Substance detection device

Abstract

Compared to conventional technologies, this invention provides a substance detection device that is less susceptible to a decrease in detection accuracy due to condensation. [Solution] The substance detection device according to the present invention comprises a measuring unit that measures a physical quantity for detecting a specific substance contained in a gas, an intake flow path forming body that forms a flow path for guiding the surrounding gas to the measuring unit, and a cooling and heating unit having a Peltier element, which cools the gas flowing through the flow path before reaching the measuring unit by the heat-absorbing part of the Peltier element, and heats the measuring unit by the heat-generating part of the Peltier element.

Description

Technical Field

[0001] The present invention relates to a substance detection device that detects specific substances contained in ambient gas.

Background Art

[0002] There are devices for detecting abnormalities such as the occurrence of a fire or the generation of toxic gas. For example, in Patent Document 1, light is irradiated from a light emitting unit onto air taken in from the surroundings, and scattered light scattered by particles contained in the air is received by a light receiving unit, thereby determining whether the air contains a predetermined amount or more of smoke particles, and a scattered light type smoke detection device for detecting smoke generated in the surroundings is described.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a substance detection device that detects specific substances (such as smoke particles, carbon monoxide, etc.) contained in ambient gas (such as air), if water droplets generated by condensation adhere to a measurement unit that measures a physical quantity to detect the substance, the detection accuracy decreases.

[0005] In view of the above circumstances, the present invention provides a substance detection device in which a decrease in detection accuracy due to condensation is less likely to occur as compared with the prior art.

Means for Solving the Problems

[0006] The substance detection device according to the present invention comprises a measuring unit that measures a physical quantity for detecting a specific substance contained in a gas; an intake flow path forming body that forms a flow path for guiding the surrounding gas to the measuring unit; and a cooling and heating unit having a Peltier element, which cools the gas flowing through the flow path before reaching the measuring unit by the heat-absorbing part of the Peltier element, and heats the measuring unit by the heat-generating part of the Peltier element. [Effects of the Invention]

[0007] According to the present invention, a substance detection device is provided that is less susceptible to a decrease in detection accuracy due to condensation compared to the prior art. [Brief explanation of the drawing]

[0008] [Figure 1] A diagram showing the configuration of a substance detection device according to one embodiment. [Figure 2] A diagram showing the configuration of a substance detection device according to one modified example. [Figure 3] A diagram showing the configuration of a substance detection device according to one modified example. [Figure 4] A diagram showing the configuration of a substance detection device according to one modified example. [Figure 5] A diagram showing the configuration of a substance detection device according to one modified example. [Figure 6] A diagram showing the configuration of a substance detection device according to one modified example. [Modes for carrying out the invention]

[0009] [Embodiment] Figure 1 is a schematic diagram showing the configuration of a substance detection device 1 according to one embodiment of the present invention. The substance detection device 1 is a device that detects smoke particles (an example of a specific substance) contained in the surrounding air (an example of a gas).

[0010] Note that Figure 1 shows the front covers of the housings 10 and 110 of the substance detection device 1 removed, revealing the inside of the housings. However, these covers are attached when the substance detection device 1 is in operation. Also, the vertical direction in Figure 1 is the vertical direction when the substance detection device 1 is installed. The solid or dashed white arrows shown in Figure 1 indicate the direction of airflow, the solid arrows indicate the direction of water droplets (water) flowing due to condensation, and the dashed arrows indicate the direction of light emitted from the light-emitting part.

[0011] The substance detection device 1 comprises a housing 10, which is a box-shaped structure housing the other components of the substance detection device 1; a measuring unit 11 that measures physical quantities for detecting smoke particles contained in the air; a flow path forming body 12, which is a structure that forms a flow path that guides air from the monitoring area TA, which is the space outside the housing 10, to the measuring unit 11 and then guides that air out of the housing 10; a blower unit 13 that sends the air on the flow path formed by the flow path forming body 12 from the upstream side to the downstream side; a thermometer 14 that measures the temperature of the air in the monitoring area TA; a hygrometer 15 that measures the humidity of the air in the monitoring area TA; a thermometer 16 that measures the temperature of the measuring unit 11; a Peltier element 17 that is positioned between the measuring unit 11 and the flow path forming body 12 to cool the flow path forming body 12 and heat the measuring unit 11; a user interface 18 that notifies the user of information and accepts user instructions; and a controller 19, which is a computer that controls the operation of the substance detection device 1.

[0012] The measuring unit 11 measures the intensity of light scattered by particles in the air (scattered light) as a physical quantity for detecting smoke particles. The measuring unit 11 has a housing 110, which is a box-shaped structure that blocks light from the outside, and a light-emitting unit 111 and a light-receiving unit 112 located inside the housing 110.

[0013] The housing 110 is provided with an opening for taking in air flowing in from the flow channel forming body 12, and an opening for sending the air that has passed through the measuring unit 11 back into the flow channel forming body 12.

[0014] The housing 110 is made of a material with high thermal conductivity (for example, a metal such as aluminum) so that when heated by the heat-generating part 172 of the Peltier element 17, it heats the light-emitting part 111 and the light-receiving part 112 located inside it.

[0015] The light-emitting unit 111 continuously emits light in a predetermined direction. The light-receiving unit 112 continuously receives light coming from the predetermined direction and sequentially outputs signals indicating the intensity of the received light to the controller 19.

[0016] The path of light emitted from the light-emitting unit 111 (hereinafter referred to as the "light-emitting axis") and the path of light received by the light-receiving unit 112 (hereinafter referred to as the "light-receiving axis") are different. For example, the light-emitting unit 111 and the light-receiving unit 112 are arranged so that the light-emitting axis and the light-receiving axis intersect at a predetermined angle. Therefore, when the air does not contain smoke particles, the light emitted from the light-emitting unit 111 does not go towards the light-receiving unit 112, and the intensity of the light indicated by the signal output by the light-receiving unit 112 is very small. On the other hand, when the air contains smoke particles, some of the light emitted from the light-emitting unit 111 is scattered by the smoke particles and goes towards the light-receiving unit 112, so the intensity of the light indicated by the signal output by the light-receiving unit 112 is relatively large.

[0017] The controller 19 receives signals sequentially output from the light receiving unit 112, and if the intensity of the received signal satisfies a predetermined condition (for example, if the signal intensity remains above a predetermined threshold for a predetermined duration), it determines that smoke particles are present in the air. Subsequently, if the intensity of the received signal satisfies a predetermined condition (for example, if the signal intensity remains below a predetermined threshold for a predetermined duration), it determines that smoke particles are not present in the air. In other words, the controller 19 acts as a detection unit that detects smoke particles contained in the air within the monitoring area TA based on the intensity of scattered light measured by the measurement unit 11.

[0018] As shown in Fig. 1, the flow path forming body 12 is a tubular structure having two U-shaped bent portions. When the flow path forming body 12 is cooled by the heat absorption portion 171 of the Peltier element 17, it is made of a material with high thermal conductivity (e.g., metal such as aluminum) so as to cool the air flowing inside. One end of the flow path forming body 12 (hereinafter referred to as the "upstream end") is arranged to penetrate an opening O1 formed in the side wall of the housing 10, and a part of it protrudes outside the housing 10. The other end of the flow path forming body 12 (hereinafter referred to as the "downstream end") is arranged to penetrate an opening O2 formed in the bottom wall of the housing 10, and a part of it protrudes outside the housing 10.

[0019] Threads are cut on the outer surfaces of the portions of the upstream end and the downstream end of the flow path forming body 12 that protrude outside the housing 10. The upstream end of the flow path forming body 12 is connected to the sampling tube S1 by screwing in the nut N1. The downstream end of the flow path forming body 12 is connected to the exhaust pipe S2 by screwing in the nut N2.

[0020] The sampling tube S1 is a tubular structure for taking in air at a plurality of different locations in the monitoring area TA and guiding the taken-in air to the substance detection device 1. Therefore, the sampling tube S1 is laid along the ceiling, wall, etc. so as to pass through different locations in the monitoring area TA, and a large number of air intake ports I for taking in air are provided on its tube wall.

[0021] The exhaust pipe S2 is a tubular structure for guiding the air that has passed through the substance detection device 1 to the inside of the monitoring area TA or to an exhaust location outside the monitoring area TA.

[0022] The flow path forming body 12 is divided into an intake flow path forming body 121 from the upstream end to the measurement unit 11 and an exhaust flow path forming body 122 from the measurement unit 11 to the downstream end. That is, air flows into the measurement unit 11 from the intake flow path forming body 121, and the air that has passed through the measurement unit 11 flows out to the exhaust flow path forming body 122.

[0023] The air blower 13 is, for example, a fan, which generates an airflow within the flow path forming body 12 from the upstream end to the downstream end. As a result, air from within the monitoring area TA flows into the sampling tube S1 through the intake port I, then passes through the intake flow path forming body 121 to the measurement unit 11, and is subsequently exhausted at the exhaust location through the exhaust flow path forming body 122 and the exhaust pipe S2. In Figure 1, the air blower 13 is located on the exhaust flow path forming body 122, but the air blower 13 may also be located on the intake flow path forming body 121. Also, in Figure 1, the air blower 13 is located inside the housing 10, but the air blower 13 may also be located outside the housing 10.

[0024] The thermometer 14 and hygrometer 15 are positioned on the outer surface of the housing 10. The thermometer 14 (an example of a temperature information generation unit that generates temperature information, which is information about the temperature of the surrounding gas) continuously measures the temperature of the air in the monitoring area TA and sequentially outputs signals indicating the measurement results to the controller 19. The hygrometer 15 (an example of a humidity information generation unit that generates humidity information, which is information about the humidity of the surrounding gas) continuously measures the humidity of the air in the monitoring area TA and sequentially outputs signals indicating the measurement results to the controller 19.

[0025] The thermometer 16 (an example of a temperature information generation unit that generates temperature information, which is information related to the temperature of the measurement unit) is positioned on the inner surface of the housing 110 of the measurement unit 11, and continuously measures the temperature of the measurement unit 11, and sequentially outputs signals indicating the measurement results to the controller 19. In the example shown in Figure 1, the thermometer 16 measures the temperature of the part of the housing 110 that is close to the light receiving unit 112 (an approximate value of the temperature of the light receiving unit 112).

[0026] The Peltier element 17 has a heat-absorbing section 171 and a heat-generating section 172. When energized under the control of the controller 19, the heat-absorbing section 171 becomes colder than before energization, and the heat-generating section 172 becomes hotter than before energization. The Peltier element 17 is positioned between the intake airflow channel forming body 121 and the measurement section 11, with the heat-absorbing section 171 in contact with the intake airflow channel forming body 121 and the heat-generating section 172 in contact with the measurement section 11. Therefore, when energized, the Peltier element 17 cools the intake airflow channel forming body 121, causing air to flow through the inner channel and cool the air before it reaches the measurement section 11. Also, when energized, the Peltier element 17 heats the measurement section 11.

[0027] The Peltier element 17 and the controller 19 that controls the power supply to the Peltier element 17 constitute a cooling and heating unit, in which the heat absorption unit 171 cools the gas flowing through the air intake channel forming body 121 before it reaches the measurement unit 11, and the heat generating unit 172 heats the measurement unit 11.

[0028] In the example shown in Figure 1, the heating element 172 is in contact with the wall surface of the housing 110 of the measuring unit 11 where the light receiving unit 112 is located. Therefore, the light receiving unit 112 is heated more quickly by the heating element 172 than the light emitting unit 111.

[0029] The user interface 18 includes, for example, a touchscreen and a speaker. Under the control of the controller 19, the user interface 18 displays various information to the user and displays virtual buttons and other controls, accepts user touch operations on these controls, and outputs signals corresponding to those operations to the controller 19. Furthermore, if the controller 19 detects smoke, the user interface 18, under the control of the controller 19, displays and sounds a message such as "Fire has broken out," to notify people nearby that a fire has occurred.

[0030] As previously described, the controller 19 is a computer that controls the substance detection device 1. The control performed by the controller 19 includes the following:

[0031] (1) The blower unit 13 is kept running at all times while the substance detection device 1 is in operation. In addition, the amount of air generated by the blower unit 13 is adjusted according to, for example, user operation. (2) While the substance detection device 1 is in operation, the light-emitting unit 111 of the measuring unit 11 is controlled so that light is constantly emitted from it, and smoke particles are detected as described above based on the intensity of the light indicated by the signal output from the light-receiving unit 112. (3) If smoke particles are detected in (2) above, the operation of the user interface 18 is controlled to notify people in the vicinity of the occurrence of a fire. Also, if the substance detection device 1 can communicate with an external device (for example, a terminal device used by the administrator of the monitoring area TA), it notifies (fires) that external device of the occurrence of a fire. (4) The system determines whether the temperature and humidity indicated by the signals output from the thermometer 14, hygrometer 15, and thermometer 16 meet predetermined conditions regarding the possibility of condensation occurring in the measurement unit 11, and turns the power to the Peltier element 17 ON or OFF according to the result of that determination.

[0032] Regarding (4) above, a specific example of the control performed by the controller 19 (an example of a control unit) is shown. For example, if the value obtained by subtracting the dew point of the air, which is determined based on the temperature indicated by the signal output by the thermometer 14 and the humidity indicated by the signal output by the hygrometer 15, from the temperature of the measurement unit 11 indicated by the signal output by the thermometer 16 is below a predetermined threshold, the controller 19 determines that condensation may occur in the measurement unit 11 and electrically connects the power supply and the Peltier element 17. If the value exceeds the predetermined threshold, the controller 19 determines that condensation may not occur in the measurement unit 11 and disconnects the power supply and the Peltier element 17.

[0033] Furthermore, to determine the dew point of air, any method may be employed, such as using a known correspondence table or using a known calculation formula.

[0034] A typical example of condensation occurring in the measurement unit 11 is when the temperature drops at night, the measurement unit 11 becomes cold, and then when the sun rises, the air becomes hot and humid due to heating by sunlight and flows into the monitoring area TA. In such a case, the temperature of the measurement unit 11 falls below the dew point of the air in the monitoring area TA, and if cooling and heating by the Peltier element 17 is not performed, there is a risk that, for example, water droplets due to condensation will adhere to the lens of the light receiving unit 112, preventing sufficient reception of scattered light that should be received, and thus making it impossible to detect smoke even though smoke is actually being generated.

[0035] However, according to the substance detection device 1, the Peltier element 17 starts cooling the intake channel forming body 121 and heating the measurement unit 11 before the temperature of the measurement unit 11 falls below the dew point of the air in the monitoring area TA. As a result, the air taken in from the monitoring area TA into the intake channel forming body 121 is cooled by the intake channel forming body 121, which has been cooled by the heat-absorbing part 171 of the Peltier element 17, before it reaches the measurement unit 11, thus lowering the dew point of the air that reaches the measurement unit 11. In addition, the measurement unit 11 is heated by the heat-generating part 172 of the Peltier element 17, and the temperature of the measurement unit 11 (for example, the temperature of the lens of the light-receiving unit 112) rises. Therefore, the temperature of the measurement unit 11 does not fall below the dew point of the air passing around the measurement unit 11, and the occurrence of condensation in the measurement unit 11 is prevented.

[0036] As described above, according to the substance detection device 1, condensation does not occur in the measurement unit 11. However, the temperature of the part cooled by the heat-absorbing part 171 of the intake air channel forming body 121, that is, the region indicated by A1 in Figure 1 (hereinafter referred to as "region A1"), may fall below the dew point of the air flowing around it. In that case, water droplets (an example of liquid) formed by condensation adhere to region A1 of the intake air channel forming body 121, and as their size increases, the water droplets (water) flow downward due to their own weight and reach the region indicated by A2 in Figure 1 (hereinafter referred to as "region A2").

[0037] An opening O3 is provided at the lower end of the intake channel forming body 121 to send the water flowing down into region A2 to the outside, as described above. The channel forming body 12 is further equipped with a drain channel forming body 123 that guides the water flowing out of the opening O3 downward by gravity and forms a channel for discharge to the outside of the housing 110. The drain channel forming body 123 is a tubular structure and is connected to the intake channel forming body 121 such that its upper end closes the opening O3.

[0038] An opening O4 is provided in the bottom wall of the housing 110 for the drain channel forming body 123 to pass through. The drain channel forming body 123 penetrates the bottom wall of the housing 110 through the opening O4, with its lower end protruding outside the housing 110. The upper end of the drain pipe S3 is connected to the lower end of the drain channel forming body 123.

[0039] The drain pipe S3 is a tubular structure that guides water flowing down through the drainage channel forming body 123 by its own weight to a drainage location within or outside the monitoring area TA.

[0040] The drain pipe S3 is made of, for example, flexible plastic, and when the drain channel forming body 123 is inserted into it, that part expands in diameter and elastically tightens the drain channel forming body 123 from the outside. Therefore, the user can connect the drain channel forming body 123 and the drain pipe S3 simply by inserting the drain channel forming body 123 into the drain pipe S3.

[0041] Water droplets (water) generated in region A1 of the intake channel forming body 121 are sequentially discharged to the outside of the intake channel forming body 121 through the drain channel forming body 123. Therefore, problems such as water accumulating in region A2 within the intake channel forming body 121 and blocking the airflow channel formed by the intake channel forming body 121 do not occur.

[0042] [Differentiation] The embodiments described above can be modified in various ways within the scope of the technical concept of the present invention. These modifications are shown below. Note that two or more of the following modifications may be combined as appropriate.

[0043] (1) The shape and arrangement of each component of the substance detection device 1 shown in Figure 1 are examples and may be modified in various ways.

[0044] Figure 2 shows an example of a substance detection device 1 that differs from the substance detection device 1 shown in Figure 1 in terms of the shape and arrangement of its components. The substance detection device 1 shown in Figure 2 differs from the substance detection device 1 shown in Figure 1 mainly in the following points.

[0045] An opening O1 is made in the upper wall of the casing 10. An opening O2 is made in the side wall of the housing 10. The channel forming body 12 has an overall L-shaped bend.

[0046] Figures 3 to 5 show examples in which the arrangement of the measurement unit 11 and the Peltier element 17 has been changed from the substance detection device 1 shown in Figure 2.

[0047] In the substance detection device 1 shown in Figures 1 and 2, the Peltier element 17 is positioned between the intake flow path forming body 121 and the measurement unit 11 such that the heat-absorbing part 171 is in contact with the intake flow path forming body 121 and the heat-generating part 172 is in contact with the measurement unit 11.

[0048] On the other hand, in the substance detection device 1 shown in Figure 3, the heat-generating part 172 is in contact with the measuring part 11, but the heat-absorbing part 171 is not in contact with the intake flow path forming body 121, so it cannot be said that the Peltier element 17 is positioned between the intake flow path forming body 121 and the measuring part 11.

[0049] The substance detection device 1 shown in Figure 3 includes a heat conductor 21 that is in contact with the intake flow path forming body 121 and the heat absorption device 171, and guides heat from the intake flow path forming body 121 to the heat absorption device 171, so that the heat absorption device 171 can cool the intake flow path forming body 121.

[0050] Furthermore, in the substance detection device 1 shown in Figure 4, the heat-absorbing part 171 is in contact with the intake flow path forming body 121, but the heat-generating part 172 is not in contact with the measurement unit 11, so it cannot be said that the Peltier element 17 is positioned between the intake flow path forming body 121 and the measurement unit 11.

[0051] The substance detection device 1 shown in Figure 4 includes a heat conductor 22 that is in contact with the heating element 172 and the measuring element 11, and guides heat from the heating element 172 to the measuring element 11, so that the heating element 172 can heat the measuring element 11.

[0052] Furthermore, in the substance detection device 1 shown in Figure 5, the heat-absorbing section 171 is not in contact with the intake airflow channel forming body 121, and the heat-generating section 172 is not in contact with the measurement section 11. Therefore, it cannot be said that the Peltier element 17 is positioned between the intake airflow channel forming body 121 and the measurement section 11.

[0053] The substance detection device 1 shown in Figure 5 includes a heat conductor 23 that contacts the intake air channel forming body 121 and the heat absorption device 171, and guides heat from the intake air channel forming body 121 to the heat absorption device 171, so that the heat absorption device 171 can cool the intake air channel forming body 121. In order for the heating element 172 to heat the measuring element 11, a heat conductor 24 is provided that is in contact with the heating element 172 and the measuring element 11, and that guides heat from the heating element 172 to the measuring element 11.

[0054] The thermal conductors 21 and 22 are made of a material with high thermal conductivity (for example, a metal such as aluminum).

[0055] (2) In the substance detection device 1 according to the above embodiment, the power supply to the Peltier element 17 is controlled by the controller 19 based on the temperature and humidity of the air outside the substance detection device 1 and the temperature of the air inside the measuring unit 11.

[0056] The information used by the controller 19 to control the energization of the Peltier element 17 is not limited to the temperature and humidity of the air outside the substance detection device 1 and the temperature of the air inside the measuring unit 11.

[0057] In the above-described embodiment, the temperature measured by the thermometer 14 is the temperature of the air in the monitoring area TA. However, if the Peltier element 17 is not energized, this temperature does not change significantly from the time the air passes through the flow path formed by the sampling tube S1 and the intake flow path forming body 121 until it reaches the measurement unit 11. The same applies after the air has passed through the measurement unit 11.

[0058] Based on the above, the thermometer 14 may be placed at any position inside the flow path forming body 12 instead of outside the housing 10, as long as it measures the temperature of the surrounding air.

[0059] Furthermore, in the above-described embodiment, the humidity measured by the hygrometer 15 is the humidity of the air within the monitoring area TA. However, unless the Peltier element 17 is energized, this humidity does not change significantly from the time the air passes through the flow path formed by the sampling tube S1 and the intake flow path forming body 121 until it reaches the measurement unit 11. The same applies after the air has passed through the measurement unit 11.

[0060] Based on the above, the hygrometer 15 may be placed at any position inside the flow path forming body 12 instead of outside the housing 10, as long as it measures the humidity of the surrounding air.

[0061] Figure 6 shows an example in which the thermometer 14 and hygrometer 15 are positioned to measure the temperature of the air just before it flows into the measuring unit 11.

[0062] Alternatively, for example, the controller 19 may determine the current temperature of the measurement unit 11 based on past temperatures measured by the thermometer 14, which change over time, as temperature information related to the temperature of the measurement unit, and control the energization of the Peltier element 17 based on the temperature determined in this way. When the ambient air temperature changes, the measurement unit 11 is cooled or heated by that air, resulting in the temperature of the measurement unit 11 changing to follow the temperature of the air in the monitoring area TA. Therefore, for example, the temperature measured by the thermometer 14 a predetermined time before the present may be used as an approximation of the temperature of the measurement unit 11. In that case, the thermometer 16 becomes unnecessary.

[0063] (3) In the substance detection device 1 according to the above embodiment, the controller 19 identifies the dew point of the air and controls the energization of the Peltier element 17 based on the comparison result between the temperature of the measurement unit 11 and the dew point. The dew point does not necessarily have to be identified as long as condensation in the measurement unit 11 can be prevented.

[0064] Condensation will not occur unless the air temperature is higher than the temperature of the measuring unit 11. Therefore, for example, the controller 19 may control the system so that if the value obtained by subtracting the temperature of the measuring unit 11 measured by the thermometer 16 from the air temperature measured by the thermometer 14 is greater than or equal to a predetermined threshold, the Peltier element 17 is energized, and if it is less than the predetermined threshold, the Peltier element 17 is not energized. In this case, the substance detection device 1 does not need to be equipped with a hygrometer 15.

[0065] Furthermore, condensation will not occur unless the humidity of the air is sufficiently high. Therefore, for example, the controller 19 may control the system so that the Peltier element 17 is energized if the humidity measured by the hygrometer 15 is above a predetermined threshold, and not energized if it is below the predetermined threshold. In this case, the substance detection device 1 does not need to be equipped with thermometers 14 and 16.

[0066] Furthermore, for example, the controller 19 may control the system so that if the value obtained by subtracting the temperature of the measuring unit 11 measured by the thermometer 16 from the temperature of the air measured by the thermometer 14 is equal to or greater than a predetermined threshold, and the humidity measured by the hygrometer 15 is equal to or greater than a predetermined threshold, the Peltier element 17 is energized, but otherwise the Peltier element 17 is not energized.

[0067] (4) In the above embodiment, the controller 19 controls the energization of the Peltier element 17 based on the temperature measured by the thermometer 14 and thermometer 16 and the humidity measured by the hygrometer 15. As a result, the Peltier element 17 is not energized during periods when condensation is not likely to occur in the measurement unit 11, thereby suppressing unnecessary power consumption.

[0068] If the amount of power consumed by the Peltier element 17 is sufficiently small, the Peltier element 17 may be energized at all times while the substance detection device 1 is in operation. Alternatively, the Peltier element 17 may be controlled to be periodically turned ON / OFF at predetermined time intervals. In that case, the substance detection device 1 does not need to be equipped with a thermometer 14, a hygrometer 15, and a thermometer 16.

[0069] (5) In the above description of the embodiment, the housing 110 of the measuring unit 11 and the flow channel forming body 12 are distinguished as different components, but they may be manufactured by integral molding, for example. For example, the light-emitting unit 111 and the light-receiving unit 112 may be arranged inside the flow channel forming body 12. In that case, the portion of the flow channel forming body 12 in which the light-emitting unit 111 and the light-receiving unit 112 are arranged may be enlarged in diameter or otherwise as needed.

[0070] (6) In the above embodiment, the thermometer 16 for measuring the temperature of the measuring unit 11 is positioned near the light-receiving unit 112 and measures a temperature close to that of the light-receiving unit 112. The light-receiving unit 112 is positioned in the part of the housing 110 that is heated by the heat-generating part 172 of the Peltier element 17. This configuration is desirable when the light-emitting unit 111 generates heat when emitting light, while the light-receiving unit 112 generates almost no heat. However, if, for example, the light-emitting unit 111 generates almost no heat, similar to the light-receiving unit 112, a different configuration is desirable. In that case, for example, both the light-emitting unit 111 and the light-receiving unit 112 may be positioned in the part of the housing 110 that is heated by the heat-generating part 172 of the Peltier element 17, and the thermometer 16 may be positioned to measure the temperature of the part of the housing 110 that is roughly midway between the light-emitting unit 111 and the light-receiving unit 112.

[0071] (7) In the embodiments described above, the flow channel forming body 12 is assumed to be made entirely of a material with high thermal conductivity (for example, a metal such as aluminum), but it is sufficient that the portion of the intake flow channel forming body 121 that is in contact with the heat absorption portion 171 (or the heat conductor that carries heat to the heat absorption portion 171) has high thermal conductivity, and the thermal conductivity of other portions may be low.

[0072] Similarly, the thermal conductivity of the part of the housing 110 of the measuring unit 11 that is in contact with the heat-generating part 172 (or the heat conductor that carries heat from the heat-generating part 172) should be high, while the thermal conductivity of other parts may be low.

[0073] (8) In the above embodiment, the measuring unit 11 measures the intensity of scattered light as a physical quantity for detecting smoke. The measuring unit 11 may also measure physical quantities other than the intensity of scattered light as physical quantities for detecting smoke. Furthermore, the substance detected by the substance detection device 1 is not limited to smoke particles. For example, when the substance detection device 1 detects carbon monoxide, the measuring unit 11 measures physical quantities such as the concentration of carbon monoxide contained in the air. [Explanation of symbols]

[0074] 1... Substance detection device, 10... Housing, 11... Measurement unit, 12... Flow channel forming body, 13... Air blowing unit, 14... Thermometer, 15... Hygrometer, 16... Thermometer, 17... Peltier element, 18... User interface, 19... Controller, 21... Heat conductor, 22... Heat conductor, 110... Housing, 111... Light emitting unit, 112... Light receiving unit, 121... Intake flow channel forming body, 122... Exhaust flow channel forming body, 123... Drainage flow channel forming body, 171... Heat absorption unit, 172... Heat generating unit.

Claims

1. A measuring unit that measures physical quantities to detect specific substances contained in a gas, An intake airflow channel forming body that forms a channel for guiding the surrounding gas to the measuring section, A cooling and heating unit having a Peltier element, which cools the gas flowing through the channel before it reaches the measuring unit by the heat-absorbing part of the Peltier element, and heats the measuring unit by the heat-generating part of the Peltier element. A substance detection device equipped with the following features.

2. The measuring unit has a light-emitting unit and a light-receiving unit, and detects smoke particles contained in the gas by receiving the scattered light emitted by the light-emitting unit with the light-receiving unit. The substance detection device according to claim 1.

3. The Peltier element is positioned between the intake airflow channel forming body and the measuring unit such that the heat-absorbing portion is in contact with the intake airflow channel forming body and the heat-generating portion is in contact with the measuring unit. The substance detection device according to claim 1.

4. The intake air passage forming body and the heat absorption portion are in contact with a heat conductor that guides heat from the intake air passage forming body to the heat absorption portion. The substance detection device according to claim 1.

5. The heat-generating section and the measuring section are in contact with a heat conductor that guides heat from the heat-generating section to the measuring section. The substance detection device according to claim 1.

6. A temperature information generation unit generates temperature information, which is information about the temperature of the surrounding gas, Based on the temperature information generated by the temperature information generation unit, a control unit controls the supply of power to the Peltier element. A substance detection device according to claim 1, comprising:

7. A temperature information generation unit that generates temperature information which is information relating to the temperature of the measurement unit, Based on the temperature information generated by the temperature information generation unit, a control unit controls the supply of power to the Peltier element. A substance detection device according to claim 1, comprising:

8. A humidity information generation unit generates humidity information, which is information about the humidity of the surrounding gas, A control unit controls the supply of power to the Peltier element based on the humidity information generated by the humidity information generation unit. A substance detection device according to claim 1, comprising:

9. The intake channel forming body includes a drain channel forming body that forms a channel for guiding liquid adhering to the portion cooled by the heat-absorbing part of the intake channel forming body downward by gravity and discharging it to the outside. The substance detection device according to claim 1.

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