Carbon dioxide measurement device, ethanol concentration measurement device, method for measuring carbon dioxide concentration, and method for measuring ethanol concentration

Abstract

To provide a carbon dioxide measurement device that is excellent in simplicity, real-time property, or sampling-free property, or is applicable to open systems or readily adaptable to existing manufacturing facilities.SOLUTION: A carbon dioxide measurement device that measures the concentration of carbon dioxide emitted from an object by bringing an end of a cylindrical probe close to or in contact with the object, comprises: a first introduction port for introducing a first gas to the probe and a second introduction port for introducing a second gas to the probe that are respectively disposed at the end; a sensor that is accommodated at an intermediate position in the longitudinal direction of the probe and measures the concentration; and an airflow unit that circulates a mixed gas of the first gas and the second gas in a direction from the end toward the sensor. The second introduction port is arranged closer to the sensor side than the first introduction port.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a carbon dioxide measuring device, an ethanol concentration measuring device, a method for measuring carbon dioxide concentration, and a method for measuring ethanol concentration.

Background Art

[0002] In the brewing process of alcoholic beverages such as sake, the ethanol concentration contained in yeast mash, moromi, etc. is measured as an index for process control and quality control. As a standard method for analyzing ethanol, the method described in Non-Patent Document 1 is known. In addition to the above, methods focusing on the correlation between the amount of carbon dioxide generated and the amount of ethanol generated in alcohol (ethanol) fermentation are disclosed in Patent Documents 1 to 3.

Prior Art Documents

Non-Patent Documents

[0003]

Non-Patent Document 1

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0005] The method disclosed in Non-Patent Document 1 requires sampling of the object, and then measures the ethanol concentration of the specimen after pretreatment by means of instrumental analysis or the like. The pretreatment is time-consuming and laborious, and the necessary equipment is specialized and sophisticated, and the operator is required to have a great deal of experience and knowledge. In addition, there is also a problem in that the ethanol concentration in the object cannot be grasped in real time. Further, since a predetermined amount of sampling (for example, 600 ml / time) is required, it causes a reduction in the final product by that amount and is often avoided from being performed frequently.

[0006] Further, the methods disclosed in Patent Documents 1 and 2 measure the amount of carbon dioxide generated by using a tank configured to be airtight. Usually, in the manufacturing process, an open-type tank is adopted, and raw materials are appropriately charged from the opening, or a “paddle (or paddle rod)” for stirring is inserted. There is a problem that using an airtight tank hinders the above-mentioned raw material charging and stirring (“paddling”). In addition, there is a possibility that fermentation failure may occur when fermentation proceeds in a closed system.

[0007] Further, the method disclosed in Patent Document 3 requires a tank capable of monitoring mass change. Such a tank is not prepared at a normal manufacturing site, and it is difficult to apply it to existing manufacturing equipment in terms of cost and the like.

[0008] As described above, there is a correlation between the amount of carbon dioxide generated and the amount of ethanol generated in alcohol fermentation, and accurately measuring the amount of carbon dioxide generated has the same meaning as measuring the amount of ethanol generated in an alcohol fermentation system. Therefore, an object of the present disclosure is to provide a carbon dioxide measuring device that can solve at least one of the above-mentioned problems of the prior art. In other words, an object is to provide a carbon dioxide measuring device that is excellent in simplicity, real-time property, or sampling-free property, or applicable to an open system, or easily applicable to existing manufacturing equipment. Further, an object of the present disclosure is to provide an ethanol concentration measuring device, a method for measuring carbon dioxide concentration, and a method for measuring ethanol concentration.

Means for Solving the Problem

[0009] A first embodiment of the carbon dioxide measuring device of the present disclosure is a carbon dioxide measuring device that measures the concentration of carbon dioxide generated from an object by bringing the end of a cylindrical probe close to or into contact with the object, and includes a first inlet disposed at the end for introducing a first gas into the probe, a second inlet for introducing a second gas, a sensor housed at an intermediate position in the longitudinal direction of the probe for measuring the concentration, and an air flow unit for flowing a mixed gas of the first gas and the second gas from the end toward the sensor. The second inlet is disposed closer to the sensor side than the first inlet, and it is a carbon dioxide measuring device.

[0010] A first embodiment of the ethanol concentration measuring device of the present disclosure is a carbon dioxide measuring device that measures the concentration of carbon dioxide generated from an object by bringing the end of a cylindrical probe into close contact with or inserting it into the liquid surface of an object that is a culture solution of microorganisms or a fermentation broth obtained by fermenting a raw material, and includes a first inlet disposed at the end for introducing a first gas into the probe, a second inlet for introducing a second gas, a sensor housed at an intermediate position in the longitudinal direction of the probe for measuring the concentration, an air flow unit for flowing a mixed gas of the first gas and the second gas from the end toward the sensor, and a controller. The second inlet is disposed closer to the sensor side than the first inlet, and the controller calculates the ethanol concentration in the object from the integrated amount of carbon dioxide calculated based on the concentration and the gas flow rate by the flow. It is an ethanol concentration measuring device.

Advantages of the Invention

[0011] According to the present disclosure, there is provided a carbon dioxide measuring device that is excellent in simplicity, real-time performance, or sampling-free property, or applicable to an open system, or easily applicable to existing manufacturing equipment. Further, according to the present disclosure, there are also provided a method for measuring carbon dioxide concentration and a method for measuring ethanol concentration.

Brief Description of Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Embodiments for Carrying Out the Invention

[0013] The carbon dioxide measuring device according to the first embodiment of the present disclosure is a carbon dioxide measuring device that measures the concentration of carbon dioxide generated from an object by bringing the end of a cylindrical probe close to or into contact with the object, and includes a first inlet for introducing a first gas and a second inlet for introducing a second gas, each arranged at the end, a sensor housed at an intermediate position in the longitudinal direction of the probe for measuring the concentration, and an air flow unit for flowing a mixed gas of the first gas and the second gas in a direction from the end to the sensor. The second inlet is arranged closer to the sensor side than the first inlet.

[0014] The probe included in the carbon dioxide measuring device according to the first embodiment has a first inlet and a second inlet at its end. The first inlet is disposed on the tip side in the longitudinal direction with respect to the second inlet, and a sensor is disposed in the probe on the opposite side in the longitudinal direction. Since the second inlet is disposed on the central side (the more rear end side of the probe, in other words, the opposite end side) in the longitudinal direction, when the object is brought into contact with the first inlet, the second inlet does not come into contact with the object and / or can be kept away from it.

[0015] When the first inlet approaches or contacts the object, a first gas containing carbon dioxide generated from the object enters the probe through the first inlet. As it is, the carbon dioxide concentration cannot be measured unless the inside of the probe is replaced with the first gas at least up to the position of the sensor. However, since the carbon dioxide measuring device according to the above embodiment includes an air flow unit that circulates the gas inside the probe from the end to the sensor, the carbon dioxide concentration can be easily measured. When the gas is sucked by the air flow unit, the first gas reaches the sensor, and the carbon dioxide concentration is measured in real time. Note that bringing the probe "close" to the object means a state where the probe is brought close to the object and not physically in direct contact, and "contact" means a state where the probe is physically in direct contact with the object. Note that "contact" may include a form in which the probe is adhered to the surface of the object and a form in which the probe enters (is inserted) from the surface of the object into the interior.

[0016] Furthermore, the above probe includes a second inlet. The second inlet is provided on the rear end side (opposite end side) with respect to the first inlet, and even when the first inlet is brought into contact with the object, the second inlet can be adjusted so as not to come into contact with the object. Then, when the gas is sucked by the suction unit, a second gas is sucked from the second inlet that is not in contact with the object, and this is mixed with the first gas in front of the sensor and moves toward the sensor position. In other words, the second gas functions as a carrier for the first gas, and the carbon dioxide concentration in the mixed gas is measured at the sensor position.

[0017] According to the carbon dioxide measuring device of the first embodiment configured as described above, even when high-concentration carbon dioxide is generated from the object, it reaches the sensor after being diluted by the second gas, so that measurement can be performed without saturation even with an inexpensive sensor. As a result, the carbon dioxide measuring device can be provided at a lower cost. In particular, since high-concentration carbon dioxide is generated from the moromi during alcoholic fermentation, when trying to measure this with a simple mechanism, it is necessary to use an expensive sensor or measure the concentration lower than the actual value by some method. In the carbon dioxide measuring device of the present embodiment, by providing the second inlet and the suction unit, for example, by simply sucking so as to obtain a constant flow rate, the first gas (carbon dioxide therein) is automatically diluted, and measurement with a general sensor becomes possible. The carbon dioxide concentration in the first gas can be calculated from the reading value of the sensor, the gas flow rate, etc. Further, in the calculation of the carbon dioxide concentration in the first gas, parameters other than those described above (for example, the pore diameters of the first inlet and the second inlet) may be used as necessary.

[0018] The carbon dioxide measuring device of the first embodiment can measure carbon dioxide simply by bringing a probe integrated with a sensor close to or into contact with the object in an open system. Further, the carbon dioxide in the sucked mixed gas can be monitored by the sensor in real time. Also, since measurement can be performed simply by bringing the probe close to or into contact with the object, there is no need for sampling (sampling-free). In addition, it can be easily made portable and is easily applicable to existing manufacturing equipment (for example, brewing tanks, etc.).

[0019] Further, when the amount of gas generated from the object is small, that is, when the inflow amount of the first gas into the probe is small, the proportion of the inflow amount of the second gas in the mixed gas increases accordingly, and the pressure inside the probe is kept constant. Therefore, it is possible to suppress the object being sucked in from the first inlet and clogging. In particular, when the object is a suspension such as "moromi", clogging often occurred with conventional measurement probes and the like, but this point has also been improved in the carbon dioxide measuring device of the present embodiment.

[0020] The carbon dioxide measuring device according to the second embodiment of the present disclosure is the carbon dioxide measuring device in which, in the first embodiment, the air flow unit is arranged on the opposite end side of the probe with respect to the first inlet.

[0021] By arranging the air flow unit on the opposite end side (rear end side) with respect to the first inlet, a gas flow (flow of the mixed gas) can be more efficiently formed in the probe. As a result, more efficient measurement becomes possible. The air flow unit includes a suction unit such as a pump and an air ejector that forms an air flow by sucking the mixed gas; a blower unit that transfers the mixed gas by a centrifugal or axial flow fan; a discharge unit that discharges the compressed second gas from the second inlet to form an air flow, and any of them can be used.

[0022] In the case of a suction unit, it is preferable that the suction port is arranged on the opposite end side of the probe with respect to the first inlet and further on the rear end side with respect to the sensor in the probe. In the case of a blower unit, it is preferable that the fan is arranged on the opposite end side of the probe with respect to the first inlet. In the case of a discharge unit, it is preferable to discharge the second gas from the inlet of the second gas. As already described, the second inlet is arranged on the sensor side (opposite end side) with respect to the first inlet.

[0023] The carbon dioxide measuring device according to the third embodiment of the present disclosure is the carbon dioxide measuring device in which, in the first embodiment, the object is a liquid, the first inlet is in close contact with or inserted into the liquid surface of the object, the first gas generated from the object is introduced, and the second gas with a known composition is introduced from the second inlet.

[0024] In the carbon dioxide measurement device according to the third embodiment, a second gas with a known composition is introduced from the second inlet. Therefore, the carbon dioxide concentration in the first gas can be calculated more accurately from the sensor reading value, gas flow rate, and the like. Further, when forming an air flow by a blower unit or a suction unit, if the first inlet is brought into close contact with or inserted into an object that is a liquid, the liquid may enter the probe due to a decrease in the internal pressure of the probe, resulting in clogging. However, in the carbon dioxide measurement device of the present embodiment, due to the contribution of the second inlet, the internal pressure of the probe can be kept constant, so the liquid itself is not drawn into the probe, and there is no problem of clogging of the probe. For example, when the liquid is a fermenting moromi in which solids and liquids are turbid, simply sucking with a probe may cause solids to enter the probe and clogging to occur. Since the probe of the carbon dioxide measurement device of the present embodiment is provided with a second inlet for introducing a second gas with a known composition, the occurrence of clogging due to a decrease in pressure inside the probe is suppressed.

[0025] The carbon dioxide measurement device according to the fourth embodiment of the present disclosure is the carbon dioxide measurement device according to the first embodiment, wherein the first inlet is an open end of the probe, and the second inlet is disposed on a side surface of the probe.

[0026] The probe included in the carbon dioxide measurement device according to the fourth embodiment is cylindrical with at least one end open, and the open end is the first inlet. Further, the second inlet is disposed on a side surface closer to the center in the longitudinal direction, that is, closer to the sensor side, from the open end. With such a configuration, by simply bringing the open end close to or into contact with the object, the second inlet is opened to the object, and measurement can be performed more easily.

[0027] The carbon dioxide measurement device according to the fifth embodiment of the present disclosure is the carbon dioxide measurement device according to claim 1, wherein a conduit for introducing the second gas is connected to the second inlet.

[0028] By connecting a conduit to the second inlet, the proportion of the gas generated from the object in the second gas introduced from the second inlet can be reduced. For example, when introducing air as the second gas, if a conduit with an open other end is connected to the second inlet, air from a space more distant from the object can be introduced, enabling more accurate measurement. That is, in this case, the side of the conduit opposite to the second inlet is open to the atmosphere, and the second gas can be introduced into the probe from this open end. Also, when using a gas introduction device (cylinder or gas generator) for a gas with a known composition (known carbon dioxide concentration) as the second gas, connecting the conduit further improves the degree of freedom in the layout of the device, making it easier to apply to existing manufacturing facilities.

[0029] The carbon dioxide measurement device according to the sixth embodiment of the present disclosure is a carbon dioxide measurement device in which, in the first embodiment, the second gas is air.

[0030] By using air as the second gas, there is no need for a special mechanism or device connection for supplying the second gas, and the device becomes more simplified and / or miniaturized. In particular, when the air flow unit is a suction unit or a blower unit and is configured to connect a conduit with an open other end to the second inlet, it is preferable in that the second gas can be supplied into the probe simply by placing the open end under the atmosphere. The device becomes more simplified and easier to make portable.

[0031] The carbon dioxide measurement device according to the seventh embodiment of the present disclosure is a carbon dioxide measurement device in which, in the fifth embodiment, the object is a liquid contained in an open container, and the second gas is taken in from a space separated from the opening of the open container by the conduit.

[0032] When the object is a liquid contained in an open container, comparing the vicinity (e.g., directly above) of the opening with the peripheral portion (e.g., the side of the container, etc.), the concentration of the gas generated from the object is lower in the peripheral portion. The carbon dioxide measuring device of this embodiment is configured to take in a second gas from a space separated from the opening of an open container by a conduit. Therefore, particularly when the second gas is air, the concentration of the gas generated from the object contained in the second gas can be suppressed to a lower level. As a result, the obtained measurement value is more likely to be accurate. Note that when the air flow unit is a suction unit or a blower unit and the second gas is air, the side of the conduit opposite to the second gas inlet may be opened to the atmosphere, simplifying the device and making it easier to make it portable.

[0033] The carbon dioxide measuring device according to the eighth embodiment of the present disclosure is the carbon dioxide measuring device according to the seventh embodiment, wherein the object is a microbial culture solution or a fermentation broth obtained by fermenting a raw material.

[0034] When the object is a microbial culture solution or a fermentation broth obtained by fermenting a raw material, by monitoring the amount of carbon dioxide generated from the object, the balance between the consumption and production of substrates and metabolites in the fermentation process can be clearly grasped. This balance is useful for the management of the fermentation process. For example, if the moromi during alcohol fermentation is used as the object, it becomes possible to estimate the alcohol concentration in the moromi by monitoring the amount of carbon dioxide.

[0035] The carbon dioxide measuring device according to the ninth embodiment of the present disclosure is the carbon dioxide measuring device according to the first embodiment, wherein the first gas inlet is configured to be larger than the second gas inlet.

[0036] By configuring the first gas inlet to be larger, the proportion of the first gas in the mixed gas measured by the sensor increases. As a result, a more accurate measurement value is more likely to be obtained. Particularly when the amount of carbon dioxide generated from the object is small (for example, in the initial stage of fermentation), it is possible to measure the amount of carbon dioxide with higher accuracy by reducing the amount of the second gas in the mixed gas.

[0037] The carbon dioxide measurement device according to the tenth embodiment of the present disclosure includes a controller in any of the first to ninth embodiments, and when the concentration or the calculation result based on the concentration satisfies an alert condition, the controller generates an alert. This is the carbon dioxide measurement device.

[0038] When the measurement result of the carbon dioxide concentration is used for the management of an object (for example, the management of the fermentation process), by generating an alert based on the concentration or the calculation result, the operator can be prompted to check the status of the object. Also, for example, if an alert is generated that the carbon dioxide concentration is high, it can also contribute to preventing accidents such as suffocation. In the case of the management of the fermentation process, the cumulative amount calculated from the carbon dioxide concentration, or the concentration of a predetermined substance in the object calculated from the cumulative value, is related to the balance of consumption and generation of the substrate and metabolite substances. Therefore, by generating an alert when a predetermined alert condition is satisfied, fermentation abnormalities can also be notified to the operator. Note that the calculation result may be the generated amount, integrated amount, increase (decrease) amount of carbon dioxide, and the differential of the increase (decrease) amount, etc. Also, it may be the amount of other substances calculated (converted) based on the measured value.

[0039] The carbon dioxide measurement device according to the eleventh embodiment of the present disclosure is the carbon dioxide measurement device according to the tenth embodiment, wherein the calculation result includes the integrated amount of carbon dioxide calculated based on the concentration and the gas flow rate by the above-mentioned flow, or the concentration of a predetermined substance in the object calculated from the integrated amount.

[0040] The integrated amount of carbon dioxide calculated from the carbon dioxide concentration and the gas flow rate is likely to reflect the change of the object over time. Also, the concentration of a predetermined substance in the object calculated from the integrated amount, for example, the ethanol concentration, is useful for grasping the balance of consumption and generation of the substrate and metabolite substances in the fermentation (culture) process when the object is a microbial culture solution or a fermentation broth obtained by fermenting a raw material.

[0041] The carbon dioxide measurement device according to the 12th embodiment of the present disclosure includes a controller in any of the 1st to 9th embodiments. The controller calculates the concentration of a predetermined substance in the object from the integrated amount of carbon dioxide calculated based on a predetermined conversion formula and the gas flow rate by suction. It is a carbon dioxide measurement device.

[0042] The controller included in the carbon dioxide measurement device according to the 12th embodiment has a function of converting the integrated amount of carbon dioxide into the concentration of a predetermined substance contained in the object based on a predetermined conversion formula. For example, when the object is a microbial culture solution or a fermentation broth obtained by fermenting a raw material, it is easier to grasp the balance of consumption and production of substrates and metabolites during the fermentation (culture) process. Specifically, it is easy to convert to other substance amounts (for example, ethanol concentration in the object).

[0043] The carbon dioxide measurement device according to the 13th embodiment of the present disclosure is a carbon dioxide measurement device in the 12th embodiment, wherein the object is a microbial culture solution or a fermentation broth obtained by fermenting a raw material, and the specific substance is ethanol.

[0044] The carbon dioxide measurement device according to the 13th embodiment has a function of calculating the ethanol concentration in a microbial culture solution as the object or a fermentation broth obtained by fermenting a raw material based on the measurement result of the carbon dioxide concentration. Therefore, it is preferably used for the management of the fermentation (culture) process. By simply bringing the probe close to or into contact with the open fermentation broth, the integrated value is calculated from the carbon dioxide concentration obtained in real time, and the ethanol concentration can be obtained. The carbon dioxide device of the present embodiment does not require sampling and is also easy to apply to existing equipment.

[0045] The first ethanol concentration measuring device of the present disclosure is a carbon dioxide measuring device that measures the concentration of carbon dioxide generated from an object, which is a culture solution of microorganisms or a fermentation solution obtained by fermenting a raw material, by bringing the end of a cylindrical probe into close contact with or inserting it into the liquid surface of the object. The first ethanol concentration measuring device is provided with a first inlet for introducing a first gas and a second inlet for introducing a second gas, which are respectively arranged at the end, a sensor for measuring the concentration, which is accommodated at an intermediate position in the longitudinal direction of the probe, and an air flow unit for flowing a mixed gas of the first gas and the second gas from the end toward the sensor, and a controller. The second inlet is arranged closer to the sensor side than the first inlet. The controller calculates the ethanol concentration in the object from the integrated amount of carbon dioxide calculated based on the concentration and the gas flow rate by the flow, according to a predetermined conversion formula.

[0046] The ethanol measuring device of the present embodiment can easily measure the ethanol concentration without sampling only by bringing the first inlet of the probe close to or into contact with a fermentation solution or the like. Further, since the mixed gas in the probe is circulated (typically, sucked by a suction unit) by the air flow unit, the carbon dioxide concentration is measured by the sensor and appropriately converted into the ethanol concentration, so that the measurement can be performed in real time. Even when the fermentation solution or the like is open to the atmosphere, the measurement can be easily performed, and the application to existing manufacturing equipment and the like is also easy. This ethanol concentration measuring device is preferably used for managing the fermentation (cultivation) process of a fermentation solution or the like.

[0047] The method for measuring the carbon dioxide concentration according to the first embodiment of the present disclosure is a method for measuring the carbon dioxide concentration, which includes measuring the concentration of carbon dioxide generated from an object using the carbon dioxide measuring device according to the first embodiment.

[0048] Since the measurement method of the present embodiment uses the carbon dioxide measurement device of the first embodiment, the carbon dioxide concentration can be easily measured simply by bringing the first inlet of the probe close to or into contact with the object without performing sampling. Further, since the mixed gas in the probe is circulated by the air flow unit and the carbon dioxide concentration is appropriately measured by the sensor, the measurement can also be performed in real time. Even when the object is in an open atmosphere, the measurement can be easily performed, and the application to existing manufacturing facilities and the like is also easy.

[0049] The method for measuring the ethanol concentration according to the first embodiment of the present disclosure uses the carbon dioxide measurement device of the first embodiment to measure the concentration of carbon dioxide generated from the object, and based on a predetermined conversion formula, from the integrated amount of carbon dioxide calculated from the above concentration and the gas flow rate by the above flow, calculating the concentration of ethanol contained in the object, which is a culture solution of microorganisms or a fermentation broth obtained by fermenting a raw material, is a method for measuring the ethanol concentration.

[0050] Since the measurement method of the present embodiment uses the carbon dioxide measurement device of the first embodiment and obtains the ethanol concentration in the object from the integrated amount, the ethanol concentration can be easily measured simply by bringing the first inlet of the probe close to or into contact with the fermentation broth or the like without performing sampling. Further, since the mixed gas in the probe is circulated by the air flow unit, the carbon dioxide concentration is measured by the sensor, and is appropriately converted into the ethanol concentration, the measurement can also be performed in real time. Even when the fermentation broth or the like is in an open atmosphere, the measurement can be easily performed, and the application to existing manufacturing facilities and the like is also easy. This measurement method is preferably used for managing the fermentation (cultivation) process of the fermentation broth or the like.

[0051] Hereinafter, embodiments of the carbon dioxide measurement device will be described with reference to the drawings. FIG. 1 is an explanatory diagram of the carbon dioxide measurement device 100. The carbon dioxide measurement device 100 includes a cylindrical probe 10, a sensor 16, and a suction unit 20.

[0052] The probe 10 is cylindrical with both ends open. At the tip 10A, a first inlet 12, which is an open end, is provided. In the central part 10B, a sensor 16 is disposed inside. At the open end of the rear end part 10C, a tube 20A connected to the suction unit 20 is airtightly connected.

[0053] FIG. 2 is an enlarged view (schematic view) of the tip 10A, which is one end of the probe 10. The tip 10A of the probe 10 is open and serves as the first inlet 12. On the other hand, a second inlet 14 having a smaller hole diameter than the first inlet 12 is provided on the side surface. A conduit 18 is airtightly connected to the second inlet 14. The second inlet 14 is provided closer to the central part 10B side than the first inlet 12.

[0054] The material of the probe 10 is not particularly limited as long as it has the airtightness required for measuring the carbon dioxide concentration. Metals, glass, plastics, etc. can be used. When the object is food or the like, from the viewpoint of easily keeping the probe 10 clean, it may be made of stainless steel. Also, the probe 10 may be integrally formed or may be in a form that is divided into a plurality of sections and assembled to be completed.

[0055] A sensor 16 is disposed in the central part 10B of the probe 10. The sensor 16 is a sensor capable of measuring the carbon dioxide concentration and is connected to a controller (not shown) by wire or wirelessly. In this example, the power source for driving the sensor 16 is housed in the central part 10B according to the sensor 16, but it may be disposed outside the probe 10 and connected to the sensor 16 from outside the probe 10.

[0056] As the sensor 16, known carbon dioxide concentration sensors can be used. Specifically, examples include the infrared absorption method (NDIR: Non-Dispersive Infrared), the wavelength tunable semiconductor laser absorption spectroscopy method (TDLAS: Tunable diode laser absorption spectroscopy), and the photoacoustic method.

[0057] A tube 20A is airtightly connected to the open end of the rear end portion 10C of the probe 10. Since a suction unit 20 is connected to the other end of the tube 20A, substantially one end (the tip portion 10A) of the probe 10 is in an open form.

[0058] The length and size (diameter) of the probe 10 are not particularly limited and can be appropriately adjusted according to the shape and size of the object 40 to be applied and the depth of the container (open container 32) in which it is accommodated. For example, when the object 40 is a liquid and the open container 32 has a diameter of 2 to 5 m and a height of 2 to 5 m, from the viewpoint of facilitating insertion of the probe 10 from the opening 30, the length is preferably 0.3 to 1.5 m, and more preferably 0.55 to 0.9 m.

[0059] Also, the inner diameter of the probe 10 is not particularly limited. However, in the carbon dioxide measuring device 100, as shown in FIG. 2, since the inner diameter of the probe 10 is directly related to the diameter of the first inlet 12, in this regard, it is appropriately selected according to the required sensitivity, measurement range, etc. That is, when the inner diameter of the probe 10 (the diameter of the first inlet 12 in the carbon dioxide measuring device 100) is smaller than the diameter of the second inlet 14, the proportion of the first gas FL1 that is inevitably sucked decreases. Along with this, the carbon dioxide concentration in the mixed gas FL3 also decreases. Therefore, if the measurable range of the sensor 16 is kept constant, it becomes easier to measure in a range where the carbon dioxide concentration generated from the object is higher. On the other hand, when the inner diameter of the probe 10 is larger than the diameter of the second inlet 14, it becomes easier to measure in a range where the carbon dioxide concentration generated from the object is lower. In one form, the inner diameter of the probe 10 is preferably 10 to 100 mm, and more preferably 13 to 50 mm.

[0060] The width of the measurable range of the sensor 16 depends on the type of the sensor 16 and the like. However, adopting a sensor 16 with a wider measurable range directly leads to an increase in the cost required for manufacturing (assembly) the carbon dioxide measuring device 100. The carbon dioxide measuring device 100 of the present embodiment can pre-adjust the ratio of the inner diameter of the probe 10 (the diameter of the first inlet 12) to the diameter of the second inlet 14 based on the predicted value of the carbon dioxide concentration generated from the object 40.

[0061] For example, when it is expected that the carbon dioxide concentration generated from the object 40 is high, the first inlet 12 may be made smaller. When it is expected that the carbon dioxide concentration is low, the first inlet 12 may be made larger. The prediction of the carbon dioxide concentration generated from the object 40 is easy, for example, when the object is a microbial culture solution or a fermentation broth obtained by fermenting a raw material. Even when using an inexpensive sensor 16 with a narrow and limited measurable range, the carbon dioxide measuring device 100 can perform measurements with sufficient accuracy and range by adjusting the probe 10.

[0062] In FIG. 1, the shape of the probe 10 is such that the tip portion 10A is a cylindrical shape with a constant inner diameter, the central portion 10B is a cylindrical shape with a larger inner diameter, and further, the rear end portion 10C is a cylindrical shape with an inner diameter similar to that of the tip portion 10A. A plurality of cylinders with different inner diameters are joined and communicated. This is because the sensor 16 is accommodated inside the central portion 10B, and the inner diameter of the central portion 10B can be adjusted to an extent that can accommodate the sensor 16 (and, if necessary, other sub-devices; power supply, controller, etc.).

[0063] On the other hand, as long as the sensor 16 can be accommodated, the inner diameter of the probe 10 may be constant. That is, the tip portion 10A - the central portion 10B - the rear end portion 10C may all have the same inner diameter. Also, a part or all of it may be tapered. Further, the cross-section does not have to be circular and may be polygonal. Also, as one form, it is preferable that the inner diameter of the rear end portion 10C is smaller than that of the tip portion 10A.

[0064] At the tip 10A of the probe 10, a first inlet 12 for introducing (suctioning) the first gas FL1 and a second inlet 14 for introducing (suctioning) the second gas FL2 are provided. The first inlet 12 is provided as the open end of the probe 10. The first inlet 12 is used in proximity to or in close contact with the surface 40A of the object 40. As will be described later, when the carbon dioxide measuring device 100 is in use, since the gas in the probe 10 is suctioned by the suction unit 20, the first gas FL1 mainly composed of the gas generated from the object 40 (or consisting of the gas generated from the object 40) is introduced from the first inlet 12 that is in proximity to or in close contact with the surface of the object 40.

[0065] As is also apparent from the partial enlarged view of FIG. 2, the first inlet 12 is configured as the open end of the tip 10A of the probe 10. However, the first inlet provided in the carbon dioxide measuring device is not limited to the above form. As long as it is arranged on the tip side of the second inlet 14 described later, it is not necessary to be arranged as the open end at the tip of the probe 10. For example, the tip of the probe 10 may be blocked, and the first inlet 12 may be provided on the side surface near the tip. The form of the first inlet 12 may be selected according to the shape of the object 40 so as to be easily in proximity to or in contact with it.

[0066] On the other hand, when the object 40 is a liquid, particularly when the object 40 is contained in the open container 32, from the viewpoint of making it easier to insert the probe 10 vertically above the open container 32, a form in which the tip of the probe 10 is open and the open end is the first inlet 12 is preferable.

[0067] The tip 10A of the probe 10 is further provided with a second inlet 14. The second gas FL2 is introduced from the second inlet 14. The introduced second gas FL2 is a gas having a composition different from that of the first gas FL1, and its composition is not particularly limited, but it is preferable that the concentration of carbon dioxide contained therein is known, and it is more preferable that the composition is known.

[0068] The second inlet 14 is provided closer to the central portion 10B than the first inlet 12. In other words, it is provided on the side of the sensor 16. That is, from the tip side of the probe 10, the first inlet 12, the second inlet 14, and the sensor 16 are provided in this order. Specifically, the second inlet 14 is disposed on the side surface of the tip portion 10A of the probe 10. With such a configuration, even when the first inlet 12 is brought close to or into contact with the object 40, the second inlet 14 can be made more separated from the object 40 and / or not in contact with the object 40 compared to the first inlet 12.

[0069] Note that the tip portion 10A, the central portion 10B, and the rear end portion 10C in this specification represent the positions in the longitudinal direction of the probe 10 and are defined according to the position where the sensor 16 is disposed. That is, the portion where the sensor 16 is disposed is defined as the central portion 10B, and based on the central portion 10B, one side is defined as the tip portion 10A and the other side is defined as the rear end portion 10C. Therefore, the second inlet 14 is disposed closer to the central portion 10B than the first inlet 12 and closer to the tip side than the central portion 10B where the sensor 16 is accommodated.

[0070] A second gas FL2 having a composition different from that of the first gas FL1 can be introduced from the second inlet 14 configured as described above. The second gas FL2 is introduced into the probe 10, forms a mixed gas FL3 together with the first gas FL1, and is sucked toward the sensor 16 side. By adjusting the positional relationship between the two inlets as described above, the second gas FL2 functions as a reference and / or a carrier.

[0071] Note that the distance between the first inlet 12 and the second inlet 14 is not particularly limited. However, from the viewpoint of more efficiently transferring the first gas FL1 introduced into the probe 10 to the sensor 16 and as a result obtaining a more real-time and / or more accurate measurement result, it is preferable that the second inlet 14 is provided in the vicinity of the first inlet 12. Specifically, it is preferable that the second introduction port 14 does not contact at least the surface 40A of the object 40 during measurement, while being closer to the first introduction port 12. As one form, when the diameter of the first introduction port 12 is 1, the lower end of the second introduction port 14 is preferably arranged at a position of 1 to 20 from the upper end of the first introduction port 12.

[0072] When the second introduction port 14 is arranged near the first introduction port 12, the gas generated from the object 40 is more likely to be introduced into the second introduction port 14 as well. From the viewpoint of obtaining more accurate measurement results, in such a case, it is preferable to connect a conduit 18 to the second introduction port 14 and configure it to introduce the second gas FL2 from a space more separated from the object 40.

[0073] In FIG. 1, a conduit 18 is connected to the second introduction port 14, and the other end of the conduit 18 is arranged outside the opening 30 of the open container 32. By being configured in this way, when the other end of the conduit 18 is opened, air is introduced as the second gas FL2 through this other end. The air sucked from the separated space outside the opening 30 can be considered to have almost the composition of the atmosphere, and its carbon dioxide concentration is about 0.03 vol%, which is known (composition is known). Thereby, more accurate measurement becomes possible.

[0074] The diameter of the second introduction port 14 is not particularly limited, but from the viewpoint of being able to increase the ratio of the first gas FL1 in the mixed gas FL3, it is preferably equal to or less than the diameter of the first introduction port 12, and more preferably less than the diameter of the first introduction port 12. For example, when the diameter of the first introduction port 12 is 1, the diameter of the second introduction port 14 is preferably 0.1 or more and less than 1.

[0075] The suction unit 20 includes a flow meter and an air pump, and has a function of sucking the gas in the probe 10 to cause a gas flow inside. Specifically, the first gas FL1 and the second gas FL2 are respectively sucked from the first inlet 12 and the second inlet 14, the mixed gas FL3 is directed toward the sensor 16, and after passing through the sensor 16 (the mixed gas FL4 after passing through the sensor), it is discharged outside the probe 10. The discharge amount at this time is preferably set to be equal to or greater than the maximum amount (speed) of the gas generated from the object, and the upper limit is not particularly limited, but is preferably 10,000 mL or less per minute.

[0076] Note that instead of the suction unit 20, other types of air flow units having a function of forming an air flow in the probe and flowing the mixed gas FL3 toward the sensor 16 can also be used. Examples of such air flow units include a suction unit including an air ejector and a blowing unit including a fan. In addition, a discharge unit that discharges the compressed second gas from the second inlet to form an air flow can also be used. Among them, in terms of enabling more accurate measurement, the suction unit and the blowing unit are preferred, and the suction unit is more preferred.

[0077] The gas flow rate by the suction unit 20 is not particularly limited, but may be appropriately adjusted according to the measurable range (concentration range) of the sensor 16 and the like. As one embodiment, if the carbon dioxide concentration in the first gas FL1 is 40,000 ppm or less and the gas generation amount from the object is 80 mL / min or less, it may be as described above.

[0078] The gas flow rate may be constant or may be changed. For example, assume that the object is the "moromi" of sake. In this case, measurements are taken from the initial stage of fermentation until a sufficient amount (designed amount) of ethanol is produced. That is, the measurement is continued for a certain period, and the change in the carbon dioxide concentration is observed. If the gas flow rate is kept constant throughout the entire measurement period, the obtained concentration measurement results can be easily converted by the cumulative generation amount of carbon dioxide. That is, if the flow rate is constant, the generation rate of carbon dioxide can be calculated by multiplying it by the concentration, and by integrating this with the observation time, the cumulative generation amount can be obtained.

[0079] On the other hand, if the gas flow rate is changed according to the amount of carbon dioxide generated from the object, while using the sensor 16 having a certain measurable range, it is also possible to change and expand the substantial measurable range (shift the measurable range according to the generation amount and the passage of time).

[0080] The object 40 is accommodated in the open container 32, and the probe 10 is inserted from the opening 30 side thereof so that the first inlet 12 approaches or contacts the surface 40A. At this time, by bringing the first inlet 12 into close contact with the surface 40A, it becomes easier to obtain a more accurate measurement result.

[0081] From the first inlet 12, the first gas FL1 generated from the object 40 enters the probe 10. At this time, the gas in the probe 10 is sucked by the suction unit 20. For example, when the gas is sucked at a constant flow rate by the suction unit 20, even when the gas generation amount from the object 40 is small and the first gas FL1 is small, the second gas FL2 is sucked accordingly, so that the object 40 itself is prevented from entering the probe 10 from the first inlet 12 which is an open end. By suppressing the suction of the object 40, as a result, the clogging of the probe 10 is suppressed. When the object 40 is a suspension medium, a greater clogging prevention effect can be obtained with the above configuration.

[0082] On the other hand, the second inlet 14 disposed at a position higher than the first inlet 12 (on the central portion 10B side) can be positioned above the liquid level even when the first inlet 12 is in close contact with the surface 40A of the object 40, so that the second gas FL2 having a different composition can be introduced. A conduit 18 is connected to the second inlet 14, and the other end of the conduit 18 is adjusted to be located in a space separated from the open container 32, specifically, a location away from the opening 30. By doing so, the ratio of the gas generated from the object 40 in the second gas FL2 can be reduced.

[0083] In FIG. 1, the object 40 is a liquid substance. The liquid substance means a substance or system that includes a liquid and has fluidity. Specifically, examples include liquids (including mixtures of two or more components), suspensions, emulsions, gels, sols, and colloidal solutions. From the perspective of being able to monitor and adjust the fermentation and culture processes by measuring the carbon dioxide concentration, the liquid substance is preferably a microbial culture solution and a fermentation broth obtained by fermenting raw materials.

[0084] Examples of microorganisms include fungi, bacteria, and microalgae. Examples of fungi include Aspergillus oryzae and yeast used in brewing, etc. Examples of bacteria include lactic acid bacteria, acetic acid bacteria, and Bacillus spp. Examples of microalgae include diatoms, cyanobacteria, dinoflagellates, green algae, and red algae.

[0085] The microbial culture solution may contain other components as long as it contains the above-mentioned microorganisms and a liquid medium. Examples of other components include saccharides, nitrogen sources, vitamins, inorganic salts, pH adjusters, and gelling agents. The microbial culture solution includes, for example, the yeast starter in sake production.

[0086] The fermentation broth obtained by fermenting raw materials is not particularly limited, and examples include moromi in the production of sake, soy sauce, and miso, must in wine production, and wort in beer production. In addition to the above, it may also be a fermentation broth for producing amino acids, organic acids, vitamins, biofuels, etc.

[0087] Among them, microorganisms that perform alcohol (ethanol) fermentation are preferred as the microorganisms. Examples of such microorganisms include yeasts such as Saccharomyces cerevisiae, Saccharomyces pastorianus, and Schizosaccharomyces pombe, and bacteria such as Zymomonas mobilis and Clostridium acetobutylicum.

[0088] Next, the calculation of the ethanol concentration in the object 40 by the carbon dioxide measuring device 100 and the flow of generating an alert will be described. FIG. 3 is a flowchart of the calculation of the ethanol concentration by the carbon dioxide measuring device 100 and the generation of an alert.

[0089] First, as step S10, the carbon dioxide concentration generated from the object 40 is measured. Specifically, the first inlet 12, which is the open end of the probe 10, is brought into contact with the surface 40A of the object 40, and the gas in the probe 10 is sucked by the suction unit 20. Thereby, from the first inlet 12, the first gas FL1 containing carbon dioxide generated from the object 40 and, from the second inlet 14, the second gas FL2 composed of air introduced through the conduit 18 are respectively sucked. Further, when these mixed gases FL3 reach the sensor 16 housed in the central portion 10B of the probe 10, the carbon dioxide therein is measured. The above is continuously performed, and the carbon dioxide concentration is measured in real time according to the data acquisition interval. At this time, the gas flow rate in the probe 10 provided from the suction unit 20 (the flow meter included therein) may also be recorded.

[0090] The data acquisition interval is not particularly limited, but as one form, a form in which data is acquired every 1 to 60 seconds can be mentioned. The actually obtained data also depends on the measurement method of the sensor 16, but generally it is in vol%.

[0091] Next, as step S11, the obtained concentration data is averaged at a predetermined time interval. For example, the data is aggregated at a time interval longer than the sampling interval (data acquisition interval). By performing data aggregation (reduction of the data amount), the calculation becomes easier. The time interval for data aggregation is not particularly limited and may be appropriately selected according to the processing speed of the controller, the type of the object 40, etc. As one form, about 5 to 50 times the sampling interval is preferable. Note that this step is not essential and can be omitted according to the purpose and the processing speed of the controller, etc. That is, instead of aggregating the data, the calculation in the next step may be performed using the measured values themselves.

[0092] Specific examples of the controller include a microcomputer (MCU: Microcontroller Unit), a PLC (Programmable Logic Controller), a PAC (Programmable Automation Controller), and a PC (personal computer), etc. Also, the controller may be implemented by an FPGA (Field-Programmable Gate Array). Note that the controller is typically preferably a computer including a memory and a processor.

[0093] Next, as step S12, calculate the generation rate (mL / min) of carbon dioxide from the gas flow rate in the probe 10 generated by the suction unit 20. Specifically, multiply the average value (or the measured value itself) of the carbon dioxide concentration calculated in step S11 by the flow rate (mL / min) at the time when the measurement was made. When the gas flow rate in the probe (near the central portion 10B) generated by the suction unit 20 is constant, that constant value is multiplied. On the other hand, when there is a change in the gas flow rate by the suction unit 20, the gas flow rate recorded together with the measured value is used in the calculation.

[0094] Note that when the second gas FL2 contains carbon dioxide, the above generation rate may be corrected using, for example, the ratio of the opening diameters of the first inlet 12 and the second inlet 14, etc., to reduce the contribution of the carbon dioxide concentration contained in the second gas FL2. On the other hand, when the content of carbon dioxide in the second gas FL2 is small enough to be ignored compared to the content of carbon dioxide in the first gas FL1, correction may not be necessary. For example, when the second gas FL2 is air, or nitrogen gas or other inert gas, etc., correction may not be necessary.

[0095] Next, as step S13, the cumulative amount of carbon dioxide generated (mL) from the object is calculated. Specifically, the time integral of the generation rate is calculated. As a specific form, it is calculated as the product of the generation rate (mL / min) calculated in step S12 and the time interval used in step S11 (the sampling interval if not data-aggregated).

[0096] Next, as step S14, the cumulative amount of carbon dioxide generated is converted into the ethanol concentration in the object. The conversion is performed based on the correlation (generation mechanism) between the generation of carbon dioxide and the generation of ethanol in the object. For example, in ethanol fermentation by yeast, it is known that 2 molecules of ethanol and 2 molecules of carbon dioxide are generated from 1 molecule of glucose. Based on this relationship, the cumulative amount of carbon dioxide generated is converted into the cumulative amount of ethanol generated, and the ethanol concentration is calculated based on the total amount of the object 40.

[0097] Next, as step S15, the obtained ethanol concentration is compared with a predetermined alert condition, and if this condition is satisfied (step S15: YES), an alert is generated (step 16). The alert condition is not particularly limited, and may be, for example, the target concentration of ethanol, etc. That is, by alerting that the concentration of ethanol has reached the target value, the operator can recognize that the fermentation has ended normally. On the other hand, an alert may be generated based on the fact that a predetermined concentration has not been reached in relation to the observation time. In this way, it is easy to detect fermentation failure. On the other hand, when the alert condition is not satisfied (step S15: NO), the measurement flow ends. Even when the flow ends, if a preset condition is satisfied (for example, within a predetermined time), the measurement may be performed, and the operations of steps S10 to S16 may be repeated each time.

[0098] Note that in the above flow, the ethanol concentration is calculated from the carbon dioxide concentration, and an alert is generated based on the ethanol concentration, but it is not limited to the above. In addition to the ethanol concentration, other substrates and / or metabolites in the fermentation process may also be calculated. For example, in the case of the above alcohol fermentation, the glucose consumption may be calculated from the cumulative amount of carbon dioxide generated, or the glucose concentration in the object 40 may be calculated by giving the initial glucose concentration in advance. In addition to the above, when the mechanism of change (metabolism) involving carbon dioxide generation in the object 40 is clear, the amount of change in components contributing thereto and the concentration in the object 40 may also be calculated.

[0099] In addition, the alert generation condition may be, in addition to the ethanol concentration, the carbon dioxide concentration or other values calculated from this concentration. Examples of other values may include substrates, other metabolites, cumulative values of carbon dioxide concentration, and changes in carbon dioxide concentration.

[0100] All of the above processes are carried out under the control of a controller. The controller is a computer having a processor, a memory, etc. The controller controls each part of the carbon dioxide measuring device 100, acquires data from the sensor 16, the suction unit 20, etc., and based on the set values stored in advance (for example, the areas of the first inlet 12 and the second inlet 14), etc., executes the processing related to each of the above steps. Note that a program for executing the above process is stored in advance in the memory of the controller.

Example

[0101] Next, the experimental results of examining the correlation between the measurement result of the carbon dioxide concentration using the carbon dioxide measuring device and the ethanol concentration in the object will be described.

[0102] (Preparation of probe) Figure 4 is an image of the probe of the carbon dioxide measuring device used in the experiment. The probe 10 is composed of a plurality of vinyl chloride pipes with different diameters connected in series. A pipe with an inner diameter of 40 mm is used at the tip 10A of the probe 10, and the inner diameter of the first inlet 12 is 40 mm. In addition, a second inlet 14 is provided at the tip 10A of the probe 10, and its diameter is 13 mm. A conduit 18 with an inner diameter of approximately the same size is connected to the second inlet 14, and a joint 18A for attaching a flexible tube is provided at its tip. Also, the length from the lower end of the probe 10 to the lower end of the second inlet 14 was approximately 415 mm.

[0103] A sensor 16 was housed in the central part 10B of the probe 10. The sensor 16 used was the SCD30 manufactured by Sensirion using the infrared absorption method. The central part 10B had an inner diameter of 51 mm. The rear end part 10C used a pipe with a smaller inner diameter than the tip part 10A and the central part 10B, and a joint 20B for connecting the suction unit 20 was provided at its tip. The length of the probe from the tip to the rear end was approximately 950 mm.

[0104] (Preparation of the object) The liquid of the object was prepared as follows. First, 2 kg of steamed rice, 1 kg of dried koji, and 5 L of purified water were added to an open tank and heated at 56 °C for 8 hours. After cooling this and brewing at 25 °C for 2 days, 300 mL of sake yeast was added and fermented to prepare the liquid.

[0105] (Measurement of carbon dioxide concentration, measurement of alcohol concentration) The tip of the probe was inserted into the object by about 5 cm, and the probe was fixed perpendicular to the liquid surface. A support stand was used to fix the probe. The measurement of carbon dioxide concentration was carried out at a measurement interval of 30 seconds and a gas flow rate of 2 L / min. The carbon dioxide concentrations at 30-second intervals were averaged over 10 minutes, and the gas flow rate was multiplied by the average value to calculate the carbon dioxide generation rate (ml / min). The cumulative value of carbon dioxide was calculated by multiplying the generation rate by the time (10 minutes) and integrating.

[0106] The measurement of the alcohol concentration of the liquid was carried out according to the analysis method specified by the National Tax Agency. First, the liquid to be measured was filtered to obtain a filtrate. Further, the alcohol concentration of the filtrate was measured using an alcoholizer (Anton Paar).

[0107] (Results) Figure 5 is a diagram showing the experimental results. The horizontal axis represents the elapsed time (h), and the first vertical axis (left) represents the CO 2 generation rate (mL / min) measured by the carbon dioxide measuring device and the alcohol concentration (%) measured by the sampling method (analysis method specified by the National Tax Agency). Also, the second vertical axis (right) represents the cumulative value (mL) of the CO 2 generation rate. Figure 6 is a diagram showing the correlation between the alcohol concentration measurement results by the sampling method (analysis method specified by the National Tax Agency) and the cumulative value of the CO 2 generation rate measured by the carbon dioxide measuring device.

[0108] From the above results, a very high correlation was shown between the cumulative value of carbon dioxide measured using the carbon dioxide measuring device and the alcohol concentration of the liquid (correlation coefficient 0.99). Thus, the effectiveness of the carbon dioxide measuring device and the measurement method could be confirmed. Also, the regression line between the two could be obtained, and the alcohol concentration could be estimated from the cumulative value of carbon dioxide.

Explanation of Symbols

[0109] 100 Carbon dioxide measuring device 10: Probe, 12: First inlet, 14: Second inlet, 16: Sensor, 18: Conduit, 20: Suction unit, 40: Object

Claims

1. A carbon dioxide measuring device for measuring a concentration of carbon dioxide generated from an object by bringing an end of a cylindrical probe into close proximity to or in contact with the object, comprising: a first inlet for introducing a first gas into the probe and a second inlet for introducing a second gas into the probe, the first inlet and the second inlet being disposed at the end portions of the probe, a sensor that is accommodated in the probe at a midpoint in the longitudinal direction and that measures the concentration; an airflow unit that circulates a mixed gas of the first gas and the second gas in a direction from the end toward the sensor, A carbon dioxide measuring device, wherein the second inlet is disposed closer to the sensor than the first inlet.

2. The carbon dioxide measuring device according to claim 1 , wherein the airflow unit is disposed on the opposite end side of the probe from the first inlet.

3. 2. The carbon dioxide measuring device of claim 1, wherein the object is a liquid, the first inlet is in close contact with or inserted into the liquid surface of the object to introduce the first gas generated from the object, and the second gas having a known composition is introduced from the second inlet.

4. 2. The carbon dioxide measuring device of claim 1, wherein the first inlet is an open end of the probe and the second inlet is disposed on a side of the probe.

5. 2. The carbon dioxide measuring device according to claim 1, wherein a conduit for introducing the second gas is connected to the second inlet.

6. 2. The carbon dioxide measuring device of claim 1, wherein the second gas is air.

7. 6. The carbon dioxide measuring device according to claim 5, wherein the target object is a liquid contained in an open container, and the second gas is taken in by the conduit from a space separated from an opening of the open container.

8. 8. The carbon dioxide measuring device according to claim 7, wherein the object is a culture solution of a microorganism or a fermentation solution obtained by fermenting a raw material.

9. The carbon dioxide measuring device according to claim 1 , wherein the first inlet is larger than the second inlet.

10. A controller is provided. The carbon dioxide measuring device according to any one of claims 1 to 9, wherein the controller generates an alert when the concentration or a calculation result based on the concentration satisfies an alert condition.

11. The carbon dioxide measuring device according to claim 10, wherein the calculation result includes an integrated amount of carbon dioxide calculated based on the concentration and a gas flow rate due to the flow, or a concentration of a predetermined substance in the object calculated from the integrated amount.

12. A controller is provided. The carbon dioxide measuring device according to any one of claims 1 to 9, wherein the controller calculates the concentration of a predetermined substance in the object from an integrated amount of carbon dioxide calculated from the concentration and the gas flow rate due to the circulation based on a predetermined conversion formula.

13. 13. The carbon dioxide measuring device according to claim 12, wherein the object is a culture solution of a microorganism or a fermentation solution obtained by fermenting a raw material, and the predetermined substance is ethanol.

14. A carbon dioxide measuring device for measuring a concentration of carbon dioxide generated from an object, which is a culture solution of a microorganism or a fermentation solution obtained by fermenting a raw material, by contacting or inserting an end of a cylindrical probe into the liquid surface of the object, a first inlet for introducing a first gas into the probe and a second inlet for introducing a second gas into the probe, the first inlet and the second inlet being disposed at the end portions of the probe, a sensor that is accommodated in a mid-point of the probe in a longitudinal direction and that measures the concentration; an airflow unit that circulates a mixed gas of the first gas and the second gas in a direction from the end toward the sensor; A controller, The second inlet is disposed closer to the sensor than the first inlet, The controller calculates the concentration of ethanol in the target object from an integrated amount of carbon dioxide calculated from the concentration and the gas flow rate due to the flow, based on a predetermined conversion formula.

15. A method for measuring a carbon dioxide concentration, comprising: measuring a concentration of carbon dioxide generated from the object by using the carbon dioxide measuring device according to claim 1.

16. Measuring a concentration of carbon dioxide generated from the object using the carbon dioxide measuring device according to claim 1; calculating an ethanol concentration contained in the target object, which is a culture solution of a microorganism or a fermentation solution obtained by fermenting a raw material, from an integrated amount of carbon dioxide calculated from the concentration and the gas flow rate due to the flow based on a predetermined conversion formula.

Images