This application is based on Japanese Patent Application No. 2022-062885 filed with Japan Patent Office on Apr. 5, 2022, the entire contents of which are hereby incorporated by reference.
The present disclosure relates to a gas measuring device.
Japanese Unexamined Patent Publication No. 2015-127642 discloses a gas detection device that includes a filter made of fibrous activated carbon and a MEMS gas sensor. The gas detection device has a function of screening gas components that are detection targets and gas components that are not detection targets from each other by causing the filter to adsorb miscellaneous gases that are not detection targets. The adsorption capacity of the filter decreases with the adsorption of the miscellaneous gases. For this reason, the gas detection device has a heater for regenerating the adsorption capacity of the filter. The filter heated by the heater desorbs the adsorbed gas. Accordingly, the adsorption capacity of the filter is regenerated.
The gas detection device disclosed in Japanese Unexamined Patent Publication No. 2015-127642 requires periodical heat cleaning of the filter. However, the gas detection device cannot detect a gas while the heat cleaning is being performed. The present disclosure provides a gas measuring device that can continuously use a screening function for gas components.
A gas measuring device according to an aspect of the present disclosure includes: a magnetic field generation unit configured to generate a magnetic field; and a gas sensor configured to detect a gas that has passed through the magnetic field generated by the magnetic field generation unit.
In this gas measuring device, the gas to be measured by the gas sensor passes through the magnetic field generated by the magnetic field generation unit. When the gas passes through the magnetic field, an attractive force due to the magnetic field acts on a paramagnetic gas. A repulsive force due to the magnetic field acts on a diamagnetic gas. For this reason, the gas measuring device can control a traveling direction of the gas according to the magnetic properties of the gas, and thus a screening function for gas components can be exhibited. Since the magnetic field acts indirectly on the gas, the screening function does not deteriorate even after continuous use. Therefore, this gas measuring device can continuously use the screening function for gas components.
In an embodiment, the magnetic field generation unit may be made of a permanent magnet. In a configuration in which the magnetic field generation unit is made of the permanent magnet, the magnetic field is generated without using electricity, and thus the screening function for gas components can be continuously used with a simple configuration.
In an embodiment, the gas measuring device may further include a power supply unit. The magnetic field generation unit may be a coil. The power supply unit may energize the coil. The coil generates the magnetic field when energized. Therefore, in a configuration in which the magnetic field generation unit is a coil energized by the power supply unit, it is possible to switch a state in which gas components are screened and a state in which gas components are not screened by interrupting the energization.
In an embodiment, the gas measuring device may further include a signal generation unit, a control unit, an acquisition unit, and an output unit. The signal generation unit outputs a synchronization signal for determining a timing. The control unit controls the power supply unit on the basis of a control signal for determining a magnitude of a voltage or current and the synchronization signal such that the voltage or current having the magnitude determined with the control signal is applied to the coil at the timing determined with the synchronization signal. The acquisition unit acquires a detection value of the gas sensor at the timing determined with the synchronization signal. The output unit outputs the detection value and the control signal in association with each other. In this case, the gas measuring device can output the detection value and the synchronization signal in association with each other.
In an embodiment, the gas measuring device may further include a determination unit configured to determine a gas type on the basis of a pre-acquired relationship among the gas type, the detection value, and the control signal, and the detection value and the control signal output from the output unit. In this case, the gas measuring device can determine the gas types of a mixed gas including a paramagnetic gas component and a diamagnetic gas component of which traveling directions are different from each other.
In an embodiment, the gas measuring device may further include a plurality of gas sensors including the gas sensor. The plurality of gas sensors includes different gas sensors capable of detecting a gas type different from a gas type detected by the gas sensor. In this case, the gas measuring device can improve gas detection accuracy compared to a gas measuring device having a gas sensor capable of detecting a single type of a gas.
In an embodiment, the gas measuring device may further include a plurality of gas sensors including the gas sensor. The plurality of gas sensors is disposed in a direction of the magnetic field generated by the magnetic field generation unit. An attractive force in the direction of the magnetic field acts on the traveling direction of the paramagnetic gas. A repulsive force in the direction of the magnetic field acts on the traveling direction of the diamagnetic gas. For this reason, the plurality of gas sensors can detect a plurality of types of gas components screened in the direction of the magnetic field.
The present disclosure provides a gas measuring device that can continuously use a screening function for gas components.
Embodiments of the present disclosure will be described below with reference to the drawings. In the following description, the same or corresponding elements are denoted by the same reference signs, and redundant description will not be repeated. The dimensional proportions of the drawings do not necessarily match those of the description.
[Configuration of Gas Measuring Device]
The base member 40 defines a space therein. The base member 40 is formed of a gas impermeable material. An upper portion of the base member 40 is open, and the base member 40 has an opening that communicates with the space. In the present embodiment, the magnetic field generation unit 10 is a coil 11. The coil 11 is disposed to cover the opening in the upper portion of the base member 40. A gap through which a gas can pass is defined in the coil 11. The coil 11 and the base member 40 are joined together such that there is no gap through which a gas permeates other than the coil 11. Accordingly, the coil 11 and the base member 40 define a gas chamber 41.
The coil 11 is an air-core coil made of a wire wound around an axial direction. As an example, the axial direction of the coil 11 and a direction in which the inside and the outside of the gas chamber 41 communicate with each other are orthogonal to each other. The wire constituting the coil 11 is connected to the power supply unit 12 capable of applying a voltage or current. In this case, a direction of a magnetic field generated in the energized coil 11 is the axial direction.
The gas sensor 30 is provided inside the gas chamber 41. As an example, the gas sensor 30 is provided downstream of the coil 11. The gas sensor 30 is provided on a side on which the gas has passed through the coil 11. As an example, the gas measuring device 1 further includes a plurality of gas sensors 30, 31, and 32 including the gas sensor 30. The gas sensors 31 and 32 are gas sensors of different types from the gas sensor 30, which can detect a gas type different from a gas type detected by the gas sensor 30. Each of the gas sensors 30, 31, and 32 detects a gas that has passed through the coil 11 and adhered to a predetermined surface of each of the gas sensors 30, 31, and 32.
The traveling directions of the paramagnetic gas and the diamagnetic gas are changed by the coil 11. An attractive force due to the magnetic field acts on the paramagnetic gas. A traveling direction C1 of the paramagnetic gas is attracted to a position where the magnetic flux density is high. In the present embodiment, the traveling direction C1 of the paramagnetic gas changes to be attracted to the center of the coil 11 in the axial direction. A repulsive force due to the magnetic field acts on the diamagnetic gas. A traveling direction C2 of the diamagnetic gas is attracted to a position where the magnetic flux density is low. In the present embodiment, the traveling direction C2 of the diamagnetic gas changes to be attracted to both ends of the coil 11 in the axial direction.
As shown in
The gas sensor 31 mainly detects the paramagnetic gas component whose traveling direction C1 is changed to the center of the coil 11 in the axial direction. The gas sensors 30 and 32 mainly detect the diamagnetic gas component whose traveling direction C2 is changed to both ends of the coil 11 in the axial direction.
[Control Circuit of Gas Measuring Device]
The signal generation unit 60 outputs a control signal and a synchronization signal to the control unit 50 and the acquisition unit 70. The control signal is a signal for determining the magnitude of the voltage or current that is applied to the coil 11 from the power supply unit 12. The synchronization signal is a signal for determining a timing of an operation of each of the control unit 50 and the acquisition unit 70. The control unit 50 controls the power supply unit 12 on the basis of the control signal and the synchronization signal. Specifically, the control unit 50 controls the power supply unit 12 such that the voltage or current having the magnitude determined with the control signal is applied to the coil 11 at the timing determined with the synchronization signal.
The control unit 50 outputs a signal for controlling the power supply unit 12 according to the control signal upon receiving the rectangular wave of the synchronization signal a predetermined number of times. As an example, the control signal that changes in three steps in
The acquisition unit 70 acquires detection values detected by the gas sensors 30, 31, and 32 at the timing determined with the synchronization signal upon receiving the rectangular wave of the synchronization signal a predetermined number of times. Therefore, the acquisition unit 70 can acquire the detection value corresponding to a change in the magnitude of the voltage or current due to the control signal. The predetermined number of times of reception of the rectangular wave when the acquisition unit 70 acquires the detection value may be equal to or greater than the number of times of reception of the rectangular wave when the control unit 50 outputs the control signal. By setting the time at which the acquisition unit 70 acquires the detection value to be later than the time at which the control unit 50 outputs the control signal, it is possible for the acquisition unit 70 to acquire the detection value when the amount of the gas that has passed through the coil 11 becomes large after the magnitude of the voltage or current changes.
The output unit 80 outputs the control signal and the detection value acquired by the acquisition unit 70 in association with each other. The determination unit 90 determines the gas type on the basis of a pre-acquired relationship among the gas type, the detection value, and the control signal, and the detection value and the control signal output from the output unit 80. Combinations of the gas type, the detection value, and the control signal are acquired in advance. Combinations of the gas type, the detection value, and the control signal are stored, for example, as a gas characteristic table. The determination unit 90 refers to the gas characteristic table on the basis of the combination output from the output unit 80 and determines the gas type.
[Operation of Gas Measuring Device]
As shown in
Next, the acquisition unit 70 acquires a first measured value output from the gas sensor 31 and second measured values output from the gas sensors 30 and 32 on the basis of the synchronization signal. The output unit 80 outputs the control signal and the detection value acquired by the acquisition unit 70 in association with each other. The determination unit 90 determines the gas type on the basis of a pre-acquired relationship among the gas type, the detection value, and the control signal, and the detection value and the control signal output from the output unit 80.
The determination unit 90 determines the gas type on the basis of the gas characteristic table, the first measured value and the second measured value acquired by the acquisition unit 70, and the control signal. On the basis of the pre-acquired relationship between the magnitude of the voltage or current indicated by the control signal and the measured value, it is determined that gases that are detection targets include oxygen (O2), nitrogen monoxide (NO), water vapor (H2O), and chlorine (Cl2).
According to the gas measuring device 1, the gases to be measured by the gas sensors 30, 31, and 32 pass through the magnetic field generated by the magnetic field generation unit 10. At this time, an attractive force due to the magnetic field acts on the traveling direction of the paramagnetic gas. A repulsive force due to the magnetic field acts on the traveling direction of the diamagnetic gas. For this reason, the gas measuring device 1 can control the traveling direction of the gas according to the magnetic properties of the gas, and thus the screening function for gas components can be exhibited. Furthermore, since the magnetic field acts indirectly on the gas, the screening function does not deteriorate even after continuous use. Therefore, this gas measuring device 1 can continuously use the screening function for gas components.
In the gas measuring device 1, the energized coil 11 generates a magnetic field. Therefore, in the gas measuring device 1, it is possible to switch a state in which gas components are screened and a state in which gas components are not screened by interrupting the energization.
In the gas measuring device 1, on the basis of the control signal for determining the magnitude of the voltage or current and the synchronization signal, the control unit 50 controls the power supply unit 12 such that the voltage or current having the magnitude determined with the control signal is applied to the coil 11 at the timing determined with the synchronization signal. Then, the acquisition unit 70 acquires the detection values of the gas sensors 30, 31, and 32 at the timing determined with the synchronization signal. In this way, the gas measuring device 1 can output the detection value and the synchronization signal in association with each other.
In the gas measuring device 1, the determination unit 90 determines the gas type on the basis of the pre-acquired relationship, and the detection value and the control signal output from the output unit 80. As a result, the gas measuring device 1 can determine the gas types of the mixed gas including the paramagnetic gas and the diamagnetic gas.
In the gas measuring device 1, the gas sensors 31 and 32 can detect the gas type different from the gas type detected by the gas sensor 30. The gas measuring device 1 can improve gas detection accuracy compared to a gas measuring device having a gas sensor capable of detecting a single type of a gas.
In the gas measuring device 1, a plurality of gas sensors 30, 31, and 32 are disposed in the direction of the magnetic field of magnetic field generation unit 10. An attractive force in the direction of the magnetic field acts on the traveling direction C1 of the paramagnetic gas. A repulsive force in the direction of the magnetic field acts on the traveling direction C2 of the diamagnetic gas. For this reason, in the gas measuring device 1, a plurality of types of gas components screened in the direction of the magnetic field can be detected by a plurality of gas sensors 30, 31, and 32.
In the above, various exemplary embodiments have been described, but the present disclosure is not limited to the above exemplary embodiments, and various omissions, substitutions, and modifications may be made.
As shown in
As shown in
The magnetic field generation unit 10 and the gas sensor 30 may be manufactured by being combined after they are separately formed. The magnetic field generation unit 10 and the gas sensor 30 may be manufactured as a single body.
The signal generation unit 60 may be integrated with the control unit 50. The acquisition unit 70 may be integrated with the output unit 80. The output unit 80 may be integrated with the determination unit 90.
The gas measuring device 1 may be configured not to include the base member 40 and the gas chamber 41. In this case, the gas measuring device 1 is configured such that the magnetic field generation unit 10 is in close contact with the gas sensor 30. The gas measuring device 1 may include M types of gas sensors (M is an integer equal to or greater than 2). In a case where M is 3 or more, the M types of gas sensors may include the same type of sensors. Further, a strength of an electrostatic force of the coil 11 may be controlled in N steps (N is an integer equal to or greater than 2). In this case, the gas measuring device 1 can measure a maximum of M×N combinations of gas types.
The gas measuring device 1 may be configured not to include the determination unit 90. In this case, in the gas measuring device 1, the output unit 80 outputs the measured value and the control signal to the outside. The gas measuring device 1 may acquire in advance the relationship between the measured value and the control signal through simulation. In this case, a strength of the magnetic field generated by the magnetic field generation unit 10 and a force generated between the paramagnetic gas and the diamagnetic gas can be obtained through calculation. The relationship between the measured value and the control signal may be calibrated with the known gas. In this case, the relationship between the control signal and a strength of electrolysis of the magnetic field generation unit 10, and the output characteristics of the gas sensor 30 are calibrated on the basis of the known gas.
Number | Date | Country | Kind |
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2022-062885 | Apr 2022 | JP | national |