JP2007071758A - Photosynthesis evaluation apparatus or evaluation method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an apparatus or an evaluation method for evaluating a fixed amount of carbon dioxide by photosynthesis with high accuracy by reproducing an accurately controlled simulated global environment in a simple and compact manner.
SOLUTION: Raw air 1 and carbon dioxide concentration gas 2 are mixed to generate test air generating means 3 for generating test air having a predetermined carbon dioxide concentration, and a test obtained by the test air generating means 3 And a test chamber 4 capable of sealing a subject T for photosynthesis inside, a light source unit 11 for irradiating the subject T with light, and a dioxide dioxide in the outlet gas of the test chamber 4 The amount of carbon dioxide immobilized by the subject from the carbon dioxide concentration measuring means 7 for measuring the carbon concentration, and the carbon dioxide concentration of the test air and the carbon dioxide concentration measured by the carbon dioxide concentration measuring means 7. And processing means 8 for calculating.
[Selection] Figure 1

Description

  The present invention relates to a photosynthesis evaluation apparatus or an evaluation method, and more particularly to an apparatus or an evaluation method for reproducing a natural environment in a simulated manner and evaluating a fixed amount of carbon dioxide by photosynthesis of a plant or a growth state of a subject by photosynthesis.

  In recent years, one of the major improvements in the global environment is the prevention of global warming, specifically the reduction of greenhouse gases, and the fixation of carbon dioxide by photosynthesis of plants is a method for reducing such greenhouse gases. It is considered as one of Therefore, in order to clarify the process of carbon dioxide immobilization by photosynthesis of plants in the natural environment, various simulations are performed to reproduce the natural environment and analyze the mechanism of carbon dioxide immobilization by photosynthesis in actual plants. Attempts have been made.

  For example, as shown in FIG. 9, a photosynthesis measurement method using a closed assimilation box has been proposed. That is, in a method for measuring a photosynthetic rate by a change over time of carbon dioxide concentration while putting a plant 92 to be measured in an assimilation box 91 constituting an air circulation path and circulating the air in the assimilation box 91, the assimilation box Although the airtightness of 91 is high but not completely airtight, the ventilation rate is measured in a state where the plant 92 is not inserted, and the ventilation rate is determined from the change in the carbon dioxide concentration measured after the plant 92 is inserted and after a predetermined time has elapsed. 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-A-8-172913

  However, with the conventional method, it is difficult to reproduce the natural environment in a simulated manner, and it is impossible to analyze the mechanism of carbon dioxide immobilization by accurate photosynthesis of plants. In other words, when dry air or humidified air and carbon dioxide gas are separately supplied to the plant chamber, the concentration distribution of moisture and carbon dioxide in the plant chamber is not uniform or the stability of the concentration is lacking. In some cases, it may not be possible to accurately evaluate photosynthesis, such as uneven plant photosynthesis. This non-uniform distribution will have a greater effect, especially when using large plant chambers where the entire plant can be installed. In addition, when a part of the external air is introduced, not only the measurement conditions change, such as “correcting the concentration of carbon dioxide”, but also the evaluation takes time and effort.

  In addition, for example, when evaluating the fixation of carbon dioxide by photosynthesis of plants using an ordinary laboratory-level plant chamber, by the index that forms the environment, such as the wavelength and light amount of irradiation light or irradiation time, Although the state of carbon dioxide immobilization varies greatly, it has been difficult to obtain correlations with such multiple indicators. In addition, when leaves or branches of vegetation in the natural state are installed in the plant chamber, it is not possible to ensure the uniformity of light irradiation, and only that part can be measured for photosynthesis. It was the current situation that the evaluation was limited.

  Accordingly, an object of the present invention is to provide an apparatus or an evaluation method for evaluating a fixed amount of carbon dioxide by highly accurate photosynthesis by reproducing a precisely controlled simulated global environment in a simple and compact manner. . Further, such immobilization of carbon dioxide by photosynthesis means a metabolic function for a living subject, and provides an apparatus or an evaluation method for evaluating the growth state of the subject by photosynthesis. One of the objects of the present invention.

  As a result of intensive studies, the present inventor has found that the above object can be achieved by a photosynthesis evaluation apparatus or evaluation method described below, and has completed the present invention.

  That is, the present invention provides (1) test air generating means for mixing raw air and carbon dioxide gas to generate test air having a predetermined carbon dioxide concentration, and (2) obtained by the test air generating means. A test chamber in which a test subject to be subjected to photosynthesis can be hermetically sealed and the internal temperature and air volume can be controlled, and (3) a light source for irradiating the subject with light And (4) a carbon dioxide concentration measuring means for measuring a carbon dioxide concentration in the test chamber outlet gas, and (5) a carbon dioxide concentration measured by the carbon dioxide concentration of the test air and the carbon dioxide concentration measuring means. And processing means for calculating the amount of carbon dioxide immobilized by the subject from the carbon concentration (claim 1).

  The present invention makes it possible to quantitatively grasp the amount of carbon dioxide fixed by photosynthesis by reproducing the global environment in a simulated closed-type device in a simple and compact manner, and is applicable to any plant. It is possible. Therefore, it is possible to provide a highly accurate photosynthesis evaluation apparatus. Here, “raw air” refers to nitrogen and oxygen that do not contain carbon dioxide and moisture (or each concentration is constant), and the composition of which is the same as that of the atmosphere. It is different from those that contain carbon dioxide and moisture, such as “atmosphere” or “external air”, in which the concentration changes.

  In addition, since this device has a structure that can be completely sealed, it enables evaluation in an extreme environment where the subject is placed, and external air is not introduced into the test chamber. From the transient comparison between the amount of carbon dioxide supplied to the test chamber and the amount of carbon dioxide delivered without the conventional “correction of carbon dioxide concentration correction”, the change in a stable environment every moment It is possible to accurately grasp and evaluate the carbon dioxide fixing function of the subject to be analyzed.

  Furthermore, since the raw air and carbon dioxide gas are mixed and test air having a predetermined carbon dioxide concentration is generated by the test air generating means and introduced into the test chamber, the carbon dioxide gas is directly supplied to the test chamber. The carbon dioxide in the test air becomes uniform as compared with the case where it is introduced into the test chamber and mixed with air in the test chamber. Therefore, since the subject can perform photosynthesis without unevenness, the evaluation is also stable.

  The fixation of carbon dioxide means a metabolic function for a subject that is a living organism, and it is possible to grasp the mechanism of the metabolic function of the subject described later.

  The present invention is the photosynthesis evaluation apparatus, wherein the test air generating means includes three flow paths for dry air, humidified air, and carbon dioxide, and a flow rate control unit provided in each flow path, A mixing section that connects these flow paths, and in the mixing section, a flow path that connects the flow path for carbon dioxide is formed after the flow path that connects the flow path for dry air and the flow path for humidified air. The dry air / humidified air and carbon dioxide whose flow rate is controlled by the flow rate control are mixed (claim 2).

  In the evaluation of the fixed amount of carbon dioxide by photosynthesis, it is important to control the concentration of the components in the test air, so it is necessary to strictly control the generated concentrations of raw air, moisture and carbon dioxide as described above. There is. The present invention is a test in which the concentration is strictly controlled by controlling the flow rate of three channels for dry air, humidified air and carbon dioxide with high accuracy and making these channels uniform in the mixing section. It is verified that working air can be supplied.

  Further, the present invention has found that it is effective to rank the connection of the three flow paths in the connection. That is, because carbon dioxide dissolves in moisture, the carbon dioxide concentration may change when the carbon dioxide channel is connected to a humidification channel containing a large amount of moisture. Therefore, there is an effect of reducing such a change by mixing carbon dioxide after mixing dry air and humidified air.

  The amount of carbon dioxide fixed by photosynthesis of the subject is related to the concentration of carbon dioxide in the environment, and often changes greatly from the start to the end of the test over time. At this time, the concentration of carbon dioxide at the test chamber outlet varies, for example, from a maximum value of several hundred ppm level to a minimum value of 1 ppm or less. To accurately measure a fixed amount means that you need a measuring means to accurately measure both these levels of concentration, while at the same time, the concentration of test air needs to be controlled with accuracy as well, In the present invention, this is made possible by setting the supply conditions of the test air to the test chamber as described above.

  The present invention is the above-described photosynthesis evaluation apparatus, characterized in that the subject is irradiated with light from the light source, and a photosensor is disposed close to the subject (claim 3).

  In the evaluation of the fixed amount of carbon dioxide by photosynthesis, it is preferable to observe the amount of light actually irradiated to the subject, while reproducing the simulated natural environment. In the present invention, the amount of light that varies depending on various conditions such as the shape of the plant is disposed in proximity to the subject to detect the amount of light at an appropriate position as an average or representative evaluation target. be able to. At the same time, it is possible to observe the amount of light that changes as the plant grows.

  The present invention also relates to the apparatus for evaluating a fixed amount of carbon dioxide by photosynthesis, wherein an optical sensor is arranged at the center of a table provided in the test chamber, and an object is arranged so as to surround the periphery thereof. And you may irradiate the whole table with the light source provided in the upper part of the said table. In other words, even in the optical sensor, the optical sensor is arranged in the center of the table provided in the test chamber, and the subject is arranged so as to surround the periphery, thereby ensuring the maximum amount of irradiation light to the subject. It is possible to secure the optimum position of the detection optical sensor. Furthermore, if there is light blockage to the photosensor as the lichen grows by photosynthesis, it can be used for grasping the growth status of the lichen as described below based on the change in the light quantity of the photosensor. Become.

  Further, the test chamber may have means for measuring the weight of the subject, and the amount of carbon dioxide immobilized by the subject and the change in the weight of the subject may be measured. The immobilization of carbon dioxide by photosynthesis means a metabolic function for a living subject, and the growth state can be grasped based on changes in the amount of carbon dioxide and the weight of the subject. . In other words, it is possible to measure the amount of metabolism of a subject from the relationship between the amount of immobilized carbon dioxide and the increase in the weight of the subject. Alternatively, it can be used for product improvement and mass production.

  The present invention is a photosynthesis evaluation method, comprising mixing raw material air and carbon dioxide gas to generate test air having a predetermined carbon dioxide concentration, and introducing the test air into a test chamber that can be sealed. A step of installing a subject in the test chamber, a step of irradiating the subject with light, a step of measuring a carbon dioxide concentration in an outlet gas of the test chamber, a carbon dioxide concentration of the test air, and the step And a step of calculating the amount of carbon dioxide immobilized by the analyte from the concentration of carbon dioxide in the test chamber outlet gas (claim 4).

  By reproducing the global environment in a simulated closed system and controlling the relevant elements through appropriate steps, it has become possible to provide a method for evaluating the fixed amount of carbon dioxide by photosynthesis with high accuracy. Further, in the present invention, the flow rate, temperature, humidity, and carbon dioxide concentration of the test air, the temperature in the test chamber, the wavelength and amount of light irradiating the subject, the irradiation time, the fan in the test chamber When the photosynthesis is evaluated using the wind speed or the like as a control element and using these control elements as indices, it is possible to provide a more accurate photosynthesis evaluation apparatus.

  As described above, according to the present invention, a highly accurate photosynthetic evaluation apparatus or evaluation method can be provided by simply and compactly reproducing a precisely controlled simulated global environment.

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

<Overall Configuration of Photosynthesis Evaluation Apparatus According to the Present Invention>
A configuration example of a carbon dioxide fixed amount evaluation apparatus by photosynthesis according to the present invention is shown in FIG. Test air humidified using raw material air 1 and carbon dioxide gas 2 of a predetermined concentration as a raw material is introduced from a test air generating means 3 into a test chamber 4 that can seal the subject T inside, and its outlet gas. Is introduced into the carbon dioxide concentration measuring means 7 through the dehumidifier 5 and the flow meter 6. The output of the carbon dioxide concentration measuring means 7 is transmitted to the processing means 8 and used for calculation of the fixed amount of carbon dioxide. For the subject T, for example, lichens such as moss are used.

  Here, the test air generating means 3 and the test chamber 4 may be disposed in the test thermostat 9 whose temperature is controlled in the range of 4 to 50 ° C., for example, in order to eliminate the influence of the external temperature. preferable. Moreover, it is preferable to connect the outlet of the test air generating means 3 and the inlet of the test chamber 4 directly or without providing other than the minimum necessary members such as a switching valve. It is possible to supply test air whose concentration is strictly controlled by eliminating moisture adsorption, permeation, and retention in a long connection channel or a channel formed by a plurality of intermediate connection members.

  FIG. 2 illustrates the appearance of the photosynthesis evaluation apparatus according to the above configuration example. Here, in order to more accurately manage the temperature of the raw material gas, an apparatus is shown in which the raw air 1 and the carbon dioxide gas 2 filled in the high-pressure vessel are stored in the test thermostat 9. It is also possible to install in. In the test chamber 4, the subject T is installed in the space 4 a which is open in FIG. 2, and a sealed state is formed by a lid (not shown) having a light source part (not shown) described later. The

(1) Details of the test air generating means In the test air generating means 3, the raw air 1 introduced in a state adjusted to the set pressure by the pressure regulating valve 10a is branched into two, and in one flow path Then, the flow rate is adjusted to a predetermined flow rate by the flow rate control unit 31a and introduced into the mixing unit 32 (hereinafter referred to as “dry air flow path D”). In the other channels, the flow rate is adjusted to a predetermined flow rate by the flow rate control unit 31b and introduced into the humidifying unit 33, and after being humidified by the water stored in the humidifying unit 33, it is introduced into the mixing unit 32 (hereinafter referred to as “humidified air”). Is referred to as a “use channel W”). The carbon dioxide gas 2 introduced in a state adjusted to the set pressure by the pressure regulating valve 10b is adjusted to a predetermined flow rate by the flow rate control unit 31c and introduced into the mixing unit 32 (hereinafter referred to as “carbon dioxide channel C”). Called).

  At this time, the flow rate of each flow path is preferably introduced into the flow rate control units 31a, 31b and 31c and controlled in a dry state. Since characteristics such as air viscosity change due to humidification, this apparatus that changes the amount of humidification may cause an error in flow rate control. By eliminating these factors, it is possible to ensure high accuracy when evaluating the fixed amount of carbon dioxide using moisture as one of the indices.

  The flow rate control units 31a, 31b, and 31c are not particularly limited as long as they have a flow rate detection function and a flow rate adjustment function, but a mass flow sensor is preferable in consideration of accuracy. FIG. 3 shows the stability of each flow rate when the mass flow sensor is used as the flow rate control units 31a, 31b and 31c.

  By controlling the flow rate of each flow path, it is possible to generate an arbitrary flow rate of the test air supply, a moisture content (humidity) in the test air, and a carbon dioxide concentration. However, since the condition of the simulated natural environment is used as a reference, the humidified air flow path W is usually about 0 to 500 mL / min, and the dry air flow path D is about 0 to 500 mL / min. For example, when the channel C uses, for example, 5% carbon dioxide gas 2 (the residual gas base has the same composition as the air), the adjustment air flow rate is set to 0 to 10 mL / min. It is possible to supply test air with 500 mL / min, moisture concentration of 0 to 98%, and carbon dioxide of 0 to 1,000 ppm.

  The humidified air flow path W is preferably provided with a bypass flow path that passes through the humidifying section 33 by providing switching valves 34 a and 34 b before and after the humidifying section 33. Test air containing a specific concentration of carbon dioxide mixed with dry air and humidified test air containing the same concentration of carbon dioxide can be supplied, and the effect of moisture on the fixed amount of carbon dioxide by photosynthesis Useful for testing to determine the degree.

  In the test air generating means 3, as illustrated in FIG. 4A, the humidifying part 33 provided in the humidified air flow path W or in the air humidified by the humidifying part 33 and the humidifying part 33 is used. It is preferable to provide the gas-liquid separation part 35 which isolate | separates a liquid component in the thermostatic water tank 36 by which temperature control was carried out. By controlling the water temperature for humidification in the humidified air supply flow path W using constant temperature water, which is the same medium having a large heat capacity, it is possible to block heat sufficiently even if there is a temperature change around the test air generating means 3. The control temperature can be maintained. The constant temperature water is supplied to the constant temperature water tank 36 under temperature control in the constant temperature water supply unit 37 and returns to the constant temperature water supply unit 37 again through heat exchange with the humidification unit 33 and the gas-liquid separation unit 35. Such a circulation system can improve energy efficiency and temperature control accuracy.

  In addition, it is preferable to connect three flow paths, that is, the dry air flow path D, the humidified air flow path W, and the carbon dioxide flow path C to one mixing unit 32. These flow paths are connected to one mixing section 32, and the test air that has been uniformly mixed in advance in the mixing section 32 is connected to the inlet of the test chamber from the supply outlet to the test chamber except for the necessary minimum members. By connecting without providing, it is possible to supply test air whose concentration is strictly controlled.

  As the mixing section 32, it is preferable to form a flow path that connects the flow path for connecting the dry air flow path D and the humidified air flow path W to the carbon dioxide flow path C. Specifically, the mixing part 32B as illustrated in FIG. 4B may be used, and the mixing of the three flow paths may be performed by such ranking in the connection and mixing. By connecting the flow path D for dry air and the flow path W for humidified air that are based on the same air excluding moisture, the efficiency of diffusion mixing of both can be increased, and condensation or adsorption can be performed by dilution of water. It is possible to prevent a change in the moisture concentration due to. Further, in this state, the carbon dioxide channel C is connected, and carbon dioxide is added and mixed to prevent loss due to dissolution or absorption in moisture or the occurrence of a minute amount of carbon dioxide concentration in the test air. Is possible.

  Further, the mixing section 32 is not limited to the integral-shaped mixing section, but may be a mixing section 32C in which the pipe connection sections 38a and 38b are combined as shown in FIG. That is, after the dry air flow path D and the humidified air flow path W are connected using the pipe connection section 38a, the outlet connection flow path of the pipe connection section 38a and the carbon dioxide flow path C are connected to the pipe connection section 38b. By using and connecting, it is possible to easily form a flow path having the same function as in FIG.

  Further, as shown in FIG. 4 (D), after connecting the dry air flow path D and the humidified air flow path W using the pipe connection section 38a as the mixing section 32, connect the spiral tube 39 and the like again. It is installed in the thermostatic water tank 36, and then the carbon dioxide channel C is connected using the pipe connecting portion 38b, and carbon dioxide is added and mixed. According to the knowledge of the present inventor, by configuring such a mixing unit 32D, the stability of the mixed air of dry air and humidified air is further increased, and the concentration of carbon dioxide in the test air even after carbon dioxide is added and mixed. No trace of unevenness was observed.

  The temperature of the test air is controlled in a temperature range of 4 to 50 ° C., for example, in the test thermostat 9 and is introduced into the test chamber 4 while being kept constant. Here, it is preferable that the temperature of the whole test air generating means 3 is set higher than the humidification temperature of the humidified air. For example, when the humidification temperature is 9 ° C., the water temperature in the constant temperature water bath 36 is maintained at 9 ° C., and the entire test air generating means 3 is controlled to 10 ° C., thereby condensing or condensing moisture in the flow path. I'm trying to prevent it.

  The humidity of the test air is determined by the mixing ratio of the humidification temperature, dry air, and carbon dioxide, and is set in the range of 0 to 98% relative humidity according to the test conditions in the test chamber 4. That is, for example, when the humidification temperature is 10 ° C., the moisture concentration of the humidified air is about 1.2%, and when mixed with dry air 1: 1, the relative humidity is 50% and the moisture concentration is about 0.6%. Test air can be obtained.

(2) Details of Test Chamber As shown in FIG. 1, a test chamber 4 into which a subject T (not shown) for photosynthesis is introduced in a sealable state is provided in the test thermostat 9; A light source unit 11 for irradiating the subject T with light is provided. The test chamber 4 is arbitrarily set in size, shape, wind speed, installation condition of the subject T, etc., depending on the type and shape of the subject T, and the details will be described later as an example.

  The light source unit 11 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 a white fluorescent lamp or a light emitting diode (LED) including light in a wavelength range of 400 to 700 nm, and a plurality of the fluorescent lamps are arranged on the entire upper surface of the test chamber 4 so that conditions close to the natural environment are satisfied. It is preferable to produce.

  The selectivity of the wavelength range of the light source unit 11 can be ensured by using an element such as a red LED, a blue LED, or a white LED, when it can be selected depending on the characteristics of the white fluorescent lamp or the 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. If the selectivity with such an element cannot be ensured, the selectivity can be secured by using an optical filter that transmits a desired wavelength region in the light source unit 11. 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.

  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 accelerated 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).

  Further, it is preferable to provide a bypass flow path that passes through the test chamber 4 by providing switching valves 12 a and 12 b before and after the test chamber 4. The test air supplied to the test chamber 4 and the test chamber 4 outlet gas can be switched and introduced into the carbon dioxide concentration measuring means 7, and the test air is supplied to the subject T at a predetermined flow rate. It is useful for the test to grasp the fixed amount of carbon dioxide by instantaneous photosynthesis in the state of being.

Next, a specific shape or function of the test chamber 4 will be described.
FIGS. 5A and 5B show an example of a test chamber 4 that has a structure capable of sealing the subject T inside and is placed in a test thermostat 9 so that the internal temperature can be controlled. Show. FIG. 5A is a view of the inside of the test chamber 4 as viewed from directly above, and FIG. 5B is a view of the test chamber 4 as viewed from the side. The entire subject T arranged on the upper surface of the subject tray 42 arranged on the table 41 is irradiated with light from the plurality of light source units 11, and the test air whose carbon dioxide concentration and moisture are controlled is introduced into the gas. It introduces from the opening | mouth 43, forms the simulated earth environment in the chamber 4 for a test, and performs the evaluation test by photosynthesis. The test air used in the test chamber 4 is supplied to the carbon dioxide concentration measuring means 7 from the discharge port 44. Further, an optical sensor 45, a temperature sensor 46, a humidity sensor 47, and a wind speed sensor 48 are disposed in the vicinity of the subject T. The positions of the optical sensor 45, the temperature sensor 46, the humidity sensor 47, and the wind speed sensor 48 can be set to arbitrary positions suitable for evaluation.

  5A and 5B illustrate the test chamber 4 when the subject T is lichen such as moss. An optical sensor 45 is arranged in the center of a table 41 provided in the test chamber 4 of the test chamber 4, and an object tray 42 in which an object T is arranged so as to surround the periphery is placed on the table 41. The entire specimen tray 42 is irradiated by the light source unit 11 provided on the upper portion 41. Among lichens such as moss among plants, it is preferable to increase the light receiving area as much as possible because it has a planar habitat and the amount of carbon dioxide fixed by photosynthesis is very small. It is possible to secure a uniform amount of irradiation light to the subject T and secure an optimal position of the optical sensor 45. In addition, by installing the subject tray 42 with a space between the table 41 and the subject tray 42, it becomes possible to equalize the temperature or the wind speed with respect to the subject T placed on the subject tray 42.

  On the upper part of the table 41, a lid 4b of the test chamber 4 in which the light source unit 11 is disposed is provided. On the space 4a side, the space 4a and the light source unit 11 are partitioned and the light source unit 11 is provided. Pyrex (registered trademark) glass is provided so that the light from can be selected in a desired wavelength range (400 to 700 nm).

  Further, in FIG. 5B, the gas inlet 43 is provided at a position corresponding to the lower part of the table 41 and as upstream as possible with respect to the subject T. By obtaining a long distance from the introduction of the test air to the subject T, and further to the discharge port 44 provided above the subject T, the introduced test air is stirred, and the subject T An environmental atmosphere can be formed.

  The light sensor 45 close to the subject T can detect the light amount effective for photosynthesis on an average or representative basis. By measuring the amount of light L effective for this photosynthesis, PPFD can be calculated from the carbon dioxide emission. In FIG. 5B, a cover 45 a is provided so as to cover the optical sensor 45 in order to protect the optical sensor 45 and play the role of an optical filter.

  By detecting the temperature in the vicinity of the subject T by the temperature sensor 46 and controlling the temperature inside the test chamber 4 based on the temperature, the function of the subject T can be accurately grasped. In addition, when the subject T is lichen such as moss, it is very sensitive to temperature, so that it is necessary to perform stable temperature control at a temperature not exceeding 15 ° C., for example. Therefore, as illustrated in FIG. 4, the temperature sensor 46 is arranged in the state as close as possible to the subject T, and the uniformity of the temperature of the entire subject T is ensured by using the function of the fan 48 described later. It becomes possible to do.

  Further, the humidity near the subject T is detected by the humidity sensor 47, and the amount of water consumption or transpiration in the subject T is detected. As illustrated in FIGS. 5A and 5B, it is preferable to dispose the humidity sensor 47 in a state as close as possible to the subject T, and at the same time dispose it at a position where the state after photosynthesis can be detected. Thus, it is possible to evaluate the effect of photosynthesis.

  Furthermore, a fan 49 and a wind speed sensor 48 capable of ensuring the uniformity of the temperature inside the test chamber 4 and changing the air volume or the wind speed are provided. The fan 49 is not particularly limited, such as an axial flow fan or a cross flow fan, but a cross flow fan is preferable in view of, for example, downsizing of the test chamber 4 and ease of control. The wind speed inside the test chamber 4 in the present invention is preferably about 0 to 0.7 m / sec, and the lichen such as moss is preferably about 0.5 m / sec. In addition, the wind speed sensor 48 is preferably provided above and in the vicinity of the subject T and at a position representing the wind flow to the entire subject T.

  As described above, the light sensor 45, the temperature sensor 46, the humidity sensor 47, and the wind speed sensor 48 are provided in the test chamber 4 to change the irradiation light, temperature, humidity, and air volume with respect to the subject T. It is possible to reproduce the simulated global environment and change its conditions.

  At this time, by using the subject tray 42 itself as a weight measuring means, it is possible to measure a change in weight due to photosynthesis of the subject T, that is, a growth state (metabolic amount) of the subject T. The amount of metabolism of the subject T can be measured from the relationship between the amount of carbon dioxide immobilized and the weight increase of the subject T, and the growth state of the subject T is evaluated by changing each index. It becomes possible to do.

(3) Regarding carbon dioxide concentration measuring means, etc. The outlet gas of the test chamber 4 is supplied to the flow meter 6 and the carbon dioxide concentration measuring means 7 via the dehumidifier 5, which is the main object of the present invention. It is considered to grasp the fixed amount of carbon dioxide, which is one of the above, with high measurement accuracy. Since the flow rate of the test air supplied to the test chamber 4 is controlled by the flow control units 31a, 31b and 31c under dry conditions, the carbon dioxide concentration should also be measured under conditions close to dry via the dehumidifier 5. Thus, it becomes possible to grasp the fixed amount of carbon dioxide as the total amount of carbon dioxide, and highly accurate evaluation can be performed.

  Since the carbon dioxide concentration measuring means 7 aims to grasp the fixed amount of carbon dioxide with high measurement accuracy as described above, it is preferable to use a non-dispersive infrared analyzer as the high-precision measurement means. . 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 processing means 8, as shown in FIG. 1, the concentration output from the carbon dioxide concentration measuring means 7, the flow rate outputs from the flow rate control units 31a, 31b, 31c of the test air generating means 3, and the test chamber 4 Each information output from the optical sensor 45, temperature sensor 46, humidity sensor 47, and wind speed sensor 48 is received by the data logger 81, and a fixed amount of carbon dioxide is calculated using the computer 82.

  Although not shown in FIGS. 1 to 5, control elements (flow rate of test air, temperature, humidity and carbon dioxide concentration, wavelength of light source unit, amount of light and irradiation time, temperature in test chamber) are separately provided by control means. , Humidity and wind speed) are preferably controlled. Each control element can be used for evaluation of a fixed amount of carbon dioxide by photosynthesis and evaluation of a growth state of a subject by 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 subject T, it is preferable to perform feedback control based on the measured values of the control elements.

  By using the fixed amount evaluation apparatus for carbon dioxide by photosynthesis having the above configuration, the flow rate of test air, temperature, humidity and carbon dioxide concentration, wavelength of light source unit 11, light quantity and irradiation time, It becomes possible to evaluate the fixed amount of carbon dioxide by photosynthesis of the subject T with high accuracy using the temperature and the air volume as indices. Furthermore, by detecting the weight change of the subject T, it is possible to evaluate the growth state of the subject T, which is a living organism.

<Method for evaluating the amount of carbon dioxide fixed by photosynthesis>
Next, a specific method for evaluating the fixed amount of carbon dioxide by photosynthesis will be described. In the present invention, as shown in FIG. 6, a method having the following steps is configured.

(1) Generation of test air Test in which flow rate, temperature, humidity, and carbon dioxide concentration are controlled by mixing raw air 1, humidified air humidified with raw air 1, and carbon dioxide gas 2 of a predetermined concentration (for example, 5%) Generate air. At this time, for example, the flow rate is arbitrarily controlled within a range of 0 to 500 mL / min, a temperature of 4 to 50 ° C., a relative humidity of 0 to 98%, and a carbon dioxide concentration of 0 to 1,000 ppm, and a constant condition is continued for a predetermined time. The amount of carbon dioxide fixed by photosynthesis under the conditions can be obtained.

(2) Introduction of test air into the test chamber The test air is introduced into the test chamber 4. At this time, it is preferable to purge for a predetermined time in order to remove the residual components inside the test chamber 4.

(3) Measurement and memory of carbon dioxide concentration in test chamber outlet gas Carbon dioxide concentration in test chamber outlet gas after the start of the test described later is memorized by measuring the carbon dioxide concentration in the supplied test air. By comparing with the concentration, the fixed amount of carbon dioxide in the subject at an instant can be measured.

(4) Control of internal temperature of test chamber A test temperature corresponding to the subject T is set in advance within a range of 10 to 30 ° C., and the internal temperature of the test chamber 4 is controlled to be the set temperature.

(5) Placement of subject in test chamber Place subject T at a predetermined position in test chamber 4. For example, when the test chamber 4 as shown in FIG. 5 is used for lichens such as moss, the center of the subject T is previously removed in a circular shape and fitted to the optical sensor 45 or the like at the center of the table 44. By installing in, you can get the correct evaluation.

(6) Control of internal wind speed of test chamber A wind speed corresponding to the subject T is set in advance, and the fan 49 is controlled so that the wind speed inside the test chamber 4 becomes the set value. When the subject T is lichen such as moss, about 0.5 m / sec is preferable. At this time, as a test condition, it is possible to select either the case where the test air is supplied continuously or the case where the supply is stopped and performed in a completely sealed state, or the switching thereof.

(7) Irradiation of light to the subject The light source unit 11 having a wavelength range corresponding to the subject T is selected in advance, the light amount and the irradiation time are controlled under preset conditions, and the light source unit 11 is operated to turn on the subject T. Irradiate light. When the subject T is lichen such as moss, it is preferable to use a plurality of light source units 11 so as to irradiate substantially the entire surface as shown in FIG. In addition, by storing the output of the optical sensor 45 at this time, in the case of a test over a long period of time, it is possible to confirm the state of the cover due to the change of the light source 11 itself or the growth of lichens such as moss. it can.

(8) Measurement of carbon dioxide concentration in test chamber outlet gas The carbon dioxide concentration in the outlet gas delivered from the test chamber 4 is measured. As test conditions, when the test air is supplied continuously, 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. It is used as data for evaluating the fixed amount of carbon.

(9) Calculation of the amount of carbon dioxide immobilized using the control element as an index The amount of carbon dioxide immobilized by the subject T is calculated using the control element as an index. When the test conditions are (a) while supplying the test air continuously, the calculation is performed based on the carbon dioxide concentration stored in (3). 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. Further, (b) when the test is performed by periodically operating the switching valves 43a and 43b in FIG. 1 while continuously supplying the test air, (b-1) the reference value for each operation. (B-2) a method of linearly approximating the change of 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, By obtaining the difference between the integral values of the two based on the above, it becomes possible to calculate the fixed amount of carbon dioxide. Furthermore, (c) when the test air supply is stopped and the test is performed in a completely sealed state, the same calculation as in (a) above is performed on the basis of the carbon dioxide concentration memorized in (3). It is possible to calculate a fixed amount.

  By the above method for evaluating the fixed amount of carbon dioxide by photosynthesis, the flow rate of test air, temperature, humidity and carbon dioxide concentration, wavelength of light source unit 11, light quantity and irradiation time, temperature, humidity and wind speed in test chamber 4; Using this as an index, it becomes possible to evaluate the fixed amount of carbon dioxide by photosynthesis of the subject T with high accuracy.

<Example>
Based on the above method for evaluating the amount of carbon dioxide fixed by photosynthesis, a part of the test results actually conducted will be described.

(1) Test conditions (1-1) Test air conditions: flow rate 500 mL / min, temperature 11 ° C., relative humidity 90%, carbon dioxide concentration 780 ppm (humidified air: flow rate 400 mL / min, dry air: flow rate 100 mL / min , Carbon dioxide gas: Flow rate 0.3mL / min)
(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: wind speed 0.2 m / sec , Temperature 11 ℃
(1-4) Subject: Snagoke (about 125mm x 125mm)

(2) Test result (2-1) Stability of temperature and humidity in the test chamber As illustrated in FIG. 7A, in the test time of about 40 hours, the temperature is about 0 at the base temperature at the maximum. .2 ° C. The ripple accompanying the operation of the heating unit was about 0.3 ° C. at maximum. Regarding the humidity, the maximum was about 6 RH (relative humidity) at the base, and the ripple accompanying the operation of the heating unit was about 1.5 RH at maximum.
(2-2) Changes in PPFD Concentration and Carbon Dioxide at Outlet in Test Chamber As illustrated in FIG. 7B, in the test time of about 40 hours, PPFD is about 5 μmol / cm ² except for the initial stage.・ Change of sec was seen. Regarding carbon dioxide (CO ₂ ) concentration, an initial photosynthesis resulted in a decrease in concentration of about 140 ppm, but the immobilization gradually declined over about 10 hours.

<Method for evaluating growth state of subject by photosynthesis>
Next, a specific method for evaluating the growth state of a subject by photosynthesis will be described. In the present invention, as shown in FIG. 8, a method having the following steps is configured. In addition, description is abbreviate | omitted about the same matter as said <the fixed amount evaluation method of the carbon dioxide by photosynthesis>.
(1) Generation of test air (2) Introduction of test air into test chamber (3) Measurement of carbon dioxide concentration in test chamber outlet gas, memory (4) Control of internal temperature of test chamber ( 5) Measurement of the weight of the subject before the test, memory The weight of the subject T is measured in advance and compared with the weight of the subject T after the start of the test, which will be described later. Can be measured.
(6) Placement of subject in test chamber (7) Control of internal wind speed of test chamber after test (8) Irradiation of light to subject (9) Concentration of carbon dioxide in test chamber outlet gas Measurement (10) Measurement of subject weight The weight of the subject T after the start of the test is measured. Since the weight change of the subject T due to photosynthesis is estimated to be a result of the progress of metabolism in the subject T to some extent, there is a method of measuring at a predetermined time interval in addition to the method of continuously measuring. . The measured value is used as data for evaluating the growth state of the subject T together with the fixed amount of carbon dioxide by photosynthesis obtained from (9).
(11) Calculation of the amount of carbon dioxide immobilized and the change in the weight of the subject using the control element as an index Calculation of the amount of carbon dioxide immobilized by the subject T and the change in the weight of the subject T using the control element as an index To do. As the test conditions, both (a) when the test air is continuously supplied and (b) when the test air supply is stopped and the test air is completely sealed, the carbon dioxide concentration stored in (3) and The calculation is performed based on the weight of the subject T stored in (5). The calculation includes a method for obtaining the difference between the two integral values in the test time and a method for obtaining the integral value of the difference between the two, but the former method is based on obtaining a minute change in the amount of carbon dioxide and the weight of the subject. Is preferred. However, with respect to the fixed amount of carbon dioxide, it is possible to periodically check the reference value by operating the switching valves 12a and 12b in FIG. ) A method of changing the reference value for each operation, (c-2) A method of linearly approximating the change of the operation interval if there is a change in the measured value, (c-3) Approximating from the carbon dioxide concentration at each operation There is a method for obtaining a curve, and by using these as a reference, the difference between the two integrated values is obtained, whereby the fixed amount of carbon dioxide can be calculated.

  By the above-described method for evaluating the growth state of the subject T by photosynthesis, the flow rate, temperature, humidity and carbon dioxide concentration of the test air, the wavelength of the light source unit 11, the amount of light and the irradiation time, the temperature, humidity and the test chamber 4 Using the wind speed as an index, it is possible to evaluate the growth state of the subject T that is a living organism with high accuracy.

  As described above, the present invention can evaluate not only a fixed amount of carbon dioxide by photosynthesis but also an evaluation of the growth state of the subject. The subject is not limited to plants and can perform any photosynthesis. A living body can also be targeted.

  In the above description, the evaluation of the growth state of the subject is described based on the change in the weight of the subject. However, the evaluation of the growth state of the subject uses various different methods depending on the type of the subject. Is also possible. For example, when a multileaf plant is used as the subject, the growth state can be evaluated by detecting not only the weight but also the bioelectric potential. For example, when liquor such as moss is used as a subject, not only the weight but also the amount covered by the growth of moss etc., that is, the amount of light that is attenuated by the photosensor, is detected by the center. The growth state can be evaluated.

  Furthermore, by proceeding with the evaluation of the growth state of the subject, it is possible to obtain the optimum production conditions for the subject such as a plant, and the evaluation result can be used for artificial cultivation, product improvement, or mass production.

Explanatory drawing which shows the structural example of the fixed amount evaluation apparatus of the carbon dioxide which concerns on this invention. Explanatory drawing which illustrates the external appearance of the fixed amount evaluation apparatus of the carbon dioxide which concerns on this invention. Explanatory drawing showing the stability of the flow volume in the three flow paths which comprise the test air generation means which concerns on this invention. Explanatory drawing which shows the structural example of the test air generation means which concerns on this invention. Explanatory drawing which shows the structural example of the chamber for a test which concerns on this invention. Explanatory drawing which shows the process example of the fixed amount evaluation method of the carbon dioxide which concerns on this invention. Explanatory drawing which shows an example of the test result of the fixed quantity evaluation of the carbon dioxide which concerns on this invention. Explanatory drawing which shows the process example of the growth state evaluation method of the test object which concerns on this invention. Explanatory drawing which shows the embodiment of the photosynthesis measuring method which concerns on a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Raw material air 2 Carbon dioxide gas 3 Test air generation means 4 Test chamber 5 Dehumidifier 6 Flowmeter 7 Carbon dioxide concentration measurement means 8 Processing means 9 Test thermostat 10a, 10b Pressure control valve 11 Light source part 12a, 12b, 34a, 34b Switching valves 31a, 31b, 31c Flow rate control unit 32 Mixing unit 33 Humidification unit 35 Gas-liquid separation unit 36 Constant temperature water tank 41 Table 42 Subject tray 45 Optical sensor 46 Temperature sensor 47 Humidity sensor 48 Wind speed sensor 49 Fan C Carbon dioxide Flow path D Dry air flow path T Subject W Humidified air flow path

Claims (4)

Test air generating means for mixing raw material air and carbon dioxide gas to generate test air having a predetermined carbon dioxide concentration;
Test air obtained by the test air generating means is introduced, and a test chamber capable of sealing a subject for photosynthesis inside,
A light source unit for irradiating the subject with light;
Carbon dioxide concentration measuring means for measuring carbon dioxide concentration in the test chamber outlet gas;
Photosynthesis comprising: processing means for calculating the amount of carbon dioxide immobilized by the subject from the carbon dioxide concentration of the test air and the carbon dioxide concentration measured by the carbon dioxide concentration measuring means. Evaluation device.   The test air generating means includes three flow paths for dry air, humidified air, and carbon dioxide, a flow rate controller provided in each flow path, and a mixing section that connects these flow paths. In the mixing section, a flow path connecting the carbon dioxide flow path is formed after the flow path connecting the dry air flow path and the humidified air flow path, and the flow rate is controlled by the flow rate control. The photosynthesis evaluation apparatus according to claim 1, wherein air / humidified air and carbon dioxide are mixed.   3. The photosynthesis evaluation apparatus according to claim 1, wherein the subject is irradiated with light from the light source, and a photosensor is disposed in proximity to the subject.   Mixing raw material air and carbon dioxide gas to generate test air having a predetermined carbon dioxide concentration, introducing the test air into a sealable test chamber, and installing a subject in the test chamber The step of irradiating the subject with light, the step of measuring the carbon dioxide concentration in the test chamber outlet gas, the carbon dioxide concentration in the test air and the carbon dioxide concentration in the test chamber outlet gas. And a step of calculating the amount of carbon dioxide immobilized by the subject.

Images