and the maximum capacitance C' t The difference is less than the threshold value, and the capacitance value C t When it is greater than 1 / 2 of the capacitance value (C1-C0), it means there is water in the water tank, so continue to pump water and record the capacitance value C of the built-in water pipe at this moment. t ; Otherwise it means the water tank is short of water;

[0051] Because the water tank may be short of water at any time during the pumping process, if the water tank is short of water, air will enter the built-in water pipe at the water inlet of the water pump, resulting in bubbles in the built-in water pipe. If the water tank is short of water, the water pump will run idle for a long time if it cannot be quickly judged that the water tank is short of water. Therefore, the judgment of whether there are bubbles in the built-in water pipe is added, that is, within 1s to 3s, when the capacitance value C appears three times, the built-in water pipe will be empty. t Less than 1 / 3 of the capacitance value (C" t -C0) or capacitance C t When it is less than 1 / 2 of the capacitance value (C1–C0), it indicates that there are bubbles in the built-in water pipe, the water pump stops, and the water tank is short of water; otherwise, it indicates that there is water in the water tank and pumping continues. The detection method of this embodiment can quickly determine that the water tank is short of water when bubbles appear in the built-in water pipe, effectively avoid the problem of long-term idling of the water pump, and increase the service life of the water pump.

[0052] Embodiment 2 of the present invention provides a detection system using the above-mentioned electric steamer water shortage detection method, such as Figure 2-3As shown, the electric steamer comprises an electric steamer body, a control module 1 and a capacitance detection module 2; the control module 1 and the capacitance detection module 2 are both arranged in the electric steamer body, the control module 1 is electrically connected to the capacitance detection module 2, and the capacitance detection module 2 is arranged on the built-in water pipe 3 of the electric steamer body to realize capacitance detection of the built-in water pipe 3; the capacitance detection module 2 detects the capacitance value of the built-in water pipe 3 in real time and sends the detection result to the control module 1, and the control module 1 is used to receive the detection result sent by the capacitance detection module 2, and compare the received detection result with the stored data, so as to judge whether the water tank is short of water according to the state of water in the water pipe;

[0053] By detecting the capacitance value of the built-in water pipe 3 in real time, it is possible to quickly determine whether there are bubbles in the built-in water pipe 3, and further quickly determine whether the built-in water tank of the electric steamer body is in a water shortage state, thereby avoiding the problem of the water pump idling for a long time due to the inability to quickly determine the water shortage, which is beneficial to protecting the water pump and increasing the service life of the water pump.

[0054] The control module 1 includes a capacitance measurement integrated circuit 11, a standard reference capacitor 12 and a zero reference capacitor 13; one end of the standard reference capacitor 12 and the zero reference capacitor 13 are electrically connected to the capacitance measurement integrated circuit 11 respectively, and the other end is grounded; the capacitance detection module 2 is electrically connected to the capacitance measurement integrated circuit 11; wherein the capacitance measurement integrated circuit 11 satisfies: the capacitance result is linearly related to the change value of the capacitance, and the measurement electrodes of the integrated circuit have the same internal capacitance, that is, the empty pin capacitance is consistent. At present, ordinary touch capacitance chips can meet the above requirements. For example, the capacitance measurement integrated circuit 11 is an 8PIN touch microcontroller; the standard reference capacitor 12 and the zero reference capacitor 13 are to ensure more accurate detection.

[0055] like Figure 3 As shown, the capacitance detection module 2 includes a first measuring electrode 21 and a second measuring electrode 22; the first measuring electrode 21 and the second measuring electrode 22 are respectively arranged at intervals on the outer wall of the built-in water pipe 3 to measure the capacitance of the built-in water pipe 3; the first measuring electrode 21 is grounded, and the second measuring electrode 22 is electrically connected to the capacitance measurement integrated circuit 11;

[0056] The first measuring electrode 21 and the second measuring electrode 22 are both arc-shaped metal electrodes, and the first measuring electrode 21 and the second measuring electrode 22 are both snap-fitted onto the outer wall of the built-in water pipe 3 with a spacing of 10 mm, in order to prevent the problem of excessive capacitance when the water pipe is dry and excessive capacitance when the water pipe is full of water.

[0057] Water shortage detection process of electric steamer:

[0058] First, the standard reference capacitor 12 and the zero reference capacitor 13 are electrically connected to the capacitance measurement integrated circuit 11 respectively, and both are grounded to form a control module 1, and the control module 1 is set in the electric steamer body;

[0059] Then, the first measuring electrode 21 and the second measuring electrode 22 are respectively arranged on the outer wall of the built-in water pipe 3 at an interval of 10 mm, and the first measuring electrode 21 is grounded, and the second measuring electrode 22 is electrically connected to the capacitance measurement integrated circuit 11, so as to form an electric steamer water shortage detection system;

[0060] Finally, the water pump of the electric steamer body is started, and at the same time, the capacitance detection module 2 detects the capacitance value C of the built-in water pipe 3 in real time. t and set the capacitance C t The signal is sent to the control module 1, which determines whether the water tank is short of water, that is, whether the capacitance value C is satisfied within 1s to 3s. t and the maximum capacitance C' t The difference is less than the threshold value, and the capacitance value C t Greater than 1 / 2 of the capacitance value (C1-C0). If not, the water pump stops and indicates water shortage. If satisfied, the water tank is filled with water, the water pump continues to pump water, and the capacitance value C of the built-in water pipe is recorded. t ; The capacitance detection module 2 continues to detect the capacitance value C of the built-in water pipe 3 in real time t and set the capacitance C t The control module 1 determines whether there are bubbles in the water pipe, that is, whether the capacitance value C appears three times within 1s to 3s. t Less than 1 / 3 of the capacitance value (C" t -C0) or capacitance C t Less than 1 / 2 of the capacitance value (C1–C0), if so, the water pump stops, indicating water shortage; if not, it means there is water in the water tank and continues to pump water; that is, during the water shortage detection process, the judgment of whether there are bubbles in the water in the built-in water pipe is increased, so as to quickly judge whether the water tank is in a water shortage state, effectively avoiding idling of the water pump, which is beneficial to protecting the water pump and increasing the service life of the water pump.

[0061] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A method for detecting water shortage in an electric steamer, characterized in that: Collect the capacitance value C1 of the built-in water pipe of the electric steamer body when it is full of pure water, and the capacitance value C0 when it is dry; Start the water pump and collect the capacitance value C of the built-in water pipe in real time t , and record the maximum capacitance value C' of the built-in water pipe t , according to the capacitance value C t With capacitance value C1, maximum capacitance value C' t The relationship between the capacitance value C0 and the water tank determines whether there is water shortage. If so, the water pump stops, indicating that the water tank is short of water. Otherwise, there is water in the water tank, and the pumping continues, and the capacitance value C of the built-in water pipe is recorded at this moment. t , and then according to the capacitance value C t With capacitance value C1, capacitance value C" t The relationship between the capacitance value C0 determines whether there are bubbles in the built-in water pipe. If so, the water pump stops, indicating that the water tank is short of water; otherwise, it indicates that there is water in the water tank and continues to pump water; Within the time threshold range, according to the capacitance value C t With capacitance value C1, maximum capacitance value C' t The relationship between the capacitance value C0 and the water tank is used to determine whether the water tank is short of water, including: When the capacitance C t and the maximum capacitance C' t The difference is less than the threshold value, and the capacitance value C t When it is greater than 1 / 2 of the capacitance value (C1-C0), it means there is water in the water tank, and the pumping continues; otherwise, it means there is no water in the water tank.

2. The method for detecting water shortage in an electric steamer according to claim 1, characterized in that: Within the time threshold range, according to the capacitance value C t With capacitance value C1, capacitance value C" t The relationship between the capacitance value C0 determines whether there are bubbles in the built-in water pipe, including: When the capacitance value C appears at least three times t Less than 1 / 3 of the capacitance value (C" t -C0) or capacitance C t When it is less than 1 / 2 of the capacitance value (C1-C0), it means there are bubbles in the built-in water pipe, the water pump stops, and it indicates that the water tank is short of water; otherwise, it means there is water in the water tank and pumping continues.

3. A detection system using the electric steamer water shortage detection method according to any one of claims 1-2, characterized in that: The invention comprises an electric steamer body, a control module (1) and a capacitance detection module (2); the control module (1) and the capacitance detection module (2) are both arranged in the electric steamer body, the control module (1) is electrically connected to the capacitance detection module (2), and the capacitance detection module (2) is arranged on a built-in water pipe (3) in the electric steamer body to realize capacitance detection of the built-in water pipe (3).

4. The detection system according to claim 3, characterized in that: The control module (1) comprises a capacitance measurement integrated circuit (11), a standard reference capacitor (12) and a zero reference capacitor (13); one end of the standard reference capacitor (12) and the zero reference capacitor (13) are respectively electrically connected to the capacitance measurement integrated circuit (11), and the other end is grounded; the capacitance detection module (2) is electrically connected to the capacitance measurement integrated circuit (11).

5. The detection system according to claim 3, characterized in that: The capacitance detection module (2) comprises a first measuring electrode (21) and a second measuring electrode (22); the first measuring electrode (21) and the second measuring electrode (22) are respectively arranged at intervals on the outer side wall of the built-in water pipe (3) to measure the capacitance of the built-in water pipe (3).

6. The detection system according to claim 5, characterized in that: The first measuring electrode (21) is grounded, and the second measuring electrode (22) is electrically connected to the capacitance measuring integrated circuit (11).

7. The detection system according to claim 6, characterized in that: The first measuring electrode (21) and the second measuring electrode (22) are both arc-shaped metal electrodes.

8. The detection system according to claim 7, characterized in that: The first measuring electrode (21) and the second measuring electrode (22) are both snap-fitted onto the outer side wall of the built-in water pipe (3).

Images