Self-calibration type capacitance liquid level meter

Abstract

The utility model discloses a self-calibration type capacitance liquid level meter which comprises an insulating tube. A supporting piece is arranged at the upper end in the insulating pipe, the middle of the supporting piece is rotationally connected with a stainless steel column through a bearing, the lower end in the insulating pipe is fixedly connected with the upper end of a stainless steel pipe, and a fixed sealing sleeve is arranged at the upper end in the stainless steel pipe and rotationally connected with the upper end of the stainless steel column. A threaded groove is formed in the outer arc surface of the stainless steel column, a round nut is slidably connected to the interior of the stainless steel pipe, the round nut is in threaded connection with the threaded groove, a movable sealing sleeve is arranged on the lower surface of the round nut, and the stainless steel column, the threaded groove and the stainless steel pipe are all matched with the movable sealing sleeve. Liquid in the liquid level meter can be driven to move to a specified height and is compared with a capacitance measurement result for calibration, and automatic calibration is convenient to use.

Description

Technical Field

[0001] The utility model relates to the technical field of capacitance liquid level gauges, in particular to a self-calibration capacitance liquid level gauge. Background Art

[0002] With the development of science and technology, humans have invented countless methods of liquid level measurement, from ancient rulers to modern floats, ultrasonic waves, reed switches, photoelectric water level sensors and capacitive level gauges. Capacitive level gauges are a type of sensor commonly used to measure liquid levels. Their working principle is based on the concept of capacitance, and the relationship between capacitance value and liquid level is used to achieve measurement. Capacitive level sensors are composed of sensing electrodes, reference electrodes and capacitance measurement circuits. When the measured medium (such as liquid) is filled between the two electrodes, a capacitor is formed, the size of which is related to the liquid level of the measured medium, and then the liquid level can be measured. The structure is simple and convenient to use. Existing capacitive level gauges generally cannot be automatically calibrated, and often require manual control of the insertion depth of the capacitive level gauge, or the liquid level inside the container, to achieve control of the liquid level inside the capacitive level, and then compare it with the measured value to achieve calibration, which results in poor calibration convenience and affects the convenience of use. Utility Model Content

[0003] The technical problem to be solved by the utility model is to overcome the existing defects and provide a self-calibrating capacitance level meter. During use, the liquid inside the level meter can be driven by a servo motor to move to a specified height, and the liquid is compared and calibrated with the capacitance measurement result. The automatic calibration is convenient to use and ensures the measurement accuracy, which can effectively solve the problems in the background technology.

[0004] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: a self-calibration capacitance level gauge, comprising an insulating tube;

[0005] Insulating tube: A supporting plate is provided at the upper end of the interior thereof, and a stainless steel column is rotatably connected to the middle of the supporting plate through a bearing, and the lower end of the interior of the insulating tube is fixedly connected to the upper end of the stainless steel tube, and a fixed sealing sleeve is provided at the upper end of the interior of the stainless steel tube, and the fixed sealing sleeve is rotatably connected to the upper end of the stainless steel column, and a threaded groove is provided on the outer arc surface of the stainless steel column, and a round nut is slidably connected to the interior of the stainless steel tube, and the round nut is threadedly connected to the threaded groove, and a movable sealing sleeve is provided on the lower surface of the round nut, and the stainless steel column, the threaded groove and the stainless steel tube are all arranged in cooperation with the movable sealing sleeve, and an exhaust hole is provided at the upper end of the outer arc surface of the stainless steel tube, and a liquid inlet hole is provided at the lower end of the outer arc surface of the stainless steel tube, and a conductive sheet is provided at the upper end of the insulating tube, and the conductive sheet is slidably connected to the upper end of the outer arc surface of the stainless steel column;

[0006] Among them: it also includes a single-chip microcomputer, which is fixedly connected to the support plate on the front side of the insulating tube, a capacitive sensor is provided on the right side of the front side of the support plate, the output ends of the conductive sheet and the stainless steel tube are electrically connected to the input ends of the capacitive sensor, the output ends of the capacitive sensor are electrically connected to the input ends of the single-chip microcomputer, and the input ends of the single-chip microcomputer are electrically connected to an external power supply. During use, the liquid inside the liquid level meter can be driven by a servo motor to move to a specified height, and compared and calibrated with the capacitance measurement result. Automatic calibration is convenient to use and ensures measurement accuracy.

[0007] Furthermore, a slide groove is provided on the inner arc wall of the stainless steel tube, a slide bar is provided on the outer arc surface of the round nut, the slide bar is slidably connected to the slide groove, and the left end of the movable sealing sleeve is slidably connected to the slide groove to limit the rotation of the round nut.

[0008] Furthermore, a servo motor is provided at the upper end of the insulating tube through a supporting column, the output shaft of the servo motor is fixedly connected to the upper end of the stainless steel column, and the input end of the servo motor is electrically connected to the power transmission end of the single chip microcomputer to facilitate the control of the rotation of the stainless steel column.

[0009] Furthermore, a support ring is provided at the lower end of the interior of the stainless steel tube, and the lower end of the stainless steel column is rotatably connected to the support ring, thereby providing rotational support for the lower end of the stainless steel column.

[0010] Furthermore, a flange is provided on the lower end fixing sleeve of the outer arc surface of the insulating tube, and a rubber pad is provided on the lower surface of the flange to facilitate its own fixing and installation.

[0011] Furthermore, a protective shell is provided on the upper surface of the flange, and the servo motor, the single-chip microcomputer and the capacitive sensor are all located inside the protective shell to provide protection for the internal components.

[0012] Furthermore, a cable gland is provided at the cable outlet hole on the outer arc surface of the protective shell to fix and seal the cable.

[0013] Compared with the prior art, the beneficial effects of the utility model are: the self-calibration capacitance level meter has the following advantages:

[0014] During self-calibration, the single-chip microcomputer controls the operation of the servo motor. The output shaft of the servo motor drives the stainless steel column to rotate a specified number of circles. The stainless steel column drives the round nut downward through the threaded groove, and the round nut drives the movable sealing sleeve and the slider downward. When the movable sealing sleeve moves to the bottom, the liquid in the stainless steel tube and the stainless steel column will be squeezed out. At this time, the capacitance sensor detects the capacitance value between the stainless steel tube and the stainless steel column and sets the lowest point for initial calibration. Then the servo motor drives the movable sealing sleeve to move upward. The movable sealing sleeve is in a sealed state with the stainless steel tube and the stainless steel column, and then the liquid is drawn into the space between the stainless steel tube and the stainless steel column, so as to control the height of the internal liquid level. The single-chip microcomputer can calculate the height of the internal liquid level by controlling the servo motor. The height of the internal liquid level is compared with the measurement result of the capacitance sensor, and continuous multi-point calibration can be performed. During use, the liquid inside the liquid level meter can be driven to move to the specified height by the drive of the servo motor, and compared and calibrated with the capacitance measurement result. Automatic calibration is convenient to use and ensures measurement accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the structure of the utility model;

[0016] Figure 2 It is a cross-sectional structural schematic diagram of the utility model;

[0017] Figure 3 It is a schematic diagram of the enlarged structure of point A of the utility model.

[0018] In the figure: 1 insulating tube, 2 supporting sheet, 3 stainless steel column, 4 threaded groove, 5 stainless steel tube, 6 fixed sealing sleeve, 7 liquid inlet hole, 8 exhaust hole, 9 movable sealing sleeve, 10 sliding groove, 11 round nut, 12 sliding bar, 13 servo motor, 14 single chip microcomputer, 15 capacitive sensor, 16 conductive sheet, 17 flange, 18 rubber pad, 19 protective shell, 20 cable gland, 21 supporting ring. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0020] See also Figure 1-3 ,This embodiment provides a technical solution: a self-calibration capacitance level gauge, comprising an insulating tube 1;

[0021] Insulating tube 1: A support sheet 2 is provided at the upper end of the interior thereof. The insulating tube 1 is a polytetrafluoroethylene insulating tube, which provides support for other parts. The middle part of the support sheet 2 is rotatably connected to a stainless steel column 3 through a bearing. The support sheet 2 provides rotation support for the stainless steel column 3. The lower end of the interior of the insulating tube 1 is fixedly connected to the upper end of the stainless steel tube 5. A fixed sealing sleeve 6 is provided at the upper end of the interior of the stainless steel tube 5. The fixed sealing sleeve 6 is rotatably connected to the upper end of the stainless steel column 3. The fixed sealing sleeve 6 seals the stainless steel column 3 and the upper end of the stainless steel tube 5. A threaded groove 4 is provided on the outer arc surface of the stainless steel column 3. A round nut 11 is slidably connected to the interior of the stainless steel tube 5. The round nut 11 is screwed to the threaded groove 4. The groove 4 is threadedly connected, and a movable sealing sleeve 9 is provided on the lower surface of the round nut 11. The stainless steel column 3, the thread groove 4 and the stainless steel tube 5 are all arranged in cooperation with the movable sealing sleeve 9. An exhaust hole 8 is provided at the upper end of the outer arc surface of the stainless steel tube 5, and a liquid inlet hole 7 is provided at the lower end of the outer arc surface of the stainless steel tube 5. The liquid inside the container enters between the stainless steel column 3 and the stainless steel tube 5 through the liquid inlet hole 7, and the air between the stainless steel column 3 and the stainless steel tube 5 is discharged from the exhaust hole 8. A conductive sheet 16 is provided at the upper end of the insulating tube 1, and the conductive sheet 16 is slidably connected to the upper end of the outer arc surface of the stainless steel column 3. A sliding groove 10 is provided on the inner arc wall of the stainless steel tube 5, and a The slide bar 12 is slidably connected with the slide groove 10 to limit the rotation of the round nut 11. The left end of the movable sealing sleeve 9 is slidably connected with the slide groove 10. The stainless steel column 3 drives the round nut 11 to move downward through the threaded groove 4. The round nut 11 drives the movable sealing sleeve 9 and the slide bar 12 to move downward. When the movable sealing sleeve 9 moves to the bottom, the liquid in the stainless steel pipe 5 and the stainless steel column 3 will be squeezed out. The upper end of the insulating tube 1 is provided with a servo motor 13 through a supporting column. The output shaft of the servo motor 13 is fixedly connected to the upper end of the stainless steel column 3. The input end of the servo motor 13 is electrically connected to the transmission end of the single-chip microcomputer 14. The output shaft of the servo motor 13 drives the stainless steel column 3 to rotate a specified The number of turns, the servo motor 13 drives the movable sealing sleeve 9 to move upward, the movable sealing sleeve 9 is in a sealed state with the stainless steel tube 5 and the stainless steel column 3, and then the liquid will be drawn into between the stainless steel tube 5 and the stainless steel column 3, so as to control the height of the internal liquid level, the lower end of the stainless steel tube 5 is provided with a support ring 21, the lower end of the stainless steel column 3 is rotatably connected with the support ring 21, and the support ring 21 provides a rotation support for the lower end of the stainless steel column 3, the lower end fixed sleeve of the outer arc surface of the insulating tube 1 is provided with a flange 17, the lower surface of the flange 17 is provided with a rubber pad 18, the flange 17 is placed above the container, and the rubber pad 18 seals the connection between the flange 17 and the container;

[0022] Wherein: it also includes a single chip microcomputer 14, the single chip microcomputer 14 is fixedly connected to the support plate on the front side of the insulating tube 1, a capacitance sensor 15 is arranged on the right side of the front side of the support plate, the output end of the conductive sheet 16 and the stainless steel tube 5 is electrically connected to the input end of the capacitance sensor 15, the output end of the capacitance sensor 15 is electrically connected to the input end of the single chip microcomputer 14, the input end of the single chip microcomputer 14 is electrically connected to an external power supply, the stainless steel column 3, the stainless steel tube 5 and the internal liquid form a capacitance structure, when the liquid level in the container changes, the dielectric constant of the stainless steel column 3 and the stainless steel tube 5 will change, thereby causing the capacitance to change, and the capacitance sensor 15 controls the stainless steel column 3 and the stainless steel tube 5 through the conductive sheet 16 The capacitance value between them is detected and transmitted to the single-chip microcomputer 14, the single-chip microcomputer 14 processes the capacitance value and converts it into an electrical signal for transmission to an external controller to realize the measurement of the liquid level. The single-chip microcomputer 14 can calculate the height of the internal liquid surface by controlling the servo motor 13. The height of the internal liquid surface is compared with the measurement result of the capacitance sensor 15, and continuous multi-point calibration can be performed. A protective shell 19 is provided on the upper surface of the flange 17, and the servo motor 13, the single-chip microcomputer 14 and the capacitance sensor 15 are all located inside the protective shell 19. The protective shell 19 protects the internal components, and a cable gland 20 is provided at the outlet hole of the outer arc surface of the protective shell 19 to facilitate the fixation and sealing of the cable.

[0023] The working principle of a self-calibration capacitance liquid level meter provided by the utility model is as follows: when in use, the flange 17 is placed above the container, and the rubber pad 18 is used to seal the connection between the flange 17 and the container. The liquid inside the container enters between the stainless steel column 3 and the stainless steel tube 5 through the liquid inlet hole 7, and the air between the stainless steel column 3 and the stainless steel tube 5 is discharged from the exhaust hole 8. The stainless steel column 3, the stainless steel tube 5 and the internal liquid form a capacitor structure. When the liquid level in the container changes, the dielectric constant of the stainless steel column 3 and the stainless steel tube 5 will change, thereby causing the capacitance to change. The capacitance sensor 15 detects the capacitance value between the stainless steel column 3 and the stainless steel tube 5 through the conductive sheet 16 and transmits it to the single-chip microcomputer 14. The single-chip microcomputer 14 processes the capacitance value and converts it into an electrical signal and transmits it to the external controller to achieve liquid level measurement. During self-calibration, the single-chip microcomputer 14 controls the servo motor 13 to operate, and the output shaft of the servo motor 13 drives the stainless steel column 3 to rotate a specified number of circles. The stainless steel column 3 drives the round nut 11 through the threaded groove 4 Move downward, the round nut 11 drives the movable sealing sleeve 9 and the slide bar 12 to move downward. When the movable sealing sleeve 9 moves to the lowest point, the liquid in the stainless steel tube 5 and the stainless steel column 3 will be squeezed out. At this time, the capacitance sensor 15 detects the capacitance value between the stainless steel tube 5 and the stainless steel column 3 to set the lowest point and perform initial calibration. Then the servo motor 13 drives the movable sealing sleeve 9 to move upward. The movable sealing sleeve 9 and the stainless steel tube 5 and the stainless steel column 3 are in a sealed state, and then the liquid will be drawn into the space between the stainless steel tube 5 and the stainless steel column 3, so that the height of the internal liquid level can be controlled. The single-chip microcomputer 14 can calculate the height of the internal liquid level by controlling the servo motor 13. The height of the internal liquid level is compared with the measurement result of the capacitance sensor 15, and continuous multi-point calibration can be performed. After the movable sealing sleeve 9 moves to the highest point, it will be higher than the lowest point of the exhaust hole 8, and air will enter between the stainless steel tube 5 and the stainless steel column 3. The liquid level inside the stainless steel tube 5 and the stainless steel column 3 is level with the liquid level inside the container, and normal measurement can be performed.

[0024] It is worth noting that the servo motor 13, single-chip microcomputer 14 and capacitive sensor 15 disclosed in the above embodiments can be freely configured according to the actual application scenario. The single-chip microcomputer 14 can select the single-chip microcomputer of model AT89S51, and the capacitive sensor 15 can select the capacitive sensor of model MC11S. The single-chip microcomputer 14 controls the operation of the servo motor 13 and the capacitive sensor 15 using methods commonly used in the prior art.

[0025] The above description is only an embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A self-calibrating capacitance level meter, characterized in that: comprising an insulating tube (1); The insulating tube (1) has a support sheet (2) at its upper end, the middle of the support sheet (2) is rotatably connected to a stainless steel column (3) via a bearing, the lower end of the insulating tube (1) is fixedly connected to the upper end of a stainless steel tube (5), the upper end of the stainless steel tube (5) is provided with a fixed sealing sleeve (6), the fixed sealing sleeve (6) is rotatably connected to the upper end of the stainless steel column (3), a thread groove (4) is provided on the outer arc surface of the stainless steel column (3), the inner part of the stainless steel tube (5) is slidably connected to a round nut (11), and the round nut (11) is provided on the inner part of the stainless steel tube (5). The nut (11) is threadedly connected to the thread groove (4); a movable sealing sleeve (9) is provided on the lower surface of the round nut (11); the stainless steel column (3), the thread groove (4) and the stainless steel tube (5) are all arranged in cooperation with the movable sealing sleeve (9); an exhaust hole (8) is provided at the upper end of the outer arc surface of the stainless steel tube (5); a liquid inlet hole (7) is provided at the lower end of the outer arc surface of the stainless steel tube (5); a conductive sheet (16) is provided at the upper end of the insulating tube (1); and the conductive sheet (16) is slidably connected to the upper end of the outer arc surface of the stainless steel column (3); The device further comprises a single-chip microcomputer (14), the single-chip microcomputer (14) being fixedly connected to a support plate on the front side of the insulating tube (1), a capacitance sensor (15) being provided on the right side of the front side of the support plate, the output end of the conductive sheet (16) and the stainless steel tube (5) being electrically connected to the input end of the capacitance sensor (15), the output end of the capacitance sensor (15) being electrically connected to the input end of the single-chip microcomputer (14), and the input end of the single-chip microcomputer (14) being electrically connected to an external power supply.

2. A self-calibrating capacitance level gauge according to claim 1, characterized in that: A slide groove (10) is provided on the inner arc wall of the stainless steel tube (5), a slide bar (12) is provided on the outer arc surface of the round nut (11), the slide bar (12) is slidably connected to the slide groove (10), and the left end of the movable sealing sleeve (9) is slidably connected to the slide groove (10).

3. A self-calibrating capacitance level gauge according to claim 1, characterized in that: A servo motor (13) is provided at the upper end of the insulating tube (1) via a support column, an output shaft of the servo motor (13) is fixedly connected to the upper end of the stainless steel column (3), and an input end of the servo motor (13) is electrically connected to a power transmission end of a single chip computer (14).

4. A self-calibrating capacitance level gauge according to claim 1, characterized in that: A support ring (21) is provided at the lower end of the interior of the stainless steel tube (5), and the lower end of the stainless steel column (3) is rotatably connected to the support ring (21).

5. A self-calibrating capacitance level gauge according to claim 3, characterized in that: A flange (17) is fixedly mounted at the lower end of the outer arc surface of the insulating tube (1), and a rubber pad (18) is disposed on the lower surface of the flange (17).

6. A self-calibrating capacitance level gauge according to claim 5, characterized in that: A protective shell (19) is provided on the upper surface of the flange (17), and the servo motor (13), the single-chip microcomputer (14) and the capacitive sensor (15) are all located inside the protective shell (19).

7. A self-calibrating capacitance level gauge according to claim 6, characterized in that: A cable gland (20) is provided at the wire outlet hole on the outer arc surface of the protective shell (19).

Images