Abstract:
The present invention discloses an electronic circuit for acousto-optoelectronic angle indication and a level gauge thereof. The electronic circuit for acousto-optoelectronic angle indication comprises a main control circuit (a), a power circuit (b), a key circuit (c), a sensor module circuit (d), an LED indicator module circuit (e), a buzzer module circuit (f) and a data storage module (g). The control circuit (a) comprises a microcontroller (U 2 ), a capacitor (C 2 ), a capacitor (C 3 ), a capacitor (C 4 ), a capacitor (C 5 ), a capacitor (C 6 ), a capacitor (C 8 ), an electrolytic capacitor (E 1 ), a resistor (R 11 ), a resistor (R 12 ) and a resistor (R 20 ). The invention realizes an acousto-optoelectronically indicated design circuit device with high precision, so that the current angular value state can be accurately displayed through acoustic and photoelectric changes by simply placing a measuring device on a test plane.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application claims the benefit of Chinese Patent Application No. 201610077786.6 filed on Feb. 3, 2016, the contents of which are hereby incorporated by reference. 
     FIELD OF THE INVENTION 
     The invention relates to an electronic circuit, in particular to an electronic circuit for acousto-optoelectronic angle indication and a level gauge thereof. 
     BACKGROUND 
     During such work as house decoration, maintenance and installation of equipment and materials, the angular value states (e.g., horizontal and vertical) of objects are usually measured and corrected. Existing level bars are mainly read by unaided eyes. It takes time to analyze in work with higher precision, and large precision errors exist, bringing inconvenience to the work, mainly because the control design of the level bar is imperfect. Since observing whether the level bubble is in the middle position of two scale lines with eyes easily results in visual errors, and it is difficult to accurately observe the position of the level bubble in environment with poor light, it is difficult to accurately judge whether an object reaches the set planar state, and thus it is uncertain whether the checked and corrected object can reach the required planar state. 
     SUMMARY OF THE INVENTION 
     To overcome the defects in the prior art, the invention provides an acousto-optoelectronically indicated design circuit device with high precision, so that the current angular value state can be accurately displayed through acoustic and photoelectric changes by simply placing a measuring device on a test plane, thus dispensing with routine complex operations. 
     The purpose of the invention is realized by the following technical scheme: 
     an electronic circuit for acousto-optoelectronic angle indication, comprising a main control circuit (a), a power circuit (b), a key circuit (c), a sensor module circuit (d), an LED indicator module circuit (e), a buzzer module circuit (f) and a data storage module (g), wherein: 
     the control circuit (a) comprises a microcontroller U 2 , a capacitor C 2 , a capacitor C 3 , a capacitor C 4 , a capacitor C 5 , a capacitor C 6 , a capacitor C 8 , an electrolytic capacitor E 1 , a resistor R 11 , a resistor R 12  and a resistor R 20 , one end of the capacitor C 2  is connected with the 6th pin of the microcontroller U 2 , and the other end of the capacitor C 2  is grounded; the 5th pin of the microcontroller U 2  is connected with a +2.4V power supply, and connected with one end of the capacitor C 3 , one end of the capacitor C 6 , one end of the resistor R 12  and the 9th pin of the microcontroller U 2  in parallel, the other end of the capacitor C 3  is grounded, the other end of the capacitor C 6  is grounded, the other end of the resistor R 12  is connected with one end of the resistor R 11 , one end of the capacitor C 8  and the 10th pin of the microcontroller U 2  in parallel, the other end of the resistor R 11  is grounded, and the other end of the capacitor C 8  is grounded; the 24th pin of the microcontroller U 2  is connected with a +3.3V power supply, and connected with one end of the resistor R 20 , one end of the electrolytic capacitor E 1  and one end of the capacitor C 5  in parallel, the other end of the capacitor C 5  is grounded, the other end of the electrolytic capacitor E 1  is grounded, and the other end of the resistor R 20  is connected with one end of the capacitor C 4  and the 15th pin of the microcontroller U 2  in parallel; 
     the power circuit (b) comprises a power interface (BATT), a field effect transistor Q 8 , a resistor R 1 , a capacitor C 11 , an electrolytic capacitor E 2  and a voltage regulator module U 1 , one positive input end of the power interface (BATT) is connected with one end of the resistor R 1 , one end of the electrolytic capacitor E 2  and the 2nd pin of the voltage regulator module U 1  in parallel, and the other end of the power interface (BATT) is connected with a D pole of the field effect transistor Q 8 ; the other end of the resistor R 1  is connected with a G pole of the field effect transistor Q 8  and one end of the capacitor C 11  in parallel; the other end of the capacitor C 11  and a S pole of the field effect transistor Q 8  are grounded in parallel; the 1st pin of the voltage regulator module and the electrolytic capacitor E 2  are grounded in parallel; and the 3rd pin of the voltage regulator module U 1  is connected with a +3.3V power voltage; 
     the key circuit (c) comprises a key (SW), one end of the key (SW) is connected with the 16th pin of the microcontroller U 2 , and the other end of the key (SW) is grounded; 
     the sensor module circuit (d) comprises a sensor chip U 4 , a resistor R 21 , a capacitor C 13 , a capacitor C 14  and a capacitor C 18 , the 1st, 3rd, 4th, 5th, 6th, 7th, 9th, 11th, 13th and the 16th pins of the sensor chip U 4  are grounded, and connected with one end of the capacitor C 13 , one end of the capacitor C 14  and one end of the capacitor C 18  in parallel; the 14th pin and the 15th pin of the sensor chip U 4  are connected with the other end of the capacitor C 18  and one end of the resistor R 21  in parallel; the other end of the resistor R 21  is connected with a +2.4V power supply; the 10th pin of the sensor chip U 4  is connected with the other end of the capacitor C 13  and the 13th pin of the microcontroller U 2 ; and the 12th pin of the sensor chip U 4  is connected with the other end of the capacitor C 14  and the 11th pin of the microcontroller U 2 ; 
     the LED indicator module circuit (e) comprises a red-green light LED 1 , a red-green light LED 2 , a red-green light LED 3 , a resistor R 3 , a resistor R 4 , a resistor R 5 , a resistor R 14 , a resistor R 17  and a resistor R 19 , one end of the red-green light LED 1  is connected with a 3.3V power supply, one green end of the red-green light LED 1  is connected with one end of the resistor R 5 , and the other end of the resistor R 5  is connected with the 4th pin of the microcontroller U 2 ; one red end of the red-green light LED 1  is connected with the resistor R 4 , and the other end of the resistor R 4  is connected with the 3rd pin of the microcontroller U 2 ; one end of the red-green light LED 2  is grounded, one green end of the red-green light LED 2  is connected with one end of the resistor R 14 , and the other end of the resistor R 14  is connected with the 26th pin of the microcontroller U 2 ; one red end of the red-green light LED 2  is connected with the resistor R 17 , and the other end of the resistor R 17  is connected with the 25th pin of the microcontroller U 2 ; one end of the red-green light LED 3  is grounded, one green end of the red-green light LED 3  is connected with the resistor R 3 , and the other end of the resistor R 3  is connected with the 23rd pin of the microcontroller U 2 ; and one red end of the red-green light LED 3  is connected with one end of the resistor R 19 , and the other end of the resistor R 19  is connected with the 22nd pin  22  of the microcontroller U 2 ; 
     the buzzer module circuit (f) comprises a buzzer (BUZ) and a resistor R 22 , one end of the buzzer BUZ is connected with the 2nd pin of the microcontroller U 2 , the other end of the buzzer is connected with one end of the resistor R 22 , and the other end of the R 22  is connected with the 1rst pin of the microcontroller U 2 ; and 
     the data storage module g comprises a memory U 3 , a resistor R 10  and a resistor R 13 , the 8th pin of the memory U 3  is connected with a power supply, the 1st, 2nd, 3rd, and 4th pins of the memory U 3  are grounded, the 5th pin of the memory U 3  is connected with one end of the resistor R 13 , the other end of the resistor R 13  is connected with the 26th pin of the microcontroller U 2  and also connected with the resistor R 10 , the 6th pin of the memory U 3  is connected with the 27th pin of the microcontroller U 2 , and the 6th pin of the memory U 3  is grounded. 
     A level gauge comprising the aforementioned electronic circuit for acousto-optoelectronic angle indication, an end cover, a level gauge body, a vertical level bubble mechanism, an LED indicator mechanism and a 45° level bubble mechanism, wherein the end cover is arranged on two ends of the level gauge body, the vertical level bubble mechanism and the 45° level bubble mechanism are respectively arranged at two sides of the level gauge body, and the LED indicator mechanism is arranged in the middle of the level gauge body. The LED indicator mechanism of the level gauge comprises a horizontal bubble seat, a horizontal bubble cover, a horizontal bubble, a backlight, a battery holder, a battery cover, a PCB with angle sensor circuit, a front cover, a switch key, a calibration button, a buzzer, an anchor screw A, a horizontal bubble LED light, a vertical bubble seat and an anchor screw B, wherein the horizontal bubble cover is arranged above the horizontal bubble and at two sides thereof, the backlight is arranged below the horizontal bubble, the horizontal bubble cover, the horizontal bubble and the backlight are installed on the horizontal bubble seat, the horizontal bubble seat is fixed to the level gauge body through buckles at two ends, the PCB with angle sensor circuit is fixed to the battery holder through the anchor screw A, the battery holder is fixed to the level gauge body through the anchor screw C, and the front cover fixes the battery cover to the level gauge body through the anchor screw B. 
     The level gauge thereof is characterized in that the vertical level bubble mechanism comprises a bubble bracket, a vertical level bubble, a vertical level bubble seat, a vertical state LED light, an anchor screw D and a vertical bubble cover plate, wherein the vertical level bubble is installed on the horizontal level bubble seat, the vertical level bubble seat is fixed to the level gauge body through the anchor screw D, the vertical state LED light is installed in an LED fixing hole of the vertical level bubble seat, the vertical state LED light is connected with the PCB with angle sensor circuit through a power line, and the angle sensor circuit controls the lighting form of the LED light and changes in light colors. 
     The level gauge thereof is characterized in that the 45° level bubble mechanism comprises a 45° level bubble, a 45° level bubble seat, a 45° state LED light, an anchor screw E and a 45° bubble cover plate, wherein the 45° level bubble is installed on the 45° level bubble seat, the 45° level bubble seat is fixed to the level gauge body through the anchor screw E, the 45° state LED light is installed in an LED fixing hole of the 45° level bubble seat, the 45° state LED light is connected with the PCB with angle sensor circuit through a power line, and the angle sensor circuit controls the lighting form of the LED light and changes in light colors. 
     The level gauge thereof is characterized in that the level gauge body is made of an aluminum alloy profile. 
     The beneficial effects of the invention are as follows: the invention provides an electronic circuit of an acousto-optoelectronically indicated level gauge, i.e., an acousto-optoelectronically indicated design circuit device with high precision, so that a measuring device can be simply placed on a test plane to accurately display whether the current angle is in the preset angular range, thus dispensing with routine complex operations. The level gauge thereof is characterized by good reliability and high accuracy. For an ordinary level gauge, an operator can only judge whether the level gauge is in a horizontal, vertical or 45° angular position by visually observing whether the level bubble is in the middle position of two scale lines, thus there are uncertain factors. But the level gauge thereof is provided with an angle sensor circuit system, integrating the function that a measuring tool such as a level bar can measure and correct a measured object in a horizontal, vertical or 45° angular positions. In addition, an LED indicator mechanism is arranged on the level gauge, so that the level gauge thereof can display whether the current position of the level gauge is in a horizontal, vertical or 45° angular state or inclined state by changing the color of an LED backlight installed below the level bubble and changing the LED backlight to light on or flash. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an outline drawing of a level gauge thereof in the invention. 
         FIG. 2  is a structural diagram of an LED indicator mechanism of the level gauge thereof in the invention. 
         FIG. 3  is an internal structural diagram of the LED indicator mechanism of the level gauge thereof in the invention. 
         FIG. 4  is a structural diagram of a vertical level bubble mechanism of the level gauge thereof in the invention. 
         FIG. 5  is a structural diagram of a 45° level bubble mechanism of the level gauge thereof in the invention. 
         FIG. 6  is a block circuit diagram of an electronic circuit for acousto-optoelectronic angle indication in the invention. 
         FIG. 7  is a key circuit diagram of the electronic circuit for acousto-optoelectronic angle indication in the invention. 
         FIG. 8  is a control circuit diagram of the electronic circuit for acousto-optoelectronic angle indication in the invention. 
         FIG. 9  is a power circuit diagram of the electronic circuit for acousto-optoelectronic angle indication in the invention. 
         FIG. 10  is a sensor module circuit diagram of the electronic circuit for acousto-optoelectronic angle indication in the invention. 
         FIG. 11  is a display module circuit diagram of the electronic circuit for acousto-optoelectronic angle indication in the invention. 
         FIG. 12  is a buzzer module circuit diagram of the electronic circuit for acousto-optoelectronic angle indication in the invention. 
         FIG. 13  is a data storage module circuit diagram of the electronic circuit for acousto-optoelectronic angle indication in the invention. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The invention will be further described in combination with accompanying drawings. 
     Please refer to  FIGS. 6-13  for an electronic circuit of an acousto-optoelectronically indicated level gauge, the electronic circuit for acousto-optoelectronic angle indication comprises a main control circuit (a), a power circuit (b), a key circuit (c), a sensor module circuit (d), an LED indicator module circuit (e), a buzzer module circuit (f) and a data storage module (g). 
     The control circuit (a) comprises a microcontroller U 2 , a capacitor C 2 , a capacitor C 3 , a capacitor C 4 , a capacitor C 5 , a capacitor C 6 , a capacitor C 8 , an electrolytic capacitor E 1 , a resistor R 11 , a resistor R 12  and a resistor R 20 , one end of the capacitor C 2  is connected with the 6th pin of the microcontroller U 2 , and the other end of the capacitor C 2  is grounded; the 5th pin of the microcontroller U 2  is connected with a +2.4V power supply, and connected with one end of the capacitor C 3 , one end of the capacitor C 6 , one end of the resistor R 12  and the 9th pin of the microcontroller U 2  in parallel, the other end of the capacitor C 3  is grounded, the other end of the capacitor C 6  is grounded, the other end of the resistor R 12  is connected with one end of the resistor R 11 , one end of the capacitor C 8  and the 10th pin of the microcontroller U 2  in parallel, the other end of the resistor R 11  is grounded, and the other end of the capacitor C 8  is grounded; the 24th pin of the microcontroller U 2  is connected with a +3.3V power supply, and connected with one end of the resistor R 20 , one end of the electrolytic capacitor E 1  and one end of the capacitor C 5  in parallel, the other end of the capacitor C 5  is grounded, the other end of the electrolytic capacitor E 1  is grounded, and the other end of the resistor R 20  is connected with one end of the capacitor C 4  and the 15th pin of the microcontroller U 2 . 
     The power circuit b comprises a power interface BATT, a field effect transistor Q 8 , a resistor R 1 , a capacitor C 11 , an electrolytic capacitor E 2  and a voltage regulator module U 1 , one positive input end of the power interface BATT is connected with one end of the resistor R 1 , one end of the electrolytic capacitor E 2  and the 2nd pin of the voltage regulator module U 1  in parallel, and the other end of the power interface BATT is connected with a D pole of the field effect transistor Q 8 ; the other end of the resistor R 1  is connected with a G pole of the field effect transistor Q 8  and one end of the capacitor C 11  in parallel; the other end of the capacitor C 11  and a S pole of the field effect transistor Q 8  are grounded in parallel; the  1 st pin of the voltage regulator module and the electrolytic capacitor E 2  are grounded in parallel; and the 3rd pin of the voltage regulator module is connected with a +3.3V power voltage. 
     The key circuit c comprises a key SW, one end of the key SW is connected with the  16 th pin of the microcontroller U 2 , and the other end of the key SW is grounded. 
     The sensor module circuit d comprises a sensor chip U 4 , a resistor R 21 , a capacitor C 13 , a capacitor C 14  and a capacitor C 18 , the 1st, 3rd, 4th, 5th, 6th, 7th, 9th, 11th, 13th and the 16th pins of the sensor chip U 4  are grounded, and connected with one end of the capacitor C 13 , one end of the capacitor C 14  and one end of the capacitor C 18  in parallel; the 14th pin and the 15th pin of the sensor chip U 4  are connected with the other end of the capacitor C 18  and one end of the resistor R 21  in parallel; the other end of the resistor R 21  is connected with a +2.4V power supply; the 10th pin of the sensor chip U 4  is connected with the other end of the capacitor C 13  and the 13th pin of the microcontroller U 2 ; and the 12th pin of the sensor chip U 4  is connected with the other end of the capacitor C 14  and the 11th pin of the microcontroller U 2 . 
     The LED indicator module circuit (e) comprises a red-green light LED 1 , a red-green light LED 2 , a red-green light LED 3 , a resistor R 3 , a resistor R 4 , a resistor R 5 , a resistor R 14 , a resistor R 17  and a resistor R 19 , one end of the red-green light LED 1  is connected with a 3.3V power supply, one green end of the red-green light LED 1  is connected with one end of the resistor R 5 , and the other end of the resistor R 5  is connected with the 4th pin of the microcontroller U 2 ; one red end of the LED 1  is connected with the resistor R 4 , and the other end of the resistor R 4  is connected with the 3rd pin of the microcontroller U 2 ; one end of the LED 2  is grounded, one green end of the LED 2  is connected with one end of the resistor R 14 , and the other end of the resistor R 14  is connected with the 26th pin of the microcontroller U 2 ; one red end of the LED 2  is connected with the resistor R 17 , and the other end of the resistor R 17  is connected with the 25th pin of the microcontroller U 2 ; one end of the LED 3  is grounded, one green end of the LED 3  is connected with the resistor R 3 , and the other end of the resistor R 3  is connected with pin  23  of the microcontroller U 2 ; and one red end of the LED 3  is connected with one end of the resistor R 19 , and the other end of the resistor R 19  is connected with the 22nd pin of the microcontroller U 2 . 
     The buzzer module circuit (f) comprises a buzzer BUZ and a resistor R 22 , one end of the buzzer BUZ is connected with the 2nd pin of the microcontroller U 2 , the other end of the buzzer is connected with one end of the resistor R 22 , and the other end of the R 22  is connected with the 1st pin of the microcontroller U 2 . 
     The data storage module (g) comprises a memory U 3 , a resistor R 10  and a resistor R 13 , the 8th pin of the memory U 3  is connected with a power supply, the 1st, 2nd, 3rd and the 4th pins of the memory U 3  are grounded, the 5th pin of the memory U 3  is connected with one end of the resistor R 13 , the other end of the resistor R 13  is connected with the 26th pin of the microcontroller U 2  and also connected with the resistor R 10 , the 6th pin of the memory U 3  is connected with the 27th pin of the microcontroller U 2 , and the 6th pin of the memory U 3  is grounded. 
     Refer to  FIG. 1 , a level gauge thereof comprises an end cover  1 , a level gauge body  2 , a vertical level bubble mechanism  3 , an LED indicator mechanism  4  and a 45° level bubble mechanism  5 , wherein the level gauge body  2  is made of an aluminum alloy profile, the end cover  1  is arranged on two ends of the level gauge body  2 , a battery holder  10  is arranged on the back of the LED indicator mechanism  4 , the vertical level bubble mechanism  3  and the 45° level bubble mechanism  5  are respectively arranged at two sides of the LED indicator mechanism  4 , and the LED indicator mechanism  4  is arranged in the middle of the level gauge body  2 . 
     Refer to  FIG. 2  and  FIG. 3 , the LED indicator mechanism  4  of the invention comprises a horizontal bubble seat  6 , a horizontal bubble cover  7 , a horizontal bubble  8 , a backlight  9 , a battery holder  10 , a battery cover  11 , a PCB with angle sensor circuit  12 , a front cover  13 , a switch key  14 , a calibration button  15 , a buzzer  16  and an anchor screw A 17 , wherein the horizontal bubble cover  7  is arranged above the horizontal bubble and at two sides thereof, the backlight  9  is arranged below the horizontal bubble  8 , the horizontal bubble cover  7 , the horizontal bubble  8  and the backlight  9  are installed on the horizontal bubble seat  6 , the horizontal bubble seat  6  is fixed to the level gauge body  2  through buckles at two ends, the PCB with angle sensor circuit  12  is fixed to the battery cover  11  through an anchor screw A 17   a , the battery cover  11  is fixed to the level gauge body  2  through an anchor screw C  17   c , and the front cover  13  fixes the battery cover  1  to the level gauge body  2  through an anchor screw B 17   b.    
     Operating instructions: when the angle sensor circuit system detects that the level gauge thereof is currently in a horizontal state, the LED backlight  11  of the LED indicator mechanism  4  will give out normally-on green backlight. The backlight lights up the horizontal level bubble  8 , and meanwhile, the buzzer  16  makes a voice prompt. When the angle sensor circuit system detects that the level gauge thereof is currently in a sub-horizontal state, that is, a specific angular range between the inclined state and the judged horizontal state set by the angle sensor circuit system, the LED backlight  11  of the LED indicator mechanism  4  will give out flashing light to alert the operator that horizontal correction has to be performed on the measured object. When the angle sensor circuit system detects that the level gauge thereof is currently in an inclined state, the LED backlight of the LED indicator mechanism  4  will give out normally-on red backlight to alert the operator that the measured object is currently in an inclined state. The calibration button  15  is used for initial angle calibration of the level gauge thereof. 
     Refer to  FIG. 4 , the vertical level bubble mechanism  3  of the invention comprises a vertical bubble LED light  18 , a vertical bubble seat  19 , an anchor screw D 20 , a bubble bracket  21 , a vertical level bubble  23 , a vertical level bubble seat  19 , a vertical state LED light  18 , an anchor screw D  20  and a vertical bubble cover plate  22 , wherein the vertical level bubble  23  is installed on the horizontal level bubble seat  19 , the vertical level bubble seat  23  is fixed to the level gauge body  2  through the anchor screw D  20 , the vertical state LED light  18  of the vertical bubble cover plate  22  is installed in an LED fixing hole of the vertical level bubble seat  19 , the vertical state LED light  18  is connected with the PCB with angle sensor circuit  12  through a power line, and the angle sensor circuit controls the lighting form of the LED light and changes in light colors. 
     Operating instructions: a red-green LED light is installed on the vertical level bubble seat  19 , when the angle sensor circuit system detects that the level gauge thereof is currently in a vertical state, the green LED light on the vertical level bubble seat  19  is normally on, lighting up the vertical level bubble  23 , and meanwhile, the buzzer  16  makes a voice prompt. When the angle sensor circuit system detects that the level gauge thereof is currently in a sub-vertical state, that is, a specific angular range between the inclined state and the judged vertical state set by the angle sensor circuit system, the green LED light on the vertical level bubble seat  23  will give out flashing light to alert the operator that vertical correction has to be performed on the measured object. When the angle sensor circuit system detects that the level gauge thereof is currently in an inclined state, the red LED light on the vertical level bubble seat  23  is normally on to alert the operator that the measured object is currently in an inclined state. 
     Refer to  FIG. 5 , the 45° level bubble mechanism  5  of the invention comprises a 45° level bubble  29 , a 45° level bubble seat  25 , a 45° state LED light  24 , an anchor screw E 26  and a 45° bubble cover plate  28 , wherein the 45° level bubble  29  is installed on the 45° level bubble seat  25 , the 45° level bubble seat  25  is fixed to the level gauge body  2  through the anchor screw E 26 , the 45° state LED light  24  is installed in an LED fixing hole of the 45° level bubble seat  25 , the 45° state LED light  24  is connected with the PCB with angle sensor circuit  12  through a power line, and the angle sensor circuit controls the lighting form of the LED light and changes in light colors. 
     Operating instructions: a red-green LED light is installed on the 45° bubble seat  25 , when the angle sensor circuit system detects that the level gauge thereof is currently in a 45° state, the green LED light on the 45° bubble seat  25  is normally on, lighting up the 45° level bubble  29 , and meanwhile, the buzzer  16  makes a voice prompt. When the angle sensor circuit system detects that the level gauge thereof is currently in a sub-45° state, that is, a specific angular range between the inclined state and the judged 45° state set by the angle sensor circuit system, the green LED light on the 45° bubble seat  25  will give out flashing light to alert the operator that 45° correction has to be performed on the measured object. When the angle sensor circuit system detects that the level gauge thereof is currently not in a 45° state, the red LED light of the LED indicator mechanism is normally on to alert the operator that the measured object is currently not in a 45° state. 
     In the preferred embodiment of the level gauge thereof in the invention, the vertical level bubble mechanism and the 45° level bubble mechanism can be eliminated, or either of the vertical level bubble mechanism and the 45° level bubble mechanism can be reserved to form different level gauges thereof so as to meet different requirements. 
     In the preferred embodiment of the level gauge thereof in the invention, the LED backlight of the LED indicator mechanism, the vertical state LED light of the vertical level gauge and the 45° state LED light of the 45° level gauge can be set to other colors to form different level gauges thereof so as to meet different requirements. 
     In the preferred embodiment of the level gauge thereof in the invention, the LED backlight of the LED indicator mechanism, the vertical state LED light of the vertical level bubble mechanism and the LED light of the LED indicator mechanism of the 45° state LED light of the 45° level bubble mechanism can be set to normally open, transiently on, flashing or other lighting forms to form different level gauges thereof so as to meet different requirements. 
     The invention is described in details in combination with the accompanying drawings and embodiments. Various changes can be made to the invention by those skilled in the art based on the description. Any modification, equivalent replacement and improvement made within the spirits and rules of the invention shall be incorporated in the protection scope of the invention. Therefore, the invention shall not be restricted to some details in the embodiments, and the protection scope of the invention is to be specified by the claims of the invention.