Optical fiber sensor for measuring liquid level height of solution

Abstract

The utility model discloses an optical fiber sensor for measuring the liquid level height of a solution, which comprises a laser light source, a triangular prism arranged at the bottom of the laser light source, a coupling mirror arranged at the bottom of the triangular prism, a communicating pipe arranged at the bottom of the coupling mirror, a naked core processing optical fiber arranged at the center of the communicating pipe, and a photodiode arranged at one end of the communicating pipe far away from the coupling mirror. The communication pipe is connected with the AD620 amplifier through the photodiode, the AD620 amplifier is connected with the amplifier power supply voltage, the AD620 amplifier is connected with the reverse power supply, the voltmeter and the switch, and the communication pipe is installed in the container. Compared with the prior art, the device has the advantages that the illumination intensity of the output end of the optical fiber at different liquid levels can be effectively measured, the liquid level of a solution is indirectly reflected, the purpose of measuring the liquid level of the liquid is achieved, the liquid level in a container can be accurately and directly measured, and the measurement accuracy is high. And the reading error caused by direct manual observation is greatly reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to liquid level measurement technical field especially relates to a device of solution liquid level accurate measurement using optical fiber sensor. BACKGROUND

[0002] Optical fiber is the abbreviation of optical fiber, which is a kind of fiber made of glass or plastic, which can be used as light transmission tool. The principle of optical fiber transmission is total reflection of light, which refers to when light is incident from a light dense medium into a light sparse medium, the incident angle is greater than the critical angle, the light will be completely reflected back to the original medium, and will not propagate to another medium. When the external environmental factors such as temperature, concentration and vibration change, the light wave transmitted in the optical fiber will be modulated by these external physical quantities, so that the characteristic parameters of the light wave such as intensity, phase, frequency and polarization state will change accordingly. By detecting the changes of these parameters of light wave, the information of the measured external quantity can be obtained, and the functions of "transmission" and "sensing" of the measured external quantity can be realized, which is also the basic principle of optical fiber sensor.

[0003] Optical fiber sensor is a new type of sensor developed rapidly with the related technologies of optical fiber communication and optical fiber sensing. This kind of sensor has the advantages of high sensitivity, high precision, good anti-electromagnetic interference, good electrical insulation, small transmission loss, large transmission capacity, long service life, distributed measurement, geometric shape plasticity and easy connection with computer and optical fiber transmission system, etc. It has shown great application potential and value in many fields.

[0004] In many industrial production, scientific research and daily life scenes, the accurate measurement of solution liquid level is very important. For example, in the chemical production process, accurate control of the liquid level of the solution in the reaction container has a direct impact on the progress of chemical reaction and product quality; in oil exploitation, the monitoring of the liquid level in the oil tank is related to production safety and inventory management; in environmental monitoring, the measurement of water level helps to understand the storage and flow of water resources. The traditional liquid level measurement methods mainly include direct reading method of connecting device and liquid level meter measurement method. The direct reading method of connecting device will produce large reading error due to factors such as line of sight angle and human judgment when facing large volume containers. Although the liquid level meter measurement method improves the convenience of measurement to some extent, some liquid level meters have the problems of low precision and large environmental interference. In addition, some traditional measurement methods may face challenges such as equipment corrosion and inaccurate measurement when measuring the liquid level of corrosive solution or in special environments such as high temperature, high pressure and strong electromagnetic interference. With the development of science and technology, optical fiber sensor technology has gradually emerged, which has the advantages of high sensitivity, high precision, anti-electromagnetic interference, good electrical insulation and many others, providing a new solution for accurate measurement of solution liquid level. CONTENT OF THE UTILITY MODEL

[0005] The utility model aims at providing a kind of optical fiber sensor for measuring solution liquid level height, solve the problems of traditional liquid level height measurement method in precision, applicable scope, anti-interference ability etc., realize the accurate, reliable measurement of solution liquid level height under different environments, improve measurement efficiency and accuracy, reduce measurement error.

[0006] To solve the above technical problems, the technical scheme provided by the utility model is as follows: an optical fiber sensor for measuring solution liquid level height, comprising a laser light source, the laser light source bottom is equipped with three-prism, three-prism bottom is equipped with coupling mirror, coupling mirror bottom is equipped with communicating pipe, the center of communicating pipe is equipped with bare core processing optical fiber, the end of communicating pipe away from coupling mirror is equipped with photodiode, communicating pipe is connected AD620 amplifier by photodiode, AD620 amplifier is connected amplifier power supply voltage, AD620 amplifier is connected reverse power supply, voltmeter and switch, communicating pipe is installed in container.

[0007] As an improvement, three-prism can divide single laser into three beams.

[0008] As an improvement, the bare core processing mode of bare core processing optical fiber is to remove the inner and outer cladding of optical fiber by physical or chemical method, and to moderately damage the inner core of optical fiber.

[0009] As an improvement, communicating pipe is made of transparent, corrosion-resistant material, and its inner diameter matches the outer diameter of bare core processing optical fiber.

[0010] As an improvement, AD620 amplifier has the characteristics of low noise, high gain and high precision, and its amplification factor can be adjusted.

[0011] The utility model compared with prior art has the advantages that: the present application can effectively measure the light intensity of optical fiber output end under different liquid level height, indirectly reflect the liquid level height of solution, achieve the purpose of measuring liquid level height, for the container of too large volume, compared with the reading error of traditional communicating vessel directly reading liquid level height, the present application can accurately and directly measure the liquid level height in container, greatly reduce the reading error of human direct observation. BRIEF DESCRIPTION OF DRAWINGS

[0012] Figure 1 It is a kind of optical fiber sensor for measuring solution liquid level height structure schematic diagram.

[0013] Figure 2 It is a kind of optical fiber sensor for measuring solution liquid level height optical fiber internal structure schematic diagram.

[0014] Figure 3 It is a kind of optical fiber sensor for measuring solution liquid level height bare core processing optical fiber structure schematic diagram.

[0015] As shown in the figure: 1. Laser light source, 2. Three prism, 3. Coupling mirror, 4. Communication tube, 5. Bare core processing optical fiber, 6. Photodiode, 7. AD620 amplifier, 8. Amplifier power supply voltage, 9. Reverse power supply, 10. Voltmeter, 11 switch, 12. Container. DETAILED DESCRIPTION

[0016] The utility model makes further detailed description in combination with the drawing.

[0017] The utility model in specific implementation, the overall structure

[0018] The utility model discloses a fiber sensor, including laser light source 1, three prism 2, bare core processing optical fiber 5, communication tube 4, photodiode 6, AD620 amplifier 7, voltmeter 10 and reverse voltage source 9. Laser light source 1 is used to emit laser, and after opening, laser is shot into three prism 2 at specific angle. Three prism 2 has unique optical structure, and after the fold reflection of its three mirror surfaces, the original single laser beam can be divided into three beams. The one end of optical fiber is accurately coupled with the laser emission part through coupling mirror 3, to ensure that the emergent light can enter the optical fiber efficiently and be smoothly conducted to the optical fiber output end. Bare core processing optical fiber 5 is one of the key components of the device, and the middle part is subjected to bare core processing, that is, the inner and outer cladding of the optical fiber is removed by physical or chemical method, and the inner core of the optical fiber is subjected to moderate damage processing, so that a certain amount of laser can escape at the damaged place, to cause the light intensity of the output end to change. The bare core part of communication tube 4 is connected with bare core processing optical fiber 5, and according to the principle of communicating vessel, the liquid level in communication tube 4 is always consistent with the liquid level in container 12. Photodiode 6 is installed at the output end of the optical fiber, and is used to output the light intensity in the form of electric signal through photoelectric conversion. AD620 amplifier 7 amplifies the electric signal output by photodiode 6, to enhance the signal intensity and facilitate subsequent measurement. Voltmeter 10 is used to display the voltage value after amplification, and reverse voltage source 9 is used to solve the problem that the voltmeter cannot display when the output photo-voltage is too weak or too strong, and the difference between the photo-voltage and the reverse voltage is used to reflect the actual voltage change.

[0019] Key component characteristics and connection relationship

[0020] The laser wavelength and power emitted by laser source 1 are selected according to measurement requirements to ensure sufficient energy and stability after beam splitting by prism 2 and transmission through optical fiber, enabling accurate detection of changes in solution level. Prism 2 is made of glass or crystal material with excellent optical properties, and its optical surfaces are precision polished to ensure accurate and stable laser refraction and reflection. The bare-core fiber 5 is made of fiber material with good optical transmission performance and certain corrosion resistance, such as silica fiber. During bare-core processing, the degree of cladding removal and core damage is strictly controlled to ensure that the laser emission amount reflects changes in liquid level without affecting measurement accuracy due to excessive or insufficient emission. The connecting tube 4 is made of transparent, corrosion-resistant material, such as glass or plexiglass, and its inner diameter matches the outer diameter of the bare-core fiber 5, ensuring a tight connection without affecting solution flow and liquid level balance within the connecting tube 4. The photodiode 6 has high sensitivity and fast response characteristics, accurately converting changes in light intensity into electrical signals. The AD620 amplifier 7 features low noise, high gain, and high accuracy, and its amplification factor can be adjusted according to actual measurement needs. The reverse voltage output of the reverse voltage source 9 is adjustable to adapt to the optical voltage compensation requirements under different measurement conditions.

[0021] Working principle of this utility model: device assembly and debugging

[0022] First, according to Figure 1 The structural layout shown connects and installs components such as laser source 1, prism 2, coupling mirror 3, connecting tube 4, bare-core fiber 5, photodiode 6, AD620 amplifier 7, reverse voltage source 9, voltmeter 10, and switch 11. Ensure the optical paths of laser source 1 and prism 2 are aligned, and coupler 3 accurately couples the laser into the input end of bare-core fiber 5. During the bare-core treatment of fiber 5, appropriate physical or chemical methods are selected to remove the inner and outer cladding of the fiber according to predetermined measurement accuracy and sensitivity requirements, and the inner core is moderately damaged. For example, when using chemical etching, parameters such as the concentration of the etchant, treatment time, and temperature must be precisely controlled to achieve the desired bare-core effect. Connecting tube 4 is tightly connected to the bare core portion of bare-core fiber 5 to prevent solution leakage. Photodiode 6 is precisely coupled to the output end of bare-core fiber 5 to ensure maximum reception of emitted light and photoelectric conversion. AD620 amplifier 7 is correctly connected to photodiode 6 and voltmeter 10, and an appropriate amplification factor is set. The reverse voltage source 9 adjusts the output reverse voltage value according to the actual measurement situation, so that the voltmeter 10 can accurately display the measurement result.

[0023] Measurement process and data acquisition

[0024] Place the assembled and debugged device next to the container 12 where the liquid level needs to be measured. Connect the communication tube 4 with the container 12 through appropriate connection methods such as pipe connection or direct immersion into the solution in the container, ensuring that the liquid level in the communication tube 4 is consistent with the liquid level in the container 12. Turn on the laser light source 1, and the laser light enters the bare core processing optical fiber 5 after being split by the three-prism 2. Part of the laser light escapes and interacts with the solution in the communication tube 4. As the liquid level changes, the degree of absorption of the escaping light by the solution changes, causing the light intensity at the output end of the optical fiber to change. The photodiode 6 converts the change in light intensity into an electrical signal in real time, which is amplified by the AD620 amplifier 7 and displayed as a voltage value on the voltmeter 10. During the measurement process, start from a lower position of the liquid level in the container 12, slowly inject the solution, and record the voltage value displayed on the voltmeter 10 every certain liquid level interval, such as 1 centimeter, while recording the corresponding liquid level. Repeat the measurement multiple times and take the average to improve the accuracy of the measurement data.

[0025] Data processing and liquid level calculation

[0026] According to the collected voltage values and corresponding liquid level data, use data processing software such as Excel to perform data fitting and establish a mathematical relationship model between the photoelectric voltage and the liquid level. For example, through linear regression analysis or polynomial fitting, a function expression that accurately describes the relationship between the two can be obtained. When a certain volume of solution is injected into the container 12, the voltmeter 10 displays a new voltage value, which is substituted into the established mathematical relationship model to calculate the liquid level of the solution in the container 12 at that time. In practical applications, in order to improve the accuracy of the calculation results, the mathematical relationship model can be appropriately modified and optimized according to different measurement environments and solution characteristics. For example, for solutions of different colors or concentrations, their light absorption characteristics may be different, and the model parameters need to be adjusted accordingly.

[0027] Device performance verification and optimization

[0028] The performance verification test of the optical fiber sensor of the utility model is carried out under different environmental conditions such as different temperatures, humidities, electromagnetic interference intensities, etc. The measurement results are compared with the measurement results of standard measurement methods such as high-precision liquid level meters, and the measurement error and stability of the device are analyzed. If it is found that the measurement error exceeds the allowable range, the components and parameters of the device are checked and optimized. For example, the power stability of the laser light source 1, the optical performance of the triangular prism 2, the bare core state of the bare core processing optical fiber 5, the sensitivity of the photodiode 6, etc. are checked. According to the inspection results, the corresponding components are adjusted or replaced, and the parameter settings are optimized to improve the performance and measurement accuracy of the device. At the same time, according to the actual use feedback, the structure design of the device is improved, such as optimizing the connection mode of the communication pipe 4, enhancing the anti-vibration performance of the device, etc., so that the utility model is more perfect, reliable, and suitable for more extensive application scenarios.

[0029] In addition, the terms "first", "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Therefore, the features defined as "first", "second" can explicitly or implicitly include one or more of the features, and in the description of the utility model, the meaning of "multiple" is two or more, unless otherwise explicitly specified.

[0030] In the utility model, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection", "fixing" and the like should be broadly understood, for example, it can be fixedly connected, or it can be detachably connected or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be connected inside two elements. For ordinary skilled in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances.

[0031] In the utility model, unless otherwise explicitly specified and limited, the "upper" or "lower" of the first feature to the second feature can include that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, the "upper", "upper" and "upper" of the first feature to the second feature include that the first feature is directly above and obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The "below", "below" and "below" of the first feature to the second feature include that the first feature is directly below and obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0032] In the description of the present specification, the description referring to the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily mean the same embodiment or example. Furthermore, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0033] Although the embodiments of the present application have been shown and described above, it should be understood that the above-described embodiments are exemplary, and should not be construed as limiting the present application, and those skilled in the art can make changes, modifications, replacements and variations to the above-described embodiments within the scope of the present application without departing from the principles and spirits of the present application.

Claims

1. An optical fiber sensor for measuring the level of a solution comprising a laser light source (1), characterized in that: The bottom of the laser light source (1) is provided with a triangular prism (2), the bottom of the triangular prism (2) is provided with a coupling mirror (3), the bottom of the coupling mirror (3) is provided with a communication pipe (4), the center of the communication pipe (4) is provided with a bare core processing optical fiber (5), the end of the communication pipe (4) away from the coupling mirror (3) is provided with a photodiode (6), the communication pipe (4) is connected with an AD620 amplifier (7) through the photodiode (6), the AD620 amplifier (7) is connected with an amplifier power supply voltage (8), the AD620 amplifier (7) is connected with a reverse power supply (9), a voltmeter (10) and a switch (11), and the communication pipe (4) is installed in a container (12).

2. The optical fiber sensor for measuring the liquid level of a solution according to claim 1, wherein: The triangular prism (2) can divide a single laser beam into three beams.

3. The optical fiber sensor for measuring the liquid level of a solution according to claim 1, wherein: The bare core processing mode of the bare core processing optical fiber (5) is to remove the inner and outer cladding of the optical fiber by physical or chemical methods.

4. The optical fiber sensor for measuring the liquid level of a solution according to claim 1, wherein: The inner diameter of the communication pipe (4) matches the outer diameter of the bare core processing optical fiber (5).

5. The optical fiber sensor for measuring the liquid level of a solution according to claim 1, wherein: The amplification multiple of the AD620 amplifier (7) is adjustable.

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