KR100295693B1 - One-touch type spectrophotometer for analyzing component of soil - Google Patents

Abstract

PURPOSE: Provided is an one touch typed spectrometer for analysing soil to measure of an extinction ratio of soil leachate and calculate or output ingredients automatically by equipping an operating button corresponding to each substance on a keypad. CONSTITUTION: The one touch typed spectrometer comprises: a cell transfer unit for transferring a cell containing soil leachate to a measurement site; an optical system irradiating light to the cell and detecting penetrated light into an electric signal; a spectrum unit for selecting wavelength of light to be irradiated, and a control unit.

Description

One-touch spectrophotometer for soil analysis {ONE-TOUCH TYPE SPECTROPHOTOMETER FOR ANALYZING COMPONENT OF SOIL}

The present invention is a spectrophotometer used for analyzing soil components for fertilization, in particular, has a keypad on which operation buttons corresponding to the soil components are arranged, and one-touch of each operation button. It is a one-touch spectrophotometer for soil analysis that is programmed to automatically analyze soil components according to manipulation.

When growing crops, fertilize them for the purpose of growing them well. When giving fertilizer, it is necessary to select the appropriate fertilizer and adjust the fertilizer according to the amount of plant nutrient content in the soil in the area. For this purpose, organic matter, phosphate, calcium, calcium, magnesium in the soil that serve as nutrients of crops · Prescription application through accurate analysis of each component such as silicic acid should be prioritized.

The conventional soil composition analysis method for application of fertilization is selected by manual manipulation of the maximum absorption wavelength of the soil component to be measured, and by adding a coloring reagent to a standard solution having a known concentration, the absorbance is measured by a spectrophotometer. A standard curve representing the change in concentration with respect to each absorbance is prepared. Next, a color developing reagent is added to a part of the leaching liquor leaching the soil to be analyzed, and the absorbance of the leaching liquor is measured on a spectrophotometer. Then, the measured absorbance of the soil leachate is converted to the concentration of the constituents in the leachate using the above-prepared standard curve, and the component content of the soil is calculated manually from the converted concentration by inverting the method used for leaching the soil. do. By repeating this process every component, the soil composition can be analyzed.

Conventional spectrophotometers used in the prior art are measured by irradiating a single beam on the structure of the optical system and sequentially exposing the prepared reference solution together with the sample solution to the single beam, and are separated from the light source and are separated from each other. The double beams irradiated with the NSA can simultaneously measure the sample solution and the reference solution. One of the major disadvantages of the optical system using a single beam is that it is impossible to measure the reference solution and the sample solution at the same time, and thus there is a time gap. During this time, the measurement condition of the reference solution is changed due to the changing ambient light. As the measurement conditions of the sample solution and the solution do not exactly match, the degree of absorbance measured is lowered due to the situational error that may be caused by the temporal gap. Therefore, the conventional soil analysis using a single beam spectrophotometer has a disadvantage of low reliability of the analysis results.

The spectrophotometer with a double beam does not have a problem of a situational error that may occur in the above-described time gap, but the cost burden such as the use of a high power light source due to the large amount of optical components and particularly low light efficiency. Is holding.

Meanwhile, in order to measure the absorbance of various components of soil, it is necessary to irradiate monochromatic light of different wavelengths so as to have the maximum absorption point for each component to be measured. And a spectrometer for spectroscopy monochromatic light wavelength corresponding to each component.

However, in the conventional spectrophotometer used in the prior art, such a spectrometer is manually operated according to the soil component to be measured, which is very difficult to handle and manipulate. This is because optical adjustment such as spectral wavelength is not properly performed. It is a factor that further lowers the reliability. In addition, the conventionally used spectrophotometer can measure only the absorbance of the soil components, and specifically does not have an algorithm for calculating the content of each component. Therefore, since the standard curve as described above must be prepared separately, it takes a lot of reagents and time to prepare the standard curve. In addition, only a trained expert in the method of operating the spectrophotometer was possible because the complex manual operation and the complicated calculations were required when operating the spectrophotometer. The complexity is likely to cause errors.

Therefore, the first object of the present invention is to measure the absorbance of the soil leachate by automatically selecting the wavelength having the maximum absorption point for each component such as organic matter, phosphoric acid, calcium, calcium, magnesium, silicic acid, etc. of the soil leachate by one touch operation. To provide a one-touch spectrophotometer for soil analysis.

In addition, the second object of the present invention is to eliminate the need to prepare a separate standard curve for the analysis of the soil composition, the absorbance of each component such as organic matter, phosphoric acid, calcium, calcium, magnesium, silicic acid, etc. It is to provide a one-touch spectrophotometer for soil analysis equipped with a ROM with a program that calculates the content from the standard curve data of each component and the absorbance so as to automatically analyze the content by the measured content.

1 is a perspective view showing a one-touch spectrophotometer for soil analysis according to the present invention with a peripheral device.

2 is a system block diagram of a one-touch spectrophotometer for soil analysis according to the present invention.

Figure 3 is an optical system profile of the one-touch spectrophotometer for soil analysis according to the present invention.

Figure 4 is a perspective view showing a diffraction grating driving mechanism of the spectroscopic portion constituting the one-touch spectrophotometer for soil analysis according to the present invention.

Figure 5 is a perspective view showing a cell and a transport mechanism for receiving the reference solution and the sample solution of the soil components respectively introduced into the soil analysis one-touch spectrophotometer according to the present invention.

Figure 6a is a schematic view showing the main portion showing the dark value measurement state of the one-touch spectrophotometer for soil analysis according to the present invention.

Figure 6b is a schematic view of the main part showing a reference value measurement state of the soil analysis one-touch spectrophotometer according to the invention.

Figure 6c is a schematic view of the main part showing a sample value measurement state of the soil analysis one-touch spectrophotometer according to the present invention.

Figure 7 is a flow chart of the operation of the one-touch spectrophotometer for soil analysis according to the present invention.

Figure 8a is a graph showing the change in the content of the absorbance of the organic component as a standard curve used in soil analysis one-touch spectrophotometer according to the present invention.

Figure 8b is a graph showing the change in concentration for the absorbance of the phosphoric acid component as a standard curve used in the soil analysis one-touch spectrophotometer according to the present invention.

Figure 8c is a graph showing the concentration change for the absorbance of the Kali component as a standard curve used in the soil analysis one-touch spectrophotometer according to the present invention.

Figure 8d is a graph showing the change in concentration of the absorbance of the calcium component as a standard curve used in the soil analysis one-touch spectrophotometer according to the present invention.

Figure 8e is a graph showing the concentration change for the absorbance of the magnesium component as a standard curve used in the soil analysis one-touch spectrophotometer according to the present invention.

Figure 8f is a graph showing the concentration change of the absorbance of the silicic acid component as a standard curve used in the soil analysis one-touch spectrophotometer according to the present invention.

Explanation of symbols on the main parts of the drawings

1: Spectrophotometer 10: Optical system

20: system control unit 31, 32: lamp

33: broadband filter 41: condensing lens

44,59: Shutter 45: diffraction grating

51; 51R, 51S: cell 52: cell housing

In order to achieve the first object described above, the present invention is equipped with a control button corresponding to each component of the organic matter, phosphoric acid, calcium, calcium, magnesium, silicic acid, etc. of the soil to be measured on the keypad of the spectrophotometer. When the button is pressed, the internal optical system is provided with control means for automatically selecting a wavelength given according to the component corresponding to the pressed button and measuring the absorbance of the soil leachate injected at the selected wavelength.

In addition, in achieving the second object, the absorbance is measured by varying the concentration of each component such as organic matter, phosphoric acid, calcium, calcium, magnesium, and silicic acid in the soil using a standard material known in advance. The standard curve representing the change of concentration for each component is prepared, and the standard curve data and the calculated data using the standard curve from the absorbance of the measured soil leachate are calculated in the ROM, and the data are calculated. By measuring the absorbance of the soil leachate by the control means, the calculation to calculate the concentration and content from the measured absorbance is automatically programmed.

According to the present invention, a spectrophotometer includes a keypad input means in which operation buttons corresponding to each component of soil are arranged, and a cell transfer capable of selectively transferring the cells to a measurement position by mounting cells containing the leachate of the soil. Means, a measuring optical system for irradiating light to a transported cell located at a measuring position and detecting the transmitted light as an electrical signal, spectroscopic means for spectroscopy for selecting a wavelength of light irradiated to the cell, at least each component of the soil Has a ROM storing data information for selecting a wavelength corresponding to the control unit, and has control means for controlling the absorbance after selecting the wavelength by driving the spectroscopic means according to the operation of the operation button.

Herein, the control means embeds the above-described standard curve data prepared in the ROM, calculates the concentration of components in the leaching liquid from the measured absorbance of the soil leaching liquid using the built-in standard curve, and calculates the calculated concentration as a content. Can be.

Hereinafter, a preferred embodiment of a one-touch spectrophotometer for soil analysis according to the present invention will be described with reference to the drawings.

1 shows a peripheral device together with a spectrophotometer for soil analysis according to the present invention. As shown, the spectrophotometer 1 according to the present invention has a display unit 2 for displaying an operation state and an analysis result, etc. on one side of the front surface of the outer body, and a keypad 3 for key input by a user. The keypad 3 is arranged with operation buttons corresponding to each component such as organic matter, phosphoric acid, calcium, calcium, magnesium and silicic acid in the soil. In addition, although not shown in the figure has a communication port on the rear of the external body can be connected via a cable to exchange data with external systems such as a personal computer (6) and the printer (7). Reference numeral 4 is an inlet for injecting the cells containing the soil leaching solution and the reference solution, and 5 is a cover for opening and closing the inlet 4.

2, the spectrophotometer according to the present invention comprises a measuring optical system 10 and a system control unit 20. In addition, the measurement optical system 10 includes a light source unit 11, a spectroscopic unit 12, a sample unit 13, and a detector unit 14, and the sample unit 13 between the spectroscopic unit 12 and the detector unit 14 is provided. Sample cells introduced through the inlet 4 shown in FIG. 1 described above are selectively positioned automatically. The system control unit 20 includes a key input unit 21 for receiving an input by the user's selection operation from the above-described keypad, and an optical system 10 including setting operating conditions of the system according to the contents input from the key input unit 21. A central processing unit 22 which controls actuators in each part of the control unit and performs a control and calculation algorithm for calculating absorbance and soil content based on the electrical signal detected by the detection unit 14, the central processing unit ( 22) an interface 23 for connecting each part of the optical system 10, an amplifier 24 for amplifying the electric signal detected by the detector 14 of the optical system 10, and an analog value of the amplified signal. The conversion unit 25 converts the value to the central processing unit 22 and transmits the data table to be referred to by the central processing unit 22 and the read-only memory and the random-acces memory which store the processed values. Storage unit (26) And a display unit 27 for displaying the system operation state processed by the central processing unit 22, output data, and the like, and peripheral devices such as the personal computer 6 and the printer 7 described above.

Here, the ROM constituting the storage unit 26 is absorbed by the spectroscopic unit 12 of the optical system 10 described above according to the component according to the present invention in accordance with the one-touch operation of the operation button corresponding to each component of the soil according to the present invention. Waveform data, previously prepared standard curve data, and calculation data for sequentially calculating absorbance, concentration and content based on signals detected by the measuring optical system are included.

Referring to FIG. 3, the light source unit 11 includes a visible light lamp 31 that emits light in a visible light region and an ultraviolet light lamp 32 that emits light in an ultraviolet region as a light source, and the visible light lamp 31 and the ultraviolet light. With the lamps 32 all lit up, the broadband filter 33 and the light directed to the spectroscope 12 allow the light of one lamp to be directed to the spectroscope 12 and the light of the other lamp can be blocked. The concave mirror 34 which reflects may be arrange | positioned. Since the two lamps 31 and 32 require a delay time such as preheating when the lamp is turned on, it is preferable that both lamps 31 and 32 be turned on when the power is applied to the set so that the time is not delayed when selecting the spectral wavelength. The broadband filter 33 is operated by an actuator (not shown), and the actuator is automatically controlled by the system controller described above according to the spectral wavelength region.

The spectroscope 12 receives the light of the broadband wavelength from the light source unit 11 and spectroscope 35 for spectroscopy monochromatic light of a specific wavelength and the concave mirror 36 to adjust the incident and exit path of the light to the spectrometer 35. It is arranged to face each other, and the slit (37, 38) and the reflection mirror (39, 40) having an opening for removing the ambient noise of the incident and emitted light is arranged on both sides.

The condensing lens 41 disposed between the spectroscopic section 12 and the sample section 13 has a spectroscopic section (maximum intensity of light of the portion irradiated to the sample 42 positioned in the sample section 13). 12) arranged to focus monochromatic light incident from it.

The photodetector 14 receives a part of the amount of light transmitted through the sample 42 by the light irradiated to the sample 42 and detects an electric signal indicating the light intensity of the received light. The shutter 44 capable of blocking the light reaching the detector 43 may be disposed. The shutter 44 is operated to block light or transmit light as it is by an actuator (not shown), and the actuator is automatically controlled by the system controller described above.

Fig. 4 shows a spectrometer as a spectroscopic means for driving a spectroscope in the spectroscopic section of the optical system to spectroscopic monochromatic light of a desired wavelength, and a driving mechanism thereof. As a spectrometer, a diffraction grating 45 is used to diffract incident light according to its incidence angle to spectroscopic monochromatic light of different wavelengths, and to be supported to be rotated by supporting the diffraction grating 45 to rotate it at a desired angle. Linear gear 46, worm 47 engaged with linear gear 46, large gear 48 coupled coaxially with worm 47, small gear 49 engaged with large gear 48, and small diameter It consists of a motor 50 for driving the gear 49. Here, the motor 50 is automatically controlled to rotate the diffraction grating 45 at a predetermined angle according to the spectral wavelength by the system controller described above.

5 shows a cell and a cell transfer mechanism for placing a sample in the sample portion of the optical system described above. The cell 51 is a transparent container through which light can pass, and includes one reference cell 51R for accommodating the above-mentioned reference solution and several sample cells for collecting the sample solutions of soils, respectively. 51S). Although seven sample cells 51S are illustrated in the drawing, more or fewer sample cells 51S may be provided as necessary. The cell transfer mechanism includes a cell housing 52 in which openings 53 are formed to mount the cells 51 at regular intervals and to irradiate light to each mounted cell 51. A fixed mounted carrier 54, a guide rod 55 for slidably penetrating the carrier to guide the linear movement thereof, and a bracket for fixing both ends of the guide rod 55; ), A timing belt (57) hypothesized on an endless track to guide the carrier (54), and a motor (58) for driving the timing belt (57). Here, the motor 58 is automatically controlled to transfer one of the cells 51 to the sample position in the sample portion of the optical system according to the sample number by the system controller described above.

6A to 6C show a preferred form of the shutter provided between the detection unit and the sample unit. The illustrated shutter 59 is composed of a blocking part 60 which is processed to block light absorption as a part shaded in the figure, and a transmitting part 61 which becomes the remaining part. Although not shown, the disc-shaped shutter 59 is intermittently rotated by a predetermined angle by a rotary actuator such as a motor to block or transmit light as shown. For reference, FIG. 6A illustrates a dark measurement state in which light is blocked by the blocking unit 60 of the shutter 59 to the photodetector 53, and FIGS. 6B and 6C illustrate a reference solution measurement state and a sample, respectively. The solution measurement status is shown.

Hereinafter, the operation of the spectrophotometer according to the present invention will be described with reference to FIG. 7.

First, as a preparation step, the reference cell and the sample cell described above are attached to the cell transfer mechanism in the spectrophotometer, and the sample number (i = 1, 2, ..., n), which is the cell information, and the operating conditions of the set are set in the setting mode. Leave it. When one of the operation buttons corresponding to each component on the keypad is touched by the user in this prepared state (step S1), the wavelength of the spectroscope is driven by the built-in program to select the wavelength (step S2), and the measurement is performed. The optical system is driven and measured (steps S3 to S5). In the measurement, first, the dark value Di is measured while the light is blocked by driving the above-described shutter (step S3), and the reference cell and the sample cell are placed in sequence to determine the reference value Ri and the sample value Si. Each measurement is made (steps S4 and S5). The measured values at each step are stored in memory. When the measurement of the last sample is completed by repeating these measurement steps (step S6), the absorbance and concentration and content for each sample are calculated based on the measured values (step S7), and the calculated analysis data is output. (Step S8).

The maximum absorption wavelength corresponding to each component of the soil referred to in the wavelength selection step is shown in Table 1.

ingredient Absorption wavelength (nm) Available wavelengths (nm) Organic matter 590 500-720 Phosphoric Acid 720 420-720 Carly 690 Visible light calcium 540 450-690 magnesium 520 400-600 Silicic acid 460 400-570

The measurement wavelength used in the spectrophotometer of the present invention was set based on the maximum absorption wavelength. However, since measurable absorption occurs in the available wavelength band other than the maximum absorption wavelength presented in the present invention, it can be arbitrarily modified and programmed in the spectrophotometer of the present invention and stored in the ROM.

In the selection of the wavelength, the above-mentioned diffraction grating 45 is initialized and a standard material which is generally known is used to properly calibrate the angle of the diffraction grating so that the characteristics of the wavelength change according to the characteristics of the standard material. In the method of subtracting the wavelength of the component to be measured by one-touch operation, the predetermined wavelength may be selected by rotating the diffraction grating 45 at an angle of the following equation.

Where Δθ is the angle of the diffraction grating to be moved at the initial spectral angle, m is a constant representing the diffraction order, λ ₁ is the initial wavelength (fixed at 600 nm), λ ₂ is the wavelength to be searched, and d is the grating of the diffraction grating. A constant representing the interval, A is a constant given by (α-β) / 2 (where α is an incident angle and β is an exit angle).

Equation 1 is a function of λ ₂ alone, and this function is built in the ROM so that when the above-described component to be measured is one-touched on the keypad, the angle to be moved is determined by the operation of Equation 1 of the ROM having the λ ₂ value embedded therein. In order to rotate this angle, the spectrometer motor can be controlled electronically to select the measurement wavelength.

Next, the process of calculating the absorbance and concentration and content of the soil leachate will be described in detail.

First, the dark value Di, the reference value Ri, and the sample value Si, which are detected in the measuring step, for calculating the absorbance are converted into an electric signal by the intensity of light passing through the sample, and then the transmittances as shown in Equation 2 are used. After obtaining Ti (T), the absorbance Xi (A) may be calculated by a conventional method.

The dark value Di detected in the state in which the sample is blocked in Equation 2 is for removing the situational error that may be caused by the temporal gap as described in connection with the above-described prior art, and the reference value Ri is a change in the ambient illuminance. In response.

The absorbance Xi calculated in this way can be stored in an array and then the component concentration in the leachate of the sample can be calculated by substituting the absorbance stored in each array element into a standard curve already stored. A general standard curve embedded in the spectrophotometer of the present invention is defined as in Equation 3.

Yi is the concentration of each component of the soil, Xi is the absorbance, a is the slope of the standard curve, b is a constant.

Equation 3 is a first-order function that shows the change in concentration versus absorbance, and the slopes a and constant b use a standard material whose concentration is known in advance, and change the wavelength in the spectrophotometer according to the concentration of the standard material. Obtained through

8A to 8G show graphs measured to obtain a standard curve for each component such as organic matter, phosphoric acid, calcium, calcium, magnesium, and silicic acid in soil, and as a result, the standard curve of Equation 2 to be stored in the ROM is shown. The data could be summarized as shown in Table 2 for each component.

Yi a b Organic matter content 13.869 0.0000 Phosphoric Acid Concentration (mg / L) 7.665 0.0000 Kali concentration (mg / L) 166.500 0.0000 Calcium Concentration (mg / L) 74.029 0.0000 Magnesium Concentration (mg / L) 73.019 0.2135 Silicic acid concentration (mg / L) 21.971 0.0000

That is, the concentration (or content) of the leachate can be calculated by substituting the absorbance of the soil leachate sample into the standard curve based on Equation (3).

Next, the method of calculating the concentration as the content of the soil is as follows.

In order to calculate the concentration of the sample by applying the absorbance of the sample to the standard curve, it can be calculated according to the soil leaching pretreatment method before measuring with the spectrophotometer. That is, the soil leaching method undergoes a pretreatment process in which a soil leaching solution is added to an appropriate amount of soil to leach the above-mentioned components and dilute to an appropriate concentration for measurement by the spectrophotometer of the present invention. It is possible to calculate the content of soil by multiplying the reciprocal and the dilution factor. The equation that is generally defined to calculate the content in the soil is the following equation (4).

Where Ci is the component content in the soil, Yi is the component concentration calculated according to the standard curve, V is the amount of leachate added during the pretreatment, g is the weight of the soil sample, d is the dilution factor, and D is the unit. The conversion factor, and f is the calculation correction factor.

When the calculation method is analyzed using the soil analysis method, it can be arbitrarily modified according to the analysis conditions. In the present invention, the equation (4) is defined as shown in the following equation (5) according to each component to be calculated.

Here, 1 / M is calculated using the weight of 1 gram equivalent (milliequivalent) of kali calcium magnesium

(Cal) = 1 / 3.91

(Calcium) = 1 / 2.004

(Magnesium) = 1 / 1.216.

The following Table 3 is actually taking five soil samples to leach the soil in accordance with the soil analysis method and by the one-touch operation of the spectrophotometer according to the present invention to obtain the content of organic matter, phosphoric acid, calcium, calcium, magnesium, silicic acid, etc. The result is shown in comparison with the conventional method (comparative example). The measurement wavelength was 590 nm, effective phosphoric acid 720 nm, kali 690 nm, calcium 540 nm, magnesium 520 nm and silicic acid 460 nm to automatically select the measurement wavelength by one-touch operation, and the graphs shown in FIGS. 8A to 8F The concentration was calculated based on the standard curve of Equation 3 given by Equation 3, and then analyzed by the content according to Equation 5 and outputted.

sample Method Organic matter content () Effective Phosphate Content (mg / kg) Substituted Cationic (cmol / kg) Silicic acid content (mg / kg) Carly calcium magnesium Soil 1 Comparative example 2.31 231.3 0.56 3.27 1.11 78.5 Example 2.32 230.2 0.56 3.27 1.09 78.3 Soil 2 Comparative example 0.17 112.8 1.15 3.26 0.78 132.3 Example 0.17 112.7 1.14 3.24 0.79 132.0 Soil 3 Comparative example 0.56 782.3 1.23 2.18 2.06 99.8 Example 0.55 780.9 1.23 2.16 2.01 100.0 Soil 4 Comparative example 3.26 1,231.2 0.78 7.15 3.83 125.0 Example 3.28 1,230.9 0.75 7.10 3.85 125.6 Soil 5 Comparative example 5.72 562.5 2.04 6.34 1.56 114.3 Example 5.70 562.5 2.03 6.38 1.56 113.9 Soil 6 Comparative example 7.82 987.5 4.83 9.23 0.56 152.6 Example 7.84 986.3 4.86 9.20 0.53 152.9

As described above, in the construction of the spectrophotometer, an operation button corresponding to a component such as organic matter, phosphate, calcium, calcium, magnesium, and silicic acid of the soil is provided on the keypad, and the component content is measured from the absorbance measurement of the soil leachate. All processing operations, including operation to the output and output, are automatically performed by the one-touch operation method.

According to the present invention, the inconvenience of manually manipulating the device when analyzing soil using a conventional general spectrophotometer is improved. In addition, it is not necessary to prepare a standard curve separately for calculating the absorbance measured by the spectrophotometer in terms of concentration and content, and also does not have to perform complicated calculations, which significantly reduces time and reduces reagent usage. In addition, it is possible to provide accurate analytical results by spectroscopicly measuring the wavelength of measurement and improving the measurement environment, thereby increasing the efficiency of soil management.

Claims (4)

Keypad input means arranged with operation buttons corresponding to each component of the soil, cell transfer means for mounting the cells containing the leachate of the soil to selectively transfer the cells to the measurement position, the transferred cell located at the measurement position A measuring optical system that irradiates light with and detects the transmitted light as an electrical signal, spectroscopic means for selecting a wavelength of light irradiated to a cell, data information for selecting a wavelength corresponding to at least each component of soil One-touch spectrophotometer for soil analysis, characterized in that it has a ROM that stores the control means for controlling the absorbance after selecting the wavelength by driving the spectroscopic means according to the one-touch operation of the operation button. The method of claim 1, wherein the control means has a ROM containing a standard curve data indicating a change in concentration of the absorbance for each component of the soil leachate, and the measured absorbance of the soil leachate is substituted into the standard curve One-touch spectrophotometer for soil analysis, characterized in that it is programmed to calculate the component concentration. The one-touch spectrophotometer for soil analysis according to claim 2, wherein the control means is programmed to analyze the calculated component concentration as a component content of the soil. The soil analysis one-touch spectrophotometer according to any one of claims 1 to 3, wherein said control means further comprises a communication port connectable for data communication with an external system.