JPH06197897A - Alcohol detector - Google Patents

Abstract

(57) [Summary] [Purpose] To provide an alcohol detection device suitable for driver's exhalation determination, correction for variation in inhaled expiratory volume, and improvement of determination speed, for example, for preventing a drunk person from driving a car. [Arrangement] The alcohol detection device has one opening 12a.
Is installed toward the space to be measured, and has an inhalation section 10 provided with suction means 14 on the other opening side communicating with the opening 12a. In the inhaler 10, a sulfide sensor 26 for determining whether or not the exhaled gas to be detected contains human exhaled gas, and the amount of exhaled air contained in the gas to be detected is calculated. A humidity sensor 24 and an alcohol sensor 22 for detecting alcohol contained in the gas to be detected are installed. Then, the breath presence / absence determiner 4 for determining presence / absence of exhalation from the ratio of the detection signal of the sulfide sensor 26 and the detection signal of the humidity sensor 24.
0, and an alcohol concentration determiner 30 that determines the alcohol concentration from the ratio of the detection signal of the alcohol sensor 22 and the detection signal of the humidity sensor 24.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an alcohol detecting device used for preventing a drunk person from driving a car.

[0002]

2. Description of the Related Art In recent years, automobile traffic accidents have become a major social problem. Above all, accidents due to drunk driving are highly likely to be serious accidents, and there is no tendency to decrease.

Conventionally, as a device for preventing such drunk driving, as described in Japanese Patent Publication No. 51-21698 and US Pat. No. 3,855,573, one end of a pipe is connected to a suction pump and the other is connected. The end is placed near the driver's seat in the passenger compartment and opened, and a portion of the driver's exhaled breath is introduced into the pipe by a suction pump, and the alcohol component detection element installed in the middle of the pipe actuates the alcohol in the driver's exhaled breath. There are devices that determine the concentration and make the vehicle inoperable.

However, in the above-mentioned prior art, when actually determining the breath alcohol concentration of the driver,
There were some problems.

The first problem is that the gas inhaled by the pump is mixed with not only the driver's exhaled air but also the air in the passenger compartment. Therefore, whether or not the driver's exhaled gas is contained in the inhaled gas. It is necessary to judge whether or not it is, but the above-mentioned conventional technique is not provided with such a judging means, and there is a possibility of erroneous judgment.

For this problem, Japanese Patent Publication No. 56-18898
As described in the publication, a technique has been proposed in which a pressure sensor is installed in a pipe and a pressure change in the pipe is measured.
However, although such a method is effective for deception such as blocking the intake port, the accuracy is not sufficient to determine whether or not the driver has exhaled toward the intake port. Even if the pressure sensor of No. 1 is used, if proper air is sent instead of exhalation, it may be erroneously determined as exhalation.

Further, as disclosed in Japanese Patent Publication No. 56-18898, there is disclosed a technique for judging exhalation by changes in humidity and temperature. However, cheating such as holding a wet hand near the inhalation port is disclosed. It is easily possible.

The second problem is that the state in which the exhaled air is blown toward the suction port usually depends on the driver, and therefore the amount of blown air, the direction in which the air is blown out, etc. are not constant, and are therefore contained in the inhaled gas. This is because the rate of exhalation is not constant, which causes an error in the alcohol concentration determination. In addition, it is practically impossible for the driver to blow out the determined expiratory volume with good reproducibility.

The third problem is the determination speed of the alcohol concentration. That is, since this type of device is operated immediately before traveling of the automobile, it is often uncomfortable for the driver to take a long time for this determination, and it is necessary to make the determination as quickly as possible. However,
The response time of the currently known alcohol detection element (the time until the output signal of the element stabilizes at a value according to the alcohol concentration after the alcohol gas contacts the element)
There is nothing that can satisfy me enough.

[0010]

SUMMARY OF THE INVENTION The present invention solves the above three problems, that is, determination of driver's exhalation, correction for variations in inhaled expiratory volume and improvement of determination speed. An object is to provide an alcohol detection device suitable for driving prevention.

[0011]

According to a first aspect of the present invention, one opening portion (first opening portion) is installed toward a space to be measured, and the other opening portion side communicates with the opening portion. A suction unit provided with a suction means, a sulfide sensor provided in the suction unit for determining whether or not human exhalation is contained in the inhaled gas to be detected, and a sulfide sensor provided in the suction unit. A humidity sensor for calculating the amount of exhaled air contained in the gas to be detected, an alcohol sensor provided in the inhaler for detecting alcohol contained in the gas to be detected, and the sulfide A breath presence / absence determiner that determines the presence or absence of exhalation from the ratio of the detection signal of the sensor and the detection signal of the humidity sensor, and an alcohol concentration determination unit that determines the alcohol concentration from the ratio of the detection signal of the alcohol sensor and the detection signal of the humidity sensor. It includes a call concentration determination unit, and is characterized by detecting the alcohol concentration of the detection target gas passing through the suction portion.

In the above invention, the sulfide sensor is a device for detecting a sulfide component contained in the air flowing in the inhalation part, and specifically, for detecting methyl mercaptan which is a main component of human bad breath. It is what As the sulfide sensor, for example, a gas detector that uses an oxide semiconductor such as tin oxide and causes a resistance change accompanying the oxidation reaction of sulfide is used.

The humidity sensor is a device used to detect water vapor contained in the air flowing through the inhalation part and correct the influence of the variation in the inhaled expiratory amount. As the humidity sensor, for example, a humidity detector that causes a capacitance change of the polymer film due to adsorption of water can be used.

The alcohol sensor is a device for detecting an alcohol component contained in the air flowing in the suction portion.
As the alcohol sensor, for example, a gas detector that uses an oxide semiconductor such as tin oxide and causes a resistance change due to the oxidation reaction of alcohol can be used.

Further, the breath presence / absence determiner is provided with a ratio (Δsulfide / Δhumidity) of a change amount of the detection signal of the sulfide sensor (Δsulfide) and a change amount of the detection signal of the humidity sensor (Δhumidity). ) Determines whether or not there is exhalation.

Further, the alcohol concentration determining device determines the alcohol from the ratio (Δalcohol / Δhumidity) of the change amount (Δalcohol) of the detection signal of the alcohol sensor and the change amount (Δhumidity) of the detection signal of the humidity sensor. The density is determined.

A second invention of the present invention is the alcohol detection device according to the above invention, wherein the alcohol sensor, the sulfide sensor and the humidity sensor have the same gas response time constant. That is, when the response time constants of the alcohol sensor, the humidity sensor, and the sulfide sensor are different, for example, a film that delays the diffusion of gas is attached around the sensor element to make the time constants of the three sensors equal. Further, in order to sufficiently exert the effect of making the time constants of the responses equal, it is preferable that the three sensors are installed close to each other and the inhaled air is brought into contact with each other at the same time.

A third invention of the present invention is the above invention, wherein a three-way valve is installed between the three sensors and a first opening installed toward a space to be measured (vehicle interior),
One end side of a pipe forming the second suction part is connected to the three-way valve, and the other end of the pipe is provided with a second opening provided near the driver's seat and at a position where the driver's exhalation is difficult to be inhaled. It is an alcohol detection device characterized in that a second inhaler is added. The three-way valve is a valve having valve means for switching suction from the first opening and suction from the second opening, and the first opening and the second opening and the three sensors. Is installed between. The first opening is for inhaling the driver's exhaled air, and is installed at a position where it is easy to inhale the exhaled air when the driver is seated in a driving posture. For example, the vicinity of the steering column is suitable. is there. The second opening is for inhaling air in the passenger compartment near the driver, and is installed in the vicinity of the driver's seat where breath of the driver is difficult to be inhaled. For example, the vicinity of the ceiling above the driver's seat is suitable.

As another structure of the present invention, in the above-mentioned invention, a device for disabling the running of the vehicle by a warning by a lamp or a buzzer, an ignition interlock or a shift lever interlock is added based on the alcohol concentration judgment value. It is an alcohol detection device characterized by the above.

[0020]

In the present invention, the sulfide sensor is an effective means for determining the driver's expiration, which is the first problem of the above-mentioned prior art. That is, in order to determine whether or not the driver's breath is present in the air (gas to be measured) that has been sucked into the suction portion, it is preferable to use a substance or characteristic peculiar to human breath. Then, as a result of the investigation, it was found that methyl mercaptan is suitable as a specific substance contained in human breath. Methyl mercaptan is a kind of sulfide and is a main component of bad breath, and it has an unpleasant odor even at a low concentration. The concentration of methyl mercaptan in the mouth varies depending on individual differences and the state of the mouth, but it is known that most adults always have a certain concentration or more. Methyl mercaptan is present in normal air at a very low concentration, and if it is present at a high concentration, it has a very unpleasant odor, so it can be said that it is a very exceptional vehicle interior environment. Therefore, by using a sulfide sensor capable of measuring methyl mercaptan,
It is possible to accurately determine whether it is exhalation,
It is difficult to cheat.

In the present invention, the humidity sensor is an effective means for correcting the above-mentioned second problem of the prior art, which is caused by the fluctuation of the expiratory amount in the gas to be detected. In order to correct the influence of the change in the inhaled expiratory volume, it is preferable to measure the concentration of the substance proportional to the expiratory volume, and it has been found that water vapor is suitable as such a substance. The amount of water contained in human exhaled air is almost constant, and is usually 34
Corresponds to a saturated vapor pressure of ° C. Therefore, as shown in FIG. 1, there is a proportional relationship between the alcohol concentration in the mouth and the (alcohol concentration / water vapor concentration) in the mouth. Since it is considered that this proportional relationship does not change even when the exhaled air is diluted in the air, this ratio, that is, the change amount of the detection signal of the alcohol sensor (Δ alcohol) and the change amount of the detection signal of the humidity sensor ( If the ratio with (Δhumidity) (Δalcohol / Δhumidity) can be measured, the alcohol concentration in the mouth can be calculated using FIG. 1.

The slope of the correlation diagram shown in FIG. 1 corresponds to the reciprocal of the water vapor concentration in the mouth. If the saturated water vapor pressure at 34 ° C. (39.9 mmHg or 52,500 ppm) is adopted as the water vapor concentration in the mouth, the inclination is 1
/39.9 (mmHg ^-1 ) or 1/52500 (p
pm ⁻¹ ).

As described above, by measuring the water vapor concentration using the humidity sensor and determining the alcohol concentration as a function of Δ alcohol / Δ humidity of the gas to be detected, the influence of the change in the exhaled amount in the gas to be detected is corrected. It becomes possible to do.
Of course, there are many things that cause changes in humidity other than exhaled breath, but since only the gas determined to be exhaled by the sulfide sensor is targeted, it is possible to avoid erroneous determination due to the act of holding a wet hand over the suction port. .

In the present invention, making the response time constants of the alcohol sensor, the sulfide sensor, and the humidity sensor equal to each other contributes to the improvement of the determination speed and the measurement accuracy in the determination of the alcohol concentration and the sulfide concentration. This is an effective means with respect to the above-mentioned third problem of the conventional technique. Taking the determination of the alcohol concentration as an example, as shown in FIG. 2, the detection gas including the exhaled breath is inhaled, and the determination is made at time A when the alcohol sensor and the humidity sensor have stabilized to a constant value corresponding to the gas. It is quicker to calculate the ratio of the output changes of the two sensors and make a determination at time B when the ratio becomes constant. Then, in order to perform the concentration determination using such a method, it is preferable to make the response time constants of the sensors equal. The same applies to the detection of sulphides.

In the present invention, the two openings for inhalation are provided because the effect of the gas containing alcohol such as hair tonic or the effect of the drinker in the passenger seat is utilized by utilizing the difference in the positions of the openings. Is to deduct. Since hair tonics and perfumes contain alcohol in their components, it is possible that a driver who is not drinking may be falsely detected as breath alcohol. Therefore, in the present invention, the amount of change in the detection signal of the air entering through the first opening and the amount of change in the detection signal of the air entering through the second opening are compared, and by subtraction thereof, they are included in other than exhalation such as hair tonic. It cancels the effects of alcohol.

That is, in the case where air is introduced through the first opening provided at a position where exhalation easily enters, as shown in FIG. 3 (A), both exhaled alcohol and alcohol such as hair tonic are introduced. The sensor responds and the output appears as the sum of the two (see curve a). On the other hand, the second
When air enters through the opening of the sensor, the output of the sensor appears for alcohol such as hair tonic as shown in FIG. 3B (see curve b). The reason is that since the driver blows out the exhaled air forward, most of the exhaled air reaches the sensor through the first opening, and thus the difference in the exhalation component amount depending on the positions of the first and second openings is large. On the other hand, in the case of a hair tonic or the like, since the gas reaches the sensor by natural diffusion of gas, the difference in gas concentration between the positions of the first and second openings is small. Further, the alcohol generated by the drinker in the passenger seat has a long distance to the opening, so that the difference depending on the position of the opening is small like the hair tonic. Therefore, by subtracting the detection signal amount of the alcohol sensor of the air sucked in from the second opening from the detection signal amount of the alcohol sensor of the air sucked in from the first opening, the sensor response to the true breath alcohol component is obtained. (ΔAc) can be obtained.

According to the detection device of the present invention, about 10-1,
000 ppm of breath alcohol can be detected. However, the concentration of breath alcohol is 1,000 ppm
In the case of, it is usually a deep paralysis condition or lethal level, and there is practically no concentration.

[0028]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings.

[0029]First embodiment  FIG. 4 is a schematic diagram showing the arrangement relationship of this embodiment.

The detected gas suction portion 10 comprises a suction pipe 12 and a suction pump 14. The suction pipe 12
Has one end fixed to the pipe 140 of the steering column 120, and the other end inserted and supported by a wall portion of a box-shaped mounting portion 160 provided in the engine room 100. Further, one end of the suction pipe 12 has a trumpet-shaped opening 12a opened at a position where the breath of the driver can be collected efficiently.

The suction pump 14 is installed in the mounting portion 160, and the exhaust port 1 formed in the wall of the mounting portion 160.
The gas to be detected is discharged via 6.

Further, in the middle of the suction pipe 12,
The sensor mounting portion 20 is configured, and the alcohol sensor 22,
The humidity sensor 24 and the sulfide sensor 26 are installed in a predetermined arrangement relationship.

The alcohol sensor 22 is the suction pipe 12
This is a sensor for detecting alcohol components contained in the air flowing inside, and for example, "TGS822" manufactured by Figaro Giken Co., Ltd. using a tin oxide semiconductor can be used.

The humidity sensor 24 is a sensor for detecting water vapor contained in the air flowing through the suction pipe 12,
For example, a variable capacitance humidity sensor manufactured by Vaisala can be used.

The sulfide sensor 26 is a sensor for detecting a sulfide component contained in the air flowing through the suction pipe 12. In this embodiment, the sulfide sensor 26 is intended to detect methyl mercaptan which is a main component of human bad breath. There is. As the sulfide sensor, for example, "TGS825" manufactured by Figaro Giken using a semiconductor of tin oxide can be used.

The alcohol sensor 22, the humidity sensor 24, and the sulfide sensor 26 have a film for delaying the diffusion of gas around each of these three sensor elements in order to make the time constants of these responses equal. For example, it is preferable to attach a porous cellulose membrane (film thickness 100 μm, pore diameter 0.1 μm).

Further, in order to sufficiently bring out the effect of making the response time constants of the respective sensors 22, 24, 26 equal, it is preferable to install these sensors as close as possible.

FIG. 5 is a circuit diagram of the detection device of this embodiment. The detection circuit of the present embodiment includes an alcohol sensor 22, a humidity sensor 24, and a sulfide sensor 26. Detection signals of the alcohol sensor 22 and the humidity sensor 24 are output to the alcohol concentration determination device 30, and the humidity sensor 24.
And the detection signal of the sulfide sensor 26 is an exhalation presence / absence determiner 4
It is configured to output toward 0.

The alcohol concentration determiner 30 is configured to calculate the alcohol concentration based on the input detection signal and determine the alcohol concentration. Specifically, the divider 32, the reference value setting circuit 36 and It comprises a comparison circuit 34.

The divider 34 calculates the alcohol concentration (Δ alcohol) and the water vapor concentration (Δ) based on the detection signals output from the alcohol sensor 22 and the humidity sensor 24.
The humidity is calculated and the calculated value is output to the comparison circuit 34.

The reference value setting circuit 36 is a circuit for giving a reference value for setting the alcohol concentration. For example, the alcohol driving level is 120 ppm
Is set, a voltage signal corresponding to that value is output.

The comparison circuit 34 includes a reference value setting circuit 36.
The display device 50 is configured to give the magnitude relation between the signal of 1 and the signal of the divider as a signal. For example, if the voltage signal of the divider 32 is larger than the voltage signal of the reference value setting circuit 36, the comparison circuit 34 outputs an L level voltage signal, and if the voltage signal of the divider 32 is opposite, outputs an H level voltage signal.

The exhalation presence / absence determiner 40 is configured to calculate the concentration of sulfide (methyl mercaptan) based on the input detection signal and determine the presence or absence of exhalation. Specifically, the divider 42, the reference Value setting circuit 46 and comparison circuit 4
It is composed of 4.

The divider 42 obtains the ratio between the sulfide concentration (Δsulfide) and water vapor (Δhumidity) based on the detection signals output from the humidity sensor 24 and the sulfide sensor 26, and the calculated value is obtained. To the comparison circuit 44.

The reference value setting circuit 46 is a circuit for giving a reference value for determining the presence or absence of exhalation. For example,
The reference value setting circuit 46 is configured to output a voltage signal corresponding to the value when the methyl mercaptan concentration of 0.1 ppm is set as the level of presence or absence of exhalation.

Similar to the comparison circuit 34, the comparison circuit 44 is configured to give a magnitude relation between the signal of the reference value setting circuit 46 and the signal of the divider 42 to the display device 50 as a signal. For example, if the voltage signal of the divider 42 is smaller than the voltage signal of the reference value setting circuit 46, the comparison circuit 44 outputs an L level voltage signal, and vice versa.
Output voltage signal of level.

In the display device 50, the operating status of the alcohol detection device and the alcohol concentration determination result are shown to the driver from the signals given by the alcohol concentration determination device 30 and the breath presence determination device 40.

For example, if the voltage signal of the exhalation presence / absence determiner 40 is at L level, it indicates that the measurement is in a standby state waiting for the exhalation of breath, and if the voltage signal is at H level, it indicates that the measurement is in progress. .

Further, the voltage signal of the exhalation presence / absence determiner 40 is H.
In the case of the level, when the voltage signal of the alcohol concentration determiner 30 is at the L level, it indicates that it is the drunk driving level, and when the voltage signal is at the H level, it indicates that it is the normal level.

Second Embodiment FIG. 6 is a schematic diagram showing a second embodiment of the present invention. The members having substantially the same structure and function as those of the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

The second embodiment differs from the first embodiment in that the second opening 60a is provided at a position different from the opening (first opening) 12a. The second opening 60a is connected to the detected gas suction portion 10 through the suction pipe 60.
Is connected to the suction pipe 12. The second opening 60
“A” is installed near the driver and at a position where it is difficult for the breath to be inhaled. In the case of this example, the second opening 60a is
The suction pipe 60 is provided in the roof header portion located slightly in front of the driver, and the suction pipe 60 passes through the inside of the roof lining of the roof header, the inside of the right front pillar, and the inside of the lower part of the instrument panel to attach a sensor to the suction pipe 12. Part 20
And the first opening 12a are connected via a three-way valve 62.

FIG. 7 is a circuit diagram of the detector of the second embodiment.

In this detection circuit, the three-way valve 62
Timer relay 64 for controlling the switching of the alcohol, and a memory circuit 66 for storing the detection signal from the alcohol sensor 22.
And the subtracter 68 to which the signal from the memory circuit 66 is input is different from the first embodiment.

The signal output from the timer relay 64 controls the switching of the three-way valve 62 at a predetermined time, and the first opening 12a or the second opening 60a is controlled.
Therefore, the gas to be detected is selectively sucked into the suction pipe 12. Then, the detection signal S1 of the alcohol sensor 22 for the gas to be detected sucked through the first opening 12a and the detection signal S2 of the alcohol sensor 22 for the gas to be detected sucked through the second opening 60a are The signals of the relay 64 are separately stored in synchronization with the opening and closing of the three-way valve 60, and these detection signals are output to the subtractor 68. In the subtractor 68, the difference between the detection signal S1 and the detection signal S2 output from the alcohol sensor 22 is obtained, and the calculated value is output to the alcohol concentration determination unit 30. The configurations and functions of the alcohol concentration determiner 30, the exhalation presence / absence determiner 40, and the display device 50 are the same as those in the first embodiment, and detailed description thereof will be omitted.

According to the present embodiment, from the alcohol content in the gas to be detected that is inhaled through the first opening 12a to the alcohol content other than exhaled air that is inhaled through the second opening 60a,
For example, it is possible to detect alcohol contained in the breath of a driver with higher accuracy by subtracting alcohol contained in cosmetics or drugs such as hair tonics and perfumes and alcohol contained in the breath of passengers other than the driver. it can.

Further, in the present invention, it is possible to add a device for disabling the running of the vehicle by means of a warning by a lamp or a buzzer, an ignition interlock or a shift lever interlock based on the alcohol concentration judgment value. desirable.

An example of the control circuit for the ignition interlock is shown in FIG. In this control circuit, the signals from the alcohol concentration determiner 30 and the breath presence / absence determiner 40 are output to the AND circuit 70, and the AND circuit 7
The signal from 0 is output to the relay 72. The relay 72 is connected to a normally open OK switch 74 for driving the ignition circuit 78, and the operation of the relay 72 controls ON / OFF of the OK switch 74. Figure 8
Inside, 76 shows a main switch and 80 shows a battery.

In such a circuit, the driver cannot operate the ignition circuit 78 only by turning on the main switch 76. That is, when the output signals from the alcohol concentration determiner 30 and the exhalation presence / absence determiner 40 are both H level voltages (when the alcohol concentration is below a predetermined value and it is determined that there is exhalation).
Only, the relay 72 turns on the OK switch 74,
The ignition circuit 78 can be activated and the vehicle can be started.

In the control circuit for the shift lever interlock, the relay 72 is connected to a normally closed electromagnetic lock switch 82 for driving the shift lever electromagnetic lock circuit 84, as shown in FIG. 9, for example. In this circuit, the driver can start the engine with a switch (not shown), but the shift lever has an electromagnetic lock switch 8
It is fixed by the operation of 2 and is in an inoperable state. Then, the alcohol concentration determiner 30 and the exhalation presence / absence determiner 4
Only when both output signals of 0 are at the H level, the electromagnetic lock switch 82 is opened by the relay 72, the operation of the shift lever electromagnetic lock circuit 84 is stopped, and the shift lever becomes operable.

The preferred embodiments of the present invention have been described above, but the present invention is not limited to these, and various modifications can be made within the scope of the gist of the invention.

The present invention can be applied not only to a vehicle but also to a portable alcohol detection device suitable for self-management of drinking, for example.

[0062]

According to the present invention, it is possible to detect the exhaled breath alcohol of a measured gas with high accuracy by determining the exhaled breath of a driver, correcting the fluctuation of the inhaled expiratory amount, and improving the determination speed. It is possible to provide an alcohol detection device suitable for preventing automobile driving.

[Brief description of drawings]

FIG. 1 is a diagram showing the correlation between the alcohol concentration in the mouth and the alcohol concentration / water vapor concentration in the mouth.

2 shows a response curve of a sensor, FIG. 2 (a) shows a response curve of an alcohol sensor, FIG. 2 (b) shows a response curve of a humidity sensor, and FIG. 2 (c) shows a response curve of an alcohol sensor. It is a curve showing (change) / (response change of humidity sensor).

3 shows a response curve of the alcohol sensor, and FIG.
3A shows a response curve of the gas to be detected sucked from the first opening, and FIG. 3B shows a response curve of the gas to be detected sucked from the second opening.

FIG. 4 is a schematic view showing a first embodiment of the present invention.

5 is a circuit diagram of the detection device shown in FIG.

FIG. 6 is a schematic view showing a second embodiment of the present invention.

FIG. 7 is a circuit diagram of the detection device shown in FIG.

FIG. 8 is a control circuit diagram of an ignition interlock.

FIG. 9 is a control circuit diagram of a shift lever interlock.

[Explanation of symbols]

 10 Detected Gas Inhalation Part 12 Inhalation Pipe 12a Opening 20 Sensor Attachment Part 22 Alcohol Sensor 24 Humidity Sensor 26 Sulfide Sensor 30 Alcohol Concentration Judgment Device 40 Exhalation Existence Judgment Device 50 Display Device 60 Inhalation Pipe 60a Opening 62 Three Way Valve

Claims (3)

[Claims] 1. An inhaler having one opening (first opening) directed toward the space to be measured and a suction means provided on the side of the other opening communicating with the opening, and the inhaler. A sulfide sensor for determining whether or not human inhalation is included in the inhaled detected gas, and an amount of exhaled air included in the inspected gas provided in the inhalation part A humidity sensor for calculating, an alcohol sensor for detecting alcohol contained in the gas to be detected, which is provided in the inhalation section, and a detection signal of the sulfide sensor and a detection signal of the humidity sensor An inhalation presence / absence determiner for determining presence / absence of exhalation based on a ratio; and an alcohol concentration determiner for determining alcohol concentration from a ratio between the detection signal of the alcohol sensor and the detection signal of the humidity sensor. An alcohol detection device, characterized in that the alcohol concentration in a gas to be detected passing through the inside is detected. 2. The method according to claim 1, wherein a film for delaying diffusion of gas is mounted around the alcohol sensor, the sulfide sensor and the humidity sensor so that gas response time constants become equal. And alcohol detection device. 3. The three-way valve according to claim 1 or 2, wherein the three-way valve is provided between the alcohol sensor, the sulfide sensor, the humidity sensor and the first opening, and one end of the pipe is the three-way valve. And a second inhaler having a second opening installed at the other end of the pipe near the driver's seat in the passenger compartment and at a position where the exhaled air of the driver is difficult to be inhaled. Characteristic alcohol detection device.