JP3140378B2 - Liquid phase alcohol concentration measurement method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vapor-phase alcohol which is injected into a chamber of a fixed volume, which is made airtight and warmed up to a predetermined temperature, is evaporated, and diffuses into the chamber. Is measured by a contact combustion gas sensor, and based on a conversion table obtained by measuring the gas phase alcohol concentration when the calibration liquid alcohol having a known concentration is evaporated in the same manner as described above by the contact combustion gas sensor. The present invention relates to a liquid alcohol concentration measuring method for converting the measured gas phase concentration into a liquid phase concentration so as to obtain a liquid alcohol concentration.
By switching the rotation speed of the fan at each stage of the measurement cycle, the gaseous alcohol remaining in the chamber after concentration measurement is exhausted to the outside of the chamber as much as possible, while fresh air is introduced into the chamber. The present invention relates to a method for measuring the concentration of a liquid alcohol, which can dramatically increase ventilation efficiency and thereby shorten the waiting time from the end of one measurement to the standby state allowing the next measurement.

[0002]

2. Description of the Related Art Conventionally, liquid-phase alcohol is injected into a chamber of a fixed volume which is made airtight and warmed up to a predetermined temperature and evaporated, and the concentration of gas-phase alcohol diffused into this chamber is reduced. Based on a conversion table obtained by measuring with a contact combustion gas sensor, measuring a gas phase alcohol concentration when the calibration liquid alcohol having a known concentration is evaporated in the same manner as described above by measuring with a contact combustion gas sensor. 2. Description of the Related Art There is generally known a method for measuring the concentration of a liquid alcohol in which the measured gas phase concentration is converted into a liquid phase concentration to obtain a liquid alcohol concentration.

[0003] An outline of an apparatus used for measuring the concentration of this type of liquid alcohol will be described. The concentration measuring apparatus comprises a device base having a chamber therein, and a lid provided on the upper portion of the device base so as to be openable and closable. When the lid is opened and closed by an operator, the inside of the chamber is kept airtight when the lid is closed, and the vapor phase alcohol diffused in the chamber can be ventilated when the lid is opened. ing. In addition, when the lid is open, 2
There are two modes.

One is a full-open mode in which the lid is greatly opened, and the gas-phase alcohol remaining in the chamber immediately after the measurement is discharged to the outside of the chamber, and the ventilation is performed when fresh outside air is introduced into the chamber. Used.
The purpose of this ventilation is that if even a small amount of alcohol remains in the chamber at the next measurement, the residual alcohol causes a measurement error.

[0005] The other is a half-open mode in which the lid is slightly opened, and is used for warming-up after the ventilation in the fully-open mode to raise the temperature in the chamber lowered by the ventilation to a predetermined temperature again. The warm-up in the half-open mode is intended to completely discharge the alcohol remaining in the chamber while maintaining a certain degree of warm-up efficiency.

On the other hand, when the lid is closed, the gas in the chamber is agitated when the lid is closed to form a uniform gas phase in the chamber, and when the lid is opened, the function of promoting ventilation in the chamber is provided. , A heater arranged in the chamber so as to increase the temperature of the gas in the chamber, a catalytic combustion type gas sensor for detecting the concentration of gaseous alcohol diffused in the chamber by converting the concentration into a voltage signal, and the like. Have been.

Further, the concentration measuring device has a display for displaying the measured liquid alcohol concentration, controls the display of the display, and controls the driving of the fan, the temperature of the heater, and the contact combustion type gas sensor. And a control unit having a function of, for example, inputting a voltage signal representing the concentration of the gaseous phase alcohol detected in step (1), converting the input signal into a liquid phase alcohol concentration with reference to the above-mentioned conversion table, and outputting the result. .

The outline of the measuring cycle in the liquid alcohol concentration measuring apparatus constructed as described above will be described. First, as a concentration measuring procedure, the temperature in a chamber having a fixed volume is set to, for example, about 60 to 80 ° C. by a heater. After warming up, a certain volume of liquid-phase alcohol as a sample is injected into this chamber, and the concentration of gas-phase alcohol diffused into the chamber is detected in the form of a voltage signal by a contact combustion gas sensor. Based on the conversion table and the conversion table, the liquid-phase alcohol concentration is obtained by converting the gas-phase concentration into the liquid-phase concentration.

Further, as a next measurement preparation procedure, first, the fan is driven while the lid is kept in the full-open mode for a predetermined time to ventilate the chamber. Next, in order to completely discharge the alcohol remaining in the chamber while maintaining a certain degree of warming-up efficiency, the fan is driven and the heater is operated with the lid kept in the half-open mode for a predetermined time. Warm up the chamber. When this ventilation + warm-up is completed, the preparation for the next measurement of the liquid alcohol concentration is completed, and the apparatus enters a standby state.

[0010]

However, according to the above-described conventional method for measuring the concentration of liquid alcohol, when sequentially measuring the concentration of liquid alcohol of a plurality of samples, it is necessary to wait until one measurement is completed. However, there is a problem to be solved that it takes a long time for the apparatus to enter a standby state allowing the next measurement.

In detail, when measuring the concentration of the liquid alcohol in the first place, if the ventilation in the chamber is insufficient, there is a possibility that a concentration measurement error may occur due to the influence of the alcohol remaining in the chamber. Must be considered.

However, if the full opening time of the lid is increased to sufficiently ventilate the chamber, the ventilation efficiency is increased, but the temperature in the chamber is considerably reduced. , The total time required for the above becomes longer, and as a result, the waiting time becomes longer.

In view of such circumstances, a new liquid alcohol concentration that can reduce the waiting time from the end of one measurement to the time when the apparatus enters a standby state allowing the next measurement. The development of a measurement method has long been awaited among those involved.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem. By switching the rotation speed of a fan at each stage of a measurement cycle, gas-phase alcohol remaining in a chamber after concentration measurement can be removed. While venting to the outside of the chamber as much as possible, fresh air is introduced into the chamber to dramatically increase the ventilation efficiency. With this, after one measurement is completed, the stand-by state allows the next measurement. It is an object of the present invention to provide a method for measuring the concentration of a liquid alcohol, which can reduce the waiting time until the concentration becomes lower.

[0015]

According to a first aspect of the present invention, a liquid alcohol is injected into a chamber of a constant volume which is hermetically sealed and warmed to a predetermined temperature. Gas-phase concentration measuring step of measuring the concentration of gas-phase alcohol diffused into the chamber by a contact combustion type gas sensor, and the gas-phase alcohol when the calibration-use liquid-phase alcohol having a known concentration is evaporated in the same manner as described above. A liquid-phase concentration obtaining step of converting the gas-phase alcohol concentration measured in the gas-phase concentration measuring step into a liquid-phase alcohol concentration based on a conversion table obtained by measuring the concentration with the contact combustion gas sensor; Wherein at least in the gas phase concentration measuring step, the concentration of the liquid alcohol, which is configured to rotate a fan for stirring the gas in the chamber at a low speed, is provided. In the measurement method, after the gas phase concentration measurement step, while the chamber is in a fully open state in which the chamber is largely opened from an airtight state, the ventilation step of switching the fan to high-speed rotation and ventilating the inside of the chamber for a predetermined time, After the ventilation step, while the chamber is in a half-open state in which the chamber is slightly opened from a full-open state, the fan is switched to low-speed rotation, and a warm-up step of raising the temperature of gas in the chamber to the predetermined temperature is further provided. The gist is to become

According to the first aspect of the present invention, after measuring the gas phase concentration, the chamber is brought into a fully open state in which the chamber is largely opened from an airtight state, while the fan is switched to high-speed rotation to ventilate the inside of the chamber for a predetermined time. While the chamber is changed from a fully open state to a half open state in which the chamber is slightly opened, the fan is switched to low-speed rotation, and the temperature of the gas in the chamber is raised to a predetermined temperature. As described above, the ventilation in the fully open state of the chamber is performed with the fan rotated at a high speed, so that the ventilation is performed in a shorter time as compared with the ventilation that maintains the low speed rotation of the fan as in the conventional measurement. A predetermined level of ventilation can be achieved, and as a result, the waiting time from the end of one measurement to the standby state allowing the next measurement can be shortened.

Further, according to a second aspect of the present invention, a liquid-phase alcohol is injected into a chamber of a fixed volume which is made airtight and warmed up to a predetermined temperature, and is evaporated to diffuse the gaseous phase into the chamber. A gas phase concentration measuring step of measuring the alcohol concentration by a contact combustion gas sensor, and a gas phase alcohol concentration when the calibration liquid alcohol having a known concentration is evaporated in the same manner as described above is measured by the contact combustion gas sensor. A liquid-phase concentration acquiring step of converting the gas-phase alcohol concentration measured in the gas-phase concentration measuring step into a liquid-phase alcohol concentration based on the obtained conversion table, and acquiring the liquid-phase alcohol concentration. A method for measuring the concentration of liquid alcohol, which is configured to rotate a fan for stirring gas in the chamber at a low speed,
After the gas phase concentration measurement step, while the chamber is in a fully open state in which the chamber is largely opened from an airtight state, the ventilation step of alternately switching the fan between high-speed rotation and low-speed rotation and ventilating the chamber for a predetermined time, After the ventilation step, while the chamber is in a half-open state in which the chamber is slightly opened from a full-open state, the fan is switched to low-speed rotation, and a warm-up step of raising the temperature of gas in the chamber to the predetermined temperature is further provided. The gist is to become

According to the second aspect of the present invention, after measuring the gas phase concentration, the chamber is brought into a fully open state in which the chamber is largely opened from an airtight state, and the fan is alternately switched between a high-speed rotation and a low-speed rotation to move the inside of the chamber for a predetermined time. Ventilation is performed, and after this ventilation, the chamber is set to a half-open state in which the chamber is slightly opened from a full-open state, while the fan is switched to low-speed rotation, and the temperature of gas in the chamber is increased to a predetermined temperature.
As described above, the ventilation in the fully opened state of the chamber is performed by alternately switching the fan between the high-speed rotation and the low-speed rotation, so that the ventilation maintaining the low-speed rotation of the fan is performed similarly to the conventional measurement. In comparison, the forced exhaust of the gaseous phase alcohol remaining in the chamber and the intake of fresh outside air are alternately performed, so that the ventilation efficiency can be drastically increased, and therefore, a predetermined level of ventilation can be achieved in a short time As a result, it is possible to reduce the waiting time from the end of one measurement to the standby state allowing the next measurement.

According to a third aspect of the present invention, a liquid phase alcohol is injected into a chamber of a constant volume which is made airtight and warmed up to a predetermined temperature, and is evaporated to diffuse the gaseous phase into the chamber. A gas phase concentration measuring step of measuring the alcohol concentration by a contact combustion gas sensor, and a gas phase alcohol concentration when the calibration liquid alcohol having a known concentration is evaporated in the same manner as described above is measured by the contact combustion gas sensor. A liquid-phase concentration acquiring step of converting the gas-phase alcohol concentration measured in the gas-phase concentration measuring step into a liquid-phase alcohol concentration based on the obtained conversion table, and acquiring the liquid-phase alcohol concentration. A method for measuring the concentration of a liquid alcohol, the method comprising: rotating a fan for stirring gas in the chamber at a low speed; After the step, the chamber is fully opened from the airtight state to a fully open state, while the fan is switched to high-speed rotation to ventilate the chamber for a predetermined time, and after the ventilation step, the chamber is slightly opened from the fully opened state. A warming-up step in which the fan is maintained at a high speed for a predetermined time and then switched to a low speed while the temperature of the gas in the chamber is raised to the predetermined temperature while the fan is maintained at a high speed for a predetermined time. Is the gist.

According to the third aspect of the present invention, after the gas phase concentration measurement, the chamber is brought into a fully open state in which the chamber is largely opened from an airtight state, while the fan is switched to high speed rotation to ventilate the inside of the chamber for a predetermined time. While the chamber is changed from a fully open state to a half open state in which the fan is slightly opened, the fan is maintained at a high speed for a predetermined time and then switched to a low speed, and the temperature of the gas in the chamber is raised to a predetermined temperature. As described above, the ventilation in the fully open state of the chamber is performed with the fan rotated at a high speed, so that the ventilation is performed in a shorter time as compared with the ventilation that maintains the low speed rotation of the fan as in the conventional measurement. A predetermined level of ventilation can be achieved. Furthermore, even in the chamber half-open state, the fan is maintained at a high speed for a predetermined time,
This contributes to a further reduction in ventilation time, and as a result, the waiting time from the end of one measurement to the standby state allowing the next measurement can be reduced.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the method for measuring the concentration of liquid alcohol according to the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a block diagram of a concentration measuring apparatus for realizing a liquid alcohol concentration measuring method according to the present invention.
FIG. 2 is an explanatory view showing a plurality of embodiments of the method for measuring the concentration of liquid alcohol according to the present invention. FIG. 3 is an external view of a concentration measuring device that realizes the method for measuring concentration of liquid alcohol according to the present invention. FIG. 4 is a cross-sectional view of a concentration measuring device for realizing the liquid alcohol concentration measuring method according to the present invention, and FIG. 5 is a diagram provided for explaining the present invention.

First, a schematic configuration of a concentration measuring device for realizing the liquid alcohol concentration measuring method according to the present invention will be described.
Referring to FIGS. 3 and 4, as shown in FIG. 3, the concentration measuring device 1 includes a device base 3 having a chamber 25 therein, and a lid provided on the upper portion of the device base 3 so as to be openable and closable. And a body 5. When the lid 5 is opened and closed by an operator, when the lid is closed, the semi-conical projection 9 provided to project from the lower surface of the lid 5 into the chamber 25, and the projection 9 is engaged. As described above, an airtight state is maintained by fitting an opening 7 opened at the upper part of the apparatus base 3 through a sealing material (not shown), while the gaseous alcohol diffused into the chamber 25 is opened at the time of opening. It is configured to allow ventilation. In addition, the lid 5
As shown in FIG. 4, a sample injection section 23 made of an elastic member such as rubber is provided on the
, For example, with a needle of a syringe 19 to inject the liquid alcohol L. In order to receive the injected liquid alcohol L, the protrusion 9 provided on the lower surface of the lid 5 is provided with a concave portion 21 which spreads downward and divergent, and the liquid alcohol L serving as a sample is provided. Is provided. The sample holder 13 is provided with the lid 5
4 is configured so as to protrude into the chamber 25 as shown in FIG. Also,
A filter member 15 having a function of promoting vaporization and diffusion by impregnation with the liquid phase alcohol L is provided at the bottom of the sample holding unit 13. There are two modes in the open state of the lid 5.

One is a full-open mode in which the lid 5 is largely opened, in which the gas-phase alcohol remaining in the chamber 25 immediately after the measurement is discharged to the outside of the chamber 25 and fresh outside air is taken into the chamber 25. Used for ventilation. The purpose of this ventilation is that if even a small amount of alcohol remains in the chamber 25 at the time of the next measurement, the residual alcohol causes a measurement error.

The other is a half-open mode in which the lid 5 is slightly opened, and is used for warming up the temperature in the chamber 25 lowered by the ventilation to a predetermined temperature after the ventilation in the full-open mode. The warm-up in the half-open mode is intended to completely discharge the alcohol remaining in the chamber while maintaining a certain degree of warm-up efficiency.

On the other hand, in the chamber 25, a plurality of heaters 27 are arranged at intervals in the chamber 25 so as to increase the temperature of the gas in the chamber 25, and the gas in the chamber 25 is closed when the lid 5 is closed. Chamber 2 by stirring
5 has a uniform gaseous state, while fan 3 plays a role of promoting ventilation in chamber 25 when lid 5 is opened.
1, a cylindrical air blowing guide member 29 provided with a large number of diffusion holes for guiding air supply from the fan 31, and a contact for converting the concentration of gaseous alcohol diffused into the chamber 25 into a voltage signal and detecting the voltage signal. A combustion type gas sensor 35 and a temperature sensor 37 for detecting the temperature of the gas phase in the chamber 25 are provided.

The concentration measuring device 1 further includes a display unit 17 for displaying the measured concentration of the liquid alcohol L, a display control of the display unit 17, and the above-described fan 31.
, The temperature control in the chamber 25 by the heater 27, and a voltage signal representing the concentration of the gaseous alcohol detected by the contact combustion type gas sensor 35, and this input signal is converted into, for example, a conversion table shown in FIG. And a control unit 39 having a function of converting the concentration into the concentration of the liquid alcohol L and outputting the same.

The control section 39 will be described in more detail. As shown in FIG. 1, the control section 39 is connected to a fan motor 33 for driving the fan 31 and the fan motor 3
3, a motor control circuit 41 for controlling the rotation speed, a sensor detection circuit 43 for amplifying a voltage signal proportional to the gas-phase alcohol concentration detected by the catalytic combustion gas sensor 35 to an appropriate amplitude, a temperature sensor 37 and a heater 27. Connected to
A temperature control circuit 45 for controlling the temperature inside the chamber 25 to a set temperature of, for example, 60 to 80 ° C .; a motor control circuit 41; a sensor detection circuit 43;
5. A ROM 49 for storing programs and the like and a RAM 51 for storing data and the like are connected, and the rotation speed control of the fan motor 33, the temperature control in the chamber 25 by the heater 27, and the gas phase detected by the contact combustion type gas sensor 35 A CPU 47 having a function of inputting a voltage signal representing the concentration of alcohol, converting the input signal into a concentration of liquid alcohol L with reference to a conversion table and outputting the concentration, and transferred from the CPU 47 to the CPU 47 And a display control circuit 53 for sending the concentration data of the liquid alcohol L to the display unit 17.

Next, an outline of a concentration measuring method realized by the liquid alcohol concentration measuring device configured as described above will be described with reference to FIG.

Prior to this description, a procedure for creating a conversion table referred to when converting the vapor-phase alcohol concentration into the liquid-phase concentration will be described. The gaseous phase concentrations of two samples, ie, purified water that becomes 0 and a calibration liquid phase alcohol having a known concentration of, for example, 25 Vol%, are measured by the contact combustion gas sensor 35, and the respective voltage values obtained at this time are represented by straight lines. By linking, a conversion table as shown in FIG. 5, for example, is created. This conversion table is, for example, in the form of a calculation formula or in the form of a look-up table.
It is stored at a predetermined address of the AM 51 and is referred to as needed.

Next, as a procedure in the measurement mode for performing concentration measurement, first, the temperature in the chamber 25 having a fixed volume is warmed up to about 60 to 80 ° C. by the heater 27, and A liquid alcohol L serving as a fixed volume sample is injected (step 1). Further, the concentration of the vapor-phase alcohol diffused into the chamber 25 is sequentially detected in the form of a voltage signal by the catalytic combustion type gas sensor 35 for a predetermined sampling time for a predetermined time, and the obtained sampling data is stored in a predetermined address of the RAM 51. Store. Then, data having a maximum value is extracted from the obtained sampling data, and the concentration of the liquid alcohol L is converted by converting the gas phase concentration into the liquid phase concentration based on the maximum value data and the conversion table. (Step 2). In step 1, the fan 31 is used to make the inside of the chamber 25 a uniform gas phase.
Is controlled to rotate at a constant low speed. Here, fan 31
Is rotated at a low speed because if the fan 31 is rotated at a high speed when measuring the gas phase concentration, an error may occur in the detection value of the contact combustion type gas sensor 35 due to the influence of the air volume.

Further, as a procedure in the preparation mode for preparing for the next measurement, the fan 31 is driven while the lid 5 is kept in the fully open mode for a predetermined time to ventilate the inside of the chamber 25 (step 3). Next, in order to completely discharge the alcohol remaining in the chamber 25 while maintaining a certain degree of warming-up efficiency, the drive of the fan 31 is performed with the lid 5 maintained in the half-open mode for a predetermined time. Then, the inside of the chamber 25 is warmed up by the heater 27 (step 4). When this ventilation + warm-up is completed, the preparation for the next measurement of the liquid alcohol concentration is completed, and the apparatus enters a standby state.

The important point here is that the rotation speed of the fan 31 is switched in step 3 or step 4 in the above-described measurement cycle.

That is, in the first embodiment, when the measurement cycle shifts from the measurement mode to the preparation mode, the chamber 25 is changed from the airtight state to the fully opened state in which the lid 5 is largely opened, and the fan 31 is rotated at a high speed. After switching, the inside of the chamber 25 is ventilated for a predetermined time, and after this ventilation, the chamber 25 is set to a half-open state in which the chamber 25 is slightly opened from a fully open state.
The fan 31 is switched to low-speed rotation, and the temperature of the gas in the chamber 25 is raised to a predetermined temperature. Thus, the ventilation in step 3
Since the rotation of the fan 1 is performed at a high speed, the ventilation at a predetermined level can be achieved in a short time as compared with the ventilation that maintains the low speed rotation of the fan 31 in the measurement mode which has been conventionally performed.

In the second embodiment, when the measurement cycle shifts from the measurement mode to the preparation mode, the chamber 25 is changed from the airtight state to the fully opened state in which the lid 5 is largely opened, while the fan 31 is rotated at a high speed. The chamber 25 is ventilated for a predetermined time by alternately switching to low-speed rotation. After this ventilation, the chamber 25 is set to a half-open state in which the chamber 25 is slightly opened from a full-open state. Is raised to a predetermined temperature. As described above, since the ventilation in step 3 is performed by alternately switching the fan 31 between the high-speed rotation and the low-speed rotation, the ventilation is compared with the ventilation in the conventional measurement mode in which the low-speed rotation of the fan 31 is maintained. As a result, the forced exhaust of the gaseous alcohol remaining in the chamber 25 and the intake of fresh outside air are alternately performed, so that the ventilation efficiency can be dramatically increased. As a result, a predetermined level of ventilation can be achieved in a short time. Can be achieved.

In the third embodiment, when the measurement cycle shifts from the measurement mode to the preparation mode, the chamber 25 is changed from the airtight state to the fully opened state in which the lid 5 is largely opened, while the fan 31 is rotated at a high speed. The chamber 25 is switched to ventilate the inside of the chamber 25 for a predetermined time.
5 is changed from a fully open state to a half open state where the fan 31 is slightly opened, while the fan 31 is maintained at a high speed for a predetermined time and then switched to a low speed, and the temperature of the gas in the chamber 25 is raised to a predetermined temperature. As described above, since the ventilation in step 3 is performed with the fan 31 rotating at a high speed, the ventilation is performed in a short time in comparison with the ventilation that maintains the low speed rotation of the fan 31 in the conventional measurement mode. A standard level of ventilation can be achieved. In addition, even when the lid 5 is in the half-open state, the fan 31 is maintained at a high speed for a predetermined time, thereby contributing to a further reduction in ventilation time.

It should be noted that the present invention is not limited to the example of the above-described embodiment, but by making appropriate changes,
It can be implemented in other aspects.

That is, for example, in the first to third embodiments, in the warming-up in step 4, the temperature of the chamber is heated and warmed up by increasing the temperature of the heater compared to the related art.
It can also be configured to achieve a reduction in warm-up time. By doing so, it is possible to realize a reduction in the waiting time in the preparation mode in addition to the reduction in the ventilation time.

[0039]

As described above in detail, according to the first aspect of the present invention, after measuring the gas phase concentration, the chamber is fully opened from the airtight state, and the fan is switched to high speed rotation to switch the chamber to high speed. Ventilation inside for a predetermined time, and after this ventilation, while the chamber is in a half-open state in which the chamber is slightly opened from a full-open state, the fan is switched to low-speed rotation,
The temperature of the gas in the chamber is raised to a predetermined temperature. As described above, the ventilation in the fully open state of the chamber is performed with the fan rotated at a high speed, so that the ventilation is performed in a shorter time as compared with the ventilation that maintains the low speed rotation of the fan as in the conventional measurement. A predetermined level of ventilation can be achieved, and as a result, the waiting time from the end of one measurement to the standby state allowing the next measurement can be shortened.

According to the second aspect of the present invention, after measuring the gas phase concentration, the chamber is brought into a fully open state in which the chamber is largely opened from an airtight state, and the fan is alternately switched between a high-speed rotation and a low-speed rotation so that the inside of the chamber is changed. Ventilation is performed for a predetermined time, and after this ventilation, the chamber is set to a half-open state in which the chamber is slightly opened from a full-open state, while the fan is switched to low-speed rotation and the temperature of gas in the chamber is raised to a predetermined temperature. As described above, the ventilation in the fully opened state of the chamber is performed by alternately switching the fan between the high-speed rotation and the low-speed rotation, so that the ventilation maintaining the low-speed rotation of the fan is performed similarly to the conventional measurement. In comparison, the forced exhaust of the gaseous phase alcohol remaining in the chamber and the intake of fresh outside air are alternately performed, so that the ventilation efficiency can be drastically increased, and therefore, a predetermined level of ventilation can be achieved in a short time As a result, it is possible to reduce the waiting time from the end of one measurement to the standby state allowing the next measurement.

According to the third aspect of the present invention, after measuring the gas phase concentration, the chamber is brought into a fully open state in which the chamber is largely opened from an airtight state, and the fan is switched to high speed to ventilate the inside of the chamber for a predetermined time. After ventilation, the chamber is set to a half-open state where the chamber is slightly opened from a fully open state, while the fan is maintained at a high speed for a predetermined time and then switched to a low speed, and the temperature of the gas in the chamber is raised to a predetermined temperature. In this way, ventilation in the fully open state of the chamber is performed with the fan rotating at high speed,
A predetermined level of ventilation can be achieved in a short time as compared with the ventilation in which the low-speed rotation of the fan is maintained as in the conventional measurement. Furthermore, even in the chamber half-open state, the fan is maintained at a high speed for a predetermined time, which contributes to further reduction in ventilation time,
As a result, there is an extremely excellent effect that the waiting time from the end of one measurement to the standby state allowing the next measurement can be reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram of a concentration measuring device for realizing a liquid alcohol concentration measuring method according to the present invention.

FIG. 2 is an explanatory view showing a plurality of embodiments of a liquid alcohol concentration measuring method according to the present invention.

FIG. 3 is an external view of a concentration measuring device for realizing the liquid alcohol concentration measuring method according to the present invention.

FIG. 4 is a cross-sectional view of a concentration measuring device for realizing the liquid alcohol concentration measuring method according to the present invention.

FIG. 5 is a diagram provided for explanation of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Concentration measuring device 3 Device base 5 Lid 7 Opening 9 Projecting part 13 Sample holding part 15 Filter member 17 Display part 19 Syringe 21 Concave part 23 Sample injection part 25 Chamber 27 Heater 29 Ventilation guide member 31 Fan 33 Fan motor 35 Contact combustion Gas sensor 37 Temperature sensor 39 Control unit 41 Motor control circuit 43 Sensor detection circuit 45 Temperature control circuit 47 CPU 49 ROM 51 RAM 53 Display control circuit L Liquid alcohol

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-181153 (JP, A) JP-A-7-12962 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01N 27/00-27/24 G01N 25/28-27/32 G01N 33/14

Claims (3)

(57) [Claims] 1. A gaseous alcohol having a gaseous alcohol concentration, which is injected into a chamber of a fixed volume which is made airtight and warmed up to a predetermined temperature, is vaporized, and diffuses the alcohol in the chamber. And a gas phase concentration measurement step of measuring the concentration of the gaseous alcohol when the calibration liquid alcohol having a known concentration is evaporated in the same manner as described above, based on the conversion table obtained by measuring the gas phase alcohol concentration with the contact combustion gas sensor. A liquid phase concentration obtaining step of converting the gas phase alcohol concentration measured in the gas phase concentration measuring step into a liquid phase alcohol concentration, and obtaining the liquid phase alcohol concentration.In at least the gas phase concentration measuring step, the gas in the chamber is A method for measuring the concentration of liquid-phase alcohol configured to rotate a stirring fan at a low speed, comprising: A ventilation step of switching the fan to high-speed rotation and ventilating the inside of the chamber for a predetermined time, and a semi-open state of slightly opening the chamber from the fully opened state after the ventilation step. And a warming-up step of switching the fan to low-speed rotation and increasing the temperature of the gas in the chamber to the predetermined temperature. 2. A catalytic combustion type gas sensor in which a liquid alcohol is injected into a chamber of a fixed volume which is made airtight and warmed up to a predetermined temperature and evaporated, and a concentration of a gaseous alcohol diffused into the chamber is obtained. And a gas phase concentration measurement step of measuring the concentration of the gaseous alcohol when the calibration liquid alcohol having a known concentration is evaporated in the same manner as described above, based on the conversion table obtained by measuring the gas phase alcohol concentration with the contact combustion gas sensor. A liquid phase concentration obtaining step of converting the gas phase alcohol concentration measured in the gas phase concentration measuring step into a liquid phase alcohol concentration, and obtaining the liquid phase alcohol concentration.In at least the gas phase concentration measuring step, the gas in the chamber is A method for measuring the concentration of liquid-phase alcohol configured to rotate a stirring fan at a low speed, comprising: A fully open state in which the airtight state is largely opened, while the fan is alternately switched between high-speed rotation and low-speed rotation to ventilate the chamber for a predetermined period of time, and after the ventilation step, the chamber is fully opened. A warming-up step of switching the fan to low-speed rotation while raising the temperature of the gas in the chamber to the predetermined temperature while setting the fan to a low-speed half-open state, and further comprising: Concentration measurement method. 3. A catalytic combustion type gas sensor in which a liquid alcohol is injected into a chamber of a constant volume which is made airtight and warmed up to a predetermined temperature and evaporated, and a concentration of a gaseous alcohol diffused into the chamber is obtained. And a gas phase concentration measurement step of measuring the concentration of the gaseous alcohol when the calibration liquid alcohol having a known concentration is evaporated in the same manner as described above, based on the conversion table obtained by measuring the gas phase alcohol concentration with the contact combustion gas sensor. A liquid phase concentration obtaining step of converting the gas phase alcohol concentration measured in the gas phase concentration measuring step into a liquid phase alcohol concentration, and obtaining the liquid phase alcohol concentration.In at least the gas phase concentration measuring step, the gas in the chamber is A method for measuring the concentration of liquid-phase alcohol configured to rotate a stirring fan at a low speed, comprising: A ventilation step of switching the fan to high-speed rotation and ventilating the inside of the chamber for a predetermined time, and a semi-open state of slightly opening the chamber from the fully opened state after the ventilation step. On the other hand, while maintaining the high-speed rotation of the fan for a predetermined time, switching to low-speed rotation, and further increasing the temperature of the gas in the chamber to the predetermined temperature, a warm-up step, further comprising: Phase alcohol concentration measurement method.