JP2010000010A - Apparatus for evaluating carbon dioxide absorption or emission function of plant - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a simple and compact apparatus for evaluating carbon dioxide absorption or emission function of plants, which can carry out highly-accurate evaluation of the function to absorb or emit carbon dioxide via plant photosynthesis. <P>SOLUTION: The apparatus comprises a chamber 2 into which atmospheric air is induced and in which plants are housed, a light source part 3 irradiating light to the plants, a light-intensity adjustment part 4 adjusting the light intensity of the light source part, a background carbon dioxide concentration measurement part 5 measuring the carbon dioxide concentration in the atmospheric air under set conditions and a chamber carbon dioxide concentration measurement part 5 measuring the carbon dioxide concentration in gas led out from the chamber. The light intensity adjustment part 4 adjusts the light intensity of the light source part 3 so as to change in the measured value by the chamber carbon dioxide concentration measurement part 5 from the background carbon dioxide concentration measurement part, based on the measured value by the background carbon dioxide concentration measurement part 5. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an apparatus for evaluating a carbon dioxide absorption or emission function of a plant, and relates to an apparatus for evaluating a carbon dioxide absorption or emission function by photosynthesis of a plant in a natural environment.

  In recent years, one of the major improvements in the global environment has been the prevention of global warming, specifically the reduction of greenhouse gases, and the absorption of carbon dioxide by plant photosynthesis is one of the methods for reducing such greenhouse gases. It is considered as one. Therefore, in order to clarify the process of carbon dioxide absorption by plant photosynthesis in the natural environment, various attempts have been made to simulate the natural environment and analyze the mechanism of carbon dioxide absorption by actual plant photosynthesis. Has been made.

  For example, as shown in FIG. 5, a photosynthesis measurement method using a closed assimilation box has been proposed. That is, in a method of measuring the photosynthetic rate by changing the carbon dioxide concentration with time while putting the plant 52 to be measured in the assimilation box 51 constituting the air circulation path and circulating the air in the assimilation box 51, the assimilation box 51. Although the airtightness of 51 is high but not completely airtight, the ventilation rate is measured in a state where the plant 52 is not inserted, and the change in the carbon dioxide concentration measured after the passage of a predetermined time after the plant 52 is inserted The photosynthesis rate can be calculated from the amount excluding the change in the carbon dioxide concentration due to (see, for example, Patent Document 1).

JP 08-172913 A

However, the conventional method has some problems shown below.
(I) When a test is performed by supplying air to the plant chamber, a comparison between the concentration of carbon dioxide in the supplied air and the concentration of carbon dioxide at the outlet of the plant chamber indicates that accurate photosynthesis in the natural environment is evaluated. There are things that cannot be done. In other words, plants generally generate carbon dioxide by maintaining the biological functions of plants at the same time as absorption of carbon dioxide through photosynthesis. The mechanism of absorption cannot be analyzed.
(Ii) In addition, in the natural environment, the external light changes greatly, the fluctuation of carbon dioxide absorption due to photosynthesis accompanying the change is large, and the mechanism of carbon dioxide absorption by accurate plant photosynthesis is analyzed. Is difficult.
(Iii) Furthermore, the mechanism of carbon dioxide absorption by plant photosynthesis varies greatly in the surrounding natural environment as well as the type and growth conditions of the plant, so it is easy to evaluate the carbon dioxide absorption function in the field. It is indispensable to use a device that can respond to the request, and no device that can meet these requirements has been realized. In particular, there has been a strong demand for such devices in research and school education in the natural environment.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an apparatus capable of evaluating the absorption or emission function of carbon dioxide by photosynthesis of plants with high accuracy in a natural environment.

  As a result of intensive studies, the present inventor has found that the above-described object can be achieved by an apparatus for evaluating the carbon dioxide absorption or discharge function of plants described below, and has completed the present invention.

  That is, the evaluation apparatus for carbon dioxide absorption or emission function of a plant according to the present invention includes a chamber in which air is introduced and the plant is accommodated therein, a light source unit that irradiates light to the plant, and a light amount of the light source unit. A light intensity adjusting unit to adjust, a background carbon dioxide concentration measuring unit for measuring the carbon dioxide concentration in the atmosphere under installed conditions, and a chamber carbon dioxide concentration for measuring the carbon dioxide concentration in the gas derived from the chamber A measurement unit, and the light amount adjustment unit is configured to change the measurement value of the chamber carbon dioxide concentration measurement unit from the measurement value based on the measurement value of the background carbon dioxide concentration measurement unit. It is characterized by adjusting the amount of light.

  A simple and compact evaluation device with such a configuration or function makes it possible to easily grasp the amount of change in carbon dioxide concentration due to photosynthesis in a natural environment, that is, the absorption or emission function of carbon dioxide quantitatively. . Further, the present invention can be applied to any plant, and can provide a highly accurate evaluation apparatus or evaluation method for the photosynthesis carbon dioxide absorption or emission function of plants. Here, “atmosphere” means “atmosphere” of the ambient environment atmosphere where the evaluation apparatus is installed.

  In other words, an evaluation device having a very simple configuration such as a test chamber (chamber), a light source unit, a carbon dioxide concentration measurement unit, or an evaluation method operated based on such a function is used, and the atmosphere is a natural environment where the atmosphere is an environmental atmosphere. Accurately measure the absorption or emission function of plants in natural environment by increasing the amount of light (hereinafter referred to as “shift light amount”) in a step-like manner based on the balance of plant carbon dioxide exchange in Japan It became possible. In addition, stable and objective quantitative evaluation can be performed by irradiating light from a controlled light source unit by eliminating the influence of external light in a natural environment.

  The present invention is an apparatus for evaluating the carbon dioxide absorption or emission function of the plant, wherein the light amount adjustment unit has a measurement value of the background carbon dioxide concentration measurement unit and a measurement value of the chamber carbon dioxide concentration measurement unit approximately The light source unit is adjusted to a first light amount so as to match, and then the light source unit is adjusted to a second light amount so as to change a measurement value of the chamber carbon dioxide concentration measuring unit. Carbon dioxide absorption means a metabolic function for a living plant, and the plant's metabolic function is determined from the amount of light irradiated to the plant so that the background carbon dioxide concentration matches the chamber carbon dioxide concentration. It is also possible to grasp the mechanism.

  Further, the present invention is an apparatus for evaluating the carbon dioxide absorption or discharge function of the plant, wherein the second light amount is adjusted with a light amount equal to or greater than a condition that does not cause fluctuations in the measurement value of the chamber carbon dioxide concentration measuring unit. It is characterized by doing. “The amount of light exceeding the condition that the measurement value of the chamber carbon dioxide concentration measurement unit does not fluctuate” refers to the amount of light above the light saturation point (the light intensity at which the photosynthesis speed is maximized), for example.

The present invention is an evaluation method of the carbon dioxide absorption or emission function of the plant, comprising a display unit for displaying a measurement value in the chamber carbon dioxide concentration measurement unit,
The display unit may change a displayable carbon dioxide concentration range based on a measurement value of the background carbon dioxide concentration measurement unit or a measurement value of the chamber carbon dioxide concentration measurement unit.

  The present invention relates to a method for evaluating the absorption or emission function of carbon dioxide in the plant, wherein the atmosphere under installed conditions is introduced and connected to the chamber, and carbon dioxide is absorbed or emitted by the plant. A first flow path for deriving gas, a second flow path for introducing air under the installed conditions, a flow path switching unit connected to the first and second flow paths, and a connection to the switching unit And a single carbon dioxide concentration measuring unit in which the background carbon dioxide concentration measuring unit and the chamber carbon dioxide concentration measuring unit are integrated.

  As described above, according to the evaluation apparatus for carbon dioxide absorption or emission function according to the present invention, evaluation of carbon dioxide absorption or emission function by plant photosynthesis is simple, compact and highly accurate in a natural environment. be able to. In addition, it is possible to provide an apparatus that secures a display function that is required in school education and the like to easily grasp a visual change.

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

<Whole structure of the evaluation apparatus of the carbon dioxide absorption or discharge | emission function of the plant based on this invention>
FIG. 1 shows a configuration example of a plant carbon dioxide absorption or discharge function evaluation apparatus (hereinafter referred to as “the present apparatus”) according to the present invention. This apparatus adjusts the light quantity of the light source part 3, the light source part 3 which irradiates light to the plant 1 which feeds air | atmosphere, the test chamber 2 which can seal the plant T which performs photosynthesis inside, and light A light amount adjusting unit 4, a flow path L2 for introducing a part of the atmosphere into the test chamber 2, and a CO ₂ analyzer for measuring the carbon dioxide concentration Da in the atmosphere and the carbon dioxide concentration Ds in the test chamber outlet gas ( Equivalent to a carbon dioxide concentration measuring unit) 5, a control calculation processing unit 6 that controls these and performs processing such as calculation of the output of the CO ₂ analyzer 5, and a display unit 7 that displays the carbon dioxide concentration and the like.

The atmosphere is collected by pumps P1 and P2 (constituting means 1 for supplying the atmosphere) through the primary filter F1. The air sucked by the pump P2 is introduced into the test chamber 2 in the flow path L2, and the flow rate thereof is adjusted by the control valve NV2 disposed downstream thereof, and is detected by the flow meter M2 and switched. It is introduced into the CO ₂ analyzer 5 via the valve SV2. The inside of the test chamber 2 is hermetically filled with the plant T, and photosynthesis is performed by light emitted from the light source unit 3 disposed around the plant T to absorb carbon dioxide. On the other hand, the air sucked by the pump P1 is introduced into the CO ₂ analyzer 5 through the control valve NV1, the flow meter M1, and the switching valve SV1 in the flow path L1. Upstream of the CO ₂ analyzer 5, a gas-liquid separation tank 8 and a secondary filter F 2 for dust removal are disposed.

  Here, the plant T can target various plants such as trees, flowers, or lichens such as moss that can be arranged in the test chamber 2. In Examples to be described later, flowers such as summer dress and pentath were targeted.

  The test chamber 2 is preferably sealed in order to install the plant T for photosynthesis and to vent the atmosphere, and to eliminate external influences during the test period. The test chamber 2 can arbitrarily set the size, shape, wind speed, installation condition of the plant T, etc., depending on the type and shape of the plant T. Moreover, although it is preferable to set it as the same temperature as natural environment, in order to eliminate the influence of an external temperature change, it is preferable to arrange | position in the thermostat for the test temperature-controlled in the range of 4-50 degreeC, for example. . Furthermore, in order to make the conditions approximate to natural light, a configuration in which one surface of the test chamber 2 is covered with the light source unit 3 so that the light from the light source unit 3 is uniformly irradiated to the plant from a specific direction is preferable.

  The light source unit 3 is composed of an element capable of variably irradiating photons having wavelengths necessary for photosynthesis and chlorophyll activation in sunlight. Specifically, it is preferable to use white fluorescent lamps or light emitting diodes (LEDs) that include light in the wavelength range of 400 to 700 nm. It is preferable to produce. The selectivity of the wavelength range of the light source unit 3 can be ensured by using an element such as a red LED, a blue LED, or a white LED, for example, when it can be selected depending on the characteristics of the white fluorescent lamp or LED. Therefore, in the evaluation test, it is possible to adopt a method of changing the wavelength by preparing elements in a plurality of wavelength regions and replacing them appropriately. When the selectivity cannot be ensured with such an element, the selectivity can be ensured by using an optical filter that transmits a desired wavelength range for the light source unit 3. Therefore, in the evaluation test, it is possible to adopt a method of changing the wavelength by preparing optical filters in a plurality of wavelength regions and replacing them appropriately.

The light intensity is preferably a photosynthesis effective photon flux density (PPFD) of 0 to 500 [μmol / m ² · sec] in the wavelength range of 400 to 700 nm, and the applied voltage is controlled in the evaluation test. The method of changing the light quantity can be taken. The light amount adjusting unit 4 may be, for example, a CPU that controls the applied voltage, or a converter that converts a signal from a dial-type knob that instructs to increase or decrease the light amount into a voltage control signal. Furthermore, the irradiation time of the light source is set to a condition close to the natural environment, such as a method using ON / OFF control by a program, or an acceleration test or a test under conditions different from the natural environment, such as a pulse lighting type white fluorescent lamp or LED. In some cases, it is possible to adopt a method of changing the pulse width (duty). The apparatus preferably has a function of changing the light quantity (shift light quantity) in a step-like manner and a function of increasing or decreasing the shift light quantity corresponding to the carbon dioxide concentration in the atmosphere in response to a command from the control arithmetic processing unit 6. At this time, a light sensor (not shown) can be provided inside the test chamber 2 to monitor the amount of light from the light source unit 3. By adjusting based on the output of such an optical sensor, the amount of light actually irradiated to the plant T can be adjusted.

Since the CO ₂ analyzer 5 is intended to grasp the absorption or emission function of carbon dioxide with high measurement accuracy as described above, a non-dispersive infrared analyzer (NDIR) is used as a high-precision measurement unit. It is preferable to use it. In addition, the analyzer is optimal for the present invention as an analyzer capable of continuous measurement with high resolution and fast response. In the NDIR type CO ₂ analyzer 5, the analyzer itself may be affected by the atmosphere (influence of carbon dioxide in the atmosphere mixed into the optical system), and therefore an inert gas (for example, nitrogen It is preferable to perform purging with gas). Specifically, in FIG. 1, purging by introducing a small amount (for example, several mL to several hundred mL / min) of nitrogen gas from the nitrogen gas supply unit 9 into the CO ₂ analyzer 5 through the flow meter M3. Can do.

The control arithmetic processing unit 6 receives information output from the light amount adjustment unit 4, concentration output from the CO ₂ analyzer 5, or information such as temperature and flow rate, and controls the light amount of the light source unit 3 and the switching valves SV1 and SV2. In addition to having the following functions:
(I) The atmospheric carbon dioxide concentration Da measured by the CO ₂ analyzer 5 is compared with the carbon dioxide concentration Ds in the outlet gas of the test chamber 2;
(Ii) adjusting the light amount of the light source unit 3 so that the carbon dioxide concentrations Da and Ds match,
(Iii) Increasing the light amount of the light source unit 3 from the state in which the light amount is adjusted,
(Iv) The amount of carbon dioxide absorbed by the plant T is calculated from the change amount ΔDs of the carbon dioxide concentration in the exit gas of the test chamber 2 caused by the change in the amount of light.

  The control elements are preferably targeted for the atmospheric flow rate, temperature, humidity and carbon dioxide concentration, the wavelength of the light source, the amount of light and the irradiation time, the temperature in the test chamber, the humidity and the wind speed, and the like. Each control element can be used for evaluating the absorption or emission function of carbon dioxide by plant photosynthesis, using each control element as an index. In the present invention, since the control method requires accurate control such as the temperature at a position close to the plant T, it is preferable to perform feedback control based on the measured values of the respective control elements.

  By using this apparatus having the above-described configuration, high-accuracy photosynthesis of the plant T is performed using the carbon dioxide concentration in the atmosphere, the light amount and irradiation time of the light source unit 3, and the temperature and air volume in the test chamber 2 as indices. It becomes possible to evaluate the absorption or emission function of carbon dioxide. The display unit 7 in this apparatus will be described later.

<Evaluation method of absorption or emission function of carbon dioxide by photosynthesis of plants>
Next, a specific method for evaluating the absorption or emission function of carbon dioxide by photosynthesis of plants will be described. In the present invention, as shown in FIG. 2, a method having the following steps is configured. In addition, FIG. 3 illustrates temporal changes in the carbon dioxide concentration Da in the atmosphere and the carbon dioxide concentration Ds in the outlet gas of the test chamber 2 at this time.

(1) Measuring the carbon dioxide concentration Da in the atmosphere First, the air in the natural environment is collected, and the carbon dioxide concentration Da in the atmosphere is measured. This corresponds to FIG. Specifically, in this apparatus, the pump P1 and the switching valve SV1 are activated, and the air sucked from the primary filter F1 is adjusted in flow rate by the control valve NV1 (usually about 1 to 5 L / min), and the flow rate While being detected by the meter M1, it is further cleaned by the tank 8 and the secondary filter F2 through the switching valve SV1, and introduced into the CO ₂ analyzer 5, and the carbon dioxide concentration Da is measured. The measured carbon dioxide concentration Da is stored in memory, and by comparing it with the carbon dioxide concentration Ds in the outlet gas of the test chamber 2, which will be described later, the absorption or emission function of carbon dioxide in the plant can be measured.

(2) Introducing air into the test chamber Next, the air is introduced into the test chamber 2. Specifically, in this apparatus, by starting the pump P2, the air sucked from the primary filter F1 is introduced into the test chamber 2, the flow rate is adjusted by the control valve NV2, and detected by the flow meter M2. And discharged through the switching valve SV2. The flow rate is set in advance from the air volume corresponding to the plant T, and is usually adjusted to about 1 to 5 L / min. At this time, as a test condition, it is possible to select either the case where it is performed while continuously supplying air or the case where the supply is stopped and performed in a completely sealed state, or the switching thereof, but in this apparatus, The former is selected in consideration of the natural environment. At this time, it is preferable to perform purging for a predetermined time in order to remove residual components in the test chamber 2. Further, the internal temperature of the test chamber is set in advance within a test temperature corresponding to the plant T in the natural environment, for example, within a range of 10 to 30 ° C., and the internal temperature of the test chamber 2 is controlled to be the set temperature. To do.

(3) Installation of plant in test chamber Plant T is arranged at a predetermined position in test chamber 2. At this time, it arrange | positions in the state close | similar to the growth conditions in natural environment, such as the direction of the leaf with respect to the light from a light source part, for example. In the case of arranging a plurality of flowers, the same applies to the distance between the flowers. With this installation, a correct evaluation can be obtained.

(4) Irradiating light to a plant The light source unit 3 having a wavelength range corresponding to the plant T is selected in advance, the light amount and the irradiation time are controlled under preset conditions, and the light source unit 3 is activated to irradiate the plant T with light. To do. At this time, it is preferable to use the plurality of light source units 3 so as to irradiate substantially the entire surface of the plant T as in the natural environment. At this time, if an optical sensor is provided in the test chamber 2, the amount of light from the light source unit 3 can be monitored and adjusted based on the output of the optical sensor, and the output of the optical sensor can be adjusted. By memorizing, in the case of a test over a long time, it is possible to confirm a change in the light source unit 3 itself.

(5) Measurement of carbon dioxide concentration Ds in test chamber outlet gas The carbon dioxide concentration Ds in the outlet gas delivered from the test chamber 2 is measured. This corresponds to FIG. When the test is performed while continuously supplying air, the measurement is continuously performed.When the supply is stopped and the test is performed in a completely sealed state, the measurement is performed batchwise. Used as data to evaluate absorption or discharge function. FIG. 3 (3) shows a state in which the light source unit 3 is not operated, that is, a case where there is no irradiation light to the plant T and photosynthesis is not performed, and corresponds to an increased state of carbon dioxide accompanying the generation of carbon dioxide by metabolism of the plant T. To do.

(6) Comparison of Carbon Dioxide Concentrations Da and Ds The atmospheric carbon dioxide concentration Da measured in (1) is compared with the carbon dioxide concentration Ds in the test chamber outlet gas measured in (5). That is, it is a result of the balance between the carbon dioxide absorption or discharge function accompanying the photosynthesis of the plant T at the light amount set in (4) above and the carbon dioxide generating function accompanying metabolism, and this apparatus depends on the target plant T. In evaluating carbon dioxide absorption or emission function, the coincidence point between the two is the starting point.

(7) Adjusting the light amount so that the carbon dioxide concentrations Da and Ds match. Based on the comparison in (6) above, the light amount is adjusted so that the carbon dioxide concentrations Da and Ds match. The amount of light such that the carbon dioxide concentrations Da and Ds coincide with each other is, for example, the amount of light having a light intensity near the light compensation point. However, when purging with air is performed, strict adjustment is not required due to the effect. It can be the amount of light. This corresponds to FIG. Since this is the starting point for the evaluation of the carbon dioxide absorption or emission function by the plant T, the light quantity and the carbon dioxide concentration Ds (= Da) at this time are stored. Further, the adjustment is completed when the change in the carbon dioxide concentration Ds accompanying the adjustment of the light amount is stabilized.

(8) Increasing the amount of light When the carbon dioxide concentration Ds accompanying the adjustment of (6) is stabilized and coincides with the carbon dioxide concentration Da, the amount of light is increased. This corresponds to FIG. The amount of light at this time is memorized because it becomes an evaluation criterion even if there is a change in the evaluation object or a change in the evaluation conditions. The amount of light to be changed can be set based on the following criteria.
(8-1) A relationship with a change amount ΔDs (described later) with respect to a shift light amount in a specific plant T is obtained in advance, and is set to a light amount equal to or greater than a condition (referred to as a maximum change amount ΔDs (max)) that does not cause a change in the change amount ΔDs To do. Using the maximum change amount ΔDs (max) as an index, the maximum absorption or excretion function of each plant can be evaluated as a reference.
(8-2) The shift light amount is set based on the light amount of external light in a natural environment. By setting standards according to geographical conditions, local conditions such as surrounding forests and roads, or seasons, it becomes possible to evaluate according to the individual natural environment.
(8-3) A plant To serving as a reference is set, and the above (8-1) or (8-2) or an arbitrary shift light amount in the plant is set. By setting the shift light amount to a constant value, it is possible to make an evaluation according to the type and growth status of the plant T.
(8-4) In any of the above cases, it is preferable to increase or decrease the shift light amount set corresponding to the carbon dioxide concentration in the atmosphere. The change (increase) in the carbon dioxide concentration in the atmosphere changes (increases) the load of the absorption or discharge function of the plant T at the starting point of the evaluation in (7), and the amount of change (increase) increases. Even if the shift amount is constant, it is difficult to standardize the evaluation standard. Therefore, it is possible to perform an equivalent evaluation by obtaining an optimal shift light amount corresponding to the carbon dioxide concentration in the atmosphere in advance.

(9) Detection of change amount ΔDs of carbon dioxide concentration in test chamber outlet gas After increasing the shift light quantity, the carbon dioxide concentration Ds in the outlet gas delivered from the test chamber 2 is measured and before the shift. The difference from the carbon dioxide concentration Da, that is, the change amount ΔDs is detected. This corresponds to FIG.

(10) Calculation of the amount of carbon dioxide absorbed by the plant from the change amount ΔDs The amount of carbon dioxide absorbed by the plant T is calculated from the change amount ΔDs obtained by the above (9). When the test conditions are (a) when the atmosphere is continuously supplied, the calculation is performed based on the carbon dioxide concentration Da or Ds (= Da) stored in the above (1) or (7). The calculation includes a method for obtaining a difference between the two integral values in the test time, a method for obtaining an integral value of the difference between the two, and the like, and the former method is preferable because a minute change in the amount of carbon dioxide is obtained. In addition, (b) when conducting a test by periodically operating the switching valves SV1 and SV2 in FIG. 1 while continuously supplying air, (b-1) changing the reference value for each operation. (B-2) a method of linearly approximating the change in the operation interval if there is a change in the measured value, and (b-3) a method of obtaining an approximate curve from the carbon dioxide concentration at each operation, As described above, it is possible to calculate the carbon dioxide absorption or discharge function by calculating the difference between the two integrated values. Further, (c) when the supply of air is stopped and the operation is performed in a completely sealed state, the same calculation as in (a) is performed based on the carbon dioxide concentration Da or Ds stored in (1) or (7). This makes it possible to calculate the function of absorbing or discharging carbon dioxide.

  By the above-described method for evaluating the absorption or emission function of carbon dioxide by photosynthesis, the temperature and carbon dioxide concentration of the atmosphere, the wavelength of the light source unit 3, the amount of light and the irradiation time, the temperature and the wind speed in the test chamber 2 are used as indices, It becomes possible to evaluate the absorption or emission function of carbon dioxide by high photosynthesis of the plant T.

<About the display>
The display unit 7 includes a receiving unit (corresponding to receiving means) that receives signals of the carbon dioxide concentrations Da and Ds and their variation ΔDs from the control arithmetic processing unit 6, and is shown in FIG. ), The signals are displayed in correspondence with these signals. Specifically, a switch 7a divided into a plurality of stages corresponding to the output illustrated in FIG. 4A and a concentration display 7b illustrated in FIG. 4B are arranged, and the carbon dioxide concentration set by the switch 7a By turning on the density display 7b of the density range corresponding to Da and the density display 7b of the density range that changes corresponding to the change amount ΔDs accompanying the shift of the light amount, or all the density displays 7b of the density range lower than that, The absolute value and change can be grasped immediately and visually. Alternatively, as illustrated in FIG. 4B, by arranging the concentration display 7b in a code bar shape, it is easier to grasp visually and is suitable as a device for school education or the like.

  At this time, it is preferable that the upper limit value or the lower limit value of the divided concentration range can be freely set. Moreover, it is preferable to set it as the structure which can set an upper limit with the measured value of a background carbon dioxide concentration measurement part. Further, a configuration in which the concentration range can be changed according to the change amount of the carbon dioxide concentration in the chamber is preferable, and a configuration in which the displayed concentration scale can be arbitrarily set to 1 ppm, 2 ppm, 3 ppm, or the like is preferable.

（iii）次に、光量をシフトさせる（例えばパネルの操作スイッチを押す）。試験用チャンバ出口ガス中の二酸化炭素濃度Ｄｓが測定され、その値により、表示部７の濃度範囲の濃度表示７ｂが順次点燈する。 More specific operations can be performed by the following procedure.
(I) When measuring the carbon dioxide concentration Da in the atmosphere, it is confirmed that the indicated value is stable, and the concentration range of the display unit 7 is set based on the value.
(Ii) The switch corresponding to each concentration range compares the carbon dioxide concentration Da with the upper limit value of each switch as shown in Table 1 below, and selects the switch having a stable value> the upper limit value. For example, if the carbon dioxide concentration Da is 408 ppm, the switch No. 3 is selected.

(Iii) Next, the light amount is shifted (for example, an operation switch on the panel is pressed). The carbon dioxide concentration Ds in the test chamber outlet gas is measured, and the concentration display 7b of the concentration range of the display unit 7 is sequentially turned on by the value.

  Here, it is possible to set the density range so as to be sequentially reduced immediately after the light quantity switching. The carbon dioxide absorption or emission function of a plant tends to be a large amount of change initially in response to a step-like change in the amount of light, and the amount of change tends to be gradually reduced. On the other hand, in the display function, it is preferable that the change state of the measured value can be continuously confirmed. This device does not switch the display evenly in response to the amount of change immediately after switching the light amount, but switches the display when the amount of change is large immediately after switching the light amount, and changes after a predetermined time has elapsed after switching the light amount. When the amount is small, the state of change can be accurately grasped by switching the display even if the amount of change is small.

<Example>
Based on the method for evaluating the function of absorption or emission of carbon dioxide by photosynthesis of plants described above, some of the results of actual tests are described.

(1) Test conditions (1-1) Atmospheric conditions: flow rate 1.5 L / min, temperature 20 ° C., carbon dioxide concentration about 400 ppm
(1-2) Conditions of the light source part: red LED (center wavelength: 660 nm), PPFD 102 to 178 [μmol / cm ² · sec], continuous irradiation (1-3) Conditions in the test chamber: flow rate 1.5 L / min , Temperature 20 ° C, carbon dioxide concentration about 400ppm
(1-4) Plant: A flower mixed with summer dress and pentaths (approx. 125mm x 125mm)
(1-5) Measurement of carbon dioxide concentration: Perform the above processes (1) to (10), measure each for about 5 minutes in order to confirm the stability of the instructions accompanying the switching of the flow path and light quantity, and after 5 minutes The data was adopted.

(2) Test results Changes in carbon dioxide concentration at the test chamber outlet As shown in Table 2 below, stable carbon dioxide concentrations were indicated in each flow path. At a test time of about 30 minutes, a change of about 34-40 ppm was seen with respect to the carbon dioxide concentration due to the initial photosynthesis. Each numerical value is the CO ₂ concentration, and the unit is ppm. Each is a measurement result after about 5 minutes of stabilization time. Measured data with good reproducibility is obtained. It has been confirmed that the carbon dioxide concentration in the atmosphere matches the carbon dioxide concentration in the chamber outlet gas before the light amount shift.

  As described above, the present invention can evaluate not only the absorption or emission function of carbon dioxide by photosynthesis of plants but also the evaluation of the growth state of plants. Can also be targeted. Furthermore, by proceeding with the evaluation of the growth state of the plant, it is possible to obtain the optimum production conditions for plants such as plants, and the evaluation results can be used for artificial cultivation, product improvement, and mass production.

Explanatory drawing which shows the structural example of the evaluation apparatus of the absorption or discharge | emission function of the carbon dioxide of the plant which concerns on this invention Explanatory drawing which illustrates the process of the evaluation method of the absorption or discharge | emission function of the carbon dioxide of the plant concerning this invention Explanatory drawing which illustrates the time change of the carbon dioxide concentration in the evaluation method according to the present invention Explanatory drawing which illustrates the display part of the evaluation apparatus which concerns on this invention Explanatory drawing which shows the embodiment of the photosynthesis measuring method based on a prior art

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Means to feed air 2 Test chamber 3 Light source unit 4 Light amount adjustment unit 5 CO ₂ analyzer (carbon dioxide concentration measurement unit)
6 Control arithmetic processing section 7 Display section 8 Tank 9 Purge gas F1 Primary filter F2 Secondary filters L1, L2 Flow paths M1-M3 Flowmeters NV1, NV2 Control valves P1, P2 Pumps SV1, SV2 Switching valve T Plant

Claims (5)

A chamber in which the atmosphere is introduced and houses the plant, a light source unit that irradiates light to the plant, a light amount adjustment unit that adjusts the light amount of the light source unit, and a carbon dioxide concentration in the atmosphere under the installed conditions A background carbon dioxide concentration measuring unit for measuring the carbon dioxide concentration measuring unit for measuring the carbon dioxide concentration in the gas derived from the chamber,
The light amount adjustment unit adjusts the light amount of the light source unit so as to change the measurement value of the chamber carbon dioxide concentration measurement unit from the measurement value based on the measurement value of the background carbon dioxide concentration measurement unit. An apparatus for evaluating the carbon dioxide absorption or emission function of plants.   The light amount adjustment unit adjusts the light source unit to a first light amount so that a measurement value of the background carbon dioxide concentration measurement unit and a measurement value of the chamber carbon dioxide concentration measurement unit substantially coincide, and then the chamber 2. The apparatus for evaluating the function of absorbing or discharging carbon dioxide of a plant according to claim 1, wherein the light source unit is adjusted to the second light quantity so as to change the measurement value of the carbon dioxide concentration measuring unit.   3. The apparatus for evaluating carbon dioxide absorption or discharge according to claim 1, wherein the second light quantity is adjusted with a light quantity that is equal to or greater than a condition that does not cause fluctuations in the measurement value of the chamber carbon dioxide concentration measurement unit. . A display unit for displaying a measurement value in the chamber carbon dioxide concentration measurement unit;
The display unit changes a displayable carbon dioxide concentration range based on a measurement value of the background carbon dioxide concentration measurement unit or a measurement value of the chamber carbon dioxide concentration measurement unit. 4. The apparatus for evaluating carbon dioxide absorption or discharge function of a plant according to any one of 3 above.   A first flow path for introducing the atmosphere under the installed condition and for deriving a gas that is connected to the chamber and that has absorbed or discharged carbon dioxide by the plant, and for introducing the atmosphere under the installed condition. 2 channels, a channel switching unit connected to the first and second channels, and a background carbon dioxide concentration measuring unit and a chamber carbon dioxide concentration measuring unit, which are connected to the switching unit and integrated The apparatus for evaluating the function of absorbing or discharging carbon dioxide of a plant according to claim 1, comprising two carbon dioxide concentration measuring units.

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