KR101229398B1 - Apparatus for measuring soil physical property portable - Google Patents

Abstract

The present invention relates to a portable soil physical measurement apparatus, comprising: a measuring sensor unit which is formed in a rod shape to penetrate the soil, and which has an electrode unit fastened to a lower end thereof; A monitor unit installed above the measurement sensor unit to display various data measured by the measurement sensor unit and to select various channels; A load cell installed between an upper portion of the measurement sensor unit and a monitor unit to measure hardness of the soil; A GPS module embedded in the monitor to receive a current measurement position; Handles provided at both sides of the monitor unit; And a control unit which is built in the monitor unit and stores various data measured by the measurement sensor unit, the load cell, and the GPS module and outputs the data to the monitor unit.

Description

Portable soil physical property measuring device {Apparatus for measuring soil physical property portable}

The present invention relates to a portable soil physical measurement apparatus, and more particularly, to a portable soil physical measurement apparatus that can simultaneously measure the electrical conductivity, moisture content, hardness, temperature, etc. by the depth of the soil in the field.

In general, facility cultivation has a large number of crop cultivation in a closed environment, too many chemical fertilizers and livestock compost used in each small period, so that the crop is absorbed and used is nitrate or hydrochloride, and salts accumulate as the year goes on. An obstacle occurs.

The causes can be divided into direct fertilization disorders caused by the direct application of fertilizer components to the roots, and the other, indirect fertilization disorders caused by the accumulation of fertilizer components each year and the accompanying components.

Reasonable fertilization is the best way to reduce serial disturbance caused by salt accumulation. For rational fertilization, it is necessary to accurately determine the salt concentration in the soil. Soil electrical conductivity (EC) has a certain correlation with soil salt concentration, which is very important for diagnosing salt contact.

However, the conventional method for measuring soil electrical conductivity has a problem that takes a lot of cost, effort and time due to the soil sampling and laboratory analysis process.

The present invention has been made to solve the above problems, it is convenient to carry and the simultaneous measurement of soil electrical conductivity, water content, hardness, temperature and relative correction is possible by using each measured data to improve the measurement accuracy The purpose of the present invention is to provide a portable soil physical property measuring device that can be increased.

In addition, since the occurrence of salt accumulation can be determined at an early stage, an object of the present invention is to provide a portable soil physical measurement apparatus that can improve the harvest and quality of various vegetables or fruits grown in the facility cultivation.

Portable soil physical measurement apparatus according to the present invention comprises a measuring sensor unit made of a rod shape to penetrate the soil and the electrode unit is fastened to the bottom; A monitor unit installed above the measurement sensor unit to display various data measured by the measurement sensor unit and to select various channels; A load cell installed between an upper portion of the measurement sensor unit and a monitor unit to measure hardness of the soil; A GPS module embedded in the monitor to receive a current measurement position; Handles provided at both sides of the monitor unit; And a control unit which is built in the monitor unit and stores various data measured by the measurement sensor unit, the load cell, and the GPS module and outputs the data to the monitor unit.

The portable soil physical property measuring apparatus according to the present invention is manufactured to be portable, so that real-time measurement of the soil in the field has the effect of reducing the cost and time.

In addition, it is possible to immediately determine whether the soil environment in the root zone of the crop is suitable for crop growth, and there is an effect that farmers can directly use in crop management.

In addition, in the case of facility cultivation, it is possible to determine salt concentration at an early stage, thereby preventing yield reduction and quality deterioration, thereby contributing to profit generation.

1 is a perspective view showing a portable soil physical measurement apparatus according to the present invention.
Figure 2 is a sectional view showing a portable soil physical measurement apparatus according to the present invention.
Figure 3 is a block diagram showing a portable soil physical measurement apparatus according to the present invention.
4 is a view showing a display of the portable soil physical measurement apparatus according to the present invention.
5 is a diagram illustrating a detailed selection menu of the mode change button of the monitor unit according to the present invention.
Figure 6 is a graph showing the water content relationship between the portable soil physical property measuring apparatus and the analysis value according to the present invention.
7 is a graph showing the electrical conductivity relationship between the portable soil physical property measuring apparatus and the analysis value according to the present invention.
8 is a graph showing the conductivity correction according to the soil moisture content change and soil electrical conductivity change of the portable soil physical properties measuring apparatus according to the present invention.

Portable soil physical measurement apparatus according to the present invention comprises a measuring sensor unit made of a rod shape to penetrate the soil and the electrode unit is fastened to the bottom; A monitor unit installed above the measurement sensor unit to display various data measured by the measurement sensor unit and to select various channels; A load cell installed between an upper portion of the measurement sensor unit and a monitor unit to measure hardness of the soil; A GPS module embedded in the monitor to receive a current measurement position; Handles provided at both sides of the monitor unit; And a control unit which is built in the monitor unit and stores various data measured by the measurement sensor unit, the load cell, and the GPS module and outputs the data to the monitor unit.

The electrode unit may include an inverted triangular fastening assembly fastened to the lower end of the measurement sensor unit, two electrodes formed at a predetermined interval on the fastening assembly, and an insulator integrally assembled while dividing the electrodes. .

The monitor may include a display for displaying various data output by the controller, a power button for turning the power on and off, and a mode screen when the button is pressed once, and a mode change button for pressing the button again to return to the main measurement screen. And a measurement and selection button used to select a function setting on a measurement and mode screen of the measurement sensor unit, and a setting change button used to change a function setting on a mode screen.

In addition, the mode change button is a measurement channel function for selecting the type of soil, a channel detail adjustment function for zeroing the water content rate, a real-time storage function used to store the data measured in the field, and the real-time storage function Average number setting function to set the average number, storage folder selection function to select the storage folder to distinguish the measurement data, graph view function to view the stored average value data by real time storage function, and numerical correction to correct the sensor measurement value. It is characterized by including a function.

In addition, the monitor is characterized in that the infrared sensor is built in to measure the measurement depth of the soil.

In addition, the one handle is provided with a USB connector to store the measurement data, the other handle is characterized in that the battery charging connector is provided.

In addition, one side of the measuring sensor unit is characterized in that the temperature sensor is installed to detect the temperature in the soil.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

1 is a perspective view showing a portable soil physical measurement apparatus according to the present invention, Figure 2 is a cross-sectional view showing a portable soil physical measurement apparatus according to the present invention, Figure 3 is a portable soil physical measurement according to the present invention Figure 4 is a block diagram showing the device, Figure 4 is a view showing a display of a portable soil physical properties measuring apparatus according to the present invention, Figure 5 is a view showing a detailed selection menu of the mode change button of the monitor unit according to the present invention 6 is a graph showing the water content relationship between the portable soil physical measurement device and the analysis value according to the present invention, Figure 7 is a diagram showing the electrical conductivity relationship between the portable soil physical measurement device and the analysis value according to the present invention 8 is a graph showing the electrical conductivity correction according to the soil moisture content change and the soil electrical conductivity change of the portable soil physical property measuring apparatus according to the present invention. All.

As shown in Figures 1 to 3, the portable soil physical measurement apparatus according to the present invention is made of a rod-shaped so as to penetrate the soil and the measurement sensor unit 1 is fastened to the electrode portion 11 at the bottom, and A monitor unit 2 installed on the upper part of the measuring sensor unit 1 to display various data measured by the measuring sensor unit 1 and to select various channels, and an upper part of the measuring sensor unit 1 and A load cell 3 installed between the monitor unit 2 to measure the hardness of the soil; a GPS module 4 embedded in the monitor unit 2 to receive a current measurement position; 2) the handles 5 which are installed at both sides, and the monitor unit 2 are built in to store various data measured by the measurement sensor unit 1, the load cell 3, GPS module 4 and It comprises a control unit 6 to output this to the monitor unit (2).

The measuring sensor unit 1 uses a rod of stainless steel having a diameter of 10 mm, a length of about 680 mm, a maximum measuring depth of 500 mm, and a measuring time of about 5 seconds. Soil electrical conductivity and water content are measured by the electrode unit 11 installed at the lower end of the measurement sensor unit 1. One side of the measurement sensor unit 1 is provided with a temperature sensor 8 to detect the temperature in the soil.

The electrode part 11 includes a fastening assembly 111 having an inverted triangle shape fastened to the lower end of the measurement sensor part 1, two electrodes 112 formed at predetermined intervals on the fastening assembly 111, and The insulator 113 is integrally assembled while dividing the electrode 112.

The two electrodes 112 are connected to the controller 6 through wirings provided in the fastening assembly 111.

The load cell (3) is a device for measuring the amount of deformation is compressed when the weight is transmitted, it measures the force received when injecting the measuring device and the measured value is divided by the cone index (selected by the US Agricultural Research Service) soil strength It can be represented as.

The hardness of the soil is measured using the load cell 3, and the load cell 3 outputs an output value in mV.

CI = {DN / (R _da × G _am × G _lc × V _in ) × 10 ^-3 } / A _tip

= 15.92 × 10 ^-3 DN

Where R _da = system resolution, 1024 (5V) ^-1

G _am = maximum amplification, 1250

G _lc = load cell resolution, 2 × 10 ^-3 VV ^-1 (1.96kN) ^-1

V _in = load cell input voltage, 3.7 V

A _tip : Cross section of sensor cone (1.30 × 10 ^-4 m ² )

         DN: Output value across the amplifier (Digital Number, dimensionless)

The monitor 2 is simply designed to be easily handled by the user, the electrical conductivity, moisture content, hardness, temperature is displayed and the measured data is GPS coordinates, depth, moisture content, electrical conductivity, hardness, temperature txt file format About 2,000 points can be saved, and the saved data can be downloaded using external memory USB. The monitor 2 has a built-in infrared sensor 7 to measure the measurement depth of the soil.

As shown in FIGS. 4 and 5, the monitor unit 2 includes a display 21 for displaying various data output by the control unit 6, a power button 22 for turning on / off the power, Press the button once to display the mode screen, and press it again to return to the main measurement screen.The measurement and selection buttons used to select the function settings on the measurement and mode screens of the measurement sensor unit 1 ( 24) and a setting change button 25 used to change a function setting on a mode screen.

Using the portable soil physical property measuring device, the measured data is displayed after about 5 seconds is inserted into the soil to be measured and the measurement and selection button 24 is pressed.

When the setting change button 25 is pressed, the cursor moves, and when the measurement and selection button 24 is pressed on the moved cursor, the cursor moves to the numerical value, and the value can be changed by the setting change button 25. After changing the numerical value, pressing the measurement and selection button 24 again stores the changed data.

In particular, the mode change button 23 is a measurement channel function for selecting the type of soil, a channel detail adjustment function for zeroing the moisture content value, a real-time storage function used to store the data measured in the field, and the real-time storage Function to set the average number in the function, select the storage folder to select the storage folder to distinguish the measurement data, graph view function to view the stored average value data by real-time storage function, and sensor measurement correction Numerical correction function is included.

The measurement channel function is a general user can select the soil weight moisture content, if you want a different type of non-volcanic-dark brown soil, volcanic-dark brown soil, volcanic ash-black soil, effective moisture content-loam soil, effective water content-loam, effective water content -You can use it by selecting from the loam.

The channel detail adjustment function is a function of adjusting the moisture content. When the + value is added, the channel detail adjustment function is increased by 2% from the measured value.

The real-time storage function is stored up to 50 addresses for each folder, and there are 1 to 4 folders, and the average number is used when the average value is to be measured where you want to measure. Value and average value)

In the average number setting function, when the average number is 5, when the measurement is performed in the real time storage function, the measured value and the average value of 5 times are stored. (Possible 1-8)

The storage folder selection function is easy to distinguish the measured data by using folder 1 in cucumber packaging and folder 2 in strawberry packaging.

The graph viewing function is a soil moisture content * 5: you can see a graph of the average value of five addresses.

In the numerical correction function, the default value is 0 and the device measured value is smaller than the desired measured value, the + value can be raised and in many cases, the-value can be corrected to the desired value.

The handle (5) was to be held on both sides, and when the handle (5) is removed, the handle (5a) is provided with a USB connector (51) for storing measurement data, and the handle (b) for charging a battery ( 52) is provided so that it is not damaged by soil and water.

In the present invention, the electrical conductivity and the water content are measured using impedance, and are sequentially measured using different frequency domain bands.

More specifically, impedance refers to resistance (resistance in the case of DC power, impedance in the case of AC power), and when the water content is high in the soil, electricity flows well and the resistance is low. As such, there is a high correlation between resistance and water content, so the measurement of resistance allows the estimation of soil water content, and electrical conductivity is the same principle. In other words, if there are many ions in the water, the resistance is low, and if the resistance is low, the ionic component (mainly fertilizer component) in the soil is high and the electrical conductivity is high.

Impedance has different output values even in the same state according to applied frequency, and measurement sensitivity varies depending on which frequency is used. Therefore, in the present invention, in order to select the frequency with the highest sensitivity, a moisture content of 50 MHz and an electric conductivity of 1 MHz are selected and used in the experimental results measured by 1 MHz between 1 and 300 MHz.

The electrical conductivity (EC) is expressed as the inverse of the resistance (R), and is expressed and used as S / m (Siemens per meter). The equation of electrical conductivity is as follows.

EC = 1 / R ---------- (1)

EC: Conductivity (dS / m)

R: resistance

The resistance is closely related to the material, area, and distance of the electrode.

R = ρ ㅇ L / A ---------- (2)

ρ: resistivity (material specific property-property constant)

L: distance between electrodes (m)

A: electrode area (m ² )

However, the soil resistance is very difficult to measure the resistance (R) of the direct current power source. Therefore, the impedance (Z _c ) of AC power is measured and used.

Z _c = (R _s ² + (2πfC _s ) ^-2 } ^1/2 ---------- (3)

Z _c : Impedance

R _s : soil electrical resistance

f: power frequency (Hz)

C _s : Soil capacity (F)

That is, Z _c is measured and electrical conductivity is computed using Formula (1) and (2). It is important to select the appropriate f because f has a lot of influence when measuring Z _c .

Meanwhile, the measurement accuracy of the conductivity can be improved by correcting the conductivity using the measured soil moisture content. As shown in FIG. 8, the relationship between the soil conductivity and the soil moisture content can be expressed by a quadratic function and a linear function. The corrected electrical conductivity can be obtained from the following equation.

EC _c = {(EC _s / θ) -b} / (a + θ) ---------- (4)

Where EC _c : corrected conductivity (mS / m)

EC _s : Measured Conductivity (mS / m)

        θ: measured soil moisture content (%)

a, b: Constant obtained by the least-squares method in FIG. 8 (a = 1.45, b = 0.102)

In addition, the electrical conductivity was changed by about 2% according to the temperature change of 1 ° C., and was corrected by using Equation (5) because it was to be expressed based on 25 ° C. Using equation (5), it is possible to improve the measurement accuracy of the electrical conductivity by temperature compensation.

EC _c25 = EC _st / (1 + 0.02 (t-25)} ---------- (5)

Where EC _c25 : electrical conductivity corrected to 25 ° C (mS / m)

EC _st : Electrical conductivity measured at t ℃ (mS / m)

t: measured soil temperature (℃)

<Test Example of Measurement of Electrical Conductivity and Water Content>

Basic experiments were performed to evaluate the measurement performance of electrical conductivity and water content of the portable soil physical property measuring apparatus according to the present invention.

First, in order to evaluate the soil electrical conductivity, the relationship between the analysis value according to the change of the salt concentration under the constant soil moisture content condition and the measured value of the portable soil physical measuring device was confirmed.

The ground soil was prepared by mixing sand and clay in a weight ratio (50:50) using sand and clay. Sodium chloride (NaCI) was used as a solute to change the electrical conductivity in the soil. Sodium chloride aqueous solution was prepared at level of 0.01, 0.03, 0.05, 0.08, 0.1, 0.3, 0.5wt%, and the soil moisture content. Was set to 10%.

The soil weight was determined to be 1780kg considering the filling height of the soil container (diameter 108mm, height 1500mm, PVC material). The soil density composition in the soil container was adjusted to a predetermined height in the container of a certain volume.

After the filling of the soil container, the cap was placed on the soil container to stabilize the soil moisture content in the container, and then measured after 24 hours of stabilization. Soil electrical conductivity was measured using a portable soil physical measuring device and soil analysis method (EC1: 5).

In order to evaluate the portable soil physical property measuring device, the relationship between the analysis value and the measured value of the portable soil physical property measuring device was verified while changing the soil moisture content condition of the soil. Test materials and test methods were performed in the same manner as the performance evaluation experiments of the portable soil physical property measuring device.

Soil moisture control was performed by mixing distilled water and ground soil in weight ratio, and the change of soil moisture content was prepared in 7 levels between 2-25%. Soil moisture content was measured using a portable soil physical measuring device and soil drying method.

As shown in FIG. 6 and FIG. 7, the result of confirming the relationship between the analysis value according to the change of the salt concentration under the constant soil moisture content condition and the measured value of the portable soil physical measuring device for the evaluation of the soil electrical conductivity measurement, analysis The relationship between the conductivity measurement value and the portable soil physical property measuring device is expressed by an exponential function, and a high correlation of 0.9691 was confirmed, and thus it was determined that it can be used as an conductivity sensor.

In addition, the soil moisture content obtained by the drying method and the portable soil physical properties were measured by confirming the relationship between the analytical value and the measured value of the portable soil physical property measuring device while changing the soil moisture content condition of the soil for evaluation of soil moisture content measurement. The relationship with the device was converged to the first function and the high correlation of 0.9741 was confirmed, so it could be used as a soil moisture sensor.

<Test Example of Correction of Electrical Conductivity According to Soil Water Content Change and Soil Electrical Conductivity Change>

On the other hand, the experiment was performed to correct the electrical conductivity according to the change in soil moisture content and soil conductivity.

Using sodium chloride (NaCI) to change the conductivity of soil (50% by weight sand: 50% clay) and soil conductivity, the concentration of aqueous sodium chloride solution was 0.03, 0.05, 0.1, 0.3, 0.5wt%. Levels were prepared and the soil moisture content was set at 6 levels of 5, 10, 15, 20, 25, 30%. Experimental method was carried out in the same way as the experiment of soil electrical conductivity and water content.

The correlation between soil electrical conductivity and soil moisture content was high as 0.92 ~ 0.98 according to the concentration of each sodium chloride solution. In other words, by using the correlation of Equation (1) and FIG. 8 as a change in the moisture content state and the electrical conductivity of the soil, it is possible to obtain a high soil electrical conductivity.

Although the present invention has been described with reference to the accompanying drawings, it will be apparent to those skilled in the art that many various obvious modifications are possible without departing from the scope of the invention from this description. Therefore, the scope of the invention should be construed by the claims described to include examples of many such variations.

1: measuring sensor
11: electrode part
111: fastening assembly, 112: electrode, 113: insulator
2: monitor
21: Display
22: Power button
23: Mode change button
24: Measure and Select Button
25: setting change button
3: load cell
4: GPS module
5: handle
51: USB connector
52: battery charging connector
6:
7: infrared sensor
8: temperature sensor

Claims (7)

A measuring sensor unit 1 having a rod shape to penetrate the soil and having the electrode unit 11 fastened to a lower end thereof;
A monitor unit (2) installed above the measurement sensor unit (1) to display various data measured by the measurement sensor unit (1) and to select various channels;
A load cell (3) installed between an upper portion of the measurement sensor unit (1) and a monitor unit (2) to measure the hardness of the soil;
A GPS module (4) embedded in the monitor unit (2) to receive a current measurement position;
Handles 5 respectively provided at both sides of the monitor unit 2;
A control unit 6 which is built in the monitor unit 2 and stores various data measured by the measurement sensor unit 1, the load cell 3, and the GPS module 4 and outputs the data to the monitor unit 2. ),
The electrode part 11 includes a fastening assembly 111 having an inverted triangle shape fastened to the lower end of the measurement sensor part 1, two electrodes 112 formed at predetermined intervals on the fastening assembly 111, and Portable soil physical property measuring device, characterized in that consisting of the insulator 113 is assembled integrally while dividing the electrode (112). delete The display unit (2) according to claim 1, wherein the monitor unit (2) includes a display (21) for displaying various data output by the control unit (6), a power button (22) for turning the power on / off, and a button once pressed. When the mode screen is displayed and pressed again, the mode change button 23 returns to the main measurement screen, the measurement and selection button 24 used to select a function setting on the measurement and mode screen of the measurement sensor unit 1, and the mode. Portable soil physical properties measuring device comprising a setting change button 25 used to change the function settings on the screen. The method of claim 3, wherein the mode change button 23 is a measuring channel function for selecting the type of soil, a channel detail adjustment function for zeroing the moisture content value, and a real-time storage function for storing data measured in the field. And, the average number setting function to set the average number in the real-time storage function, the storage folder selection function to select the storage folder to distinguish the measurement data, the graph view function to view the average value data stored by the real-time storage function, the sensor Portable soil physical property measuring device comprising a numerical correction function for correcting the measured value. The portable soil physical measurement apparatus according to claim 1, wherein the monitor unit (2) has an infrared sensor (7) built in to measure the measurement depth of the soil. The portable soil physics according to claim 1, wherein the one handle 5a is provided with a USB connector 51 for storing measurement data, and the other handle 5b is provided with a battery charging connector 52. Sex measuring device. The portable soil physical measurement apparatus according to claim 1, wherein a temperature sensor (8) is installed at one side of the measurement sensor unit (1) to detect a temperature in the soil.

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