Patent Publication Number: US-2021190752-A1

Title: Multi-function water quality monitoring device

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     All related applications are incorporated by reference. The present application is based on, and claims priority from, U.S. Provisional Application No. 62/951,348, filed on Dec. 20, 2019, U.S. Provisional Application No. 62/951,008, filed on Dec. 20, 2019, Taiwan Application No. 109206513, filed on May 26, 2020, and Taiwan Application No. 109126368, filed on Aug. 4, 2020, the disclosures of which are hereby incorporated by reference herein in its entirety. 
    
    
     TECHNICAL FIELD 
     The technical field relates to a water quality monitoring device, in particular to a multi-function water quality monitoring device. 
     BACKGROUND 
     Factories in an industrial district would generate a large amount of waste water. However, some factories fail to properly treat waste water, but directly discharge waste water into rivers or other important water bodies, which may pollute domestic water. Thus, it is necessary to frequently monitor domestic water. 
     The operating principle of a currently available portable water quality monitor is to perform water quality measurement via the electrodes inside the probe thereof. However, the portable water quality monitor can provide only 1-2 water quality parameter measurement functions because being limited by the size thereof. Accordingly, the user cannot obtain more water quality parameters by one measurement operation, so the application of the portable water quality monitor is limited. 
     The user should frequently replace the probe of the portable water quality monitor in order to measure different water quality parameters, which would waste a lot of time. Therefore, the portable water quality monitor is not convenient in use. 
     SUMMARY 
     An embodiment of the disclosure relates to a multi-function water quality monitoring device, which includes a multi-function water quality monitoring probe and a control module. The multi-function water quality monitoring probe includes a first signal electrode, a first sensing electrode, a second signal electrode and a second sensing electrode. The control module is connected to the multi-function water quality monitoring probe. When the control module outputs a first time-variant signal to drive the first signal electrode, the first sensing electrode outputs a first water quality signal. When the control module outputs a second time-variant signal to drive the second signal electrode, the first sensing electrode and the second sensing electrode output the first sensing signal and a second sensing signal respectively. When the control module outputs the first time-variant signal and the second time-variant signal to simultaneously drive the first signal electrode and the second signal electrode, the first sensing electrode outputs the first water quality signal. 
     Further scope of applicability of the present application will become more apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating exemplary embodiments of the disclosure, are given by way of illustration only, since various changes and modifications within the spirit and scope of the disclosure will become apparent to those skilled in the art from this detailed description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The disclosure will become more fully understood from the detailed description given herein below and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the disclosure and wherein: 
         FIG. 1  is a system schematic view of a multi-function water quality monitoring device in accordance with a first embodiment of the disclosure. 
         FIG. 2  is a system schematic view of a multi-function water quality monitoring device in accordance with a second embodiment of the disclosure. 
         FIG. 3  is a schematic view of a scheduling mechanism of the multi-function water quality monitoring device in accordance with the second embodiment of the disclosure. 
         FIG. 4  is a first schematic view of an operational process of the multi-function water quality monitoring device in accordance with the second embodiment of the disclosure. 
         FIG. 5  is a second schematic view of the operational process of the multi-function water quality monitoring device in accordance with the second embodiment of the disclosure. 
         FIG. 6  is a third schematic view of the operational process of the multi-function water quality monitoring device in accordance with the second embodiment of the disclosure. 
         FIG. 7  is a stereoscopic view of a multi-function water quality monitoring device in accordance with a third embodiment of the disclosure. 
         FIG. 8  is a side view of the multi-function water quality monitoring device in accordance with the third embodiment of the disclosure. 
         FIG. 9A  is a first schematic view of the multi-function water quality monitoring device in accordance with the third embodiment of the disclosure. 
         FIG. 9B  is a second schematic view of the multi-function water quality monitoring device in accordance with the third embodiment of the disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     In the following detailed description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the disclosed embodiments. It will be apparent, however, that one or more embodiments may be practiced without these specific details. In other instances, well-known structures and devices are schematically shown in order to simplify the drawing. 
       FIG. 1  is a system schematic view of a multi-function water quality monitoring device in accordance with a first embodiment of the disclosure. As shown in  FIG. 1 , the multi-function water quality monitoring device  1  includes a multi-function monitoring probe  11  and a control module  12 . 
     The multi-function water quality monitoring probe  11  is connected to the control module  12 , and includes a first signal electrode  111 A, a first sensing electrode  112 A, a second signal electrode  111 B and a second sensing electrode  112 B. When the control module  12  outputs a first time-variant signal V A  to the first signal electrode  111 A, such as a square wave signal, sinusoidal signal, periodic signal or other time-variant signals. When the control module  12  outputs a second time-variant signal V B  to the second signal electrode  111 B. For example, the control module  12  outputs a constant voltage to the second signal electrode  111 B within a time period and outputs another constant voltage to the second signal electrode  111 B within another time period. Besides, the second signal electrode  111 B may be also grounded. Moreover, each of the first sensing electrode  112 A and the second sensing electrode  112 B can generate a voltage signal or a current signal when contacting a liquid sample. In the embodiment, the first signal electrode  111 A may be a metal electrode, such as Pt, Au, etc. The signal electrode  111 B may be a glass electrode containing electrolyte, such as Ag/AgCl reference electrode, a calomel electrode or an electrode containing conductive material (e.g. Pt, Au, etc.). The first sensing electrode  112 A may be an inert metal electrode, such as Pt, Au, etc. The second sensing electrode  112 B may be a metal electrode containing ion-selective thin film and electrolyte, such as Ag/AgCl measurement electrode, etc. The second sensing electrode  112 B may be also an electrode containing material with high-sensitivity to pH value, such as ITO (Indium Tin Oxide) electrode, etc. 
     When the multi-function water quality monitoring probe  11  is immersed into the liquid sample L in the container C, the control module  12  outputs the first time-variant signal V A  and the second time-variant signal V B  to the first signal electrode  111 A and the second signal electrode  111 B one after another or simultaneously, and then receives the signals from the first sensing electrode  112 A and the second sensing electrode  112 B. Afterward, the control module  12  calculates several water quality parameters according to the potential difference or current between the first signal electrode  111 A, the second signal electrode  111 B, the first sensing electrode  112 A and the second sensing electrode  112 B. 
     When the control module  12  outputs the first time-variant signal V A  to the first signal electrode  111 A to drive the first signal electrode  111 A, the first sensing electrode  112 A outputs a first water quality signal V 1  to the control module  12 . Then, the control module  12  calculates a first water quality parameter according to the first time-variant signal V A  and the first water quality signal V 1 . In the embodiment, the first water quality parameter may be the EC (electrical conductivity) value. 
     When the control module  12  outputs the first time-variant signal V A  to the second signal electrode  111 B to drive the second signal electrode  111 B, the first sensing electrode  112 A and the second sensing electrode  112 B output the first water quality signal V 1  and a second water quality signal V 2  to the control module  12  respectively. Then, the control module  12  calculates a second water quality parameter and a third water quality parameter according to the first time-variant signal V A , the first water quality signal V 1  and the second water quality signal V 2 . In the embodiment, the second water quality parameter may be the ORP (Oxidation-Reduction Potential) value and the third water quality parameter may be the pH value. 
     When the control module  12  simultaneously outputs the first time-variant signal V A  and the second time-variant signal V B  to the first signal electrode  111 A and the second signal electrode  111 B so as to drive the first signal electrode  111 A and the second signal electrode  111 B at the same time, the first sensing electrode  112 A outputs the first water quality parameter V 1  to the control module  12 . However, the control module  12  calculates a fourth water quality parameter according to the first time-variant signal V A , the second time-variant signal V B  and the first water quality signal V 1 . In the embodiment, the fourth water quality parameter may be the heavy metal concentration value (e.g. Hg-ion, Cd-ion, Cr-ion, Cu-ion, Pb-ion, Zn-ion, etc.). 
     The multi-function water quality monitoring device  1  may further include a display module; in one embodiment, the display module may be a liquid crystal display or other similar displays. The display module can display the EC value, the ORP value, the pH value and the heavy metal concentration value. In addition, the multi-function water quality monitoring device  1  may further include a wireless transmission module, which may be a Bluetooth module, a Wi-Fi module or other wireless communication modules. Therefore, the control module  12  may transmit the EC value, the ORP value, the pH value and the heavy metal concentration value to an electronic device via the wireless transmission module. 
     Via the above special switching mechanism and the electrode arrangement, the multi-function water quality monitoring device  1  can provide at least 4 water quality monitoring functions at a time without increasing the number of the electrodes. Besides, the size of the multi-function water quality monitoring device  1  will not increase and the performance thereof can be effectively enhanced. 
     The embodiment just exemplifies the disclosure and is not intended to limit the scope of the disclosure. Any equivalent modification and variation according to the spirit of the disclosure is to be also included within the scope of the following claims and their equivalents. 
     It is worthy to point out that the currently available portable water quality monitor can provide only 1-2 water quality parameter measurement functions because being limited by the size thereof. Accordingly, the user cannot obtain more water quality parameters by one measurement operation, so the application of the portable water quality monitor is limited. On the contrary, according to one embodiment of the disclosure, the multi-function water quality monitoring device includes a multi-function water quality monitoring probe, which can provide more than 3 water quality monitoring functions via a special switching mechanism. Accordingly, the performance of the multi-function water quality monitoring device can be significantly enhanced. 
     Besides, the user should frequently replace the probe of the currently available portable water quality monitor in order to measure different water quality parameters, which would waste a lot of time. Therefore, the portable water quality monitor is not convenient in use. On the contrary, according to one embodiment of the disclosure, the multi-function water quality monitoring device can provide more than 3 water quality monitoring functions, so the user can measure more water quality parameters without replacing the probe of the device, which is more efficient in use. 
     Moreover, according to one embodiment of the disclosure, the multi-function water quality monitoring device has a special switching mechanism and electrode arrangement, so can provide more than 3 water quality monitoring functions via the special switching mechanism without increasing the size thereof. Thus, the multi-function water quality monitoring device can be a portable device, which is more comprehensive in use. 
     Furthermore, according to one embodiment of the disclosure, the structure of the multi-function water quality monitoring device is simple, so can achieve the desired technical effects without greatly increasing the cost thereof. Therefore, the multi-function water quality monitoring device is of high commercial value. As described above, the multi-function water quality monitoring device according to the embodiments can actually achieve unpredictable technical effects. 
       FIG. 2  is a system schematic view of a multi-function water quality monitoring device in accordance with a second embodiment of the disclosure. As shown in  FIG. 2 , the multi-function water quality monitoring device  2  includes a multi-function monitoring probe  21  and a control module  22 . 
     The multi-function water quality monitoring probe  21  is connected to the control module  22 , and includes a first signal electrode  211 A, a first sensing electrode  212 A, a second signal electrode  211 B and a second sensing electrode  212 B. The control module  22  outputs a first time-variant signal V A  and a second time-variant signal V B  to the first signal electrode  211 A and the second signal electrode  211 B one after another or simultaneously. Similarly, each of the first sensing electrode  212 A and the second sensing electrode  212 B can generate a voltage signal or a current signal when contacting a liquid sample. In the embodiment, the first signal electrode  211 A may be a metal electrode. The signal electrode  211 B may be a glass electrode containing electrolyte or an electrode containing conductive material. The first sensing electrode  212 A may be an inert metal electrode. The second sensing electrode  212 B may be a metal electrode containing ion-selective thin film and electrolyte. 
     The control module  22  includes a signal acquisition circuit  221  and a signal processing circuit  222 . The signal acquisition circuit  221  is connected to the signal processing circuit  222 . 
     When the multi-function water quality monitoring probe  21  is immersed into the liquid sample L in the container C, the signal acquisition circuit  221  outputs the first time-variant signal V A  and the second time-variant signal V B  to the first signal electrode  211 A and the second signal electrode  211 B one after another or simultaneously, and then receives the signals from the first sensing electrode  212 A and the second sensing electrode  212 B. Afterward, the signal processing circuit  222  calculates several water quality parameters according to the potential difference or current between the first signal electrode  211 A, the second signal electrode  211 B, the first sensing electrode  212 A and the second sensing electrode  212 B. 
     When the signal acquisition circuit  221  outputs the first time-variant signal V A  to the first signal electrode  221 A to drive the first signal electrode  221 A, the first sensing electrode  212 A outputs a first water quality signal V 1  to the signal acquisition circuit  221 . Then, the signal acquisition circuit  221  amplifies the potential difference between the first time-variant signal V A  and the first water quality signal V 1 , and transmits the potential difference to the signal processing circuit  222 . Then, the signal processing circuit  222  calculates the EC value C a  (the first water quality parameter) according to the potential difference between the first time-variant signal V A  and the first water quality signal V 1 . However, if the liquid sample L is a highly concentrated solution, the signal processing circuit  222  calculates the EC value C b  according to the first time-variant signal V A  and the second water quality signal V 2 . 
     When the signal acquisition circuit  221  outputs the second time-variant signal V B  to the second signal electrode  211 B to drive the second signal electrode  211 B, the first sensing electrode  212 A and the second sensing electrode  212 B outputs the first water quality signal V 1  and the second water quality signal V 2  to the signal acquisition circuit  221  respectively. Then, the signal acquisition circuit  221  amplifies the potential difference between the second time-variant signal V B , the first water quality signal V 1  and the second water quality signal V 2 , and transmits the potential difference to the signal processing circuit  222 . After that, the signal processing circuit  222  calculates the ORP value C c  (the second water quality parameter) and the pH value C d  (the third water quality parameter) according to the potential difference between the second time-variant signal V B , the first water quality signal V 1  and the second water quality signal V 2 . 
     When the signal acquisition circuit  221  outputs the first time-variant signal V A  and the second time-variant signal V B  to the first signal electrode  211 A and the second signal electrode  211 B in order to simultaneously drive the first signal electrode  211 A and the second signal electrode  211 B, the first sensing electrode  212 A outputs the first water quality signal V 1  to the signal acquisition circuit  221 . Afterward, the signal acquisition circuit  221  amplifies the potential difference between the first time-variant signal V A , second time-variant signal V B  and the first water quality signal V 1 , and transmits the potential difference to the signal processing circuit  222 . After that, the signal processing circuit  222  calculates the Cu-ion concentration value (the fourth water quality parameter) according to the potential difference between the first time-variant signal V A , the second time-variant signal V B  and the first water quality signal V 1 . 
     Similarly, the multi-function water quality monitoring device  2  may further include a display module and a wireless transmission module. The display module can display the EC value, the ORP value, the pH value and the heavy metal concentration value. The control module  22  can transmit the EC value, the ORP value, the pH value and the heavy metal concentration value to an electronic device via the wireless transmission module. 
     Via the above special switching mechanism and electrode arrangement, the multi-function water quality monitoring device  2  can provide 4 different measurement functions, including the EC value, the ORP value, the pH value and the heavy metal concentration value, at a time without increasing the number of the electrodes. The above design would not increase the size of the multi-function water quality monitoring device  2 , but can remarkably improve the performance of the multi-function water quality monitoring device  2 . 
     The embodiment just exemplifies the disclosure and is not intended to limit the scope of the disclosure. Any equivalent modification and variation according to the spirit of the disclosure is to be also included within the scope of the following claims and their equivalents. 
     Please refer to  FIG. 3 ,  FIG. 4 ,  FIG. 5  and  FIG. 6 .  FIG. 3  is a schematic view of a scheduling mechanism of the multi-function water quality monitoring device in accordance with the second embodiment of the disclosure.  FIG. 4 ,  FIG. 5  and  FIG. 6  are a first schematic view, a second schematic view and a third schematic view of an operational process of the multi-function water quality monitoring device in accordance with the second embodiment of the disclosure respectively. The multi-function water quality monitoring device  2  of the embodiment can perform a scheduling mechanism in order to measure the EC value, the ORP value, the pH value and the heavy metal concentration value respectively. Then, the multi-function water quality monitoring device  2  of the embodiment can display the EC value, the ORP value, the pH value and the heavy metal concentration value. 
     As shown in  FIG. 3  and  FIG. 4 , the signal acquisition circuit  221  outputs the first time-variant signal V A  to the first signal electrode  211 A to drive the first signal electrode  211 A between the first time point t 1  and the second time point t 2  (i.e. the first time period T 1 ). Meanwhile, the signal acquisition circuit  221  amplifies the potential difference between the first time-variant signal V A  and the first water quality signal V 1 , and transmits the potential difference to the signal processing circuit  222 . Next, the signal processing circuit  222  calculates the EC value C a  according to the potential difference between the first time-variant signal V A  and the first water quality signal V 1 , and displays the EC value C a  via the display module within the first time period T 1 . When the solution is a highly concentrated solution, the signal acquisition circuit  221  amplifies the potential difference between the first time-variant signal V A  and the second water quality signal V 2 , and transmits the potential difference to the signal processing circuit  222 . Next, the signal processing circuit  222  calculates the EC value C b  according to the potential difference between the first time-variant signal V A  and the second water quality signal V 2 , and displays the EC value C b  via the display module within the first time period T 1 . 
     As shown in  FIG. 3  and  FIG. 5 , the signal acquisition circuit  221  switches from the first signal electrode  211 A to the second signal electrode  211 B, outputs the second time-variant signal V B  to the second signal electrode  211 B to drive the second signal electrode  211 B, and receives the first water quality signal V 1  and the second water quality signal V 2  from the first sensing electrode  212 A and the second sensing electrode  212 B respectively between the second time point t 2  and the third time point t 3  (i.e. the second time period T 2 ). Meanwhile, the signal acquisition circuit  221  amplifies the potential difference between the second time-variant signal V B , the first water quality signal V 1  and the second water quality signal V 2 , and transmits the potential difference to the signal processing circuit  222 . Afterward, the signal processing circuit  222  calculates the pH value Cd and the ORP value C c  according to the potential difference between the second time-variant signal V B , the first water quality signal V 1  and the second water quality signal V 2 , and displays the pH value C d  and the ORP value C c  via the display module within the second time period T 2 . 
     Finally, the signal acquisition circuit  221  outputs first time-variant signal V A  and the second time-variant signal V B  to the first signal electrode  211 A and the second signal electrode  211 B between the third time point t 3  and the fourth time point t 4  (i.e. the third time period T 3 ) so as to simultaneously drive the first signal electrode  211 A and the second signal electrode  211 B, and receive the first water quality signal V 1  from the first sensing electrode  212 A. In the meanwhile, the signal acquisition circuit  211  amplifies the potential difference between the first time-variant signal V A , the second time-variant signal V B  and the first water quality signal V 1 , and transmits the potential difference to the signal processing circuit  222 . Afterward, the signal processing circuit  222  calculates the Cu-ion concentration value C e  according to the potential difference between the first time-variant signal V A , the second time-variant signal V B  and the first water quality signal V 1 , and displays the Cu-ion concentration value C e  within the third time period T 3  via the display module. 
     As described above, the multi-function water quality monitoring device  2  can provide a special scheduling mechanism to automatically switch the electrodes of the multi-function water quality monitoring probe  21  and can orderly display several water quality parameters via the display module. Thus, the multi-function water quality monitoring device  2  can be more convenient in use. 
     The embodiment just exemplifies the disclosure and is not intended to limit the scope of the disclosure. Any equivalent modification and variation according to the spirit of the disclosure is to be also included within the scope of the following claims and their equivalents. 
     Please refer to  FIG. 7  and  FIG. 8 , which are a stereoscopic view and a side view of a multi-function water quality monitoring device in accordance with a third embodiment of the disclosure respectively. As shown in  FIG. 7 , the multi-function water quality monitoring device  3  includes a housing  33 , a plate sensing element  34 , a rod-shaped sensing element  31  and a control module  32 . 
     The housing  33  includes a sensing window  331 . The sensing window  331  has an upper wall  331   a , a left wall  331   b , a right wall  331   c  and a lower wall  331   d . The plate sensing element  34  is disposed at the bottom of the sensing window  331 . In this way, the sensing window  331  and the plate sensing element  34  can form a storage space for containing a liquid sample. As shown in  FIG. 8 , the inclination (i.e. the included angle θ 1  between the upper wall  331   a  and the horizontal direction H) of the upper wall  331   a  is less than or equal to 15°. Similarly, the inclination of the left wall  331   b  and the inclination of the right wall  331   c  are also less than or equal to 15°. The inclination (i.e. the included angle θ 2  between the lower wall  331   d  and the horizontal direction H) of the lower wall  331   d  is 30°˜45°, and the distance D between the top of the lower wall  331   d  to the bottom thereof is 5˜7.5 mm. 
     As shown in  FIG. 7 , the plate sensing element  34  is disposed at the bottom of the sensing window  331 , and includes a first signal electrode  341 , a temperature sensor  342  and a first sensing electrode  343 . The first signal electrode  341 , the temperature sensor  342  and the first sensing electrode  343  are disposed in the sensing window  331 . The first signal electrode  341 , the temperature sensor  342  and the first sensing electrode  343  are corresponding to different water quality parameters, such as electrical conductivity (EC), pH, etc. The plate sensing element  34  can be manufactured by thin-film process or screen printing technology in order to integrate several different signal electrodes and sensing electrodes with one another; the plate sensing element  34  has many advantages, such as small size, easy to maintain, low cost, etc. In this embodiment, the first signal electrode  341  and first sensing electrode  343  may be applicable to, but not limited to, electrical conductivity measurement. In another embodiment, the first signal electrode  341  and first sensing electrode  343  may further include various electrochemical sensors. The first signal electrode  341  and first sensing electrode  343  generate sensing signals corresponding to the water quality parameters thereof respectively when contacting the liquid sample in the sensing window  331 . The functions and operational process of the plate sensing element  34  (the first signal electrode  341  and the first sensing electrode  343 ) are already described in the first embodiment and the second embodiment, so would not be described herein again. 
     The rod-shaped sensing element  31  is disposed in the housing  33 . The rod-shaped sensing element  31  extends from the top Ts of the housing  33  to the bottom Bs of the housing  33 , and protrudes from the top Ts of the housing  33  to the bottom Bs of the housing  33  respectively. In this embodiment, the diameter Dm 1  of the top Ts of the housing  33  is about 40 mm; the diameter of the bottom Bs of the housing  33  is about 20 mm; the height L of the housing  33  is about 50 mm. The length of the rod-shaped sensing element  31  is substantially equal to the height L of the housing  33 . The above structure is just for illustration; the sizes of the above elements can be adjusted according to actual requirements. 
     Similarly, the rod-shaped sensing element  31  also include a second signal electrode and a second sensing electrode. The functions and operational process of the rod-shaped sensing element  31  are already described in the first embodiment and the second embodiment, so would not be described herein again. 
     As set forth above, the multi-function water quality monitoring device  3  can further integrate different signal electrodes and sensing electrodes with one another sensors via the plate sensing element  34  and the rod-shaped sensing element  31 , so can detect different water quality parameters via the sensing window  331  and the bottom Bs, protruding from the housing  33 , of the rod-shaped sensing element  31 , which is more flexible in use. 
     As described above, the multi-function water quality monitoring device  3  has a sensing window  331  having a special structure design. Thus, when the multi-function water quality monitoring device  3  is placed to be parallel to the horizontal direction, the sensing window  331  can be filled with a liquid sample and can prevent the liquid sample from flowing out of the sensing window  331 . When the multi-function water quality monitoring device  3  is placed to be parallel to the vertical direction, the liquid sample can completely flow out of the sensing window  331  in a short time. Accordingly, the multi-function water quality monitoring device  3  can achieve great practicality. 
     Moreover, the multi-function water quality monitoring device  3  may also have a control module having several buttons and a display screen with a view to serve as a portable device. In this way, the user can operate the multi-function water quality monitoring device  3  via the control module to monitor the water quality of a liquid sample and obtain the sensing results via the display screen of the control module, which is more convenient in use. 
     The embodiment just exemplifies the disclosure and is not intended to limit the scope of the disclosure. Any equivalent modification and variation according to the spirit of the disclosure is to be also included within the scope of the following claims and their equivalents. 
     Please refer to  FIG. 9A  and  FIG. 9B , which are a first schematic view and a second schematic view of the multi-function water quality monitoring device in accordance with the third embodiment of the disclosure respectively. Please also refer to  FIG. 7 . As shown in  FIG. 7 , the sensing window  331  of the housing  33  of the multi-function water quality monitoring device  3  has the upper wall  331   a , the left wall  331   b , the right wall  331   c  and the lower wall  331   d  connected to each other. The inclination of the upper wall  331   a , the inclination of the left wall  331   b  and the inclination of the right wall  331   c  are less than or equal to 15°. The inclination of the lower wall  331   d  is 30° ˜′45°. The distance D between the top of the lower wall  331   d  to the bottom thereof is 5˜7.5 mm. As shown in  FIG. 9A , via the above structure design, when the multi-function water quality monitoring device  3  is placed to be parallel to the horizontal direction H (i.e. the sensing window  331  is parallel to the horizontal direction H), the liquid sample Q would not flow out of the sensing window  331 . As shown in  FIG. 9B , when the multi-function water quality monitoring device  3  is placed to be parallel to the vertical direction V (i.e. the sensing window  331  is parallel to the vertical direction V), the special structure design of the sensing window  331  can make the liquid sample Q completely flow out of the sensing window  331  in a short time. In this way, the multi-function water quality monitoring device  3  can swiftly and efficiently detect the water quality of the liquid sample Q, so can achieve great practicality. 
     To sum up, according to one embodiment of the disclosure, the multi-function water quality monitoring device includes a multi-function water quality monitoring probe, which can provide more than 3 water quality monitoring functions via a special switching mechanism. Accordingly, the performance of the multi-function water quality monitoring device can be significantly enhanced. 
     According to one embodiment of the disclosure, the multi-function water quality monitoring device can provide more than 3 water quality monitoring functions, so the user can measure more water quality parameters without replacing the probe of the device, which is more efficient in use. 
     According to one embodiment of the disclosure, the multi-function water quality monitoring device can provide a special scheduling mechanism to automatically switch the electrodes of the multi-function water quality monitoring probe and can orderly display several water quality parameters via the display module. Thus, the multi-function water quality monitoring device can be more convenient in use. 
     Besides, according to one embodiment of the disclosure, the multi-function water quality monitoring device has a special switching mechanism and electrode arrangement, so can provide more than 3 water quality monitoring functions via the special switching mechanism without increasing the size thereof. Thus, the multi-function water quality monitoring device can be a portable device, which is more comprehensive in use. 
     Further, according to one embodiment of the disclosure, the multi-function water quality monitoring device can integrate several sensors with different functions via a sensing window, so can detect several water quality parameters via the sensing window. Accordingly, the multi-function water quality monitoring device can be more flexible in use. 
     Moreover, according to one embodiment of the present disclosure, the multi-function water quality monitoring device has a sensing window having a special structure design. Thus, when the multi-function water quality monitoring device is placed to be parallel to the horizontal direction, the sensing window can be filled with a liquid sample and can prevent the liquid sample from flowing out of the sensing window. When the multi-function water quality monitoring device is placed to be parallel to the vertical direction, the liquid sample can completely flow out of the sensing window in a short time. Accordingly, the multi-function water quality monitoring device can achieve great practicality. 
     Furthermore, according to one embodiment of the disclosure, the structure of the multi-function water quality monitoring device is simple, so can achieve the desired technical effects without greatly increasing the cost thereof. Therefore, the multi-function water quality monitoring device is of high commercial value. 
     It will be apparent to those skilled in the art that various modifications and variations can be made to the disclosed embodiments. It is intended that the specification and examples be considered as exemplary only, with a true scope of the disclosure being indicated by the following claims and their equivalents.