Liquid detection device based on single photodiode

Abstract

The utility model provides a liquid detection device based on a single photodiode. The liquid detection device comprises a bottom plate, a laser lamp, a first container, the photodiode and a processing module, the first container is used for containing liquid to be detected, the laser lamp, the first container and the processing module are all installed on the bottom plate, the photodiode is installed on the processing module, the laser lamp is used for emitting detection laser, and the detection laser penetrates through the liquid to be detected in the first container and then irradiates the photodiode. The laser lamp, the first container and the photodiode form a light path, the photodiode is used for sensing detection light penetrating through to-be-detected liquid in the first container and then outputting a first analog signal, and the processing module is used for receiving and processing the first analog signal and outputting a voltage value corresponding to the first analog signal. The photodiode is used as the core of the detection device, so that the manufacturing cost is reduced. The liquid detection device is mainly used in the technical field of liquid detection devices.

Description

Technical Field

[0001] This technical solution relates to the field of liquid detection device technology, specifically to a liquid detection device based on a single photodiode. Background Technology

[0002] Currently, the detection of liquid substances is commonly used in food, transportation, and medical fields. However, existing technologies for liquid detection often rely on expensive equipment such as near-infrared spectrometers. These devices have very complex structures. Designing a simple liquid detection device is a pressing technical problem that needs to be addressed in the industry to enable convenient liquid detection. Utility Model Content

[0003] This invention provides a liquid detection device based on a single photodiode to solve one or more technical problems existing in the prior art, and at least provides a beneficial option or creates conditions.

[0004] A liquid detection device based on a single photodiode is provided, comprising: a base plate, a laser lamp, a first container, a photodiode, and a processing module;

[0005] The base plate is a rectangular straight plate, and the first container is a container made of light-transmitting material. The first container is used to hold the liquid to be tested. The laser lamp, the first container, and the processing module are all mounted on the base plate. The photodiode is mounted on the processing module. The laser lamp is used to emit a detection laser. The detection laser passes through the liquid to be tested in the first container and then illuminates the photodiode. An optical path is formed between the laser lamp, the first container, and the photodiode. The photodiode is used to sense the detection light after it passes through the liquid to be tested in the first container and then outputs a first analog signal. The processing module is used to receive and process the first analog signal and output the voltage value corresponding to the first analog signal.

[0006] As a further improvement to the above technical solution, the photodiode is an indium gallium arsenide photodiode.

[0007] As a further improvement to the above technical solution, the detection light band generated by the laser lamp needs to match the sensing band range of the photodiode.

[0008] As a further improvement to the above technical solution, the area of ​​the detection laser beam generated by the laser lamp needs to be matched with the sensing area of ​​the photodiode.

[0009] As a further improvement to the above technical solution, the processing module also includes an analog-to-digital converter connected to a photodiode, which is used to convert the first analog signal output by the photodiode into a first digital signal.

[0010] As a further improvement to the above technical solution, the processing module also includes a computing device, which is connected to the analog-to-digital converter. The computing device is used to read the first digital signal output by the analog-to-digital converter and output a first voltage value.

[0011] As a further improvement to the above technical solution, a second container is provided between the first container and the laser lamp. The second container is used to hold an attenuation liquid, which is used to reduce the light intensity of the detection laser when the laser lamp power is too high.

[0012] As a further improvement to the above technical solution, the second container is a container made of a light-transmitting material.

[0013] As a further improvement to the above technical solution, the laser lamp, the first container, the second container, the photodiode, and the processing module are all detachable.

[0014] As a further improvement to the above technical solution, a heat dissipation device is provided on the side of the laser lamp.

[0015] The beneficial effects of this invention are: by using a photodiode as the core of the detection device, manufacturing costs are reduced, and the entire industrial chain is more independently controllable. The structure of the device is simplified, making liquid detection more convenient and faster. This invention is mainly applicable to the field of liquid detection device technology. Attached Figure Description

[0016] The accompanying drawings are provided to further understand the technical solution of this utility model and constitute a part of the specification. They are used together with the embodiments of this utility model to explain the technical solution of this utility model, and do not constitute a limitation on the technical solution of this utility model.

[0017] Figure 1 This is a schematic diagram of the overall structure of a liquid detection device based on a single photodiode.

[0018] Figure 2 This is a schematic diagram of the calibration stage process during the testing process;

[0019] Figure 3 This is a schematic diagram of the detection process flow. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments.

[0021] Liquid testing refers to the process of analyzing and testing liquid samples to obtain information such as the liquid's composition, properties, and state, based on various physical, chemical, or biological properties.

[0022] Current technologies for liquid detection often rely on expensive near-infrared spectrometers and other equipment. The working principle of near-infrared spectrometers is primarily based on the anharmonicity of molecular vibrations. When molecular vibrations transition from the ground state to higher energy levels, near-infrared spectra are generated. They mainly record the overtone and combination frequency absorptions of hydrogen-containing groups XH (X=C, N, O). Specifically, when a signal source emits a beam of light within a scanning wavelength range onto a sample, an emission spectrum is generated. Then, a detector is used to detect the absorption wavelength, and the absorption spectrum is obtained based on the different degrees of absorption by the sample. Near-infrared spectrometers emit beams of light across different wavelength spans (amplitudes), and then detect the reaction of the emission to the sample; the results can then be used for instrumental analysis of the sample's composition. These devices often employ CCD (Charge-Coupled Device) chips. The working principle of CCD chips is based on the photoelectric effect and charge-coupled device (CCD) technology. When light enters the surface of the CCD chip, photons interact with the semiconductor material, generating electron-hole pairs. These electrons are collected in the photosensitive area and transferred to the chip's output terminal via charge-coupled device technology. During the reading process, the charge is converted into a voltage signal, which ultimately forms a digital image.

[0023] A liquid detection device based on a single photodiode is provided, comprising: a base plate 100, a laser lamp 200, a first container 400, a photodiode 500, and a processing module 600.

[0024] The base plate 100 is a rectangular straight plate. The first container 400 is a light-transmitting container used to hold the liquid to be tested. The laser lamp 200, the first container 400, and the processing module 600 are all mounted on the base plate 100. The photodiode 500 is mounted on the processing module 600. The laser lamp 200 emits a detection laser. After passing through the liquid to be tested in the first container 400, the detection laser illuminates the photodiode 500, forming an optical path between the laser lamp 200, the first container 400, and the photodiode 500. The photodiode 500 senses the detection light after passing through the liquid to be tested in the first container 400 and then outputs a first analog signal. The processing module 600 receives and processes the first analog signal and outputs the voltage value corresponding to the first analog signal.

[0025] A single photodiode is used as the core of the solution, replacing the CCD chip. A photodiode is a semiconductor device that converts light energy into electrical energy. The working principle of a photodiode is mainly based on the photoelectric effect. When light shines on a semiconductor material, photons can be absorbed by electrons, thus converting the photon's energy into electron energy. When the photon energy is greater than the semiconductor's band gap energy, electron-hole pairs are generated. In a photodiode, these electrons are pushed towards the inversion doped layer, while holes are pushed towards the positive doped layer, creating a potential difference and generating a current. Specifically, the structure of a photodiode consists of P-type and N-type semiconductors, with an electric field existing at the PN junction. When light shines on the PN junction, the photon's energy is absorbed, causing electrons to transition from the N-type semiconductor to the P-type semiconductor. This transition process generates a current, thus achieving photoelectric conversion.

[0026] To reduce manufacturing costs, in some specific examples, the photodiode 500 employs a single indium gallium arsenide (InGaAs) photodiode, a photoelectric conversion device based on indium gallium arsenide (InGaAs) material. The indium gallium arsenide photodiode utilizes the unique band structure and photoelectric conversion properties of indium gallium arsenide to convert optical signals into electrical signals. When light shines on the photodiode, photons are absorbed by the material and electrons are excited, thereby generating an electric current. my country leads the world in reserves and production of indium, gallium, and arsenic, with a mature overall industrial chain and lower manufacturing costs. Therefore, the technical solution of this invention is more independently controllable and has greater commercial prospects than the technical solution based on near-infrared spectrometers.

[0027] To improve detection accuracy, in some specific examples, the wavelength of the laser lamp 200 needs to match the sensing wavelength of the indium gallium arsenide (IGaAs) photodiode, and the area of ​​the beam emitted by the laser lamp 200 also needs to match the sensing area of ​​the IGaAs photodiode, which has a high responsivity to near-infrared light. Specifically, its sensing wavelength is typically in the near-infrared range of 700nm to 1800nm ​​(some high-performance products may extend to a wider range, such as 600nm to 2600nm). Within this wavelength range, IGaAs photodiodes exhibit stable performance, low dark current, and high responsivity. For example, some models of IGaAs photodiodes can achieve a responsivity of 0.85A / W or higher at specific wavelengths such as 1310nm or 1550nm. These characteristics make IGaAs photodiodes highly promising for applications in liquid detection.

[0028] The laser lamp 200 can be a laser diode or other similar device that emits visible or near-infrared signals.

[0029] To process the first analog signal output by the photodiode 500, in some further specific embodiments, the processing module 600 includes an analog-to-digital converter (ADC) and a computing device. The ADC converts the analog signal output by the photodiode 500 into a digital signal, and the computing device then analyzes the digital signal to obtain the voltage value. An ADC is a functional unit that converts analog signals into digital signals. The basic principle of an ADC is to sample the input analog signal at specified time intervals and compare it with a series of standard digital signals. The digital signals converge successively until the two signals are equal. The binary number representing this signal is then displayed. ADCs are widely used in communications, measurement, control, signal processing, and computer systems. They convert analog signals into digital signals for processing, storage, and transmission in digital systems.

[0030] To ensure stable operation of the laser lamp 200 at higher power, in some specific examples, a cooling device such as a fan is installed on the side of the laser lamp 200. This provides good heat dissipation during prolonged high-power operation, ensuring stable operation. Furthermore, when using a laser lamp 200 that exceeds the detection range of the photodiode 500, a second container 300 can be placed between the first container 400 and the laser lamp 200. The second container 300 is identical to the first container 400 and is used to hold a decaying liquid. This liquid absorbs the intensity of the detection laser, thus matching the detection laser's intensity with the detection range of the photodiode 500.

[0031] When using this device, the first step is calibration. First, select a reference liquid and place it into the first container 400. The reference liquid must be of the same type as the liquid being tested and must be free of any abnormalities.

[0032] Connect the analog-to-digital converter to the photodiode 500. Connect the positive terminal of the analog-to-digital converter to the anode of the photodiode 500, and the negative terminal of the analog-to-digital converter to the cathode of the photodiode 500. Connect the signal output terminal of the analog-to-digital converter to the computing device.

[0033] Laser lamp 200 is turned on, and the detection laser emitted by laser lamp 100 passes through the first container 400, finally illuminating the sensing area of ​​photodiode 500. The analog signal output from the photodiode is converted into a digital signal by an analog-to-digital converter and output to the computing device. The computing device analyzes the digital signal to obtain the voltage value. If the voltage value exceeds the range, the second container 300 is placed in, filled with attenuating fluid, and measured again. If the voltage value is within the range, it is recorded as the reference voltage. A computing device generally includes a computer, a modern electronic device capable of automatically, quickly, and accurately performing various arithmetic and logical operations according to a program. It can not only perform calculations but also make logical judgments, store data, and execute programs. The basic working principle of a computer is stored program and program control. The sequence of instructions (called a program) controlling how the computer operates and the raw data are pre-loaded into the computer's memory via input devices. When the computer runs, it first fetches the first instruction from memory, decodes it through the controller, retrieves data from memory according to the instruction's requirements, performs the specified calculations and logical operations, and then sends the result back to memory according to the address. Next, the second instruction is retrieved, and the prescribed operation is completed under the command of the controller. This process continues until a stop instruction is encountered.

[0034] Multiple reference voltages were obtained by repeatedly measuring the reference liquid using the same attenuating fluid. These multiple reference voltages are denoted as... .

[0035] The liquid to be tested is then placed into the first container 400. The attenuation solution used in the final calibration stage is placed into the second container 300.

[0036] Connect the positive terminal of the analog-to-digital converter to the anode of the photodiode 500, connect the negative terminal of the analog-to-digital converter to the cathode of the photodiode 500, and connect the signal output terminal of the analog-to-digital converter to the computing device.

[0037] Turn on laser lamp 200, and let the detection laser emitted by laser lamp 200 pass through the second container 300 and the first container 400, finally illuminating the sensing area of ​​photodiode 500. View the voltage value output by the analog-to-digital converter on the computing device and record it as the measured voltage. Compare the measured voltage with the reference voltage to determine the abnormality of the liquid being tested. The determination can be made using statistical or machine learning models. Statistics mainly uses probability theory to build mathematical models, collect data from the observed system, perform quantitative analysis and summarization, and then make inferences and predictions to provide a basis and reference for relevant decisions. It is widely used in various disciplines, from physics and social sciences to humanities, and even in industry and commerce. Machine learning (ML) is a branch of artificial intelligence that focuses on enabling computer systems to automatically learn from data and improve their performance to perform specific tasks without explicit programming. The core idea of ​​machine learning is to use data to train computer algorithms so that they can identify patterns and trends in the data and generate predictive or decision-making models accordingly. Machine learning is the scientific study of algorithms and statistical models used by computer systems to perform specific tasks efficiently without explicit instructions, relying instead on patterns and reasoning. It trains models by inputting massive amounts of training data, enabling them to grasp the underlying patterns within the data and thus accurately classify or predict new input data.

[0038] In this embodiment, the 3-sigma principle is adopted. The 3-sigma principle is a statistical concept used to measure the stability and quality of data. Based on the normal distribution curve, the 3-sigma principle divides the data distribution into different intervals. In a normal distribution, data within one standard deviation of the mean accounts for approximately 68%; data within two standard deviations accounts for approximately 95%; and data within three standard deviations accounts for approximately 99.7%. If the data conforms to a normal distribution, then approximately 99.7% of the data points should fall within the range of the mean plus or minus three standard deviations.

[0039] Calculate the reference voltage mean with standard deviation Refer to formula (1):

[0040] (1);

[0041] If the measured voltage conforms to formula (1), the liquid to be tested is determined to be normal; otherwise, it is determined to be abnormal.

[0042] In certain specific scenarios, analog-to-digital converters can be replaced by devices with similar functions, such as oscilloscopes and multimeters.

[0043] Although the description of this application has been quite detailed and particularly focused on the described embodiments, it is not intended to limit itself to any of these details or embodiments or any particular embodiment, but should be considered as effectively covering the intended scope of this application by referring to the appended claims and taking into account the prior art to provide a broad possible interpretation of these claims. Furthermore, the foregoing description of this application with respect to embodiments foreseeable by the inventors is intended to provide a useful description, and non-substantial modifications to this application that have not yet been foreseen may still represent equivalent modifications.

Claims

1. A liquid detection device based on a single photodiode, characterized in that, include: Base plate, laser light, first container, photodiode and processing module; The base plate is a rectangular straight plate, and the first container is a container made of light-transmitting material. The first container is used to hold the liquid to be tested. The laser lamp, the first container, and the processing module are all mounted on the base plate. The photodiode is mounted on the processing module. The laser lamp is used to emit a detection laser. The detection laser passes through the liquid to be tested in the first container and then illuminates the photodiode. An optical path is formed between the laser lamp, the first container, and the photodiode. The photodiode is used to sense the detection light after it passes through the liquid to be tested in the first container and then outputs a first analog signal. The processing module is used to receive and process the first analog signal and output the voltage value corresponding to the first analog signal.

2. The liquid detection device based on a single photodiode according to claim 1, characterized in that, The photodiode is an indium gallium arsenide photodiode.

3. The liquid detection device based on a single photodiode according to claim 1, characterized in that, The detection light band generated by the laser lamp needs to match the sensing band range of the photodiode.

4. The liquid detection device based on a single photodiode according to claim 1, characterized in that, The area of ​​the detection laser beam generated by the laser lamp needs to be matched with the sensing area of ​​the photodiode.

5. The liquid detection device based on a single photodiode according to claim 1, characterized in that, The processing module also includes an analog-to-digital converter connected to a photodiode, which is used to convert the first analog signal output by the photodiode into a first digital signal.

6. The liquid detection device based on a single photodiode according to claim 1, characterized in that, The processing module also includes a computing device connected to an analog-to-digital converter. The computing device is used to read the first digital signal output by the analog-to-digital converter and output a first voltage value.

7. The liquid detection device based on a single photodiode according to claim 1, characterized in that, A second container is disposed between the first container and the laser lamp. The second container is used to hold an attenuation liquid, which is used to reduce the light intensity of the detection laser when the laser lamp power is too high.

8. The liquid detection device based on a single photodiode according to claim 7, characterized in that, The second container is made of a translucent material.

9. The liquid detection device based on a single photodiode according to claim 1, characterized in that, The laser light, the first container, the second container, the photodiode, and the processing module are all detachable.

10. The liquid detection device based on a single photodiode according to claim 1, characterized in that, A heat dissipation device is provided on the side of the laser light.

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