Tree measuring electronic tape and use method thereof

Abstract

The invention discloses a tree measuring electronic tape measure and a using method thereof. The tree measuring electronic tape measure comprises a shell, a measuring rope winding and unwinding mechanism, a rope outlet distance measuring mechanism, an integrated circuit board, a power source and a display screen, wherein the measuring rope winding and unwinding mechanism, the rope outlet distance measuring mechanism, the integrated circuit board, the power source and the display screen are assembled in the shell. The measuring rope winding and unwinding mechanism is provided with a measuring rope for measurement; the rope outlet distance measuring mechanism is provided with a magnetic encoder used for measuring the single pull-out length of the measuring rope, and the magnetic encoder is electrically connected with the integrated circuit board. The display screen is electrically connected with the integrated circuit board and is used for displaying data information; the integrated circuit board is provided with a Bluetooth module used for being in communication connection with external equipment, the Bluetooth module is Bluetooth 6.0 with a positioning function, and the external equipment is provided with a GPS. The power supply is electrically connected with the magnetic encoder, the display screen and the integrated circuit board. The device is suitable for tree investigation, can realize synchronous acquisition and integration of measurement information and geographic position coordinate information, and has the advantages of high measurement precision, high automation degree, low manufacturing cost, simplicity and convenience in use and the like.

Description

Technical Field

[0001] The present invention relates to a measuring tool, specifically an electronic girth tape for measuring the diameter of trees. Background Art

[0002] In tree surveys, at present, the diameter of trees is mainly measured manually by a tree girth tape (such as a steel tape). "Tree diameter" mostly refers to breast height diameter and diameter at breast height, where: breast height diameter is the diameter of the tree at 1.3 m above the ground, which is common in forest resource surveys; diameter at breast height is the diameter of the tree at 1 m above the ground, which is common in urban landscaping tree species surveys.

[0003] When measuring the diameter of a tree, usually at least two people are required to cooperate to complete the task: one person is the measurer, who uses the tree girth tape to measure the breast height diameter and / or diameter at breast height of the tree and reports the tree species information and breast height diameter (diameter at breast height) information; the other person is the recorder, who records the relevant information reported by the measurer. The current survey method is prone to data errors because when people cooperate, the measurer may misreport information, and the recorder may also record incorrectly.

[0004] In addition, this survey method cannot accurately locate the position information of each measured tree, resulting in the survey results being unable to accurately serve forest management, especially unable to accurately serve the design of forest tending operations. As a result, in forest tending construction and supervision, it is impossible to accurately grasp the principle of "removing small trees and retaining large ones, removing bent trees and retaining straight ones", and it is impossible to accurately identify "reserved trees" and "felled trees", which is not conducive to the implementation of forest management concepts. Summary of the Invention

[0005] To solve the above deficiencies in the prior art, the present invention aims to provide a tree measuring electronic girth tape and its usage method to achieve the synchronous acquisition and integration of measurement information and geographical position coordinate information, improve measurement accuracy, and enhance the degree of automation of the device.

[0006] To achieve the above object, the technical solution adopted by the present invention is as follows: A tree measuring electronic girth tape includes a housing, a measuring rope retracting and releasing mechanism, a rope pulling and distance measuring mechanism, an integrated circuit board, a power supply assembled in the housing, and a display screen assembled on the housing; The measuring rope retracting and releasing mechanism has a measuring rope for measurement; The rope pulling and distance measuring mechanism has a magnetic encoder for measuring the single - time pulling length of the measuring rope, and the magnetic encoder is electrically connected to the integrated circuit board; The display screen is electrically connected to the integrated circuit board for displaying data information; The integrated circuit board is provided with a Bluetooth module for communication connection with an external device. The Bluetooth module is Bluetooth 6.0 with a positioning function, and the external device has a GPS; The power supply is electrically connected to the magnetic encoder, the display screen, and the integrated circuit board respectively.

[0007] As a limitation of the present invention, a plurality of buttons are further provided on the integrated circuit board, and the plurality of buttons are arranged around the display screen; The plurality of buttons include a power switch, a retraction key, and at least one tree species information key for retrieving tree species information.

[0008] As a further limitation of the present invention, a distance measuring sensor for measuring the vertical distance from the tree measuring electronic tape to the ground is further assembled in the housing, and the distance measuring sensor is electrically connected to the integrated circuit board; A buzzer electrically connected to the integrated circuit board is further assembled in the housing to prompt whether the vertical distance from the tree measuring electronic tape to the ground reaches a preset value; The distance measuring sensor and the buzzer are electrically connected to the power supply.

[0009] As a further limitation of the present invention, the plurality of buttons further include a diameter at breast height measurement selection key and a diameter at breast height measurement selection key.

[0010] As another limitation of the present invention, the measuring tape retracting and releasing mechanism further includes a winding disc rotatably assembled in the housing and a return spring assembled between the winding disc and the housing for returning the winding disc to its original position; The measuring tape is evenly wound on the winding disc, and the free end of the measuring tape can be pulled outwards from the rope outlet of the housing.

[0011] As a further limitation of the present invention, the measuring tape is made of any one of nylon, polyester, and steel wire, and is in the form of a circular filament with a diameter of 0.4 - 1 mm or a strip with a thickness of 0.4 - 1 mm.

[0012] As a further limitation of the present invention, the magnetic encoder is assembled on the winding disc for detecting the rotation angle of the winding disc.

[0013] As other limitations of the present invention, the rope outlet distance measuring mechanism further includes a distance measuring wheel and a plurality of guide wheels rotatably assembled in the housing; The measuring tape is wound around the distance measuring wheel and the plurality of guide wheels, and the plurality of guide wheels are used to guide the measuring tape to ensure that the measuring tape does not slip with the distance measuring wheel; The magnetic encoder is assembled on the distance measuring wheel for detecting the rotation angle of the distance measuring wheel.

[0014] The present invention also discloses a usage method of a tree measuring electronic tape, including the following steps: S1. Turn on the tree measurement electronic girth tape. After communicating and connecting with the external device through the Bluetooth module, the geographical location coordinate information of the tree measurement electronic girth tape is displayed on the display screen; S2. Pull out the free end of the measuring rope to surround the tree for one week. Use the magnetic encoder to detect the pulled-out length of the measuring rope, convert it into an angular signal, and calculate the tree diameter after processing by the integrated circuit board, and display it on the display screen; S3. Transmit the measurement data to the external device through the Bluetooth module, and store and process it by the external device.

[0015] As a limitation of the present invention, step S1 further includes: assigning different tree species names to the tree species information key of the tree measurement electronic girth tape through the external device, and registering the user information through the external device; Step S2 further includes: after selecting the use height of the tree measurement electronic girth tape through the diameter at breast height measurement selection key and the diameter at breast height measurement selection key, move the tree measurement electronic girth tape up and down. When the buzzer emits a prompt sound, the tree measurement electronic girth tape reaches the preset height; Step S3 further includes: manually triggering the tree species information key corresponding to the tree species being measured, and transmitting the tree species information, diameter at breast height and / or diameter at breast height information, and tree species position information to the external device, and the external device processes and generates a "Schematic Diagram of the Distribution of Tree Species Position, Diameter at Breast Height and / or Diameter at Breast Height".

[0016] Due to the adoption of the above technical solution, compared with the prior art, the beneficial effects obtained by the present invention are: (1) The biggest innovation point of the present invention is that a magnetic encoder and an integrated circuit board with a Bluetooth module are added to the existing tree measurement girth tape. Among them, the magnetic encoder can convert the pulled-out length of the measuring rope into an angular signal, and obtain the tree diameter information after being processed by the integrated circuit board; the Bluetooth module can use the GPS function of the external device to locate the tree measurement electronic girth tape, and then the geographical location coordinate information of the tree can be obtained synchronously when measuring the tree. At the same time, the Bluetooth module can also transmit the tree diameter information and geographical location coordinate information to the external device. The present invention combines the functions of the magnetic encoder and the Bluetooth module (Bluetooth 6.0) to realize the synchronous acquisition and integration of the tree diameter information and the geographical location coordinate information, meet the requirements for the geographical location coordinate information of the tree in the tree survey, and enable the survey data to accurately serve the forest tending operation design.

[0017] In addition, compared with the traditional survey method, the present invention has a high degree of automation. By assigning key actions to record the tree species information, geographical location coordinate information and diameter information, there is no need to set up a "recording personnel" role to record the measurement information, eliminating the reporting and recording links in the process of measuring trees, improving the operation efficiency and reliability, reducing the probability of data errors, and having higher measurement accuracy; at the same time, it also saves the position of the recording personnel and saves labor costs.

[0018] (2)The present invention can accurately adjust the measurement height of the tree species to be measured by setting a ranging sensor, enabling the measurer to clearly conduct breast diameter measurement or meter diameter measurement. Compared with the traditional survey method, the accuracy of tree diameter measurement is improved.

[0019] (3)In order to obtain the geographical position coordinate information of the tree, the present invention utilizes the Bluetooth module and the GPS of the external device, avoiding the deployment of additional positioning base stations and significantly reducing the cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0021] Figure 1 is a schematic structural diagram of Embodiment 1 of the present invention; Figure 2 is an internal structural diagram of Embodiment 1 of the present invention; Figure 3 is an internal structural diagram of Embodiment 1 of the present invention without the measuring rope wound; Figure 4 is a schematic structural diagram of Embodiment 2 of the present invention; Figure 5 is an internal structural diagram of Embodiment 2 of the present invention; Figure 6 is an internal structural diagram of Embodiment 2 of the present invention without the measuring rope wound; Figure 7 is a schematic diagram of the winding mode of the measuring rope on the rope winding disc in Embodiment 3 of the present invention; In the figure: 1, housing; 2, rope outlet; 3, measuring rope; 4, rope winding disc; 5, return spring; 6, magnetic encoder; 7, ranging wheel; 8, guide wheel 1; 9, guide wheel 2; 10, guide wheel 3; 11, guide wheel 4; 12, integrated circuit board; 13, display screen; 14, power supply; 15, ranging sensor. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] The following is a description of the preferred embodiments of the present invention with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are only for the purpose of illustrating and understanding the present invention, and are not intended to limit the present invention.

[0023] Embodiment 1 A tree measuring electronic tape As Figures 1 to 3 shown, this embodiment includes a housing 1 and a measuring rope retracting and releasing mechanism, a rope outlet ranging mechanism, an integrated circuit board 12, a power supply 14 assembled in the housing 1, and a display screen 13 assembled on the housing 1.

[0024] The housing 1 is used to protect the internal structure and can be 3D printed or injection molded from plastic material. As Figure 1As shown, the housing 1 is provided with a rope outlet 2 for pulling the measuring rope 3 outward.

[0025] The measuring rope retracting and releasing mechanism is used to store the measuring rope 3. When measuring, the measuring rope 3 can be released under the action of tension. When the tension is reduced or disappears, the measuring rope 3 can be automatically retracted. The measuring rope retracting and releasing mechanism is basically the same as the internal structure of the tape measure in the prior art, such as Figure 2 or Figure 3 As shown, the measuring rope retracting and releasing mechanism comprises a rope reel 4, a measuring rope 3 and a rewinding spring 5. The rope reel 4 is rotatably assembled in the housing 1; the measuring rope 3 is evenly wound on the rope reel 4, and one end of the measuring rope 3 is fixed on the rope reel 4, and the other end can be pulled out from the rope outlet 2 of the housing 1 as a free end; the rewinding spring 5 is located at the central axis of the rope reel 4, connected between the rope reel 4 and the housing 1, and is used to rotate and reset the rope reel 4 so as to automatically retract the measuring rope 3.

[0026] Furthermore, the measuring rope 3 is made of any one of nylon, polyester and steel wire, and can be a round wire with a diameter of 0.4-1 mm, or a strip with a thickness of 0.4-1 mm. The measuring rope 3 in this embodiment is made of nylon and is a strip with a thickness of 0.8 mm.

[0027] The rope distance measuring mechanism is used to measure the length of the rope 3 pulled out, and convert it into an electrical signal and transmit it to the integrated circuit board 12. Figure 2 and Figure 3 As shown, the rope-out distance measuring mechanism includes a distance measuring wheel 7, a plurality of guide wheels and a magnetic encoder 6. The distance measuring wheel 7 is rotatably assembled in the housing 1 and is located on one side of the rope winding drum 4; the plurality of guide wheels are distributed between the rope winding drum 4 and the distance measuring wheel 7, and between the distance measuring wheel 7 and the rope outlet 2 of the housing 1, and are used to guide the measurement rope 3 to increase the contact area between the measurement rope 3 and the distance measuring wheel 7, and ensure that there is no slippage between the measurement rope 3 and the distance measuring wheel 7. The present embodiment includes four guide wheels, wherein guide wheel one 8 is located between the rope winding drum 4 and the distance measuring wheel 7, guide wheel two 9, guide wheel three 10 and guide wheel four 11 are located between the distance measuring wheel 7 and the rope outlet 2 of the housing 1, and the specific winding method of the measurement rope 3 is referred to. Figure 2 .

[0028] Further, such as Figure 2 and Figure 3 As shown, the magnetic encoder 6 is assembled in the housing 1 and is drivingly connected to the rotating shaft of the distance measuring wheel 7. The magnetic encoder 6 is electrically connected to the integrated circuit board 12. When in use, the distance measuring wheel 7 rotates synchronously during the process of the measuring rope 3 being pulled out. The magnetic encoder 6 can detect the rotation angle of the distance measuring wheel 7 and transmit the angle signal to the integrated circuit board 12 in the form of an electrical signal. After the integrated circuit board 12 processes the angle signal, it can obtain the length of the measuring rope 3 pulled out in a single time.

[0029] The integrated circuit board 12 adopts the existing technology. It is assembled in the housing 1. The core part is a microprocessor, which can realize the function control of structures such as an encoder, a power supply 14, and a display screen 13; meanwhile, it has data processing and storage functions. A Bluetooth module is also provided on the integrated circuit board 12, which can realize the communication connection with external devices. In this embodiment, the Bluetooth module is Bluetooth 6.0 with positioning function.

[0030] The display screen 13 is an LED display screen 13 embedded in the housing 1, and is electrically connected to the integrated circuit board 12, and is used to display the data information processed by the integrated circuit board 12, such as tree species information, tree diameter information, and geographical location coordinate information, etc.

[0031] It should be noted that the external device has a GPS and a Bluetooth module (Bluetooth 6.0), and is also loaded with an app for controlling this embodiment. When in use, this embodiment forms a communication connection with the external device through the Bluetooth module, and uses the GPS of the external device to perform real-time positioning on this embodiment. The specific geographical location coordinate information is transmitted to the display screen 13 for display after being processed by the integrated circuit board 12; the length signal (i.e., the measured tree diameter) obtained by the integrated circuit board 12 after processing the angle signal of the magnetic encoder 6 can be transmitted to the external device through the Bluetooth module.

[0032] As Figure 1 shown, a plurality of buttons are arranged around the display screen 13, and each button is electrically connected to the integrated circuit board 12. Specifically, the buttons in this embodiment include a power-on / off key, a withdrawal key, and at least one tree species information key. Among them, the power-on / off key is used to start or close this embodiment; the withdrawal key is used to delete the previous piece of information of the measured tree; the tree species information key is used to retrieve the tree species information and transmit the measured diameter information and geographical location coordinate information of the current tree to the external device.

[0033] In this embodiment, there are three tree species information keys. In actual use, each tree species information key can be assigned a value in the app of the external device. For example: assign values to the three tree species information keys so that they represent Pinus yunnanensis, Cunninghamia lanceolata, and Betula albo-sinensis respectively. When the measurer measures the diameter information and geographical location coordinate information of the current tree, and manually determines the tree species of the current tree, if the current tree is Pinus yunnanensis, then press the tree species information key representing Pinus yunnanensis, and the tree species information, as well as the currently measured diameter information and geographical location coordinate information, will be transmitted to the external device through the Bluetooth module.

[0034] The power supply 14 is electrically connected to the encoder, the display screen 13, and the integrated circuit board 12 respectively, and is used to supply power. In this embodiment, the power supply 14 adopts a rechargeable battery in the existing technology. Of course, according to the situation, the power supply method of an external power supply 14 can also be selected.

[0035] Embodiment 2 A tree-measuring electronic tape AsFigures 4 to 6 As shown in the figure, in this embodiment, a ranging sensor 15 and a buzzer are added on the basis of the structure of Embodiment 1. When conducting a tree survey, this embodiment can determine the measurement height of the tree to be measured through the ranging sensor 15, obtain the actual measurement length (i.e., the tree diameter) through the magnetic encoder 6, obtain the geographical location coordinate information through the positioning function of the built-in Bluetooth module, and realize the integration and transmission of the measurement data and the geographical location coordinate information, having the advantages of high measurement accuracy, low manufacturing cost, and simple use.

[0036] Specifically, the ranging sensor 15 is assembled in the housing 1, and the working end is exposed outside the housing 1 for measuring the vertical distance from this embodiment to the ground. In this embodiment, the ranging sensor 15 is a laser ranging sensor 15 electrically connected to the integrated circuit board 12. And as Figure 4 shown, the laser ranging sensor 15 and the display screen 13 are located on different sides of the housing 1. During actual use, the working end of the laser ranging sensor 15 faces the ground, and the display screen 13 faces the measurement personnel.

[0037] The buzzer is assembled in the housing 1 and electrically connected to the integrated circuit board 12, and this structure is not shown in the drawings of this embodiment. When the ranging sensor 15 detects that the vertical distance from this embodiment to the ground reaches the preset value, the buzzer emits a sound to give feedback information.

[0038] The ranging sensor 15 and the buzzer are electrically connected to the power supply 14.

[0039] Furthermore, this embodiment also adds a diameter at breast height (DBH) measurement selection key and a diameter at ground level (DAGL) measurement selection key on the basis of the original keys in Embodiment 1. Both the DBH measurement selection key and the DAGL measurement selection key are electrically connected to the integrated circuit board 12, and both can independently control the opening and closing of the ranging sensor 15. The difference is that after starting the ranging sensor 15 with the DBH measurement selection key, when the ranging sensor 15 detects that the vertical distance from this embodiment to the ground is 1 m, the buzzer emits a sound to give feedback information; after starting the ranging sensor 15 with the DAGL measurement selection key, when the ranging sensor 15 detects that the vertical distance from this embodiment to the ground is 1.3 m, the buzzer emits a sound to give feedback information.

[0040] Embodiment 3 A tree measurement electronic tape This embodiment is basically the same as the structure of Embodiment 2, the differences being: Firstly, the measuring rope 3 is made of circular steel wire with a diameter of 0.6 mm.

[0041] Secondly, a spiral guiding groove is provided on the rope winding disc 4, as Figure 7As shown, the measuring rope 3 is evenly wound around the rope winding disc 4 from top to bottom along the guiding groove, rather than being stacked in multiple layers from the inside to the outside (the strip-shaped measuring rope 3 in Embodiment 1 and Embodiment 2 is wound around the rope winding disc 4 in multiple layers from the inside to the outside). The winding method of the measuring rope 3 adopted in this embodiment makes the length of the measuring rope 3 pulled out the same every time the rope winding disc 4 rotates one circle.

[0042] Thirdly, the rope-out distance measuring mechanism only includes a magnetic encoder 6, and the magnetic encoder 6 is assembled on the rope winding disc 4 for detecting the rotation angle of the rope winding disc 4. When in use, during the process of pulling out the measuring rope 3, the rope winding disc 4 rotates synchronously. The magnetic encoder 6 can detect the rotation angle of the rope winding disc 4 and transmit the angle signal to the integrated circuit board 12 in the form of an electrical signal. After the integrated circuit board 12 processes the angle signal, the length of the measuring rope 3 pulled out once can be obtained.

[0043] Embodiment 4 A method for using an electronic tree girth measuring tape This embodiment includes the following steps: S1. Initial setting: After turning on the electronic tree girth measuring tape as described in Embodiment 2 through the power key, establish a communication connection with an external device through the Bluetooth module; use the GPS positioning function of the external device to determine the geographical location coordinate information of the electronic tree girth measuring tape and display it through the display screen 13; then register the user information in the app of the external device and assign different tree species names to the tree species information keys. In this embodiment, the three tree species information keys respectively represent Pinus yunnanensis, Cunninghamia lanceolata, and Betula albo-sinensis.

[0044] S2. Diameter measurement: When measuring the diameter at breast height, turn on the distance measuring sensor 15 through the diameter at breast height measurement selection key, move the electronic tree girth measuring tape up and down. When the buzzer emits a prompt sound, the electronic tree girth measuring tape reaches the preset height (1 m); then pull out the free end of the measuring rope 3 to closely surround the tree for one week, and at the same time adjust the measuring rope 3 to be horizontal. Use the encoder to detect the pulled-out length of the measuring rope 3, convert it into an angle signal, and calculate the diameter at breast height of the tree after being processed by the integrated circuit board 12 and display it on the display screen 13; Similarly, when measuring the diameter at breast height, turn on the distance measuring sensor 15 through the diameter at breast height measurement selection key, move the electronic tree girth measuring tape up and down. When the buzzer emits a prompt sound, the electronic tree girth measuring tape reaches the preset height (1.3 m); then pull out the free end of the measuring rope 3 to closely surround the tree for one week, and at the same time adjust the measuring rope 3 to be horizontal. Use the encoder to detect the pulled-out length of the measuring rope 3, convert it into an angle signal, and calculate the diameter at breast height of the tree after being processed by the integrated circuit board 12 and display it on the display screen 13.

[0045] S3. Data processing: The surveyor judges the tree species information of the currently measured tree, manually triggers the corresponding tree species information key, and transmits data information such as tree species information, diameter at breast height (DBH) and / or diameter at 1.3 meters above ground (D1.3m), and tree species position information (the position information of the electronic girth tape for tree measurement when measuring the diameter is the tree species position information) to an external device through a Bluetooth module.

[0046] Repeat steps S2 to S3. After the tree information in the target area is surveyed, the external device processes and generates a "Schematic Diagram of Tree Species Position, DBH and / or D1.3m Distribution" and stores it.

[0047] It should be noted that the above are only the preferred embodiments of the present invention and are not used to limit the present invention. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art can still modify the technical solutions recorded in the above embodiments or perform equivalent replacements on some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An electronic girth tape for tree measurement, characterized in that: It includes a housing, a measuring rope retracting and releasing mechanism, a rope-out distance measuring mechanism, an integrated circuit board, a power supply assembled in the housing, and a display screen assembled on the housing; The measuring rope retracting and releasing mechanism has a measuring rope for measurement; The rope-out distance measuring mechanism has a magnetic encoder for measuring the single-time pulled-out length of the measuring rope, and the magnetic encoder is electrically connected to the integrated circuit board; The display screen is electrically connected to the integrated circuit board for displaying data information; The integrated circuit board is provided with a Bluetooth module for communication connection with an external device. The Bluetooth module is Bluetooth 6.0 with a positioning function, and the external device has a GPS; The power supply is electrically connected to the magnetic encoder, the display screen and the integrated circuit board respectively; 2. The electronic girth tape for tree measurement according to claim 1, wherein: The integrated circuit board is also provided with a plurality of buttons, and the plurality of buttons are arranged around the display screen; The plurality of buttons include a power-on / off key, a retraction key and at least one tree species information key for retrieving tree species information; 3. The electronic girth tape for tree measurement according to claim 2, wherein: A distance measuring sensor for measuring the vertical distance from the tree measuring electronic girth tape to the ground is also assembled in the housing, and the distance measuring sensor is electrically connected to the integrated circuit board; A buzzer electrically connected to the integrated circuit board is also assembled in the housing for prompting whether the vertical distance from the tree measuring electronic girth tape to the ground reaches a preset value; The distance measuring sensor and the buzzer are electrically connected to the power supply; 4. The electronic girth tape for tree measurement according to claim 3, characterized in that: The plurality of buttons also include a diameter at breast height measurement selection key and a diameter at breast height measurement selection key; 5. The electronic girth tape for tree measurement according to any one of claims 1-4, characterized in that: The measuring rope retracting and releasing mechanism further includes a rope winding disc rotatably assembled in the housing and a return spring assembled between the rope winding disc and the housing for returning the rope winding disc to its original position; The measuring rope is evenly wound on the rope winding disc, and the free end of the measuring rope can be pulled outwards from the rope outlet of the housing; 6. The electronic girth tape for tree measurement according to claim 5, characterized in that: The measuring rope is made of any one of nylon, polyester and steel wire, and is in the form of a round filament with a diameter of 0.4 - 1 mm or a strip with a thickness of 0.4 - 1 mm; 7. The electronic girth tape for tree measurement according to claim 5, characterized in that: The magnetic encoder is assembled on the rope winding disc for detecting the rotation angle of the rope winding disc; 8. The electronic girth tape for tree measurement according to any one of claims 1-4 and 5, characterized in that: The rope-out distance measuring mechanism further includes a distance measuring wheel and a plurality of guide wheels rotatably assembled in the housing; The measuring rope is wound around the distance measuring wheel and the plurality of guide wheels, and the plurality of guide wheels are used to guide the measuring rope to ensure that the measuring rope does not slip with the distance measuring wheel; The magnetic encoder is assembled on the distance measuring wheel for detecting the rotation angle of the distance measuring wheel; 9. A method for using an electronic girth tape for tree measurement, characterized in that: It includes the following steps: S1. Turn on the tree measuring electronic girth tape. After communicating with the external device through the Bluetooth module, the geographical location coordinate information of the tree measuring electronic girth tape is displayed on the display screen; S2. Pull out the free end of the measuring rope to surround the tree for one week. Use the magnetic encoder to detect the pulled-out length of the measuring rope, convert it into an angle signal, and calculate the tree diameter after being processed by the integrated circuit board and display it on the display screen; S3. Transmit the measurement data to the external device through the Bluetooth module and store and process it by the external device; 10. The method for using the electronic girth tape for tree measurement according to claim 9, characterized in that: Step S1 further includes: assigning different tree species names to the tree species information keys of the tree measuring electronic girth tape through the external device, and registering the user information through the external device; Step S2 further includes: after selecting the use height of the tree measurement electronic girth tape through the diameter at breast height measurement selection key and the diameter at breast height measurement selection key, moving the tree measurement electronic girth tape up and down. When a prompt sound is emitted by the buzzer, the tree measurement electronic girth tape reaches the preset height; Step S3 further includes: manually triggering the tree species information key corresponding to the tree species being measured, and transmitting the tree species information, the diameter at breast height and / or diameter at breast height information, and the tree species position information to the external device, and the external device processes and generates a "Schematic Diagram of the Distribution of Tree Species Position, Diameter at Breast Height and / or Diameter at Breast Height".

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