Liquid level detection device

Abstract

The liquid level detection device comprises a packaging shell, a fiber grating sensor, a light source, a photoelectric detector and a signal processor, the packaging shell comprises a glass sleeve, an installation block and a fixing plug, and the fiber grating sensor is installed in the installation block in an embedded mode; the mounting block is mounted in the glass tube, and the two ends of the glass tube are connected with the fixing plugs respectively; the fiber bragg grating sensor is respectively connected with two optical fibers, the two optical fibers respectively penetrate through the fixing plug to be connected with the light source and the photoelectric detector, and the photoelectric detector is connected with the signal processor. According to the utility model, the fiber bragg grating sensor is adopted and has the characteristics of electrical insulation, electromagnetic interference resistance and corrosion resistance, so that the service life is prolonged and the stability is improved; the packaging design of the glass sleeve and the fixing plug prevents impurities from entering or adhering, signals are ensured to be accurate and reliable, the device is simple in structure and easy to install and use, debugging and maintenance work is reduced, and operation cost is reduced.

Description

Technical Field

[0001] This utility model relates to the field of liquid level measurement technology, and specifically to a liquid level detection device. Background Technology

[0002] In current wastewater treatment facilities, wastewater collection wells play a crucial role. However, traditional level detection technologies face numerous challenges. For example, level sensors are prone to failure due to debris clogging the vents, and float level switches may fail to transmit accurately due to debris adhering to the float or cables. Furthermore, the wastewater in the collection well contains a large amount of corrosive substances, causing severe corrosion to level sensors and float level switches, leading to frequent malfunctions in the wastewater pump control system. This not only increases the consumption of spare parts but may also cause wastewater overflow or damage to the drainage pump due to its inability to stop properly, thereby impacting the environment and public health. To address these issues, the development of a new type of level detection device is particularly urgent. Utility Model Content

[0003] In view of the shortcomings of traditional liquid level detection technology, such as easy failure and damage, this utility model provides a liquid level detection device that is not affected by contaminants and has a long service life.

[0004] To achieve the above objectives, the technical solution of this utility model is as follows:

[0005] A liquid level detection device includes a housing, a fiber Bragg grating sensor, a light source, a photodetector, and a signal processor. The housing includes a glass sleeve, a mounting block, and a fixing plug. The fiber Bragg grating sensor is embedded in the mounting block. The mounting block is inserted into the glass sleeve, and the two ends of the glass sleeve are respectively connected to the fixing plug. The fiber Bragg grating sensor is connected to two optical fibers, which pass through the fixing plug and are connected to the light source and the photodetector, respectively. The photodetector is connected to the signal processor.

[0006] How to use:

[0007] In actual operation, the fiber Bragg grating sensor of the device is placed in the water collection well for detection. The light signal generated by the light source is transmitted to the fiber Bragg grating sensor through the optical fiber. When the liquid level in the water collection well changes, the reflection spectrum of the fiber Bragg grating sensor will change accordingly. These changes are captured by the photodetector and converted into electrical signals, which are finally analyzed and processed by the signal processor to accurately detect the liquid level information.

[0008] Furthermore, the mounting block consists of a concave block and an adhesive. The fiber Bragg grating sensor is embedded into the concave block using the adhesive, and the optical fiber connected to the fiber Bragg grating sensor passes through the concave block. The concave block is made of a non-metallic polyimide substrate material, and the adhesive is a vacuum-sealed polyimide adhesive that encapsulates the fiber Bragg grating onto the substrate. The combination of the concave block and the adhesive ensures that the entire mounting block maintains a uniform degree of expansion when the sensor is subjected to changes in external pressure, greatly reducing uneven linear expansion of the fiber Bragg grating sensor and ensuring the reliability and stability of the sensor.

[0009] Furthermore, the concave block has limiting rings on both sides of its groove that mate with the inner wall of the glass sleeve. These limiting rings connect to the inside of the glass sleeve, securing the concave block within it and improving its stability, thereby enhancing detection accuracy.

[0010] Furthermore, the fixing plug is connected to the glass sleeve via AB glue. The AB glue used is a commercially available product; this connection method, combining AB glue with the fixing plug, ensures sensor safety and reduces the problem of cross-sensitivity to stress and temperature.

[0011] Furthermore, the light source includes a light source module and a wavelength correction module electrically connected together, wherein the wavelength correction module is connected to an optical fiber. During use, the light source module is activated, generating a stable carrier optical signal and transmitting it to the wavelength correction module. This module preprocesses the optical signal to ensure its wavelength accuracy and stability before transmitting it to the fiber optic grating sensor via the optical fiber. This design integrates the light source module and the wavelength correction module, simplifying the system structure, reducing the complexity of connections between components, and improving the system's reliability and stability. The application of the wavelength correction module ensures high-quality and consistent optical signals, enhancing the accuracy of measurement results. Moreover, the light source module can be selected according to actual needs, featuring an adjustment mechanism that allows for power adjustment based on actual conditions. This not only improves detection accuracy but also ensures system safety.

[0012] Furthermore, the light source module includes an ASE light source, an optical fiber isolator, a fixed optical attenuator, and a tunable FP filter electrically connected together, wherein the tunable FP filter is connected to the wavelength correction module. The ASE light source of the light source system generates a broadband optical signal. This optical signal first passes through the optical fiber isolator to ensure that the light propagates in only one direction, preventing reflected light from damaging the light source or affecting system performance. Then, the optical signal after passing through the optical fiber isolator enters the fixed optical attenuator, is adjusted to a suitable power level, and is then input to the tunable FP filter. The latter adjusts the wavelength of the output light according to actual needs and precisely controls the filter state through its drive circuit. Subsequently, the precise wavelength optical signal output by the tunable FP filter is transmitted through optical fiber to the wavelength correction module. This module uses the FP etalon to further correct the optical signal, ensuring its wavelength accuracy and stability. Finally, the wavelength-corrected optical signal is transmitted through optical fiber to the FBG sensor in the front-end sensing optical cable to begin the actual liquid level detection process. The integration of the light source module and the wavelength correction module simplifies the system structure, reduces the complexity of connections between components, improves the reliability and stability of the system, and enhances the accuracy of the measurement results.

[0013] Furthermore, the wavelength correction module consists of an FP etalon and a PIN detector. This wavelength correction module, employing an FP etalon and a PIN detector, effectively improves the wavelength accuracy and stability of the optical signal, ensuring high precision and reliability in liquid level detection.

[0014] Furthermore, the photodetector includes an ODU module and a DDU module electrically connected together. The ODU module is connected to a fiber optic grating sensor via an optical fiber, and the DDU module is connected to a signal processor. The ODU module is short for Optical Detection Unit, and the DDU module is short for Data Detection Unit. The ODU module receives two optical signals propagating in the forward and reverse directions through the optical fiber. The DDU module analyzes the optical and electrical signals transmitted from the ODU module, and determines the pressure or strain changes at the scene by analyzing the changes in these signals. Finally, this information is sent to the signal processor for processing. By enhancing signal quality and sensitivity through the ODU module and accurately analyzing pressure and strain through the DDU module, the system structure is simplified, reliability and measurement accuracy are improved, and it is suitable for liquid level detection in complex environments.

[0015] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0016] 1. This utility model uses a fiber optic grating sensor as its core component. This sensor not only has strong electrical insulation and electromagnetic interference resistance, but also effectively resists the erosion of corrosive components in sewage, greatly improving the service life and stability of the device. The encapsulation design formed by the glass sleeve and the fixing plug can prevent foreign objects from entering or adhering to the sensor, avoiding the failure problem of traditional sensors caused by blockage or deposits, and ensuring the accuracy and reliability of the signal. The entire device has a simple structure, is easy to install and use, and reduces the workload of on-site debugging and maintenance, thus reducing operating costs.

[0017] 2. The concave block of this utility model uses a polyimide substrate and adhesive to encapsulate the fiber optic grating sensor, ensuring a consistent expansion rate, thereby improving the stability and reliability of the sensor; the limiting rings on both sides of the concave block cooperate with the glass sleeve to enhance structural stability and improve detection accuracy; the fixing plug is connected to the glass sleeve with AB glue to ensure safety and reduce stress and temperature cross-sensitivity issues; the design of the concave block improves the overall stability and accuracy, and is suitable for high-precision liquid level detection in complex environments.

[0018] 3. This utility model integrates a light source module and a wavelength correction module. It generates and adjusts a high-quality optical signal through an ASE light source, an optical fiber isolator, a fixed optical attenuator, and a tunable FP filter. The wavelength correction module ensures wavelength accuracy and stability. The ODU module enhances signal quality and sensitivity, while the DDU module accurately analyzes pressure and strain changes, improving reliability and measurement accuracy. It is suitable for high-precision liquid level detection in complex environments, ensuring system stability and safety. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0020] Figure 2 This is a structural block diagram of the present invention.

[0021] Figure 3 This is a schematic diagram showing the connection of the various electronic components of this utility model.

[0022] Figure 4 This is the circuit diagram of the photodetector of this utility model.

[0023] Figure 5 Schematic diagram of the driving circuit for the adjustable FP filter in the light source.

[0024] Attached image labels:

[0025] Encapsulation shell—1, Glass sleeve—11, Mounting block—12, Fixing plug—13, Limiting ring—14, Fiber grating sensor—2, Light source—3, Light source module—31, Wavelength correction module—32, Photodetector—4, ODU module—41, DDU module—42, Signal processor—5, Fiber optic cable—6. Detailed Implementation

[0026] The present invention will be further described below with reference to the accompanying drawings.

[0027] Example 1: A liquid level detection device includes a housing 1, a fiber Bragg grating sensor 2, a light source 3, a photodetector 4, and a signal processor 5. The housing 1 includes a glass sleeve 11, a mounting block 12, and a fixing plug 13. The fiber Bragg grating sensor 2 is embedded in the mounting block 12. The mounting block 12 is inserted into the glass sleeve, and the two ends of the glass sleeve 11 are respectively connected to the fixing plug 13. The fiber Bragg grating sensor 2 is connected to two optical fibers 6, which pass through the fixing plug 13 and are connected to the light source 3 and the photodetector 4, respectively. The photodetector 4 is connected to the signal processor 5.

[0028] How to use:

[0029] In actual operation, the fiber Bragg grating sensor 2 of the device is placed in the water collection well for detection. When the light source 3 generates light signals, the light signals are transmitted to the fiber Bragg grating sensor 2 through the optical fiber 6. When the liquid level in the water collection well changes, the reflection spectrum of the fiber Bragg grating sensor 2 will change accordingly. These changes are captured by the photodetector 4 and converted into electrical signals, which are finally analyzed and processed by the signal processor 5 to accurately detect the liquid level information.

[0030] Unless otherwise specified, all electronic components and corresponding control circuits used in this invention are existing finished components and related control circuits.

[0031] Furthermore, the mounting block 12 consists of a concave block and an adhesive. The fiber Bragg grating sensor 2 is embedded into the concave block using the adhesive, and the optical fiber 6 connected to the fiber Bragg grating sensor 2 passes through the concave block. The concave block is made of a non-metallic polyimide substrate material, and the adhesive is a vacuum-sealed polyimide adhesive that encapsulates the fiber Bragg grating 6 onto the substrate. The combination of the concave block and the adhesive ensures that the mounting block 12 can maintain a uniform degree of expansion when the sensor is affected by changes in external pressure, greatly reducing the uneven linear expansion of the fiber Bragg grating sensor 2 and ensuring the reliability and stability of the sensor.

[0032] Example 2: The difference from Example 1 is that the concave block has limiting rings 14 on both sides of the groove, which fit into the inner wall of the glass sleeve. The limiting rings 14 are connected to the inside of the glass sleeve, which stabilizes the concave block inside the glass sleeve, thereby improving the stability of the concave block and thus improving the detection accuracy.

[0033] The light source 3 includes a light source module 31 and a wavelength correction module 32 electrically connected together, wherein the wavelength correction module 32 is connected to the optical fiber 6. In use, the light source module 31 is activated, generating a stable carrier optical signal and transmitting it to the wavelength correction module 32. This module preprocesses the optical signal to ensure its wavelength accuracy and stability before transmitting it to the fiber optic grating sensor 2 via the optical fiber 6. This design integrates the light source module 31 and the wavelength correction module 32, simplifying the system structure, reducing the complexity of connections between components, and improving the system's reliability and stability. The application of the wavelength correction module 32 ensures high-quality and consistent optical signals, enhancing the accuracy of measurement results. Furthermore, the light source module 31 can be selected with an adjustment mechanism to adjust the optical power according to actual needs, which not only improves detection accuracy but also ensures system safety.

[0034] The photodetector 4 includes an ODU module 41 and a DDU module 42 electrically connected together. The ODU module 41 is connected to the fiber optic grating sensor 2 via an optical fiber 6, and the DDU module 42 is connected to the signal processor 5. The ODU module 41 is short for Optical Detection Unit, and the DDU module 42 is short for Data Detection Unit. The ODU module 41 receives two optical signals propagating forward and backward in the optical fiber 6. The DDU module 42 analyzes the optical and electrical signals transmitted from the ODU module 41, and determines the pressure or strain changes at the scene by analyzing the changes in these signals. Finally, this information is sent to the signal processor 5 for processing. By enhancing signal quality and sensitivity with the ODU module 41 and accurately analyzing pressure and strain with the DDU module 42, the system structure is simplified, reliability and measurement accuracy are improved, and it is suitable for liquid level detection in complex environments.

[0035] Example 3: The difference from Example 2 is that the fixing plug 13 is connected to the glass sleeve 11 by AB glue. The AB glue used is a commercially available product. The connection method of AB glue and fixing plug 13 ensures the safety of the sensor and reduces the problem of cross-sensitivity to stress and temperature.

[0036] The light source module 31 includes an ASE light source 3, an optical fiber 6 isolator, a fixed optical attenuator, and a tunable FP filter that are electrically connected together, wherein the tunable FP filter is connected to the wavelength correction module 32. The ASE light source 3 of the light source system generates a broadband optical signal. This optical signal first passes through an optical fiber 6 isolator to ensure that the light is transmitted in only one direction, preventing reflected light from damaging the light source 3 or affecting system performance. Next, the optical signal after passing through the optical fiber 6 isolator enters a fixed optical attenuator, is adjusted to a suitable power level, and is then input to a tunable FP filter. The latter adjusts the wavelength of the output light according to actual needs and precisely controls the filter state through its drive circuit. Subsequently, the precise wavelength optical signal output by the tunable FP filter is transmitted through optical fiber 6 to the wavelength correction module 32. This module uses an FP etalon to further correct the optical signal, ensuring its wavelength accuracy and stability. Finally, the wavelength-corrected optical signal is transmitted through optical fiber 6 to the FBG sensor in the front-end sensing optical cable to begin the actual liquid level detection process. The integration of the light source module 31 and the wavelength correction module 32 simplifies the system structure, reduces the complexity of connections between components, improves the reliability and stability of the system, and enhances the accuracy of the measurement results.

[0037] The wavelength correction module 32 consists of an FP etalon and a PIN detector. The wavelength correction module 32, composed of an FP etalon and a PIN detector, effectively improves the wavelength accuracy and stability of the optical signal, ensuring high precision and reliability in liquid level detection.

[0038] Numerous specific details are set forth in this specification. However, it will be understood that embodiments of this invention may be practiced without these specific details. In some instances, well-known methods, structures, and techniques have not been shown in detail so as not to obscure the understanding of this specification.

[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model, and they should all be covered within the scope of the claims and specification of this utility model.

Claims

1. A liquid level detection device, characterized in that: The device includes a housing (1), a fiber Bragg grating sensor (2), a light source (3), a photodetector (4), and a signal processor (5). The housing (1) includes a glass sleeve (11), a mounting block (12), and a fixing plug (13). The fiber Bragg grating sensor (2) is embedded in the mounting block (12). The mounting block (12) is inserted into the glass tube, and the two ends of the glass sleeve (11) are respectively connected to the fixing plug (13). The fiber Bragg grating sensor (2) is connected to two optical fibers (6). The two optical fibers (6) pass through the fixing plug (13) and connect to the light source (3) and the photodetector (4). The photodetector (4) is connected to the signal processor (5).

2. The liquid level detection device as described in claim 1, characterized in that: The mounting block (12) consists of a concave block and an adhesive. The fiber optic grating sensor (2) is embedded into the concave block by the adhesive, and the optical fiber (6) connected to the fiber optic grating sensor (2) passes through the concave block.

3. The liquid level detection device as described in claim 2, characterized in that: The concave block has limiting rings (14) on both sides of the groove that fit the inner wall of the glass sleeve.

4. A liquid level detection device as described in any one of claims 2 or 3, characterized in that: The fixing plug (13) is connected to the glass sleeve (11) by AB glue.

5. The liquid level detection device as described in claim 4, characterized in that: The light source (3) includes a light source module (31) and a wavelength correction module (32) electrically connected together, wherein the wavelength correction module (32) is connected to the optical fiber (6).

6. The liquid level detection device as described in claim 5, characterized in that: The light source module (31) includes an ASE light source (3) electrically connected together, an optical fiber (6) isolator, a fixed optical attenuator and a tunable FP filter, wherein the tunable FP filter is connected to the wavelength correction module (32).

7. The liquid level detection device as described in claim 5, characterized in that: The wavelength correction module (32) consists of an FP etalon and a PIN detector.

8. The liquid level detection device as described in claim 1, characterized in that: The photodetector (4) includes an ODU module (41) and a DDU module (42) electrically connected together, wherein the ODU module (41) is connected to the fiber optic grating sensor (2) via an optical fiber (6), and the DDU module (42) is connected to the signal processor (5).

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