JP2007010326A - Smell measuring device and smell measuring method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a smell measuring device that has a simple structure and is easy to use and a smell measuring method. <P>SOLUTION: Instead of a conventional smell measuring method of measuring smell of gas, this smell measuring method comprises a preparing process of preparing a smell sensor for measuring the smell of the gas, a gas supply process of supplying the gas to the smell sensor, and an odor-free gas supply process of supplying the odor-free gas to the smell sensor by a predetermined cleaning period. Just after the gas supply process is executed and completed, the odor-free gas supply process is forcibly executed, the smell sensor outputs an output value corresponding to the intensity of the smell of the gas, and the cleaning period corresponds to the output value. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an odor measuring apparatus and an odor measuring method for measuring a gas odor. In particular, the present invention relates to an odor measuring apparatus and an odor measuring method characterized by a structure and procedure for measuring odor.

An odor measuring device is used to measure the odor.
The odor measuring device includes an odor sensor.
The odor sensor outputs an output value corresponding to the intensity of gas odor.
Gas is supplied to the odor sensor and the output value of the odor sensor is recorded.
The odor sensor has a sensitive part that can sense the odor of gas. The sensitive part is made of, for example, a metal oxide semiconductor. When the odorous substance adheres to the sensitive part, the electrical specification of the sensitive part changes depending on the amount and type of the odorous substance.
When the odor measurement is completed, the odor substance remains in the sensitive part of the odor sensor.
When a new gas is supplied to the odor sensor and the odor is measured while the odor substance remains in the sensitive part, the output value of the odor sensor varies.
Therefore, before measuring the odor of a new gas, in order to remove the odorous substance remaining in the sensitive part of the odor sensor, odorless air is supplied to the odor sensor for a predetermined time (hereinafter referred to as a cleaning time). Supply.

The instruction manual of the odor measuring apparatus recommends supplying odorless gas to the odor sensor after supplying gas to the odor sensor and measuring the odor.
However, the operator does not always observe this operation guideline, which causes the measurement accuracy to vary.
In addition, investigators may not be able to determine an appropriate cleaning time.

In addition, when a gas with extremely large odor intensity is supplied to the odor sensor, the sensitivity of the odor sensor thereafter becomes unstable.
As a result, a long time is required for the subsequent cleaning time.

JP 2003-42988 A Registered Utility Model No. 3074494

  The present invention has been devised in view of the problems described above, and intends to provide an odor measuring apparatus and an odor measuring method that are easy to use with a simple configuration.

  In order to achieve the above object, an odor measurement method for measuring the odor of gas according to the present invention, a preparation step of preparing an odor sensor for measuring the odor of gas, a gas supply step of supplying gas to the odor sensor, An odorless gas supply step of supplying odorless gas to the odor sensor for a predetermined cleaning time, and the odorless gas supply step is forcibly performed immediately after the gas supply step is completed. .

  With the configuration of the present invention, the odor sensor measures the odor of gas. Immediately after the gas is supplied to the odor sensor, the odorless gas is forcibly supplied to the odor sensor for a predetermined cleaning time. As a result, odorous substances attached to the odor sensor can be automatically removed.

  The odor measuring method according to the embodiment of the present invention will be described. The present invention includes any of the embodiments described below, or a combination of two or more of them.

Furthermore, in the odor measuring method according to the embodiment of the present invention, the odor sensor outputs an output value corresponding to the intensity of gas odor, and the cleaning time corresponds to the output value.
With the configuration of the present invention, odorless gas is supplied to the odor sensor for the cleaning time corresponding to the measured odor intensity. As a result, the odorous substance adhering to the odor sensor can be automatically removed efficiently.

Further, in the odor measuring method according to the embodiment of the present invention, the odor sensor has a first odor sensor and a second odor sensor having different sensitivities depending on the kind of gas odor, and the first odor sensor is a first odor sensor. One output value is output, the second odor sensor outputs a second output value, and the cleaning time corresponds to a combined output value obtained by combining the first output value and the second output value.
According to the configuration of the present invention, the sensitivity of the first odor sensor and the sensitivity of the second odor sensor differ depending on the quality of the gas odor, and the synthesis obtained by synthesizing the first output value and the second output value Odorless gas is supplied to the odor sensor for the cleaning time corresponding to the output value. As a result, the odorous substance attached to the odor sensor can be automatically removed efficiently regardless of the odor quality.

Furthermore, the odor measurement method according to the embodiment of the present invention forcibly causes the gas supply step when the tendency of increase in odor intensity per unit time exceeds a predetermined limit value during the gas supply step. finish.
With the above-described configuration of the present invention, the gas supply is forcibly terminated when the tendency of increase in odor intensity per unit time exceeds a predetermined limit value. As a result, the gas supply is forcibly terminated when the odor intensity is likely to increase, so that it is possible to prevent many odorous substances from adhering to the odor sensor.

Furthermore, the odor measurement method according to the embodiment of the present invention forces the gas supply step when the state in which the odor intensity exceeds a predetermined limit value during the gas supply step lasts for a predetermined duration. Ends.
According to the configuration of the present invention, the supply of the gas is forcibly terminated when the state in which the odor intensity exceeds a predetermined limit value lasts for a predetermined duration. As a result, it is possible to prevent many odorous substances from adhering to the odor sensor.

  In order to achieve the above object, an odor measuring apparatus for measuring the odor of gas according to the present invention includes an odor sensor for measuring the odor of gas, a gas supply means for supplying gas to the odor sensor, and an odorless gas as a predetermined odor sensor. And an odorless gas supply means for supplying the odor sensor to the odor sensor for a cleaning time, and the odorless gas supply means is forcibly operated immediately after the operation of the gas supply means is stopped.

  With the configuration of the present invention, the odor sensor measures the odor of gas. Gas supply means supplies gas to the odor sensor. The odorless gas supply means supplies the odorless gas to the odor sensor for a predetermined cleaning time. Immediately after the operation of the gas supply means is stopped, the odorless gas supply means is forcibly operated. As a result, odorous substances attached to the odor sensor can be automatically removed.

  Hereinafter, an odor measuring apparatus according to an embodiment of the present invention will be described. The present invention includes any of the embodiments described below, or a combination of two or more of them.

Furthermore, in the odor measuring apparatus according to the embodiment of the present invention, the odor sensor outputs an output value corresponding to the intensity of gas odor, and the cleaning time corresponds to the output value.
With the configuration of the present invention, odorless gas is supplied to the odor sensor for the cleaning time corresponding to the measured odor intensity. As a result, the odorous substance adhering to the odor sensor can be automatically removed efficiently.

Furthermore, in the odor measuring apparatus according to the embodiment of the present invention, the odor sensor includes a first odor sensor and a second odor sensor, each of which has a different sensitivity depending on the type of gas odor, and the first odor sensor is a gas. A first output value corresponding to the odor intensity of the gas, the second odor sensor outputs a second output value corresponding to the odor intensity of the gas, and the cleaning time and the first output value This corresponds to the combined output value obtained by combining the two output values.
With the above-described configuration of the present invention, the sensitivity of the first odor sensor and the sensitivity of the second odor sensor differ depending on the quality of the gas odor, and the combined output obtained by combining the first output value and the second output value Odorless gas is supplied to the odor sensor for the cleaning time corresponding to the value. As a result, the odorous substance attached to the odor sensor can be automatically removed efficiently regardless of the odor quality.

Furthermore, the odor measuring apparatus according to the embodiment of the present invention is configured such that when the tendency of increase in odor intensity per unit time exceeds a predetermined limit during operation of the gas supply means, Forcibly stop operation.
According to the configuration of the present invention, the operation of the gas supply means is forcibly stopped when the tendency of increase in odor intensity per unit time exceeds a predetermined limit value. As a result, the gas supply is forcibly terminated when the odor intensity is likely to increase, so that it is possible to prevent many odorous substances from adhering to the odor sensor.

Furthermore, the odor measuring apparatus according to the embodiment of the present invention provides the gas supply when the state where the odor intensity exceeds a predetermined limit value during the operation of the gas supply means lasts for a predetermined duration. The operation of the means is forcibly stopped.
According to the configuration of the present invention, the supply of the gas is forcibly terminated when the state where the intensity of the odor exceeds a predetermined limit value lasts for a predetermined duration, so that many odor substances adhere to the odor sensor. Can be prevented.

As described above, the odor measuring apparatus and the odor measuring method for measuring odor according to the present invention have the following effects due to their configurations.
Immediately after the supply of gas to the odor sensor, the odorless gas is forcibly supplied to the odor sensor for a predetermined cleaning time, so that the odor substance attached to the odor sensor can be automatically removed.
Further, since the odorless gas is supplied to the odor sensor for the cleaning time corresponding to the measured odor intensity, the odorous substance attached to the odor sensor can be automatically removed efficiently.
In addition, the sensitivity of the first odor sensor and the sensitivity of the second odor sensor differ depending on the odor quality of the gas, and the cleaning corresponding to the combined output value obtained by combining the first output value and the second output value. Since the odorless gas is supplied to the odor sensor only for the time, the odorous substance attached to the odor sensor can be automatically removed regardless of the quality of the odor.
Also, the gas supply is forcibly terminated when the tendency of the odor intensity to increase per unit time exceeds a predetermined limit value, so the gas supply should be stopped when the odor intensity is likely to increase. Since the process is forcibly terminated, it is possible to prevent many odorous substances from adhering to the odor sensor.
In addition, the gas supply is forcibly terminated when the odor intensity exceeds a predetermined limit value for a predetermined duration, so that many odorous substances adhere to the odor sensor. Can be prevented.
Therefore, an easy-to-use odor measuring apparatus and odor measuring method can be provided with a simple configuration.

  The best mode for carrying out the present invention will be described below with reference to the drawings. In each figure, common portions are denoted by the same reference numerals, and redundant description is omitted.

First, an odor measurement method according to an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a flowchart of an odor measurement method according to an embodiment of the present invention.
The odor measurement method includes a preparation step S10, an odor measurement step S20, a gas supply step S30, and an odorless gas supply step S40.
The preparation step S10 is a step of preparing an odor sensor for measuring a gas odor.
The odor sensor outputs an output value corresponding to the intensity of gas odor.
For example, the output value increases as the odor intensity increases, and the cleaning time increases as the output value increases.

The odor sensor has a first odor sensor and a second odor sensor with different sensitivities depending on the type of gas odor, the first odor sensor outputs a first output value, and the second odor sensor outputs a second output. A value may be output.
For example, the sensitivity of the first odor sensor is high for heavy odor substances, the first output value increases as the odor increases, and the sensitivity of the second odor sensor is high for light odor substances, The second output value increases as the odor increases, and the combined output value is the square root of the sum of the square of the first output and the square of the second output value.
As the combined output value increases, the cleaning time (for example, several seconds to several minutes) becomes longer.

The odor measurement step S20 is a step of driving the odor sensor and recording the output value of the odor sensor.
For example, power is supplied to the odor sensor, and the voltage at the output terminal is digitized and taken into the CPU.

The gas supply step S30 is a step of supplying gas to the odor sensor.
For example, the sensitive part of the odor sensor is stored in the chamber, and gas is introduced into the chamber.
If the odor measurement step S20 is performed during the gas supply step S30, an output value corresponding to the gas odor can be obtained.

The odorless gas supply step S40 is a step of supplying the odorless gas to the odor sensor for a predetermined cleaning time.
For example, the sensitive part of the odor sensor is stored in the chamber, and odorless gas is introduced into the chamber.
The odorless gas is a gas that does not feel odor, such as standard air or a gas obtained by deodorizing the outside air with activated carbon.
Immediately after the completion of the gas supply step S30, the odorless gas supply step S40 is forcibly executed.
The cleaning time may correspond to the output value.
The cleaning time may correspond to a combined output value obtained by combining the first output value and the second output value.

During the gas supply step S30, the gas supply step S30 may be forcibly terminated when the increasing tendency of the odor intensity per unit time exceeds a predetermined limit value.
For example, the following determination coefficient a is calculated while the gas supply unit 200 is operating.
a = (Sb-Sa) / (Tb-Ta)
Here, Tb-Ta is a sampling time for measuring the odor. Sb-Sa is the difference between the output value of the odor sensor before and after the sampling time.
If the determination coefficient a exceeds a predetermined limit value during the gas supply step S30, the execution of the gas supply step S30 is forcibly stopped.
Immediately after finishing the gas supply step S30, the odorless gas supply step S40 is performed.

For example, the following determination coefficient a is calculated while the gas supply unit 200 is operating.
a = (STb-STa) / (Tb-Ta)
Here, Tb-Ta is a sampling time for measuring the odor. STb−STa is the difference between the first output value of the first odor sensor and the second output value of the second odor sensor before and after the sampling time.
For example, the combined output value is the square root of the sum of the square of the first output and the square of the second output value.
If the determination coefficient a exceeds a predetermined limit value during the gas supply step S30, the execution of the gas supply step S30 is forcibly stopped.
Immediately after finishing the gas supply step S30, the odorless gas supply step S40 is performed.

The gas supply step S30 may be forcibly terminated when a state where the odor intensity exceeds a predetermined limit value during the gas supply step S30 continues for a predetermined duration.
Immediately after finishing the gas supply step S30, the odorless gas supply step S40 is performed.

Next, an odor measuring apparatus according to an embodiment of the present invention will be described.
The odor measuring apparatus includes an odor sensor 100, a gas supply unit 200, and an odorless gas supply unit 300.
The odor sensor 100 measures gas odor.
The odor sensor 100 outputs an output value corresponding to the intensity of gas odor.
The gas supply means 200 supplies gas to the odor sensor 100.
The odorless gas supply means 300 supplies the odorless gas to the odor sensor for a predetermined cleaning time.

The odor measuring device forcibly operates the odorless gas supply means 300 immediately after stopping the operation of the gas supply means 200.
The cleaning time may correspond to the output value.
For example, the output value increases as the odor intensity increases, and the cleaning time increases as the output value increases.

The odor sensor consists of a first odor sensor and a second odor sensor with different sensitivities depending on the type of gas odor, and the first odor sensor outputs a first output value corresponding to the intensity of the gas odor. The second odor sensor outputs a second output value corresponding to the intensity of the gas odor, and the cleaning time corresponds to the combined output value obtained by combining the first output value and the second output value. Good.
For example, the sensitivity of the first odor sensor is high for heavy odor substances, the first output value increases as the odor increases, and the sensitivity of the second odor sensor is high for light odor substances, The second output value increases as the odor increases, and the combined output value is the square root of the sum of the square of the first output and the square of the second output value.
As the combined output value increases, the cleaning time (for example, several seconds to several minutes) becomes longer.

The odor measuring device may forcibly stop the operation of the gas supply means when the tendency of increase in odor intensity per unit time exceeds a predetermined limit value during the operation of the gas supply means. .
For example, the following determination coefficient a is calculated while the gas supply unit 200 is operating.
a = (Sb-Sa) / (Tb-Ta)
Here, Tb-Ta is a sampling time for measuring the odor. Sb-Sa is the difference between the output value of the odor sensor before and after the sampling time.
If the determination coefficient a exceeds a predetermined limit value while the gas supply means 200 is in operation, the operation of the gas supply means is forcibly stopped.
Immediately after the operation of the gas supply means 200 is stopped, the operation of the odorless gas supply means 300 is started.

For example, the following determination coefficient a is calculated while the gas supply unit 200 is operating.
a = (STb-STa) / (Tb-Ta)
Here, Tb-Ta is a sampling time for measuring the odor. STb−STa is the difference between the first output value of the first odor sensor and the second output value of the second odor sensor before and after the sampling time.
For example, the combined output value is the square root of the sum of the square of the first output and the square of the second output value.
If the determination coefficient a exceeds a predetermined limit value while the gas supply means 200 is in operation, the operation of the gas supply means is forcibly stopped.
Immediately after the operation of the gas supply means 200 is stopped, the operation of the odorless gas supply means 300 is started.

The odor measuring device forcibly stops the operation of the gas supply means when the state where the odor intensity exceeds a predetermined limit value for a predetermined duration during the operation of the gas supply means. Also good.
Immediately after the operation of the gas supply means 200 is stopped, the operation of the odorless gas supply means 300 is started.

Below, the odor measuring apparatus 10 which concerns on embodiment of this invention is explained in full detail based on a figure.
FIG. 2 is a conceptual diagram of an odor measuring apparatus according to an embodiment of the present invention. FIG. 3 is a partial conceptual diagram of a measurement unit of the measurement apparatus according to the embodiment of the present invention. FIG. 4 is a conceptual diagram of an odor sensor according to an embodiment of the present invention. FIG. 5 is an output diagram of the odor sensor according to the embodiment of the present invention. FIG. 6 is a vector diagram of odors according to the embodiment of the present invention.

  The odor measuring device is a device that measures the odor of gas, and includes an odor sensor 100, a gas supply means 200, an odorless gas supply means 300, a measurement chamber 400, a gas discharge means 500, and a data processing unit 600.

The odor sensor 100 is a sensor that outputs an output value corresponding to the intensity of the odor.
The odor sensor 100 has a sensitive unit 101 that can sense the odor of gas. The sensitive part 101 is made of, for example, a metal oxide semiconductor. When the odorous substance adheres to the sensitive part, the electrical specification of the sensitive part changes depending on the amount and type of the odorous substance.
FIG. 4 is a conceptual diagram of the odor sensor.
For example, the odor sensor 100 includes a sensitive unit 101, a heater 102, a switching element 103, a load resistor 104, and a power source 105.

The sensitive part 101 is a part where the scent of gas can be felt.
The sensitive part 101 is made of, for example, a metal oxide semiconductor to which a catalyst is added. Depending on the type of material, the type of catalyst, the structure, etc., there is a large difference in sensitivity to odor molecules constituting the odor.
The sensitive part 101 is exposed to a measurement chamber 400 described later.

The heater 102 heats the sensitive part 101, for example, a platinum thin film.
The sensitive part 101 and the heater 102 have an integral structure. The heater 102 is energized to generate heat, and can heat the sensitive unit 101 to a predetermined temperature. For example, when the sensitive part 101 is a metal oxide semiconductor, the predetermined temperature is about 400 ° C. In this way, the sensitive part 101 is less affected by changes in ambient temperature and the presence of moisture, and a decrease in the sensitivity of the odor sensor can be prevented. Moreover, it becomes easy to wash and remove odor molecules attached to the sensitive part 101 with the washing air.
The heater 102 is preferably heated by applying a pulse current.

The switching element 103 is an electronic element for supplying a current to the heater 102. The switching element 103 receives a pulsed heater heating pulse 106 and supplies a pulsed current to the heater 102.
The heater heating pulse 106 is preferably input to the switching element via an input resistor.

  The load resistor 104 is a resistor circuit connected in series with the sensitive unit 101. The load resistor 104 may be a circuit configured by a resistance element, or may be a circuit in which a resistance element and a capacitor are connected in parallel.

A power source 105 supplies current to the sensitive unit 101 and the heater 102.
An odor measurement output 107 is output from a connection point between the sensitive unit 101 and the load resistor 104.

When an odorous substance, which is a volatile reducing chemical substance, adheres to the sensitive part 101, electrons are supplied to oxygen in the sensitive part 101. Since the electrons of the sensitive part 101 increase, the electrical conductivity of the sensitive part becomes high.
By monitoring the odor measurement output Vcc of the plurality of odor sensors 100, the amount and type of the odor substance can be measured.

The odor sensor 100 includes an odor sensor A (corresponding to the first odor sensor) 100a and an odor sensor B (corresponding to the second odor sensor) 100b.
The sensitivity characteristic of the odor sensor A100a and the sensitivity characteristic of the odor sensor B100b differ depending on the quality of the odor.
For example, the odor sensor A100a has a large variation in electrical characteristics with respect to an odor substance having a large molecular weight, and the odor sensor B100b has a large variation in electrical characteristics with respect to an odor substance having a small molecular weight.

For example, the sensitive unit 101 of the odor sensor A 100a has high sensitivity to heavy odor molecules having a relatively large molecular weight and low volatility. A typical example of the heavy odor molecule is an unsaturated aromatic hydrocarbon compound.
For example, the sensitive part 101 of the odor sensor B100b has high sensitivity to light odor molecules having a relatively small molecular weight and high volatility. A typical example of light odor molecules is alcohol.
The amount of the odor substance and the kind of the odor substance can be specified from the combination of the odor measurement outputs of the odor sensor A 100a and the odor sensor B 100b.

By monitoring the odor measurement output Vcc of the plurality of odor sensors 100a and 100b, the amount and type of the odor substance can be measured.
The principle will be described below.

Odors and aromas are generally rarely present as a single chemical. A complex odor mixed with various simple chemical substances stimulates human olfaction. For this reason, the correlation between the amount of sensation given to the human sense of smell and the output value of the odor measuring device becomes extremely complicated.
A metal oxide semiconductor used as an element of an odor sensor has a good durability and a good correlation with an olfactory sense. The sensitive characteristics of this type of odor sensor react to a wide variety of odorous substances with a relatively wide range. It is also possible to select the sensitive characteristics by adjusting the oxidation-reduction reaction control by the catalyst and temperature and the molecular weight selectivity by the porous physical shape. Therefore, it is possible to provide sensitive selectivity for odor substances.
That is, sulfur compounds such as hydrogen sulfide, those having a hydroxyl group such as ammonia and alcohol, those having an aldehyde group such as acetaldehyde, those having a carboxyl group such as acetic acid, those having an amino group such as trinitroamine, acetic acid Sensor elements having characteristic sensitivity characteristics that can be classified into those having an ester bond such as ethyl and aromatic hydrocarbons such as toluene and xylene can be manufactured.
Therefore, it is possible to determine the odor and smell by combining the odor sensor elements and calculating the various combinations of the output values thereof.

Hereinafter, a method for measuring the odor intensity and the odor type using the odor measurement outputs Vcc of the two odor sensors will be described with reference to the drawings.
FIG. 5 shows an odor output vector according to an embodiment of the present invention.
In the figure,
Aо is the output value Vcc of the odor sensor 100a.
Az is the calibration value Vcc of the odor sensor 100a.
Bо is the output value Vcc of the odor sensor 100b.
Bz is the calibration value Vcc of the odor sensor 100b.
The output values Aо and Bо are odor measurement outputs Vcc when gas is supplied to the sensitive part.
The calibration values Az and Bz are odor measurement outputs Vcc when odorless air is supplied to the sensitive part.
The vector diagram shows the output value Vcc of the odor sensor A100a with high sensitivity to the heavy system (Aо-Az) calibrated with the calibration value Vcc as an X-axis element, and the output value of the odor sensor B100b with high sensitivity to the light system. This is an orthogonal coordinate system displaying vectors obtained when a value obtained by calibrating Vcc with a calibration value Vcc (B-Bz) is used as an element of the Y axis. This vector is called an odor vector.
The length of the odor vector is equal to the square root of the sum of the square of (Aо−Az) and the square of (Bо−Bz).
FIG. 5 shows an odor vector representing an odor 1 having lighter odor components than a heavy odor component, and an odor vector representing an odor 2 having a heavy odor component more than a light odor component. .
In this vector diagram, for example, the length of the odor vector is referred to as “odor intensity value”, and the value obtained by quantifying the inclination or direction of the odor vector is referred to as “odor characteristic value” representing “odor type”.
Experiments have confirmed that the correlation between the “odor intensity value” and the odor intensity, and the correlation between the “odor quality value” and the odor type approximate human sensitivity.

The gas supply means 200 is a device that can supply gas to the sensitive part.
For example, when the measurement chamber 400 is provided in the odor measurement apparatus, the gas supply unit 200 is configured by the gas introduction unit 210.
The gas introduction unit 210 is a unit that introduces gas into the measurement space H, and includes a sample suction pipe 211, a sample valve 212, and a sample introduction pipe 213.
The sample suction pipe 211 is a pipe that communicates the outside with the sample valve 212. The piping is made of a material (for example, a tube made of PTFE) to which odorous substances are difficult to adhere.
The sample valve 212 is a valve that can be opened and closed. For example, the sample valve 212 can open or close the passage according to an on signal or an off signal of the electrical signal.
The sample introduction pipe 213 is a pipe that connects the sample valve 212 and the measurement chamber 400.
Therefore, when the ON signal is given to the sample valve 212, the sample valve 212 is opened, and the sample can be introduced into the measurement space H from the outside. When the off signal is given to the sample valve 212, the sample valve 212 is closed, and the sample cannot be introduced into the measurement space H from the outside.

The odorless gas supply means 300 is a device that can supply odorless gas to the sensitive part.
For example, when the measurement chamber is provided in the odor measuring apparatus, the odorless gas supply means 300 includes an odorless gas generation means 310 and an odorless gas introduction means 320.
The odorless gas generating means 310 generates odorless gas, and is, for example, a case filled with activated carbon.
The odorless gas introducing means 320 includes a cleaning suction pipe 321, a cleaning valve 322, and a cleaning introduction pipe 323.
The cleaning suction pipe 321 is a pipe that communicates the odorless gas generating means 310 and the cleaning valve 322.
The cleaning valve 322 is a valve that can be opened and closed. For example, the flush valve 322 can open or close the passage according to an on signal or an off signal of the electrical signal.
The cleaning introduction pipe 323 is a pipe that communicates the cleaning valve 322 and the measurement chamber 400.
Accordingly, when the ON signal is given to the cleaning valve 322, the cleaning valve 322 is opened, and odorless gas can be introduced into the measurement space H. When the OFF signal is given to the cleaning valve 322, the cleaning valve 322 is closed, and the odorless gas cannot be introduced into the measurement space H.

  The measurement chamber 400 is a container-like device having a measurement space H that can be sealed. The sensitive part 101 of the odor sensor 100 is exposed to the measurement space H. Therefore, when the gas mixed with the odorous substance is introduced into the measurement space H, the gas is supplied to the sensitive part, and the odorous substance adheres to the sensitive part.

The gas discharge means 500 is a device that discharges gas from the measurement chamber 400, and includes gas discharge pipes 501, 503, 505, a discharge valve 502, and a gas discharge pump 504.
The gas discharge pipe 501 is a pipe that connects the measurement chamber 400 and the discharge valve 502.
The discharge valve 502 is a valve that can be opened and closed. For example, the discharge valve 502 can open or close the passage according to an on signal or an off signal of an electrical signal.
The gas discharge pipe 503 is a pipe that connects the discharge valve 502 and the inlet of the gas discharge pump 504.
The gas discharge pump 504 is a pump that discharges gas from the measurement space H. For example, the pump is a fan, a blower, a diaphragm pump, or the like.
The gas discharge pipe 505 is a pipe that communicates the outlet of the gas discharge pump 504 with the outside.
Accordingly, when an ON signal is given to the discharge valve 502 and the gas discharge pump 504 is driven, the gas in the measurement space H is discharged to the outside.

The data processing unit 600 is a device that controls the odor sensor 100, the gas supply unit 200, the odorless gas supply unit 300, and the gas discharge unit 500, measures the odor of gas, and performs data processing.
The data processing unit 600 includes a main control unit 601, a pulse generation unit 602, a measurement time setting timer 603, an interface unit 604, an A / D conversion unit 605, a data storage unit 606, a data calculation unit 607, and a display unit 608. The
The main control unit 601 operates according to a built-in control program, and includes a pulse generation unit 602, a measurement time setting timer 603, an interface unit 604, an A / D conversion unit 605, a data storage unit 606, a data calculation unit 607, and a display unit 608. To control.
The pulse generator 602 is a part that generates a pulse control signal having a predetermined cycle and number of pulses and supplies the pulse control signal to the switching element 103 of the odor sensor 100. The predetermined period and the number of pulses are set according to the heating temperature of the heater 102.
The measurement time setting timer 603 outputs a timing signal for measurement to the main control unit 601.

The interface unit 604 is an input / output unit that outputs a signal or data from the main control unit 601 to the outside and takes in an external signal or data into the main control unit 601. The interface unit 604 is connected to an external personal computer, for example. The time change data of the odor sensor 100 odor measurement output, and the measurement results of the odor intensity and the odor type are transferred to the external personal computer 20 via the interface unit 604.
The A / D conversion unit 605 takes the odor measurement output from the odor sensor 100 at a predetermined timing, performs analog / digital conversion, and sends digital data to the main control unit 601.
The data storage unit 606 is a device that stores the odor measurement output in accordance with the designation from the main control unit 601.
The data calculation unit 607 takes in the odor measurement data recorded in the data storage unit 606 and stores it in the data storage unit 606.
A display unit 608 displays measured values and the like.

Below, the procedure of the odor measurement using the odor measuring apparatus detailed above is demonstrated.
(Gas supply process)
The gas supply means 200 and the gas discharge means 500 are operated. Gas enters the measurement chamber 400. When the gas supply unit 200 and the gas discharge unit 500 are continuously operated, the measurement chamber 400 is filled with fresh gas.
The gaseous odor substance adheres to the sensitive part of the odor sensor A100a and the sensitive part of the odor sensor B100b.
From the output value of the odor sensor A100a and the output value of the odor sensor B100b, the length and inclination of the odor vector are recorded every predetermined sampling time (for example, 1 second).
When the change in the length and inclination of the odor vector decreases, the “odor intensity value” and “odor quality value” of the gas odor are determined from the length and inclination of the odor vector.

(Odorless gas supply process 1)
When the “odor intensity value” and the “odor quality value” of the gas odor are determined, the operation of the gas supply means 200 is stopped and the odorless gas supply means 300 and the gas discharge means 500 are forcibly operated. When the odorless gas supply means 300 and the gas discharge means 500 are operated continuously, the odorless gas fills the measurement chamber 400.
At this time, even when the investigator presses the on / off button of the odor measuring device, the operation of the odorless gas supply means 300 and the gas discharge means 500 is continued.
After the operation of the odorless gas supply means 300 and the gas discharge means 500 is continued for a predetermined cleaning time, the operation of the odorless gas supply means 300 and the gas discharge means 500 is stopped.
The washing time at this time is a time corresponding to the “odor intensity value”. For example, as the “odor intensity value” increases, the cleaning time increases.

(Odorless gas supply process 2)
When the gas supply unit 200 and the gas discharge unit 500 are operated, the determination coefficient a is calculated for each sampling time.
The determination coefficient a is a difference before and after the length of the odor vector for each sampling type.
When the determination coefficient a exceeds a predetermined limit value, the operation of the gas supply unit 200 is stopped and the odorless gas supply unit 300 and the gas discharge unit 500 are forcibly operated. When the odorless gas supply means 300 and the gas discharge means 500 are operated continuously, the odorless gas fills the measurement chamber 400.
At this time, even when the investigator presses the on / off button of the odor measuring device, the operation of the odorless gas supply means 300 and the gas discharge means 500 is continued.
After the operation of the odorless gas supply means 300 and the gas discharge means 500 is continued for a predetermined cleaning time, the operation of the odorless gas supply means 300 and the gas discharge means 500 is stopped.
The cleaning time at this time is a time corresponding to the length of the odor vector. For example, as the “odor intensity value” increases, the cleaning time increases.

(Odorless gas supply process 3)
When the gas supply unit 200 and the gas discharge unit 500 are operated, it is checked whether the length of the odor vector exceeds a predetermined limit value.
When the state where the length of the odor vector exceeds a predetermined limit value lasts for a predetermined duration, the operation of the gas supply means 200 is stopped and the odorless gas supply means 300 and the gas discharge means 500 are forcibly operated. Let When the odorless gas supply means 300 and the gas discharge means 500 are operated continuously, the odorless gas fills the measurement chamber 400.
At this time, even when the investigator presses the on / off button of the odor measuring device, the operation of the odorless gas supply means 300 and the gas discharge means 500 is continued.
After the operation of the odorless gas supply means 300 and the gas discharge means 500 is continued for a predetermined cleaning time, the operation of the odorless gas supply means 300 and the gas discharge means 500 is stopped.
The cleaning time at this time is a time corresponding to the length of the odor vector. For example, as the “odor intensity value” increases, the cleaning time increases.

If the odor measuring apparatus and the odor measuring method of the above-described embodiment are used, the following effects are exhibited.
Immediately after the gas is supplied to the odor sensor, the odorless gas is forcibly supplied to the odor sensor for a predetermined cleaning time, so that the odor substance attached to the odor sensor can be automatically removed.
Further, since the odorless gas is supplied to the odor sensor for the cleaning time corresponding to the measured odor intensity, the odorous substance attached to the odor sensor can be automatically removed efficiently.
Further, the sensitivity of the odor sensor A (first odor sensor) and the sensitivity of the odor sensor B (second odor sensor) differ depending on the quality of the gas odor, and the first output value and the second output value are combined. Since the odorless gas is supplied to the odor sensor only during the cleaning time corresponding to the resultant output value, the odorous substance attached to the odor sensor can be automatically removed efficiently regardless of the odor quality.
Further, one of the odor sensor A and the odor sensor B is sensitive to a heavy odor, the other is sensitive to a light odor, and the combined value is a square of the first output value and a square of the second output value. Therefore, the cleaning time can be set to a value that reflects the ratio of heavy and light odor substances.
Also, when the trend of increasing the odor intensity per unit time exceeds a predetermined limit value, the gas supply is forcibly terminated and the odorless gas is forcibly supplied for a predetermined cleaning time. Since the gas supply is forcibly terminated when the odor intensity is likely to increase, it is possible to prevent many odorous substances from adhering to the odor sensor.
In addition, the gas supply is forcibly terminated when the state where the odor intensity exceeds a predetermined limit value lasts for a predetermined duration, and the odorless gas is forcibly supplied for a predetermined cleaning time. Therefore, it is possible to prevent many odorous substances from adhering to the odor sensor.

The present invention is not limited to the embodiments described above, and various modifications can be made without departing from the scope of the invention.
The combined output value is described as being the square root of the sum of the squares of the two output values. However, the present invention is not limited to this. For example, the combined output value may be a product of the two output values.
Although the description has been made assuming that the combined output value is a combined value of two output values, the present invention is not limited to this. For example, the combined output value may be a combined value of N output values.

It is a flowchart figure of the measuring method which concerns on embodiment of this invention. It is a conceptual diagram of the measurement part of the measuring apparatus which concerns on embodiment of this invention. It is a partial conceptual diagram of the measurement part of the measuring device which concerns on embodiment of this invention. It is a conceptual diagram of the odor sensor which concerns on embodiment of this invention. It is an output figure of the odor sensor which concerns on embodiment of this invention. It is a vector diagram of the smell which concerns on embodiment of this invention.

Explanation of symbols

S10 preparation process S20 measurement process S30 gas supply process S40 odorless gas supply process H measurement space 10 odor measurement device 11 measurement section 12 display section 20 personal computer 30 server 40 electronic communication network 100 odor sensor 100a odor sensor A
100b Odor sensor B
DESCRIPTION OF SYMBOLS 101 Sensing part 102 Heater 103 Switching element 104 Load resistance 105 Power supply 106 Heater heating pulse 107 Odor measurement output 200 Gas introduction means 201 Sample suction pipe 202 Sample valve 203 Sample introduction pipe 300 Odorless gas supply means 310 Odorless gas generation means 320 Odorless gas introduction Means 321 Cleaning suction pipe 322 Cleaning valve 323 Cleaning introduction pipe 400 Measurement chamber 500 Gas discharge means 501 Gas discharge pipe 502 Discharge valve 503 Gas discharge pipe 504 Gas discharge pump 505 Gas discharge pipe 600 Data processing section 601 Main control section 602 Pulse generation section 603 Measurement time setting timer 604 Interface unit 605 A / D conversion unit 606 Data storage unit 607 Data operation unit 608 Display drive unit

Claims (10)

An odor measurement method for measuring the odor of gas,
A preparation step of preparing an odor sensor for measuring the odor of gas;
A gas supply step of supplying gas to the odor sensor;
An odorless gas supply step of supplying odorless gas to the odor sensor for a predetermined cleaning time;
With
Forcibly performing the odorless gas supply step immediately after completing the gas supply step,
An odor measuring method characterized by that. The odor sensor outputs an output value corresponding to the intensity of gas odor,
The cleaning time corresponds to the output value;
The odor measuring method according to claim 1. The odor sensor has a first odor sensor and a second odor sensor having different sensitivities depending on the kind of gas odor, the first odor sensor outputs a first output value, and the second odor sensor Output two output values,
The cleaning time corresponds to a combined output value obtained by combining the first output value and the second output value;
The odor measuring method according to claim 1. Forcibly terminating the gas supply step when the tendency of increase in odor intensity per unit time exceeds a predetermined limit during the gas supply step;
The odor measuring method according to claim 1. Forcibly terminating the gas supply process when the state in which the odor intensity exceeds a predetermined limit value during the gas supply process lasts for a predetermined duration;
The odor measuring method according to claim 1. An odor measuring device for measuring the odor of gas,
An odor sensor for measuring the odor of gas,
Gas supply means for supplying gas to the odor sensor;
Odorless gas supply means for supplying odorless gas to the odor sensor for a predetermined cleaning time;
With
Immediately after the operation of the gas supply means is stopped, the odorless gas supply means is forcibly operated.
An odor measuring device characterized by that. The odor sensor outputs an output value corresponding to the intensity of gas odor,
The cleaning time corresponds to the output value;
The odor measuring apparatus according to claim 6. The odor sensor has a first odor sensor and a second odor sensor having different sensitivities depending on the type of gas odor,
The first odor sensor outputs a first output value corresponding to the intensity of gas odor,
The second odor sensor outputs a second output value corresponding to the intensity of gas odor,
The cleaning time corresponds to a combined output value obtained by combining the first output value and the second output value;
The odor measuring apparatus according to claim 6. During the operation of the gas supply means, the operation of the gas supply means is forcibly stopped when the increasing tendency of the odor intensity per unit time exceeds a predetermined limit value.
The odor measuring apparatus according to claim 6. During the operation of the gas supply means, the operation of the gas supply means is forcibly stopped when a state in which the intensity of the odor exceeds a predetermined limit value lasts for a predetermined duration.
The odor measuring apparatus according to claim 6.

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