Portable soil organic matter content detection device based on multispectral technology

Abstract

The utility model discloses a portable soil organic matter content detection device based on a multispectral technology, which belongs to the technical field of soil detection and comprises a shell, a battery and a mainboard are mounted in the shell, and a display screen, a key board, a switch, a data interface and a charging port are mounted on the shell; the detection probe can be clamped at the top end of the shell and comprises a probe shell, a photodiode is fixedly connected to the center of the bottom of the probe shell, a plurality of light-emitting diodes are circumferentially distributed around the photodiode at equal angular distances, the top of the probe shell is open, and light source optical axes of the light-emitting diodes are parallel to receiving optical axes of the photodiode; the soil sample cup is bottomless, and a soil sample is contained in the soil sample cup through a glass cup; the soil sample cup is clamped at the top of the detection probe; and the calibration white board covers the top of the detection probe. The device has the remarkable advantages of simplicity and convenience in operation, accuracy and high efficiency in detection, low cost and the like, meets the soil organic matter content detection requirement, and is particularly suitable for large-scale sample detection.

Description

Technical Field

[0001] This utility model belongs to the field of soil testing technology, and in particular relates to a portable soil organic matter content detection device based on multispectral technology. Background Technology

[0002] Soil organic matter is a core indicator for evaluating soil fertility, and its content directly affects soil structure, nutrient retention capacity, and crop growth quality. Traditional soil organic matter testing mainly relies on laboratory chemical analysis methods (such as the potassium dichromate titration method). Although the detection accuracy is high, it has significant drawbacks: it requires professional operation, has a long testing cycle (4-8 hours per sample), consumes a lot of chemical reagents, and pollutes the environment, making it difficult to meet the needs of modern agriculture for real-time monitoring and precision fertilization.

[0003] With the development of visible / near-infrared spectroscopy, its application in soil testing has gradually attracted attention. Visible / near-infrared spectroscopy is an analytical method based on the absorption, scattering, and reflection characteristics of light by substances, and it is widely used in agriculture, food, and environmental fields. This technology enables rapid component detection by analyzing the chemical bond vibrations and molecular structure characteristics within substances. Multispectral technology, a novel detection method developed from visible / near-infrared spectroscopy, offers advantages such as lower cost and faster detection speed, demonstrating great potential in soil organic matter content analysis. Key components in soil organic matter (such as humus, carbohydrates, and proteins) exhibit characteristic absorption or scattering under light irradiation at different wavelengths, causing spectral characteristics to vary with organic matter content. By collecting multi-band spectral information from soil samples and combining it with mathematical modeling methods, a quantitative relationship between spectral characteristics and organic matter content can be established, enabling rapid determination. Compared with traditional chemical methods, multispectral technology has significant advantages such as fast detection speed and ease of operation, making it particularly suitable for large-scale sample testing.

[0004] Therefore, developing a portable, low-cost soil organic matter testing device based on multispectral technology has become a key technological requirement for solving practical problems in agricultural production and promoting the development of precision agriculture. Utility Model Content

[0005] To address the aforementioned technical problems, this utility model proposes a portable soil organic matter content detection device based on multispectral technology.

[0006] To achieve the above objectives, this utility model provides a portable soil organic matter content detection device based on multispectral technology, comprising:

[0007] The housing contains a battery and a motherboard, and the housing is equipped with a display screen, a keypad, a switch, a data interface, and a charging port.

[0008] The detection probe can be snapped onto the top of the housing. The detection probe includes a probe housing. A photodiode is fixedly connected to the center of the bottom of the probe housing. Several light-emitting diodes are distributed circumferentially around the photodiode at equal angles. The top of the probe housing is open. The light source optical axis of the light-emitting diodes is arranged parallel to the receiving optical axis of the photodiodes.

[0009] A soil sample cup, which has no bottom and contains a soil sample via a glass cup; the soil sample cup is snapped onto the top of the detection probe.

[0010] A calibration whiteboard is placed over the top of the detection probe.

[0011] Preferably, the top of the housing has a cylindrical protrusion, and the inner side of the cylindrical protrusion has an installation groove. The outer shell of the detection probe is snapped into the installation groove. The bottom of the calibration whiteboard is fixedly connected to a connecting cylinder, and the inner side of the connecting cylinder is slidably connected to the outer side of the cylindrical protrusion, so that the calibration whiteboard covers the top of the detection probe.

[0012] Preferably, the soil sample cup includes an outer cylinder and a flip-top, the glass cup is snapped into the outer cylinder, the flip-top is hinged to the top of the outer cylinder, the bottom of the outer cylinder is open, and the bottom of the outer cylinder is snapped into the top of the detection probe.

[0013] Preferably, a temperature sensor is fixedly connected to the inside of the flip cover.

[0014] Preferably, the photodiode is provided with light-blocking protrusions around its perimeter, and the light-blocking protrusions are fixed to the bottom of the probe housing.

[0015] Preferably, the housing includes an upper housing and a lower housing, the battery and motherboard are fixedly mounted on the lower housing, and the display screen, keypad, switch, data interface and charging port are fixedly mounted on the upper housing; a positioning baffle is fixedly connected to the top of the lower housing, the outer side of the positioning baffle abuts against the inner wall of the upper housing, and the upper housing and the lower housing are connected by screws.

[0016] Preferably, the lower housing has a battery fixing slot for fixing the battery, and four mounting posts are also fixedly connected to the lower housing. The top surfaces of the mounting posts are flush, and the main board is fixedly connected to the mounting posts by screws.

[0017] Preferably, an optical glass is fixed to the top of the probe housing, and a positioning groove is provided on the optical glass for positioning the soil sample cup.

[0018] Compared with the prior art, the present invention has the following advantages and technical effects:

[0019] This portable soil organic matter content detection device based on multispectral technology employs a modular design, where the detection probe and soil sample cup are snapped together to form a closed darkroom environment, effectively isolating ambient light interference. Combined with a symmetrically distributed circular arrangement of several light-emitting diodes (LEDs) and parallel placement of photodiodes, it achieves uniform spectral acquisition of soil samples. The casing houses the battery and mainboard and provides various operating interfaces for convenient power supply, control, and data exchange. A calibration whiteboard is placed on top of the detection probe for standardized brightness and darkness spectral calibration, ensuring accurate and reliable test results. These structural features work together to give the device significant advantages such as ease of operation, accurate and efficient detection, and low cost, meeting the needs of soil organic matter content detection, and is particularly suitable for large-scale sample testing. Attached Figure Description

[0020] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0021] Figure 1 This is a schematic diagram of the portable soil organic matter content detection device based on multispectral technology of this utility model;

[0022] Figure 2 This is an exploded view of the portable soil organic matter content detection device based on multispectral technology of this utility model;

[0023] Figure 3 This is a schematic diagram of the soil sample cup structure in this utility model;

[0024] Figure 4 This is a schematic diagram of the detection probe structure in this utility model;

[0025] Figure 5 This is a schematic diagram of the lower shell structure of this utility model;

[0026] Figure 6 This is a schematic diagram of the upper shell structure in this utility model;

[0027] Figure 7 This is a schematic diagram of the installation of the calibration whiteboard in this utility model.

[0028] In the diagram: 1. Battery; 2. Mainboard; 3. Display screen; 4. Keypad; 5. Switch; 6. Data interface; 7. Charging port; 8. Detection probe; 801. Probe housing; 802. Photodiode; 803. Light-emitting diode; 804. Light-blocking protrusion; 805. Optical glass; 806. Positioning groove; 9. Soil sample cup; 901. Outer cylinder; 902. Flip cover; 10. Calibration whiteboard; 11. Columnar protrusion; 12. Mounting groove; 13. Connecting cylinder; 14. Glass cup; 15. Temperature sensor; 16. Upper housing; 17. Lower housing; 18. Positioning baffle; 19. Battery fixing groove; 20. Mounting post. Detailed Implementation

[0029] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0030] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0031] Reference Figures 1 to 7 As shown, this embodiment provides a portable soil organic matter content detection device based on multispectral technology, comprising:

[0032] The housing contains a battery 1 and a motherboard 2, and the housing also contains a display screen 3, a button panel 4, a switch 5, a data interface 6, and a charging port 7.

[0033] The detection probe 8 can be snapped onto the top of the housing. The detection probe 8 includes a probe housing 801. A photodiode 802 is fixedly connected to the center of the bottom of the probe housing 801. Several light-emitting diodes 803 are distributed circumferentially at equal angles around the photodiode 802. The top of the probe housing 801 is open. The light source optical axis of the light-emitting diodes 803 is arranged parallel to the receiving optical axis of the photodiode 802.

[0034] Soil sample cup 9 has no bottom and contains soil sample through glass cup 14; soil sample cup 9 is snapped onto the top of detection probe 8.

[0035] The calibration whiteboard 10 is placed on top of the detection probe 8.

[0036] This portable soil organic matter content detection device based on multispectral technology employs a modular design, where the detection probe 8 and soil sample cup 9 are snapped together to form a closed darkroom environment, effectively isolating ambient light interference. Combined with the equidistant circular distribution of several light-emitting diodes 803 and parallel arrangement of photodiodes 802, uniform spectral acquisition of soil samples is achieved. The casing houses the battery 1 and mainboard 2 and provides various operating interfaces for easy power supply, control, and data interaction. A calibration whiteboard 10, positioned on top of the detection probe 8, allows for standardized brightness and darkness spectral calibration, ensuring accurate and reliable test results. These interconnected structures give the device significant advantages such as ease of operation, accurate and efficient detection, and low cost, meeting the needs of soil organic matter content detection and making it particularly suitable for large-scale sample testing.

[0037] Furthermore, data interface 6 is a USB data interface 6, and charging port 7 is a Type-C charging port.

[0038] The design is further optimized by having a cylindrical protrusion 11 protruding from the top of the housing, and an installation groove 12 on the inner side of the cylindrical protrusion 11. The housing of the detection probe 8 is snapped into the installation groove 12. A connecting cylinder 13 is fixedly connected to the bottom of the calibration white board 10. The inner side of the connecting cylinder 13 is slidably connected to the outer side of the cylindrical protrusion 11, so that the calibration white board 10 covers the top of the detection probe 8.

[0039] The design of the cylindrical protrusion 11 at the top of the housing engaging with the outer shell of the detection probe 8 in the mounting groove 12 enables rapid positioning and stable installation of the detection probe 8, ensuring the stability of the optical path during detection. The sliding connection between the bottom connecting cylinder 13 of the calibration whiteboard 10 and the cylindrical protrusion 11 ensures that the calibration whiteboard 10 accurately covers the detection probe 8 to form a closed darkroom environment to eliminate ambient light interference, while also supporting convenient removal and sliding operation of the calibration whiteboard 10, improving calibration efficiency. This structure also enhances the modularity of the equipment, allowing the detection probe 8 and the calibration whiteboard 10 to be independently disassembled and maintained, extending the service life of the equipment. These designs together achieve high-precision calibration of dual bright and dark spectrum acquisition benchmarks and ease of operation for the detection device, meeting the needs of rapid field testing.

[0040] The design is further optimized. The soil sample cup 9 includes an outer cylinder 901 and a flip cover 902. The glass cup 14 is snapped into the outer cylinder 901. The flip cover 902 is hinged to the top of the outer cylinder 901. The bottom of the outer cylinder 901 is open. The bottom of the outer cylinder 901 is snapped into the top of the detection probe 8.

[0041] The design of the open bottom of the outer cylinder 901 and the snap-fit ​​top of the detection probe 8 enables rapid installation and removal of the soil sample cup 9, significantly improving field testing efficiency. The outer cylinder 901 is hinged to the flip cover 902, facilitating the placement of the glass cup 14. When the flip cover 902 is snapped shut, it forms a closed structure, which, together with the probe housing 801, creates a sealed darkroom environment, effectively isolating ambient light interference. When the flip cover 902 is closed, it precisely matches the slot at the top of the detection probe 8, ensuring the consistency of the optical path for each test. The glass cup 14 is snapped into the outer cylinder 901, facilitating soil sample loading and cleaning. The glass cup 14 can be removed and rinsed separately, and the glass material ensures effective penetration of visible / near-infrared light. This structural design also reduces the difficulty of aligning the soil sample cup 9 and the detection probe 8, allowing non-professionals to quickly complete the test preparation, while reducing testing errors caused by improper operation.

[0042] The design was further optimized by attaching a temperature sensor 15 to the inside of the flip cover 902.

[0043] By integrating a high-precision infrared temperature sensor 15 inside the flip-top 902 of the soil sample cup 9, non-contact real-time monitoring of soil surface temperature is achieved, providing temperature compensation data for near-infrared spectroscopy detection. The temperature compensation algorithm, combined with diffuse reflectance data, can eliminate the influence of environmental temperature changes on the detection results, ensuring that the detection accuracy can still be maintained under complex temperature and humidity conditions in the field. This design also avoids the pollution risk caused by the need to insert the sensor into the soil in traditional contact temperature measurement, ensuring the long-term stable operation of the temperature sensor 15.

[0044] In a further optimized design, light-blocking protrusions 804 are provided around the photodiode 802, and the light-blocking protrusions 804 are fixed to the bottom of the probe housing 801.

[0045] By fixing a light-blocking protrusion 804 to the bottom of the probe housing 801, a physical barrier is formed, effectively isolating the direct light from the light-emitting diode 803 from the light-receiving path of the photodiode 802. This prevents stray light that has not been reflected by the soil sample from directly entering the photodiode 802, significantly improving the purity of the spectral signal. It ensures that the light emitted by each light-emitting diode 803 must be reflected by the soil sample before reaching the photodiode 802, strengthening the consistency of the optical path and reducing the repeatability error of the detection results.

[0046] The design is further optimized. The housing includes an upper housing 16 and a lower housing 17. The battery 1 and the motherboard 2 are fixedly installed on the lower housing 17. The display screen 3, button panel 4, switch 5, data interface 6 and charging port 7 are fixedly installed on the upper housing 16. A positioning baffle 18 is fixedly connected to the top of the lower housing 17. The outer side of the positioning baffle 18 abuts against the inner wall of the upper housing 16. The upper housing 16 and the lower housing 17 are connected by screws.

[0047] The modular design of the shell-separated structure enables efficient assembly and convenient maintenance. The upper shell 16 integrates the operation interface and detection probe 8, while the lower shell 17 centrally houses the battery 1 and the motherboard 2. The screws and positioning baffles 18 are used for precise docking to ensure the stability of the whole structure.

[0048] The design is further optimized by providing a battery fixing slot 19 on the lower housing 17 for fixing the battery 1. Four mounting posts 20 are also fixedly connected to the lower housing 17. The top surfaces of the mounting posts 20 are flush with each other. The main board 2 is fixedly connected to the mounting posts 20 by screws.

[0049] Battery 1 is precisely positioned by battery mounting slot 19 to ensure that battery 1 does not shift during field movement and testing, avoiding the risk of poor contact or short circuit due to loose battery 1; four mounting posts 20 with flush top surfaces form a support matrix for motherboard 2 for mounting motherboard 2. The screw fixing method enables quick disassembly and assembly of motherboard 2. During maintenance, motherboard 2 can be replaced separately without affecting other modules, reducing maintenance costs.

[0050] In a further optimized design, an optical glass 805 is fixed to the top of the probe housing 801, and a positioning groove 806 is provided on the optical glass 805. The positioning groove 806 is used to position the soil sample cup 9.

[0051] The positioning groove 806 and the bottom slot of the soil sample cup 9 work together to form a physical limit, preventing the soil sample cup 9 from tilting or shifting due to improper operation and reducing the risk of light path obstruction; the optical glass 805 acts as a dust barrier, effectively isolating soil particles from entering the probe and reducing the maintenance frequency.

[0052] Instrument usage procedure:

[0053] Startup and Initialization

[0054] When the user presses switch 5, the detection device starts and automatically completes the initialization of the hardware module.

[0055] 2. Calibration Operation

[0056] The user places the calibration whiteboard 10 into the upper slot of the detection probe 8 and presses and holds the "Detect / Calibrate" button on the keypad 4 for more than 2 seconds to perform the calibration operation. The detection device first acquires bright and dark spectra under dark chamber conditions formed by the calibration whiteboard 10 and the fixing slot of the probe housing 801. During this process, the detection device acquires diffuse reflectance spectral data of the dark spectrum when the LED 803 is not lit and the bright spectrum when the LED 803 is lit sequentially. The calibration value's bright and dark spectrum data can then be obtained. Pressing and holding the "Save" button on the keypad 4 for more than 2 seconds saves the current calibration value.

[0057] 3. Sample Placement and Data Acquisition

[0058] The user places the soil sample into the soil sample cup 9 and positions it on the detection device. Clicking the "Detection / Calibration" button causes the detection device to sequentially illuminate LEDs 803 with specific wavelengths and collect the corresponding diffuse reflectance spectral data. The diffuse reflectance of the LEDs 803 is then calculated using a formula, as follows:

[0059]

[0060] Among them I Reflected (λ) Soil sample spectral data, I White (λ) represents the brightness spectrum data, I Dark (λ) represents dark spectral data, where λ is the wavelength.

[0061] At the same time, the temperature sensor 15 reads the soil temperature and compensates for the effect of temperature on diffuse reflectance through a preset algorithm.

[0062] 4. Data Processing and Result Display

[0063] The detection device inputs the collected diffuse reflectance data into the prediction model to obtain the predicted soil organic matter content. The display screen shows the soil sample's organic matter content and temperature value. Users can click the "Save" button to save the measurement results to a USB flash drive plugged into data interface 6 for subsequent data analysis and processing.

[0064] 5. Battery 1 power monitoring and standby mode

[0065] The testing device periodically monitors the battery level of battery 1 and displays its status in real time in the upper right corner of the screen. If the battery level drops below 10%, a warning pops up, new testing operations are prohibited, and the user is prompted to save the data. After testing is complete, the instrument automatically enters sleep mode (current ≤1mA) after 3 minutes of inactivity. Pressing any button at this time will wake the instrument.

[0066] 6. Close operation

[0067] After use, the user presses switch 5 to turn off the detection device.

[0068] Any aspects of this utility model that are not detailed herein are conventional technical means known to those skilled in the art.

[0069] In the description of this utility model, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0070] The embodiments described above are merely preferred embodiments of the present utility model and are not intended to limit the scope of the present utility model. Various modifications and improvements made to the technical solutions of the present utility model by those skilled in the art without departing from the spirit of the present utility model should fall within the protection scope defined by the claims of the present utility model.

Claims

1. A portable soil organic matter content detection device based on multispectral technology, characterized in that, Include: The shell, the battery (1) and the mainboard (2) are installed in the shell, the display screen (3), the key plate (4), the switch (5), the data interface (6) and the charging port (7) are installed on the shell; Detection probe (8), can be clamped in the top of the shell, the detection probe (8) includes probe shell (801), the bottom center of the probe shell (801) is fixedly connected with photodiode (802), a plurality of light emitting diodes (803) are distributed at equal angles around the photodiode (802), the top of the probe shell (801) is open, the light source optical axis of the light emitting diode (803) is parallelly arranged with the receiving optical axis of the photodiode (802); The soil sample cup (9) is bottomless, and the soil sample is contained in the glass cup (14); the soil sample cup (9) is clamped on the top of the detection probe (8); The calibration whiteboard (10) is covered on the top of the detection probe (8).

2. The portable soil organic matter content detection device based on multispectral technology according to claim 1, characterized in that: The top of the shell protrudes a cylindrical convex (11), the inner side of the cylindrical convex (11) is provided with a mounting groove (12), the detection probe (8) shell is clamped in the mounting groove (12), the bottom of the calibration whiteboard (10) is fixedly connected with the connecting cylinder (13), the inner side of the connecting cylinder (13) is slidably connected with the outer side of the cylindrical convex (11), so that the calibration whiteboard (10) is covered on the top of the detection probe (8).

3. The portable soil organic matter content detection device based on multispectral technology according to claim 1, characterized in that: The soil sample cup (9) includes an outer cylinder (901) and a flip cover (902), the glass cup (14) is clamped in the outer cylinder (901), the flip cover (902) is hinged to the top of the outer cylinder (901), the bottom end of the outer cylinder (901) is open, and the bottom of the outer cylinder (901) is clamped on the top of the detection probe (8).

4. The portable soil organic matter content detection device based on multispectral technology according to claim 3, characterized in that: The inner side of the flip cover (902) is fixedly connected with a temperature sensor (15).

5. The portable soil organic matter content detection device based on multispectral technology according to claim 1, characterized in that: The photodiode (802) is provided with a light blocking boss (804) around, and the light blocking boss (804) is fixedly connected to the inner bottom of the probe shell (801).

6. The portable soil organic matter content detection device based on multispectral technology according to claim 1, characterized in that: The shell includes an upper shell (16) and a lower shell (17), the battery (1) and the mainboard (2) are fixedly installed on the lower shell (17), the display screen (3), the key plate (4), the switch (5), the data interface (6) and the charging port (7) are fixedly installed on the upper shell (16); the top of the lower shell (17) is fixedly connected with a positioning baffle (18), the outer side of the positioning baffle (18) abuts against the inner wall of the upper shell (16), and the upper shell (16) and the lower shell (17) are connected by screws.

7. The portable soil organic matter content detection device based on multispectral technology according to claim 6, characterized in that: The lower shell (17) is provided with a battery fixing groove (19) for fixing the battery (1), and four mounting columns (20) are further fixedly connected to the lower shell (17), the top surfaces of the mounting columns (20) are flush, and the mainboard (2) is fixedly connected with the mounting columns (20) by screws.

8. The portable soil organic matter content detection device based on multispectral technology according to claim 1, characterized in that: The top of the probe shell (801) is fixedly connected with optical glass (805), the optical glass (805) is provided with a positioning groove (806), and the positioning groove (806) is used for positioning the soil sample cup (9).

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