A technical method for detecting moisture content of forest litter on site based on pressure compensation

Abstract

The present application provides a kind of technical method for detecting moisture content of forest litter based on pressure compensation, to solve the problem that it is difficult to quickly and accurately determine the moisture content of litter in the field, a portable detection device is introduced.The method applies standardized pressure to the litter sample through the pressure control module, eliminating the influence of density difference, and uses the sensing acquisition module to obtain the dielectric constant value and temperature value related to the moisture content of litter by frequency domain reflection electromagnetic non-contact measurement method, and finally calculates the moisture content of forest litter through the moisture content calculation model pre-stored in the control processing module.The present application combines pressure compensation mechanism and frequency domain reflection electromagnetic non-contact measurement technology, realizes the rapid and accurate field determination of the moisture content of forest litter, significantly reduces the workload, measurement difficulty and measurement time of measurement personnel, improves the work efficiency, and can be widely applied in the fields of forest fire prevention and ecological monitoring.

Description

I. Technical Field

[0001] This invention relates to an apparatus and method for measuring the moisture content of forest litter during forest surveys in the field, and in particular to a technical method for rapidly determining the moisture content of forest litter on-site using a portable detection device based on the frequency domain reflectance (FDR) electromagnetic non-contact measurement principle. II. Background Technology

[0002] Forest litter is a crucial material basis for the occurrence and spread of forest fires. Its moisture content directly determines the probability of forest fires and the speed of their spread, making it an important factor in forest fire research. Therefore, leveraging the characteristics of next-generation electronic information technology to explore and invent new measurement methods and equipment for the rapid, accurate, and convenient determination of forest litter moisture content is a key means to further promote national forest fire prevention and control efforts.

[0003] Currently, the moisture content of forest litter is mainly determined by methods such as drying and resistance methods. The drying method is the traditional standard method, but its drawback is its long processing time, typically requiring several hours or even longer, which cannot meet the needs of rapid on-site measurement. The resistance method indirectly infers the moisture content by measuring the resistance value of the litter, but its measurement results are easily affected by factors such as litter density and contact conditions, leading to significant errors. Currently, in forestry surveys, especially in scenarios requiring rapid assessment of forest fire risk, there is a lack of convenient, practical, highly accurate, and easy-to-operate instruments and equipment for on-site testing of forest litter moisture content. The method of this invention is simple to use, highly accurate, and easy to operate, and is expected to be widely used in forest fire prevention, ecological monitoring, and other fields, solving the problem of difficulty in quickly and accurately determining the moisture content of litter in the field, and has broad application prospects. III. Summary of the Invention

[0004] In order to overcome the problems of long time consumption and susceptibility to density in the field application of existing methods for measuring the moisture content of forest litter, the purpose of this invention is to provide a technical method for field detection of the moisture content of forest litter based on pressure compensation.

[0005] The objective of this invention is achieved as follows:

[0006] 1. A standardized pressure is applied to the collected litter samples using the pressure control module of a portable detection device to eliminate measurement errors caused by differences in litter density.

[0007] 2. The dielectric constant H and temperature T related to the moisture content of litter are obtained by a non-contact measurement method using frequency domain reflection electromagnetic method through a sensor acquisition module.

[0008] 3. The control processing module calls the pre-stored moisture content calculation model and calculates the moisture content W of forest litter based on the obtained dielectric constant H and temperature T. The moisture content model for coniferous trees is: W = -2.075 + 1.410 * H + 0.107 * T, and the moisture content model for broad-leaved trees is: W = -2.561 + 1.420 * H + 0.121 * T.

[0009] This invention has the following advantages:

[0010] ① Introducing a pressure compensation mechanism into the measurement of forest litter moisture content effectively eliminates the influence of density variation on the measurement results, improving the accuracy and reliability of the measurement.

[0011] ② The dielectric constant is obtained by using a frequency domain reflection electromagnetic non-contact measurement method, which has the advantages of fast measurement speed and high accuracy.

[0012] ③ Through portable devices and simple operating procedures, the moisture content of forest litter can be rapidly measured on-site, which significantly reduces the workload, measurement difficulty and measurement time of measurement personnel and improves work efficiency. IV. Description of the attached drawings

[0013] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0014] Appendix Figure 1 This is a schematic diagram of a pressure-compensated forest litter moisture content detection device. V. Detailed Implementation Methods

[0015] 1. Collect forest litter samples for testing in the field.

[0016] 2. Open the detection chamber door 1, put the pretreated litter sample into the detection chamber 2, and close the detection chamber door to prevent the litter from escaping and ensure that a stable standardized pressure can be established in the detection chamber 2.

[0017] 3. Turn on the power switch 6 of the device, and the controller 11 controls the miniature electric push rod 3 to apply a preset standardized pressure to the litter sample in the detection chamber 2. This pressure value is measured and fed back in real time by the pressure detection sensor 4.

[0018] 4. Insert the sensor probe 8 from the sensing acquisition module 7 vertically into the compressed litter sample to a preset depth through the guide hole 5 at the top of the housing. The sensor 8 acquires the dielectric constant H and temperature T related to the moisture content of the litter.

[0019] 5. The microcontroller 10 built into the control processing module calls the pre-stored moisture content calculation model and calculates the moisture content W of the forest litter based on the dielectric constant H and temperature T obtained in step 4.

[0020] 6. The calculated moisture content W is transmitted in real time to the mobile terminal for display via the data transmission module 9.

[0021] 7. The device is powered by battery 13 and is equipped with a charging interface 12 for charging the battery.

Claims

1. A technical method for on-site detection of moisture content in forest litter based on pressure compensation, characterized in that: In field environments where it is difficult to directly determine the true moisture content of forest litter, a portable detection device is introduced. The device's pressure control module applies standardized pressure to the litter sample to eliminate the influence of density differences, and the sensing module acquires the dielectric parameters of the litter. Finally, the moisture content of the forest litter is calculated using a pre-stored moisture content calculation model in the control processing module.

2. The technical method for on-site detection of forest litter moisture content based on pressure compensation according to claim 1, characterized in that: The on-site detection device includes a pressure control module, which consists of a micro electric push rod and a high-precision pressure sensor forming a closed-loop control system. The micro electric push rod applies standardized pressure to the fallen material placed in the detection chamber.

3. The technical method for on-site detection of forest litter moisture content based on pressure compensation as described in claim 1, characterized in that: The sensor probe is vertically inserted into the litter sample compressed under standardized pressure through a guide hole at the top of the housing. The probe sensor obtains the dielectric constant H and temperature T related to the moisture content of the litter.

4. The technical method for on-site detection of forest litter moisture content based on pressure compensation as described in claim 1, characterized in that: The control processing module uses a pre-stored moisture content calculation model to calculate the moisture content of forest litter. The module has a built-in microcontroller that stores the moisture content calculation model established through calibration experiments. This model is used to calculate the moisture content W of the forest litter using the dielectric constant H and temperature T obtained according to claim 3. For coniferous trees: W = -2.075 + 1.410 * H + 0.107 * T; for broadleaf trees: W = -2.561 + 1.420 * H + 0.121 * T.

5. The technical method for on-site detection of forest litter moisture content based on pressure compensation according to claim 1, characterized in that: The on-site testing device also includes a data transmission module, which integrates a Bluetooth 5.0 communication unit to transmit the dielectric constant H and temperature T obtained by the sensing acquisition module and the moisture content W calculated by the control processing module to a mobile terminal for display in real time.

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