Gas concentration calculation method and gas concentration measurement device

Abstract

To provide a gas concentration computation method and a gas concentration computation device, with which it is possible to measure gas concentrations without using a container (cell) into which the gas to be measured is introduced.SOLUTION: Provided is a gas concentration computation method for computing, using a device having a distance measurement sensor and two or more infrared sensors differing in sensitivity bandwidth, the concentration of a prescribed gas component existing in a space between the device and a light source body. The gas concentration computation method comprises: a distance measurement step for measuring the distance between the device and the light source body; and a concentration computation step for computing the concentration of a prescribed gas component on the basis of a signal from each of the infrared sensors and a signal from the distance measurement sensor, which indicates the distance between the light source body and the device, when the light source body covers the entire visual field of all infrared sensors.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a gas concentration calculation method and a gas concentration measurement device. [Background technology]

[0002] One method for measuring gas concentration is to use the non-dispersive infrared absorption method. A gas concentration sensor using the non-dispersive infrared absorption method utilizes the property of the measured gas to absorb infrared rays in a specific wavelength range, and the concentration of the measured gas can be calculated from the amount of infrared rays absorbed by the measured gas. A conventionally known gas concentration measuring device includes a container (cell) into which the gas to be measured is introduced, and inside the cell is provided a light source that emits infrared rays and an infrared sensor that detects the infrared rays emitted from the light source (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2012-73098 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, as described above, conventional gas concentration measurement devices and methods are based on the premise of using a container (cell) into which the gas to be measured is introduced. Therefore, there are limitations to the practical applications of the devices due to the limitations of the size of the entire device, and the reality is that the idea of ​​installing the devices in mobile devices, etc. has not even occurred to me.

[0005] Therefore, an object of the present invention is to provide a gas concentration calculation method and a gas concentration measurement device that are capable of measuring the gas concentration without using a container (cell) into which the measurement gas is introduced. [Means for solving the problem]

[0006] The present invention is as follows. [1] A device having a distance measuring sensor and two or more infrared sensors with different wavelength sensitivity bands is used, and , facing the infrared sensor A gas concentration calculation method for calculating a concentration of a predetermined gas component present in a space between a light source body, a distance measuring step of measuring a distance between the device and the light source body by the distance measuring sensor; a concentration calculation step of calculating a concentration of the predetermined gas component based on a signal from each of the infrared sensors and a signal from the distance measuring sensor indicating a distance between the light source body and the device when it is determined that the light source body covers the entire field of view of all of the infrared sensors; a temperature measuring step of measuring the temperature of the light source body; Equipped with 、 The case where the temperature of the light source body is within a predetermined range and is caused by human movement is defined as the case where the light source body covers the entire field of view of all the infrared sensors. A gas concentration calculation method characterized by 。 [2 ] When the temperature of the light source body is within a predetermined range and is caused by human movement, and when the distance between the device and the light source body is within a predetermined range, the light source body covers the entire field of view of all the infrared sensors. 1 ] A method for calculating gas concentration 。 [3 ] The temperature of the light source body is 30°C or higher and 40°C or lower. [1] Or [2] The gas concentration calculation method according to claim 1, [ 4 ] The light source body is a part of the human body. 3 ] A gas concentration calculation method according to any one of the preceding claims. [ 5 ] The part of the human body is a human hand, 4 ] A gas concentration calculation method according to the present invention. [ 6 ] A gas concentration measurement device used in the gas concentration calculation method according to any one of [1] to [5], a first infrared sensor having sensitivity to light in an absorption wavelength band of a predetermined gas component; a second infrared sensor having sensitivity to light outside the absorption wavelength band of the predetermined gas component; Facing the first and second infrared sensors A distance measuring sensor for measuring a distance to a light source; a calculation processing unit that calculates a concentration of the predetermined gas component based on signals from the first and second infrared sensors and a signal from the distance measuring sensor when it is determined that the light source body covers the entire fields of view of the first and second infrared sensors; Equipped with 、 The temperature of the light source body can be measured. A gas concentration measuring device characterized by 。 [7 ] The infrared ray sensor further includes an optical member, and infrared rays from the light source body are incident on the first infrared sensor and the second infrared sensor via the optical member. [6] The gas concentration measuring device according to claim 1 . [ 8 ] The optical member prevents a substance from entering the inside of the gas concentration measurement device from the outside of the gas concentration measurement device. 7

[0023] A gas concentration measuring device according to the 。 [9 ] The temperature of the light source body is measured by at least one of the first infrared sensor and the second infrared sensor. [6] - [8] The gas concentration measuring device according to claim 1 . Effect of the Invention

[0007] According to the present invention, it is possible to provide a gas concentration calculation method and a gas concentration measurement device that are capable of measuring the gas concentration without using a container (cell) into which a gas to be measured is introduced. [Brief description of the drawings]

[0008] [Figure 1]FIG. 2(a) is a schematic diagram showing the positional relationship between a gas concentration measurement device and a light source body according to a first embodiment, and (b) is a partially enlarged view of (a) showing the configuration of the gas concentration measurement device. [Diagram 2] FIG. 2 is a schematic diagram showing the configuration of a gas concentration measurement device according to a second embodiment. [Diagram 3] FIG. 4 is a schematic diagram showing the configuration of a gas concentration measurement device according to a third embodiment. [Figure 4] 11 is a schematic diagram of a gas concentration measurement device according to a third embodiment mounted on an earphone and worn on a human ear. FIG. [Diagram 5] FIG. 2 is a schematic diagram showing the configuration of a gas concentration measurement device of a first embodiment further having an optical member. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Below, a form for implementing the present invention (hereinafter referred to as the "present embodiment") will be described in detail, but the present invention is not limited to the following embodiment and can be implemented in various modified forms within the scope of its gist.

[0010] <Gas concentration calculation method> A first aspect of the gas concentration calculation method of this embodiment is a gas concentration calculation method that uses a device having a distance measurement sensor and two or more infrared sensors with different sensitivity wavelength bands to calculate the concentration of a predetermined gas component present in the space between the device and a light source body, and includes a distance measurement process that measures the distance between the device and the light source body using the distance measurement sensor, and a concentration calculation process that calculates the concentration of the predetermined gas component based on a signal from each of the infrared sensors and a signal from the distance measurement sensor indicating the distance between the light source body and the device when the light source body covers the entire field of view of all of the infrared sensors. When the light source body covers the entire field of view of all the infrared sensors, a part of the infrared emitted from the light source body is absorbed by the gas to be detected that exists in the space between the light source body and the infrared sensor, and the remainder reaches the infrared sensor. In this case, for example, by making the sensitivity wavelength band of the first infrared sensor include the wavelength band absorbed by the gas to be detected and making the sensitivity wavelength band of the second infrared sensor not include the wavelength band absorbed by the gas to be detected, it is possible to derive the concentration of the gas to be measured that exists in the space between the light source body and the infrared sensor based on the signals output from these two infrared sensors and a signal from a distance measuring sensor that indicates the distance from the light source body to the device. In the present disclosure, the distance between the device and the light source body is defined as the shortest straight-line distance from one point on the surface of the device to one point on the surface of the light source body.

[0011] The distance measuring sensor is not particularly limited as long as it can measure the distance from the light source to the device, and examples of the distance measuring sensor include a LiDAR sensor, a RADAR sensor, an ultrasonic sensor, etc. Among them, a LiDAR sensor is preferable from the viewpoints of measurement accuracy and optical sensing. Further, the position of the distance measuring sensor on the device is not particularly limited, but it is preferable that the sensor be disposed in the center of the surface facing the light source.

[0012] The infrared sensor is not particularly limited as long as it can output a signal corresponding to the intensity of the incident infrared ray, and examples of the infrared sensor include a pyroelectric sensor, a thermopile, a bolometer, a quantum infrared sensor, etc. Among them, the quantum infrared sensor is preferable from the viewpoint of measurement accuracy. The number of infrared sensors having different sensitivity wavelength bands is required to be at least two: one having a sensitivity wavelength band that includes the wavelength band absorbed by the gas to be detected, and one having a sensitivity wavelength band that does not include the wavelength band absorbed by the gas to be detected.The number of infrared sensors having sensitivity wavelength bands that include each of the wavelength bands absorbed by the gas to be detected can be increased depending on the number of gas types to be detected. In addition, the placement position of the infrared sensor on the device is not particularly limited, but it is preferable that at least two infrared sensors are placed on the surface facing the light source symmetrically with respect to a short-side line passing through the center of the surface.

[0013] In the present disclosure, the sensitivity wavelength band of an infrared sensor means the wavelength band of infrared light to which the infrared sensor is sensitive. The sensitivity wavelength band can usually be adjusted by an optical filter or the like combined with the infrared sensor. The band is divided by a bandpass optical filter into a wavelength band that passes through the optical filter (for example, from the wavelength at which the transmittance peaks to the wavelength at which the transmittance drops by 5% from the peak) and other wavelength bands that do not pass through the optical filter. Although it is also influenced by the sensitivity wavelength band of the infrared sensor itself, the sensitivity wavelength band of an infrared sensor adjusted by an optical filter is equivalent to the wavelength band that passes through the optical filter. As a specific example of the sensitivity wavelength band of the infrared sensor, for example, when detecting carbon dioxide, the sensitivity wavelength band of the first infrared sensor is set to around 4.3 μm, which is the infrared wavelength band absorbed by carbon dioxide, while the sensitivity wavelength band of the second infrared sensor is preferably a wavelength band not absorbed by carbon dioxide and not absorbed by other gases, for example, around 3.8 μm.

[0014] The light source body is not particularly limited as long as it emits infrared rays, but from the viewpoint of being able to easily obtain a light source body with a specified temperature range, it is preferable that the temperature be 30°C or higher and 40°C or lower, and from the viewpoint of measurement accuracy, it is more preferable that the temperature be higher than room temperature, i.e., the temperature of the infrared sensor, and be stable in the range of 35°C or higher and 40°C or lower, like the human body. Furthermore, from the viewpoint of easily covering the field of view of the infrared sensor, it is preferable that the light source be a part of the human body, and it is more preferable that it be a human hand (palm or back of the hand) because of its relatively large area and high mobility.

[0015] There are no particular limitations on the gas to be measured so long as it is a gas capable of absorbing infrared rays, and examples of the gas to be measured include carbon dioxide and methane.

[0016] The gas concentration can be calculated based on the signals from each infrared sensor and the signal from the distance measurement sensor using the following formula (1).

number

[0017] Here, as described above, the light source body in this embodiment is not an illumination such as a lamp installed at a fixed distance as in the conventional gas concentration sensor, but a part of a human body or the like arranged outside the housing of a device in which an infrared sensor is installed, and is preferably used. In the conventional gas concentration sensor, the light source body is installed facing the infrared sensor installed at one end of a container (cell) into which a gas to be measured is introduced, so the light source optical path length d is constant. However, when the light source body becomes a part of a human body or the like as in this embodiment, the optical path length d becomes variable, so that the optical path length d is a variable and needs to be measured to obtain the gas concentration c in formula (1). Therefore, in the gas concentration calculation method of this embodiment, the optical path length d is obtained using a signal from a distance measuring sensor that measures the distance from the light source body to the device. Therefore, according to the gas concentration calculation method of this embodiment, gas concentration measurement is possible without using a container (cell) into which a gas to be measured is introduced.

[0018] There is no particular limitation on the method of determining whether the light source body covers the entire field of view of all the infrared sensors. As an example, based on the relationship between the size of the light source body and the field of view of the infrared sensors, when the distance between the device and the light source body is within a predetermined range, the light source body covers the entire field of view of all the infrared sensors. In this case, since the determination can be made based only on the distance between the device and the light source body, it is possible to efficiently calculate the gas concentration without using elements that consume a lot of power, such as an image sensor. From the standpoint of reducing power consumption and improving measurement accuracy, it is preferable to execute the concentration calculation step when the distance between the device and the light source is within a predetermined range in this manner.

[0019] Another example of a method for determining whether the light source body covers the entire field of view of all infrared sensors is to further include a temperature measurement step for measuring the temperature of the light source body, and when the temperature of the light source body is within a predetermined range and has a predetermined fluctuation pattern, the light source body is in a state of covering the entire field of view of all infrared sensors. For example, when the light source body is a part of the human body (e.g., a hand), its temperature is generally within a predetermined range (around 36°C), so when the temperature of the light source body is around 36°C for a predetermined period of time, it can be determined that the light source body covers the entire field of view of all infrared sensors. From the standpoint of reducing power consumption and improving measurement accuracy, it is preferable to execute the concentration calculation step when the temperature of the light source body is within a predetermined range and follows a predetermined fluctuation pattern. The predetermined temperature range may be appropriately determined depending on the type of light source. The predetermined temperature change pattern may be, for example, a change in temperature in a relatively short time due to human movement, rather than a gradual change from room temperature to the temperature of the light source, or a temperature fluctuation due to human movement.

[0020] In addition, combining the above examples, the time when the distance between the device and the light source body is within a specified range, the temperature of the light source body is within a specified range, and the temperature fluctuation pattern is a specified pattern may be defined as the time when the light source body covers the entire field of view of all infrared sensors. As mentioned above, from the standpoint of reducing power consumption and improving measurement accuracy, it is preferable to execute the concentration calculation process when the distance between the device and the light source body is within a specified range, the temperature of the light source body is within a specified range, and the fluctuation pattern is a specified one.

[0021] This first aspect of the gas concentration calculation method can be realized, for example, by using as a device the first aspect of the gas concentration measuring device of this embodiment described later, i.e., a gas concentration measuring device comprising a first infrared sensor sensitive to light in the absorption wavelength band of a predetermined gas component, a second infrared sensor sensitive to light outside the absorption wavelength band of the predetermined gas component, a distance measuring sensor that measures the distance to a light source, and an arithmetic processing unit that calculates the concentration of the predetermined gas component based on signals from the first and second infrared sensors and a signal from the distance measuring sensor.

[0022] A second aspect of the gas concentration calculation method of this embodiment is a gas concentration calculation method that uses a device having two or more infrared sensors with different sensitivity wavelength bands to calculate the concentration of a predetermined gas component present in a space between the device and a light source body, and includes an arrangement step of placing the light source body at a position a predetermined distance away from the device, and a concentration calculation step of calculating the concentration of the predetermined gas component based on signals from each of the infrared sensors and the predetermined distance when the light source body covers the entire field of view of all of the infrared sensors.

[0023] The difference from the gas concentration calculation method of the first embodiment is that there is no distance measurement step, but rather a placement step of placing the light source at a position a predetermined distance away from the device. By placing the light source at a predetermined distance away from the device, it is possible to calculate the gas concentration in a similar manner using the above-mentioned equation (1) without the distance measurement process required in the gas concentration calculation method of the first aspect. The infrared sensor, its sensitivity wavelength band, light source, and predetermined gas component may be the same as those in the gas concentration calculation method of the first aspect.

[0024] The method of arranging the light source body in the arranging step is not particularly limited, but an example is a method using an instruction step of instructing to arrange the light source body at a position a predetermined distance away from the device. Specifically, for example, if the device has a sound output function, the arrangement position of the light source body may be indicated by voice, and if the device has a display function, the arrangement position of the light source body may be indicated by images, characters, etc.

[0025] The second aspect of the gas concentration calculation method including this instruction step can be realized, for example, by the second aspect of the gas concentration measurement device of the present embodiment described later, i.e., a gas concentration measurement device including a first infrared sensor sensitive to light in the absorption wavelength band of a predetermined gas component, a second infrared sensor sensitive to light outside the absorption wavelength band of the predetermined gas component, an instruction unit that instructs the light source to be positioned at a position a predetermined distance away, and a calculation processing unit that calculates the concentration of the predetermined gas component based on signals from the first and second infrared sensors and the predetermined distance.

[0026] Another example of a method for arranging the light source body in the arranging step is a method using a wearing step in which a device is worn at a predetermined position on the light source body. Specifically, for example, when the device is a wearable device such as glasses, a headset, or an HMD, the device is worn on the light source body (a part of the human body, etc.) so that the distance from the light source body to the device is a predetermined distance. At this time, by arranging each infrared sensor in a position where the light source body covers the entire field of view of all infrared sensors (for example, in the case of glasses, around the bridge or hinge), when the device is worn on the light source body, the light source body covers the entire field of view of all infrared sensors, making it possible to perform the concentration calculation step. According to this method, the light source body (for example, a human) does not need to follow detailed instructions from the device, but only by the simple action of wearing the device, it is possible to arrange the infrared sensor at a position that enables gas concentration measurement.

[0027] The gas concentration calculation method of the second aspect including this mounting process can be realized, for example, by using as a device the third aspect of the gas concentration measuring device of this embodiment described later, that is, a gas concentration measuring device including a first infrared sensor sensitive to light in the absorption wavelength band of a predetermined gas component, a second infrared sensor sensitive to light outside the absorption wavelength band of the predetermined gas component, a detection unit that detects that a light source body is positioned at a position a predetermined distance away, and a calculation processing unit that calculates the concentration of the predetermined gas component based on signals from the first and second infrared sensors and the predetermined distance.

[0028] <Gas concentration measuring device> A first aspect of the gas concentration measuring device of this embodiment comprises a first infrared sensor sensitive to light in the absorption wavelength band of a specified gas component, a second infrared sensor sensitive to light outside the absorption wavelength band of the specified gas component, a distance measuring sensor that measures the distance to a light source, and a calculation processing unit that calculates the concentration of the specified gas component based on signals from the first and second infrared sensors and a signal from the distance measuring sensor.

[0029] Fig. 1 is a schematic diagram of a gas concentration measurement device of a first embodiment. Fig. 1(a) is a schematic diagram showing the positional relationship between the gas concentration measurement device and a light source body, and Fig. 1(b) is an enlarged schematic diagram of Fig. 1(a) showing the configuration of the gas concentration measurement device. FIG. 1(a) shows a state in which a light source body 100 covers the entire fields of view of two or more infrared sensors (two in FIG. 1(a)) having different sensitivity wavelength bands that a gas concentration measurement device 10 has. 1(a), as shown in FIG. 1(b), the first infrared sensor 21 and the second infrared sensor 22, which have different sensitivity wavelength bands, receive infrared light emitted from the light source body 100 and output signals S21 and S22 corresponding to the received infrared light to the calculation processing unit 40. Note that the sensitivity wavelength band of the first infrared sensor 21 includes a wavelength band absorbed by the gas to be detected, and the sensitivity wavelength band of the second infrared sensor 22 does not include a wavelength band absorbed by the gas to be detected. Further, the distance measuring sensor 30 outputs a signal S30 corresponding to the distance D from the gas concentration measuring device 10 to the light source body 100 to the calculation processing unit 40. The calculation processing unit 40 calculates the concentration of the target gas present in the space between the light source body 100 and the gas concentration measuring device 10 based on the signals S21, S22, and S30.

[0030] In addition, from the standpoint of measurement accuracy and reduced power consumption, when the signal S30 from the distance sensor 30 is higher than a predetermined threshold (the distance D between the light source body 100 and the gas concentration measuring device 10 is smaller than a predetermined threshold), it may be assumed that the light source body 100 covers the entire field of view of all infrared sensors (FOV1 and FOV2 in the case of Figure 1(b)), and the concentration of the above-mentioned gas components may be calculated.

[0031] In addition, the temperature of the light source body 100 may be measured by the first infrared sensor 21 and / or the second infrared sensor 22, or another independent temperature sensor, and the concentration of the above gas components may be calculated when the temperature is within a predetermined range and has a predetermined fluctuation pattern. The predetermined temperature range may be appropriately determined depending on the type of light source. The predetermined temperature change pattern may be, for example, a change in temperature in a relatively short time due to human movement, rather than a gradual change from room temperature to the temperature of the light source, or a temperature fluctuation due to human movement.

[0032] The distance measuring sensor, the infrared sensor and its sensitivity wavelength band, and the predetermined gas component in the gas concentration measuring device of the first aspect may be similar to those described in the gas concentration calculation method of the first aspect above.

[0033] The light source body 100 is not particularly limited as long as it emits infrared rays, but it is preferable that the temperature is constant. As an example, a temperature of 30°C or more and 40°C or less is preferable, and from the viewpoint of measurement accuracy, a temperature higher than room temperature, i.e., the temperature of the infrared sensor, and stable in the range of 35°C or more and 40°C or less, such as the human body, is more preferable. As a light source body 100 that realizes this, a part of the human body can be mentioned because it is easy to cover the field of view of the infrared sensor. In addition, it may be particularly preferable to use the palm or the back of the hand of the human body because of its relatively large area and high mobility.

[0034] The specific form of the gas concentration calculation device 10 is not particularly limited, but examples include devices such as smartphones, tablets, and personal computers, and wearable devices such as glasses, headsets, and HMDs.

[0035] A second aspect of the gas concentration measuring device of this embodiment comprises a first infrared sensor sensitive to light in the absorption wavelength band of a specified gas component, a second infrared sensor sensitive to light outside the absorption wavelength band of the specified gas component, an instruction unit that instructs the light source to be positioned at a position a specified distance away, and a calculation processing unit that calculates the concentration of the specified gas component based on signals from the first and second infrared sensors and the specified distance.

[0036] 2 is a schematic diagram of a gas concentration calculation device according to a second embodiment. The gas concentration calculation device 10 according to the second embodiment differs from the first embodiment in that it has an indicator 50 instead of the distance measurement sensor 30. The infrared sensor, its sensitivity wavelength band, light source, and predetermined gas component may be the same as those in the gas concentration measuring device of the first aspect.

[0037] The instructing unit 50 instructs the light source body 100 to be placed at a position a predetermined distance away from the gas concentration calculation device 10. In other words, the instructing unit 50 instructs the light source body 100 to be placed at a position that covers the entire field of view of the first infrared sensor 21 and the second infrared sensor 22. The method of instruction is not particularly limited, and may be an instruction by displaying an image or text, or an instruction by sound, vibration, or the like.

[0038] A third aspect of the gas concentration measuring device of this embodiment comprises a first infrared sensor sensitive to light in the absorption wavelength band of a specified gas component, a second infrared sensor sensitive to light outside the absorption wavelength band of the specified gas component, a detection unit that detects when a light source body is positioned at a predetermined distance away, and a calculation processing unit that calculates the concentration of the specified gas component based on signals from the first and second infrared sensors and the predetermined distance.

[0039] 3 is a schematic diagram of a gas concentration measurement device according to a third embodiment. The gas concentration calculation device 10 according to the third embodiment differs from the first embodiment in that it has a detection unit 60 instead of the distance measurement sensor 30. The detection unit 60 detects that the light source body 100 is placed at a position a predetermined distance away from the gas concentration calculation device 10. In other words, it detects that the light source body 100 is placed at a position that covers the entire field of view of the first infrared sensor 21 and the second infrared sensor 22. A specific example of the detection unit is a contact sensor, but is not limited to this.

[0040] 4 is a schematic diagram of the gas concentration measurement device of the third embodiment mounted on an earphone and worn on a human ear. The detection unit 60 detects that the earphone is worn on the ear and that a part of the ear is placed at a position a predetermined distance away from the gas concentration calculation device 10. In other words, it detects that the first infrared sensor 21 and the second infrared sensor 22 are placed at a position where their entire fields of view are covered by a part of the ear.

[0041] 5 is a schematic diagram of the gas concentration measurement device of the first embodiment further including an optical member 70. Similarly, the gas concentration measurement devices of the second and third embodiments may also further include the optical member 70.

[0042] When the optical member 70 is included, it is preferable that the infrared rays from the light source body 100 are incident on the first infrared sensor 21 and the second infrared sensor 22 via the optical member 70. This makes it possible to easily make the sensitivity wavelength bands of the first infrared sensor 21 and the second infrared sensor 22 different from each other.

[0043] Moreover, it is preferable that the optical member 70 can prevent external substances (for example, water or dust) from entering the inside of the gas concentration measurement device 10. In addition, it can prevent external substances that may affect the measurement accuracy from adhering to the surfaces of the infrared sensor and the distance measurement sensor, and even if they do adhere, they can be easily removed.

[0044] Moreover, from the viewpoint of improving the accuracy of gas concentration measurement, it is preferable that the gas concentration measurement device of this embodiment is capable of measuring the temperature of the light source body. The method of measuring the temperature of the light source body is not particularly limited, and may be measured by at least one of the first infrared sensor and the second infrared sensor, or may be further provided with another independent temperature sensor and measured by this.

[0045] Although the above-mentioned embodiment has been described as a representative example, it is obvious to those skilled in the art that many modifications and substitutions can be made within the spirit and scope of the present disclosure. Therefore, the present invention should not be interpreted as being limited by the above-mentioned embodiment, and various modifications and changes are possible without departing from the scope of the claims. [Explanation of symbols]

[0046] 10 Gas concentration measuring device 21 First infrared sensor 22 Second infrared sensor 30 Distance sensor 40 Processing unit 50 Instruction section 60 Detection unit 70 Optical Components 100 light source FOV1, FOV2 (infrared sensor) field of view D Distance from the light source to the gas concentration measuring device S21: signal from the first infrared sensor S22: signal from the second infrared sensor Signal from S30 distance sensor

Claims

1. A gas concentration calculation method for calculating a concentration of a predetermined gas component present in a space between a distance measuring sensor and a light source body facing the infrared sensors, the device including the distance measuring sensor and two or more infrared sensors having different sensitivity wavelength bands, the device comprising: a distance measuring step of measuring a distance between the device and the light source body by the distance measuring sensor; a concentration calculation step of calculating a concentration of the predetermined gas component based on a signal from each of the infrared sensors and a signal from the distance measuring sensor indicating a distance between the light source body and the device when it is determined that the light source body covers the entire field of view of all of the infrared sensors; a temperature measuring step of measuring the temperature of the light source body; Equipped with The case where the temperature of the light source body is within a predetermined range and is caused by human movement is defined as the case where the light source body covers the entire field of view of all the infrared sensors. A gas concentration calculation method comprising:

2. 2. The gas concentration calculation method according to claim 1, wherein a state in which the temperature of the light source body is within a predetermined range and is caused by human movement and a distance between the device and the light source body is within a predetermined range is defined as a state in which the light source body covers the entire field of view of all of the infrared sensors.

3. 3. The gas concentration calculation method according to claim 1, wherein the temperature of the light source body is 30° C. or higher and 40° C. or lower.

4. 4. The gas concentration calculation method according to claim 1, wherein the light source is a part of a human body.

5. The gas concentration calculation method according to claim 4 , wherein the part of the human body is a human hand.

6. A gas concentration measurement device used in the gas concentration calculation method according to any one of claims 1 to 5, a first infrared sensor having sensitivity to light in an absorption wavelength band of a predetermined gas component; a second infrared sensor having sensitivity to light outside the absorption wavelength band of the predetermined gas component; a distance measuring sensor that measures a distance to a light source facing the first and second infrared sensors; a calculation processing unit that calculates a concentration of the predetermined gas component based on signals from the first and second infrared sensors and a signal from the distance measuring sensor when it is determined that the light source body covers the entire fields of view of the first and second infrared sensors; Equipped with The temperature of the light source body can be measured. A gas concentration measuring device comprising:

7. 7. The gas concentration measurement device according to claim 6, further comprising an optical member, wherein the infrared light from the light source is incident on the first infrared sensor and the second infrared sensor via the optical member.

8. The gas concentration measurement device according to claim 7 , wherein the optical member prevents a substance from entering the inside of the gas concentration measurement device from the outside of the gas concentration measurement device.

9. 9. The gas concentration measurement device according to claim 6, wherein the temperature of the light source body is measured by at least one of the first infrared sensor and the second infrared sensor.

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