JPH0368847A - Alcohol concentration detector - Google Patents

Abstract

PURPOSE:To keep the relationship between an alcohol concentration detector and a liquid surface approximately constant by self-actuation by providing a float at the outer surface of a tubular member wherein a gas feeding pipe which is immersed into liquid to be detected is suspended. CONSTITUTION:An upper end 211 of a tubular member 21 is closed with an upper end closing member 20. A lower end 212 is an open end part. A gas feeding pipe 22 has a gas sending means 24. The lower end of the pipe 22 is immersed into a liquid to be detected. The gas feeding pipe 22 is made to penetrate through the upper closing member 20 and suspended in the tubular member 21. A lower end 221 is terminated at a part higher than the lower end 212 of the tubular member 21. A gas temperature detecting means 27 is provided in a gas sucking pipe 26. A gas-temperature-change detecting means 28 detects the change in gas temperature based on the detected temperature. The change in gas temperature is transduced into the concentration of alcohol to be detected, and the result is outputted. A float 31 is provided at the outer surface of the tubular member 21. An alcohol concentration detector keeps the relationship between the apparatus and a liquid level approximately constant by self- actuation, and the occurrence of measuring errors can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to improvements in alcohol concentration detection devices. In particular, the present invention relates to improvements in alcohol concentration detection devices that detect the concentration of alcohol contained in alcohol-containing liquids such as alcoholic beverages and so-called dampening water used in lithographic printing. More specifically, continuous measurement is possible without the need for a support means to support the alcohol concentration detection device in the alcohol-containing liquid to be tested, and it is possible to detect impurities in the alcohol-containing liquid to be tested. The objective is to ensure that continuous measurement is possible for a long period of time even if there is contamination, that it can be used regardless of the depth of the alcohol-containing liquid to be tested, and that the measurement accuracy is good. This invention relates to the improvement of an alcohol concentration detection device.

[Conventional technology]

2. Description of the Related Art It has been necessary to detect the concentration of alcohol contained in alcohol-containing liquids such as alcoholic beverages and so-called dampening water used in lithographic printing.

As an example of a conventional alcohol concentration detection method,
In addition to the method of using a hydrometer, etc., in each case, the test liquid containing alcohol is pumped out, the specific gravity of the test alcohol-containing aqueous solution is measured, and the specific gravity is calculated based on this specific gravity. Methods for detecting alcohol concentration are known.

However, since the above-mentioned detection method is a discontinuous measurement method, it is difficult to avoid the drawback that it is necessary to pump out the test liquid containing alcohol each time detection is performed.

Therefore, the semi-continuous measurement means shown in Fig. 3 (each time detection
No need to pump out test liquid containing alcohol;
) has now been provided.

In the diagram shown in FIG. 3, 1 is a test liquid containing alcohol, 2 is an opening provided on its lower surface facing the natural surface of the test liquid 1, and its side wall is immersed in the test liquid. immersed in
It is a box-shaped body in which a space remains between the natural liquid level of the test liquid 1, and 3 penetrates the side surface of this box-shaped body, and the box-shaped body 2 and the above-mentioned test liquid are It is a blowing pipe that sends air into the space remaining between the natural liquid level of the liquid 1, and 4 passes through the other side of this box-like body 2. 6 is an exhaust pipe that exhausts air to the outside from the space remaining between the natural liquid level of the test liquid 1, and 6 is an exhaust pipe that discharges air to the outside from the space remaining between This is a gas sensor attached to the box-shaped body 2 for the purpose of measuring the concentration of alcohol in the container.

When detecting the concentration of alcohol contained in the test liquid 1 using this alcohol concentration measuring means, air is introduced from the blower pipe 3 and then the air inside the box-shaped body 2 is discharged from the visible exhaust vibrator 4. The alcohol vapor in the space remaining between the box body 2 and the natural liquid level of the test liquid 1 is removed, and the alcohol vapor in the space remaining between the box body 2 and the natural liquid level of the test liquid 1 is removed. After purging the space remaining in the space between them and leaving it for a certain period of time to sufficiently weed out the alcohol contained in the test liquid 1, the alcohol in the gas filling the above space is removed. The concentration is measured using a gas sensor 6, and the concentration of alcohol contained in the test liquid 1 is detected based on the result.

Therefore, even when measuring alcohol concentration using this measuring means, completely continuous measurement was not possible.

At the same time, the saturated vapor pressure of alcohol is
It is clear that the concentration of alcohol in the gas containing evaporated alcohol is not necessarily representative of the concentration of alcohol contained in the liquid 1 to be tested.

Therefore, by continuously measuring the concentration of alcohol that evaporates from the alcohol-containing test liquid using a gas sensor, and also measuring the temperature of the alcohol-containing test liquid, and adding temperature correction, it is possible to A means has now been provided for measuring the alcohol concentration of a test liquid. This measuring means is shown in FIG.

In the diagram shown in FIG. 4, 1 is a test liquid containing alcohol;
3 is a ventilation pipe, one end of which is connected to a ventilation pump 9, and the other end immersed in the liquid to be tested 1. Reference numeral 4 denotes an exhaust pipe, one end of which is immersed in the liquid to be tested 1, and the other end is open to the atmosphere. 6 is a gas sensor;
It is provided in the middle of the exhaust pipe 4 described above. 7 is a porous polymer whose both ends are connected to the end of the blower pipe 3 immersed in the test liquid 1 and the end of the exhaust pipe 4 immersed in the test liquid 1. This is a gas sampling tube formed by a gas-liquid separation membrane made of a membrane or the like. Reference numeral 8 denotes a temperature sensor, which is immersed in the test liquid 1 in order to measure the temperature of the test liquid 1.

When using this measuring device to detect the alcohol concentration of the test liquid 1, the ventilation pump 9 is used to send air into the ventilation pipe and release it into the atmosphere through the gas sampling pipe, exhaust pipe, and gas sensor. Then, the inside of the gas sampling tube 7 is purged. The alcohol contained in the test liquid 1 becomes vapor and enters the gas sampling tube through a gas-liquid separation membrane made of a porous polymer membrane or the like that constitutes the gas sampling tube 7.
It is guided to the gas sensor 6 together with the blown air. The alcohol concentration is measured by the gas sensor 6, the measured alcohol concentration is temperature-corrected based on the temperature of the test liquid 1 measured by the temperature sensor 8, and the alcohol concentration contained in the test liquid 1 is corrected based on the result. It measures alcohol concentration.

[Problem to be solved by the invention]

However, the means for measuring alcohol concentration shown in Figure 4 above is not suitable for measuring the concentration of an alcohol aqueous solution that does not contain many impurities, such as a finished alcoholic beverage (alcoholic beverage that is not being brewed). However, for test liquids such as alcoholic beverages being brewed and alcohol aqueous solutions that contain insoluble matter such as ink scum, such as dampening water used in lithographic printing,
This insoluble matter covers the gas-liquid separation membrane and prevents the alcohol from passing through the gas-liquid separation membrane and becoming vaporized, resulting in an error in the measurement results.

According to the results of experiments, after about 40 days of use, the measured value decreased by about 10% even at the same alcohol concentration.

The purpose of the present invention is to eliminate the various drawbacks that have been unavoidable in the above-mentioned various alcohol concentration detection devices, and (a) continuous measurement is possible even if the sample liquid is contaminated with impurities; (b) It can be used regardless of the depth of the liquid to be tested; (c) it is also corrected for changes in the temperature of the liquid to be tested; (d) it is also corrected for changes in the ambient air temperature; An object of the present invention is to provide an improved alcohol concentration detection device so that the alcohol concentration is sufficiently good.

(Means for solving the problem) The above purpose can be distantly related to any of the following means.

The first means is a cylindrical member (2) whose upper end (211) is closed with an upper end closing member (20) and whose lower end (212) is an open end.
1), and the cylindrical member (20) passing through the upper end closing member (20).
21), its lower end (221) ends above the lower end (212) of the cylindrical member (21), and has an air supply means (24), the lower end of which is suspended in the test liquid. a gas supply pipe (22) immersed in the gas supply pipe (22) and the upper closing member (22);
a gas suction pipe (26) provided to penetrate through the gas suction pipe (26); a gas temperature detection means (27) provided in the gas suction pipe (26) for detecting the temperature of the gas; a gas temperature change detection means (2B) for detecting a temperature change of the gas based on the temperature detected by the gas temperature change detection means (27); and a temperature change/alcohol concentration correction means (29) for correcting the temperature change of the gas to a test alcohol concentration. ) and alcohol concentration output means (30) for outputting information representing the corrected alcohol concentration, wherein a float (31) is provided on the outer periphery of the cylindrical member (21). (corresponding to claim 1).

The above float (3I) has good stability and is suitable if the circumference of the upper part (311) is larger than the circumference of the lower part (312), and this is the second means (claim 2). ).

The third means is a cylindrical member (2) whose upper end (211) is closed with an upper end closing member (20) and whose lower end (212) is an open end.
1), and the cylindrical member (20) passes through the upper end closing member (20>).
21), its lower end (221) ends above the lower end (212) of the cylindrical member (21), and has an air supply means (24), the lower end of which is suspended in the test liquid. a gas supply pipe (22) immersed in the gas supply pipe (22) and the upper closing member (22);
a gas suction pipe (26) provided through the gas suction pipe (26), a gas temperature detection means (27) provided in the gas suction pipe (26) for detecting the temperature of the gas, and the upper closing member (20). ), and the lower end of the cylindrical member (21) (
221) A test liquid temperature detection means (32) for detecting the temperature of a liquid containing test alcohol provided nearby; and detecting a change in the temperature of the gas by comparing the test liquid temperature and the gas temperature. a temperature change/alcohol concentration correction means (29) for correcting the temperature change of the gas to the test alcohol concentration; and an alcohol concentration correction means (29) for outputting information representing the corrected alcohol concentration. In the alcohol concentration detection device having a concentration output means (30), a float (31) is provided on the outer periphery of the cylindrical member (21) (corresponding to claim 3).

Also in this configuration, the above-mentioned float (31) is attached to the upper part (31
It is preferable that the circumferential length of 1) is larger than the lower circumferential length (312) because stability is good, and this is the fourth means (corresponding to claim 4).

[Effect]

The alcohol concentration detection device according to the present invention includes a gas supply pipe 2
2, regardless of the liquid depth of the test liquid, an appropriate amount of air is blown into the test liquid lO to generate an amount of alcohol vapor proportional to the concentration of alcohol contained in the test liquid lO. The gas suction pipe 26 emits alcohol vapor in an amount proportional to the concentration of alcohol contained in the test liquid 10.
The alcohol vapor thus sucked out is oxidized with the oxygen in the air supplied at the same time, and the amount of heat generated during this chemical reaction is used as the gas temperature detection means 27.
For example, a temperature sensing resistor is heated, and the change in the resistance value of the gas temperature detecting means 27 is electrically measured based on the temperature change of the resistor etc. gas temperature detecting means 27 due to this heating. This device detects the concentration of alcohol contained in alcohol.

In the alcohol concentration detection device according to the present invention, a fixed amount of air is delivered into the liquid to be tested 10 via the gas supply pipe 22 per unit time. The air sent into the test liquid 10 becomes bubbles, rises in the test liquid 10, and is discharged from the liquid surface into the atmospheric space within the cylindrical member 21. At this time, since the amount of air supplied is constant per unit time, the above bubbles, that is, the gas sucked out from the gas suction pipe 26, are
It always contains an amount of alcohol that is representative of the concentration of alcohol contained in the test liquid 10. Therefore, the amount of heat generated per unit time when the gas containing alcohol vapor is oxidized by oxygen in the supplied air represents the concentration of alcohol contained in the liquid 10 to be tested. This generated heat heats the gas temperature detection means, such as a temperature sensing resistor 27, and this generated heat is
The temperature of the gas temperature detecting means 27, such as a temperature sensing resistor, is
The alcohol concentration is increased approximately in proportion to the alcohol concentration, and the amount of heat generated changes the resistance value of the gas temperature detection means 27, such as a temperature sensing resistor, in response to the temperature rise. This change in resistance value is electrically measured using gas temperature change detection means 28. At this time, the temperature of the surrounding air and the temperature of the liquid to be tested 10 are also measured, and the temperature is determined in order to eliminate the error in the measured value that is caused to the output of the gas temperature detection means due to these temperature changes. It is effective to perform correction to improve accuracy.

When using the alcohol concentration detection device according to the prior art, it is clear that it is necessary to fix it with some kind of support. Otherwise, the alcohol concentration detection device according to the prior art would sink into the sample liquid. However, when the alcohol concentration detection device according to the above-described prior art is fixed with another support, when the liquid level of the test liquid changes, the distance from the liquid level of the test liquid 10 to the lower end 221 of the gas supply pipe 22 The depth of the air fluctuates, and with the air supply means 24 that outputs a constant pressure, it is impossible to supply a constant amount of air, even if the alcohol concentration contained in the subject 10 is constant. , resulting in fluctuations in the measured concentration values, resulting in errors. FIG. 2 shows the variation in the measured value of the alcohol concentration when the immersion depth of the alcohol concentration detection device changes.

In the diagram shown in FIG. 2, three curves show fluctuations in the measured value of the concentration when the immersion depth of the alcohol concentration detection device changes, and are shown using the concentration as a parameter. Both curves have the disadvantage that when the degree of immersion increases and exceeds a certain value, the measured value tends to drop rapidly, in other words, the measurement error tends to increase rapidly.

This drawback is difficult to overlook, especially when unexpected changes in the immersion depth of the alcohol concentration detection device are unavoidable, such as when detecting the alcohol concentration of so-called dampening water used in lithographic printing. be.

In order to avoid such an increase in measurement error, the alcohol concentration detection device according to the present invention includes a cylindrical member 21.
A float 30 is provided on the outer periphery of the float. Due to the buoyant force acting on the float 30, the alcohol concentration detection device automatically detects the
The relationship with the liquid level! ``Can be maintained constant. Float 30
For example, the immersion depth in Figure 2 above is 4c.
It is selected so that it is about m.

In addition, as mentioned above, the saturated atmospheric pressure of alcohol depends on the temperature of the test liquid, so the concentration of alcohol in the gas containing evaporated alcohol is accurately determined by the concentration of alcohol contained in the test liquid. To overcome this drawback, measure the temperature of the surrounding air and the temperature of the test liquid containing alcohol, and by adding temperature correction, measure the temperature of the test liquid containing alcohol. It is intended to improve the measurement efficiency of liquid alcohol concentration.

〔Example〕

Hereinafter, alcohol concentration detection devices according to four embodiments of the present invention will be described with reference to the drawings.

In the drawing shown in FIG. 1a, 20 is an upper end closing member that supports a cylindrical member 21, a gas supply pipe 22, and a gas suction pipe 26.

The upper end 2]1 of the cylindrical member 21 is closed by the upper end closing member 20, and the lower end 212 thereof is an open end and is immersed in the test liquid 10 containing alcohol. Further, the lower end 221 of the gas supply pipe 22 is connected to the above-mentioned cylindrical member 21.
It ends above the lower end 212 of.

Since the gas supply pipe 22 is provided with an air supply means 24, air or the like is supplied into the test liquid 10 containing alcohol inside the cylindrical member 21.

By the way, since the lower end 221 of the gas supply pipe 22 ends above the lower end 212 of the above-mentioned cylindrical member 21, the supplied air, etc. is prevented from leaking to the outside of the cylindrical member 21, and air bubbles and the like are prevented. At this time, the test liquid 10 containing alcohol is vaporized, and a gas having an alcohol gas concentration representative of the alcohol concentration of the test liquid 10 containing alcohol is transferred to the cylindrical member 21. 21
supply to the space above. The gas supplied to the space above the cylindrical member 21 is sucked out through the gas suction pipe 26, reacts with oxygen in the air within the gas suction pipe 26, and generates heat.

A resistor 27 serves as a gas temperature detection means provided in the gas suction pipe 26, and is heated by heat generated when alcohol vapor is oxidized, so that its resistance value changes. The resistance value of this resistor is measured by a resistance value measuring device such as a Wheatstone bridge having the above-mentioned gas temperature detection means 27 on one side.

By the way, since the alcohol concentration of the test liquid 10 containing alcohol depends on the temperature rise of the above-mentioned resistor, that is, the change in resistance value (change in temperature), changes) need to be measured.

However, since heat is generated and heat is dissipated at the same time, the resistance value of the above-mentioned resistor depends on the temperature of the surrounding air, and also depends on the temperature of the test liquid 10 containing alcohol and the temperature of the surrounding air. The difference depends on the relative humidity of the surrounding air, etc., so in order to find the temperature rise of the above resistor, that is, the change in resistance value (change in temperature) from the resistance value of the above resistor, what must be done? This revision is necessary. The functional element that performs this correction is the gas temperature change detection means 28, and this gas temperature change detection means uses the resistance value of the resistor as well as the various parameters described above as original information to determine the resistance of the resistor. The value is converted into a temperature rise of the resistor, that is, a change in temperature, and this is output. This function can be easily implemented using a table lookup method using a table created based on the results of experiments performed using the various parameters described above.

In response to this output, temperature change/alcohol concentration correction means 29 outputs alcohol concentration based on the input temperature change value, and alcohol concentration output means 30 in the next stage outputs alcohol concentration according to a desired output method. . This function can also be easily realized by using a table lookup method using a table created based on the results of experiments conducted using the various parameters described above.

31 is a float according to the gist of the present invention, and 311 is a float 3.
1 is the upper part of the float 31, and 312 is the lower part of the float 31.

In the alcohol concentration detection device according to the present invention, a fixed amount of air is sent into the test liquid 10 via the gas supply pipe 22 per unit time, regardless of the depth of the test liquid 10. The air sent into the test liquid 10 becomes bubbles, rises in the test liquid 10, and is discharged from the liquid surface into the atmospheric space within the cylindrical member 21. At this time, since the amount of air supplied is constant per unit time, the above-mentioned air bubbles are generated in the sample liquid 10 regardless of the depth of the sample liquid 10.
It can be seen that it contains alcohol vapor in an amount representative of the concentration of alcohol contained in it. Therefore, the amount of heat generated per unit time when this alcohol vapor is oxidized by oxygen in the supplied air is the amount of heat generated per unit time of the alcohol contained in the sample 10, regardless of the depth of the sample liquid. It will represent the concentration. The amount of heat generated is the temperature sensing resistor 2.
7 is heated, the temperature of this temperature-sensitive resistor 27 rises in proportion to the above alcohol concentration, and the resistance value changes corresponding to the temperature rise. This change in resistance value is electrically measured. This temperature rise value is input to the temperature change/alcohol concentration correction means 29, and the sample is tested based on a list of alcohol concentrations using parameters such as the type of liquid to be tested and the humidity in the air. The alcohol concentration of the liquid is detected, and the alcohol concentration output means 30 outputs the alcohol concentration according to a desired output method.

A float 30 on the outer periphery of the cylindrical member 21 is the float 30 according to the gist of the present invention, and the buoyancy acting on the float 30 allows the alcohol concentration detection device to maintain a constant relationship with the liquid level with its own blade. It is possible. As a result, even if the temperature and the liquid level change, the gas supply pipe 22 allows the specimen 10 to be
The flow rate of air etc. sent into the test object 10 is not affected by fluctuations in the liquid level height, and the flow rate of air etc. sent into the subject 10 is kept constant. As a result, measurement accuracy can be improved.

See figure 1b The only difference between the first example and the second example is the shape of the float 30.

Therefore, only the float 30 will be explained, and other explanations will be omitted.

In the float 30 in this example, the circumference of the upper part 301 is selected to be larger than the circumference of the lower part 3020.

This is a measure for the purpose of increasing the restoring force when the alcohol concentration detection device is tilted due to the ripples of the subject 10. If the alcohol concentration detection device is tilted,
In order to increase the moment of buoyancy by separating the center of buoyancy from the center of gravity of the alcohol concentration detection device as much as possible, the part of the alcohol concentration detection device that is immersed in the subject 10 when tilted is The float 30 is placed as shown in the figure in order to be as far away from the center of gravity as possible.
The circumference of the upper part 301 is selected to be larger than the circumference of the lower part 302.

See Figure 1c The difference from the first example is that in the first example, the air temperature is used as the reference value for correction, whereas in the third example, the temperature of the liquid in the subject 10 is used as the reference value for correction. That's true.

In the figure, reference numeral 32 denotes a test liquid temperature detection means, which has a test liquid temperature sensor 321 at its lower end. Other operations are generally the same as in the first example.

The difference from the third example (see FIG. 1d) is the same as the difference between the first and second examples, only the shape of the float 30. The circumference is selected to be larger than the circumference of 302. As a result, even when the alcohol concentration detection device is tilted, the position of the center of buoyancy is separated from the position of the center of gravity of the alcohol concentration detection device, and the attitude of the alcohol concentration detection device is stabilized.

〔Effect of the invention〕

As explained above, the alcohol concentration detection device according to the present invention uses an air supply means to send gas such as air through a gas supply pipe into a subject as bubbles, and the bubbles are proportional to the concentration of alcohol contained in the subject. The gas suction pipe enters the gas suction pipe with a certain amount of alcohol vapor, and the heat of reaction when this alcohol vapor oxidizes causes the temperature of the temperature-sensitive resistor in the gas suction pipe to rise and change its resistance value. It is said that the alcohol concentration in the sample is detected by measuring the change in alcohol concentration, and since a float is provided on the outer periphery of the cylindrical member of the alcohol concentration detection device, a support member for the alcohol concentration detection device is no longer required, and it is possible to detect alcohol concentration in the sample. Continuous measurement is possible even if the sample is contaminated with impurities, and it can be used regardless of the depth of the liquid in the sample, and is highly accurate. In good condition.

[Brief explanation of drawings]

FIG. 1a is a sectional view of an alcohol concentration detection device according to a first embodiment of the present invention. FIG. 1b is a sectional view of an alcohol concentration detection device according to a second embodiment of the present invention. FIG. 1c is a sectional view of the alcohol concentration detection device according to claim 3 according to an embodiment of the present invention. FIG. 1d is a sectional view of an alcohol concentration detection device according to a fourth aspect of the present invention. FIG. 2 is a characteristic curve diagram showing the relationship between the immersion depth in the sample and the measured value of the alcohol concentration detection device according to the embodiment of the present invention. FIG. 3 is a sectional view of an alcohol concentration detection device according to the prior art. FIG. 4 is a sectional view of another alcohol concentration detection device according to the prior art. l... Subject, 2... Box-shaped body, 3... Ventilation vibrator, 4... Exhaust vibe, 6... Gas sensor, 7... Gas sampling tube, 8... Temperature sensor, 9... Ventilation pump, 10... Test liquid, 20... Upper end closing member, 21... Cylindrical member, 211... Upper end of the cylindrical member, 212... Lower end of the cylindrical member , 22...Gas supply pipe, 221...Lower end of gas supply pipe, 24...Air supply means, 26...Gas suction pipe, 27...Gas temperature detection means, 28...Gas temperature Change detection means, 29... Temperature change/alcohol concentration correction means, 30.
... Alcohol concentration output means, 31 ... Float, 311 ... Upper part of the float, 312 ... Lower part of the float, 32 ... Test object temperature detection means, 321 ... Test object temperature sensor, 33. ...Gas temperature change detection means.

Claims (1)

[Scope of Claims] [1] A cylindrical member (21) whose upper end (211) is closed with an upper end closing member (20) and whose lower end (212) is an open end; and the upper end closing member (20). The cylindrical member (
21), its lower end (221) ends above the lower end (212) of the cylindrical member (21), and has an air supply means (24), the lower end of which is suspended in the test liquid. a gas supply pipe (22) immersed in the gas supply pipe (22) and the upper closing member (22);
a gas suction pipe (26) provided to penetrate through the gas suction pipe (26); a gas temperature detection means (27) provided in the gas suction pipe (26) for detecting the temperature of the gas; a gas temperature change detection means (28) for detecting a temperature change of the gas based on the temperature detected by the gas temperature change detection means (27); and a temperature change/alcohol concentration correction means (29) for correcting the temperature change of the gas to a test alcohol concentration. ) and alcohol concentration output means (30) for outputting information representing the corrected alcohol concentration, wherein a float (31) is provided on the outer periphery of the cylindrical member (21). An alcohol concentration detection device characterized by: [2] Claim 1, wherein the float (31) has an upper circumference (311) larger in circumference than a lower circumference (312).
The alcohol concentration detection device described. [3] A cylindrical member (21) whose upper end (211) is closed with an upper end closing member (20) and whose lower end (212) is an open end; Cylindrical member (
21), its lower end (221) ends above the lower end (212) of the cylindrical member (21), and has an air supply means (24), the lower end of which is suspended in the test liquid. a gas supply pipe (22) immersed in the gas supply pipe (22) and the upper closing member (22);
a gas suction pipe (26) provided through the gas suction pipe (26), a gas temperature detection means (27) provided in the gas suction pipe (26) for detecting the temperature of the gas, and the upper closing member (20). ), and the lower end of the cylindrical member (21) (
221) A test liquid temperature detection means (32) provided nearby and having a test object temperature sensor (321) for detecting the temperature of the liquid containing the test alcohol, and detecting the test liquid temperature and the gas temperature. a gas temperature change detection means (33) that compares and detects a temperature change of the gas; a temperature change/alcohol concentration correction means (29) that corrects the temperature change of the gas to a test alcohol concentration; and an alcohol concentration output means (30) for outputting information representing the alcohol concentration, characterized in that a float (31) is provided on the outer periphery of the cylindrical member (21). Alcohol concentration detection device. [4] Claim 3, wherein the float (31) has an upper circumference (311) larger in circumference than a lower circumference (312).
The alcohol concentration detection device described.