JP2007010521A - Gas detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas detection device capable of recognizing surely the state of an inspection part, and performing quick and precise gas detection. <P>SOLUTION: This gas detection device X is provided with a gas detection element 1 equipped with a gas sensitive part provided in the contactable state with a detection gas, an output detection part 3 for acquiring an output from the gas detection element 1, a discrimination means 9 for discriminating the concentration level of the detection gas based on a value acquired by the output detection part 3, and a gas collection part 8 for collecting the detection gas from the inspection part which is a gas detection object. The device X is also provided with an illumination means 4 capable of irradiating an illumination light toward at least either of the tip part 81 of the gas collection part 8 and its periphery. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention is based on a gas detection element having a gas sensitive part provided so as to be in contact with a gas to be detected, an output detection part for obtaining an output from the gas detection element, and a value obtained by the output detection part. The present invention relates to a gas detection apparatus provided with a discriminating means for discriminating a concentration level of a gas to be detected and a gas sampling part for sampling the gas to be detected from a part to be inspected as a gas detection target.

  Conventionally, as a gas detection device, a gas to be detected, which may contain a gas to be detected, is introduced into the device main body from a gas sampling unit provided in the device main body, and the gas sensitivity is provided so as to be in contact with the gas to be detected. A device that obtains an output from a gas detection element by an output detection unit when a predetermined voltage is applied to the gas detection element including the unit is known.

  As the gas detection element, for example, a semiconductor type gas detection element is known. In this case, when a voltage is applied to the gas detection element, the gas to be detected existing in the detection target gas reacts on the surface of the gas detection element and gives a change in resistance value to the semiconductor. And since the output based on this resistance value change is obtained by the output detector, the gas to be detected can be detected.

  The gas sampling part is formed by a nozzle-like member made of, for example, a flexible material. The gas to be detected can be detected by collecting the gas to be detected by bringing the tip of the gas sampling part close to the part to be inspected and sucking it.

  Since such a gas detection apparatus is widely known to those skilled in the art, prior art document information is not disclosed.

  When the gas to be detected is detected in the dark place, that is, in the dark or dim place by using the gas detection device described above, it is difficult to recognize the situation such as the shape of the portion to be inspected which is a gas detection target. Therefore, the positional relationship between the part to be inspected and the gas detection device becomes unclear, and there is a problem that it is difficult to detect gas quickly and accurately.

  When the positional relationship between the part to be inspected and the gas detection device is not clear, an appropriate distance between the two cannot be maintained. For example, if the part to be inspected is a pipe, ground, or gas appliance, and there are foreign objects such as dust or water droplets on these surfaces, the gas sampling unit will accidentally remove dust or water droplets from the gas sampling unit because it is a dark place. There was a risk of inhalation. If dust or water droplets enter the inside of the gas detection device, there is a possibility of causing a failure of the gas detection device.

  Accordingly, it is an object of the present invention to provide a gas detection device that can reliably recognize the state of a part to be inspected and perform rapid and accurate gas detection.

  In order to achieve the above object, a gas detection device according to the present invention includes a gas detection element including a gas sensing unit provided so as to be in contact with a gas to be detected, an output detection unit for obtaining an output from the gas detection element, Gas detection provided with a discriminating means for discriminating the concentration level of the gas to be detected based on the value obtained by the output detection unit, and a gas sampling unit for sampling the gas to be detected from the part to be inspected as a gas detection target The first characteristic configuration of the apparatus is that an illuminating means capable of irradiating illumination light toward at least one of the distal end portion of the gas sampling unit and its periphery is provided.

  The direction in which the illumination means according to this configuration irradiates illumination light is at least one of the distal end portion of the gas sampling unit and its periphery. That is, if the illumination means is irradiated toward the tip portion of the gas sampling unit, the tip portion and its vicinity can be irradiated. Moreover, if the illumination means is irradiated toward the periphery of the distal end portion of the gas sampling unit, the outer edge range of the irradiation range when the illumination means is irradiated toward the distal end portion can be irradiated.

  At the time of gas detection, the detection target gas is sampled by bringing the tip of the gas sampling unit close to the part to be inspected. Therefore, if the illumination means irradiates at least one of the distal end portion and its periphery with illumination light as in this configuration, the illumination light can be reliably irradiated to the part to be inspected.

  Here, simply providing illumination means on the surface of the gas detection device facing the part to be inspected can simply irradiate the illumination light in front of the gas detection device, and the positional relationship between the gas sampling part and the part to be inspected is not necessarily clear. It will not be. Therefore, as in this configuration, the illumination means can be configured to irradiate illumination light toward at least one of the distal end portion and the periphery of the gas sampling portion, and the positional relationship between the gas sampling portion and the inspected portion is It should be clear.

Therefore, with this configuration, even in a dark place, the situation of the part to be inspected can be reliably recognized, the positional relationship between the part to be inspected and the gas detection device becomes clear, and gas detection can be performed quickly and accurately.
In addition, even when foreign matter such as dust or water droplets is present on the surface of the part to be inspected, it is difficult to accidentally suck these foreign matter from the gas sampling part during gas detection, and gas detection due to the suction of these foreign matter It is possible to prevent device failure.

  A second characteristic configuration of the gas detection device according to the present invention is that the illuminating means irradiates a spot irradiation mode for irradiating the vicinity of a tip portion of the gas sampling unit, and a range wider than an irradiation range in the spot irradiation mode. It has a wide irradiation mode.

The spot irradiation mode is effective when, for example, it is desired to intensively irradiate the tip portion and the vicinity thereof, and to detect the gas mainly in the vicinity of the tip portion. On the other hand, in the wide irradiation mode, it is possible to irradiate the tip part and its periphery in a diffused manner, for example, to irradiate a wider range than the spot irradiation mode. It is effective in some cases.
Note that “near the tip portion” indicates a region relatively close to the tip portion, and “periphery of the tip portion” indicates a range on the outer edge side of the “near tip portion” region.

  Therefore, according to this configuration, it is possible to select the irradiation pattern according to the situation such as the brightness and shape of the part to be inspected, and to irradiate the illumination unit, so that more accurate gas detection can be performed.

  A third characteristic configuration of the gas detection device according to the present invention is that an irradiation mode setting means for setting an irradiation mode of the illumination means is provided.

  According to this configuration, it is possible to change the illumination state by switching the illumination means to the illumination mode such as the spot illumination mode and the wide illumination mode at the timing desired by the operator.

  A fourth characteristic configuration of the gas detection device according to the present invention is that an irradiation mode switching control unit that switches an irradiation mode of the illumination unit according to the concentration of the detected gas detected by the determination unit is provided.

  If the irradiation mode switching control unit is configured as in this configuration, the operator can know the determination result of the determination unit by recognizing that the irradiation mode has changed. That is, since the control by the irradiation mode switching control means is control based on the concentration of the gas to be detected, if the irradiation mode is changed, information on the distance to the leaked portion of the gas to be detected can be obtained to some extent. If the concentration level of the gas to be detected for this registration is set to a predetermined level, for example, it is an illumination state suitable for specifying the leaked portion of the gas to be detected when the leaked portion has been found. The illumination means can be switched so as to be in the spot irradiation mode, and at the same time, it becomes possible to make an awareness such as adjusting the speed at which the operator moves the gas detection device, and it becomes easy to accurately identify the leaked portion of the gas to be detected.

  A fifth characteristic configuration of the gas detection device according to the present invention is that the illumination means is provided with a color switching means for changing the color of the illumination light.

  According to this configuration, the operator can change the color of the illumination light at a desired timing. And according to the color of a to-be-inspected part, since it can set to the color of the illumination light in which an operator can recognize a gas leak location easily, it can make it easy to discover the said gas leak location exactly.

  A sixth characteristic configuration of the gas detection device according to the present invention is that a color switching control means for changing the color of the illumination light according to the concentration of the detected gas detected by the determination means is provided.

  If the color switching control means is configured to select the color of the illumination light according to the concentration of the gas to be detected as in this configuration, the discrimination result of the discrimination means by the operator recognizing the change in the color of the illumination light Can know. The color of the illumination light when the gas to be detected is detected may be appropriately set to the color of the illumination light that makes it easy for the operator to recognize the gas leakage location.

  The seventh characteristic configuration of the gas detector according to the present invention is that the illumination means is provided with a brightness switching means for changing the brightness of the illumination light.

  According to this configuration, since the operator can change the brightness of the illumination light at a desired timing, it is possible to easily find the gas leak location accurately.

  An eighth characteristic configuration of the gas detection device according to the present invention is that a brightness switching control means for changing the brightness of the illumination light according to the concentration of the detected gas detected by the determination means is provided.

  When the brightness switching control means is configured to select the brightness of the illumination light according to the concentration of the gas to be detected as in this configuration, the operator recognizes the change in the brightness of the illumination light, so that the discrimination result of the discrimination means Can know. The brightness of the illumination light when the gas to be detected is detected may be appropriately set to the brightness of the illumination light that makes it easy for the operator to recognize the gas leakage location.

  A ninth characteristic configuration of the gas detection device according to the present invention is that the detection mode of the detected gas can be changed in accordance with the concentration of the detected gas detected by the discrimination means.

In gas detection, there is a case where it is only necessary to determine whether or not a target gas to be detected exists without detecting an accurate gas concentration of the gas to be detected. At this time, the presence of the gas to be detected can be accurately detected by configuring the detection mode of the gas to be detected according to the situation.
The “detected gas detection mode” can be changed by changing the threshold value set as an index for determining the presence of the detected gas, or by changing the volume of the detected gas per unit time. Become.

  For example, the concentration of the gas to be detected decreases with increasing distance from the gas leakage location. At this time, when it is desired to detect the gas to be detected with high sensitivity even if it is away from the gas leakage point, control is performed to lower the threshold value, and if the gas to be detected is detected in this state, the gas to be detected exists. It can be judged.

  A tenth characteristic configuration of the gas detection device according to the present invention is configured such that the gas sampling unit is configured by a transparent member through which irradiation light is transmitted, and illumination light can be irradiated from a tip portion of the transparent member. It is in the point.

  According to this configuration, it is possible to configure so that the irradiation light from the illumination unit can be emitted from the tip portion through the inside of the transparent member. Thereby, since the irradiation light which reached the opposite side of the tip part of the gas sampling unit can be irradiated from the tip part, the illumination light can be reliably irradiated toward the tip part of the gas sampling unit.

Embodiments of the present invention will be described below with reference to the drawings.
In the present embodiment, the gas detection device X exemplifies a handy type that an operator holds and operates, but is not limited to this, and a gas detection device that may perform gas detection in a dark place. If so, it is applicable.

As shown in FIGS. 1 to 3, the gas detection device X of the present invention obtains an output from the gas detection element 1 including the gas sensing unit 12 provided to be in contact with the gas to be detected, and the gas detection element 1. Output detector 3; discriminating means 9 for discriminating the concentration level of the gas to be detected based on the value obtained by the output detector 3; And are provided.
Further, the gas detection device X is provided with illumination means 4 capable of irradiating illumination light toward at least one of the distal end portion 81 of the gas sampling unit 8 and its periphery.

  The gas to be detected detected by the gas detector X is a combustible gas such as methane gas or hydrogen gas, or a sulfur compound, amine, carboxylic acid or ketone as a component causing odor depending on the configuration of the gas detection element 1 to be applied. Various gases such as malodorous gas containing aldehydes and volatile gas containing alcohol can be set. The inspection target gas includes or is considered to include a detection target gas.

(Gas detection element)
As the gas detection element 1, for example, various types of gas detection elements can be used in addition to a semiconductor type gas detection element of a hot wire type and a substrate type. In the gas detection element 1 of this embodiment, the case where a hot-wire semiconductor gas detection element is used will be described.
The gas detection element 1 includes a metal oxide semiconductor paste mainly composed of a metal oxide semiconductor such as indium oxide, tungsten oxide, tin oxide, or zinc oxide particles on a noble metal wire 11 such as platinum, palladium, or platinum-palladium alloy. It has a gas sensitive part 12 that is applied and covered, dried and fired.

(Output detector)
When the output detection unit 3 applies a predetermined voltage to the gas detection element 1 including the gas sensing unit 12 provided to be in contact with the detection gas in the detection target gas including the detection gas, the output detection unit 3 1 so that the output can be obtained from 1.

  For example, the gas detection element 1 is provided with a pulse voltage supply device 2 that periodically applies a predetermined voltage in a pulse shape, and the gas detection element 1 is incorporated in the bridge circuit 13.

  At this time, the bridge circuit 13 connects the fixed resistance R0 to the gas detection element 1 in series. Further, the combined resistance of the fixed resistance R1 and the fixed resistance R2 is opposed to the combined resistance of the gas detection element 1 and the fixed resistance R0, and the fixed resistance R0 and the fixed resistance R2 are opposed to the gas detection element 1 and the fixed resistance R2. Connect in parallel.

  The output detection unit 3 is connected so as to extract the potential difference between the gas detection element 1 and the fixed resistor R0 and between the fixed resistor R1 and the fixed resistor R2 as an output. And the output detection part 3 outputs the output when the pulse-shaped predetermined voltage applied to the gas detection element 1 is applied for a predetermined period as a bridge voltage.

(Determination means)
Based on the output value obtained by the output detector 3, the concentration level of the gas to be detected is determined by the determining means 9. The discriminating means 9 holds information such as an abnormal concentration in the atmosphere of the target gas to be detected in advance in a microcomputer or the like in order to discriminate the concentration level. Then, for example, whether or not the detected gas reaches the abnormal concentration by setting the abnormal concentration as a threshold and comparing the detected gas concentration in the detection target gas collected at the time of gas detection with the threshold. Is determined.

  The threshold value can be changed according to the concentration of the gas to be detected detected by the determination means 9. That is, the detection mode of the gas to be detected can be changed according to the concentration of the gas to be detected detected by the determination unit 9.

In gas detection by the gas detection device X, there is a case where it is only necessary to determine whether or not the target gas to be detected has an abnormal concentration, for example, without detecting the accurate gas concentration of the gas to be detected.
Further, normally, the concentration of the gas to be detected decreases as the distance from the gas leakage location increases. At this time, when it is desired to detect the gas to be detected with high sensitivity even if it is far from the gas leaking point, control is performed to lower the threshold value, and if the gas to be detected is detected in this state, an abnormal concentration is detected at the gas leaking point. It can be determined that the gas to be detected exists.

  If the determination means 9 determines that the concentration of the gas to be detected has reached an abnormal level, it outputs an alarm signal to the alarm mechanism 5. Upon receiving the alarm signal, the alarm mechanism 5 sounds an alarm buzzer or alarm sound.

(Gas sampling part)
In the gas detection device X, in order to collect the detection target gas including the detection target gas, for example, a nozzle-like shape made of a flexible material such as a rubber material on the surface of the gas detection device main body Y that faces the inspection target portion. Gas sampling section 8 is provided. The gas sampling part 8 is open at the tip part 81 and is configured to be able to introduce the detection target gas into the gas detection device X.
That is, the detection target gas can be sampled by bringing the tip 81 of the gas sampling unit 8 close to the part to be inspected and sucking it by a pump (not shown) provided inside the gas detection device main body Y.

If the suction force of the pump can be changed variously, the detection mode of the gas to be detected can be changed.
For example, if the suction force of the pump is set strongly, more detection target gas can be sucked in a short time, and therefore gas detection can be performed efficiently. On the other hand, if the suction force of the pump is set weak, suction can be performed without disturbing the state of the detection target gas existing in the inspected part. Thus, if the suction force of the pump can be appropriately changed according to the size and width of the part to be inspected, the state of the detection target gas, etc., the gas detection capability of the gas detection device X can be variously changed. .

(Lighting means)
The illumination means 4 is configured to be able to irradiate illumination light toward at least one of the distal end portion 81 of the gas sampling unit 8 and its periphery. A power supply unit 41 for supplying power is connected to the illumination means 4. Note that the pulse voltage supply device 2 and the power supply unit 41 described above are members that supply power to a target member, and thus may be shared.

  When the inspected part has a certain level of brightness, it is possible to perform gas detection without using the illumination unit 4, but when performing gas detection in a dark place, the illumination unit 4 is turned on and the gas is detected. Irradiate the inspection section. The on / off operation of the illumination unit 4 may be manually performed by an operator, but may be configured so that the on / off operation of the illumination unit 4 can be automatically performed by a sensor or the like that detects brightness.

The direction in which the illumination means 4 according to this configuration irradiates illumination light is at least one of the distal end portion 81 of the gas sampling unit 8 and its periphery. That is, if the illumination means 4 is irradiated toward the distal end portion 81 of the gas sampling unit 8, the distal end portion 81 and the vicinity thereof can be irradiated. In addition, if the illumination unit 4 is irradiated toward the periphery of the distal end portion of the gas sampling unit 8, the outer edge range of the irradiation range when the illumination unit 4 is irradiated toward the distal end portion 81 can be irradiated.
Note that “near the tip portion 81” indicates a region relatively close to the tip portion 81, and “the periphery of the tip portion 81” indicates a range on the outer edge side of the “near the tip portion 81” region. Show.

Thereby, even in a dark place, the situation of the part to be inspected can be surely recognized, the positional relationship between the part to be inspected and the gas detection device becomes clear, and gas detection can be performed quickly and accurately.
In addition, even when foreign matter such as dust or water droplets is present on the surface of the inspected part, it is difficult to accidentally suck these foreign matter from the gas sampling unit 8 when detecting the gas, and gas caused by the suction of these foreign matter Failure of the detection device X can be prevented in advance.

The illumination unit 4 can be provided with a single light source or a plurality of light sources. The plurality of light sources can be configured by combining, for example, white LEDs and single-color LEDs of red (R), green (G), and blue (B). It is also possible to combine a plurality of light sources having the same color.
Although LED is suitable as a light source, it is not restricted to this, Well-known light sources, such as an incandescent lamp and a laser light source, are applicable.

  FIG. 4 shows an example in which four illumination means 4a to 4d are provided. As will be described later, the part to be inspected is irradiated using at least one of the plurality of illumination units 4a to 4d depending on the situation.

  If it is the structure which provides the illumination means 4 with two or more, than the irradiation range by the spot irradiation mode (FIG. 4 (a)) which concentrates and irradiates the vicinity of the front-end | tip part 81 of the gas sampling part 8, and the irradiation range by the said spot irradiation mode A wide irradiation mode (FIG. 4B) for irradiating a wide range can be configured. Furthermore, a side irradiation mode (FIG. 4C) in which only the periphery of the distal end portion 81 of the gas sampling unit 8 is irradiated can be used.

In particular, in the case of the spot irradiation mode, it is effective when it is desired to detect gas mainly in the vicinity of the tip portion 81. In the case of the wide irradiation mode, it is effective when, for example, it is desired to detect a gas over a wide range extending from the inspected portion and its outer edge by irradiating the tip portion 81 and its periphery in a diffuse manner.
On the other hand, in the side irradiation mode, for example, the illumination light can be irradiated in substantially the same range as the wide irradiation mode, but the power consumption of the illumination unit 4 can be saved by omitting the illumination unit 4 directed toward the tip portion 81.

  When only one illumination unit 4 is turned on, the spot irradiation mode in which the vicinity of the tip portion 81 of the gas sampling unit 8 is irradiated can be set. When a plurality of parallel illumination means 4 are turned on, the wide irradiation mode can be set. In the side irradiation mode, for example, only the lighting means 4 at both ends of the plurality of lighting means 4 arranged in parallel are turned on.

  As described above, since a plurality of types of irradiation patterns can be selected and irradiated with the illumination unit 4 in accordance with the conditions such as the brightness and shape of the part to be inspected, more accurate gas detection can be performed.

(Lighting state switching means)
By changing the illumination state of the illumination means 4, it is possible to deal with various situations of the inspected part.
“Illumination state” refers to “a state in which the illumination means irradiates the part to be inspected at a certain point in time”. It is determined by factors such as brightness.
And the gas detection apparatus X of this invention is equipped with the means to change these factors separately.

Switching the illumination mode of the illumination means For example, the irradiation range and the number of illumination means to be illuminated by the illumination means 4 of the inspected part can be adjusted by switching the illumination mode of the illumination means 4. That is, there is provided an irradiation mode setting means 61 constituted by a switch mechanism or the like for switching between the spot irradiation mode and the wide irradiation mode. Thereby, since an operator can set an illumination mode manually, for example, the illumination state of the illumination means 4 can be changed at an operator's desired timing.

  On the other hand, the setting of the illumination mode can be controlled automatically, not manually by the operator. For this reason, the irradiation mode switching control means 71 is connected to the irradiation mode setting means 61. For example, the irradiation mode switching control unit 71 is configured to switch the irradiation mode of the illumination unit 4 in accordance with the concentration of the detected gas detected by the determination unit 9.

  The concentration level of the gas to be detected is, for example, the following three regions, that is, the initial level at which the gas to be detected is not detected, the detection level at which the gas to be detected is slightly detected, and the alarm level at which the gas to be detected having a predetermined concentration or more is detected Divide into For example, when it is determined that the detection level has reached the detection level from the initial level, or the alarm level or more from the detection level, the irradiation mode switching control unit 71 sets the irradiation mode of the illumination unit 4 to the spot irradiation mode. The switching control means 71 is configured.

Specific embodiments will be described below.
When the discrimination result of the discrimination means 9 is at the initial level, the wide illumination mode (FIG. 4 (b)) in which the part to be inspected is illuminated by, for example, three illumination means 4b to 4d, or the illumination means 4b and 4d are illuminated. The side irradiation mode to be used (FIG. 4C) can be selected and used. In the side irradiation mode, the tip portion 81 is not directly irradiated with irradiation light, so that power consumption can be reduced. By irradiating the tip portion 81 with the two illumination means 4b and 4d sandwiching the tip portion 81, the position of the tip portion 81 can be recognized even in a dark place.

  When it is determined that the determination result of the determination unit 9 has reached the detection level or more from the initial level, the spot irradiation mode (FIG. 4A) in which the tip portion 81 of the gas sampling unit 8 is irradiated by one illumination unit 4a is changed. To do. In the spot irradiation mode, only the illumination means 4c may be turned on to irradiate the tip 81 of the gas sampling unit 8.

If the irradiation mode switching control means 71 is configured in this way, the operator can know the leakage of the gas to be detected by changing to the spot irradiation mode. Thereby, the operator can easily specify the leaked portion of the gas to be detected with high accuracy by adjusting the speed at which the gas detection device X is moved.
The concentration level of the gas to be detected for mode switching is not limited to the above-described three regions, and other desired levels can be set. It is also possible to perform control for switching the irradiation mode from the spot irradiation mode to the wide irradiation mode or the side irradiation mode. This is applied, for example, when the gas detection of the leaked part is finished and the process moves to another part to be inspected.

If the illumination means 4 of different colors is provided in the color switching illumination means 4 of the illumination means, the illumination color for the inspection object part can be changed by turning on / off each illumination means 4. For this purpose, it is possible to provide color switching means 62 for turning off and on a certain light source.

  Thereby, the worker can change the color of the illumination light at a desired timing, and can easily find the gas leak location accurately.

The color switching means 62 can be set so that automatic switching can be performed instead of manual switching. That is, the color switching control means 72 is configured to change the color of the illumination light in accordance with the concentration of the gas to be detected detected by the determination means 9. For example, the color switching control means 72 is set so as to change the color of the illumination light when the concentration of the gas to be detected exceeds a predetermined threshold.
This automatic switching control may be executed in combination with the irradiation mode. For example, in at least one of the spot irradiation mode and the wide irradiation mode, the color switching control unit 72 is configured to change the color of the illumination light according to the concentration of the gas to be detected detected by the determination unit 9. The illumination mode can change the color of the illumination light not only in the two modes described above but also in the side illumination mode.
The color of the illumination light can be set so that, for example, the spot illumination mode (illumination means 4a) is blue light and the wide illumination mode (illumination means 4b to 4d) is white light, but is not limited to this. Absent.

  If the color switching control means 72 is configured in this way, the operator can know the leakage of the gas to be detected by recognizing the change in the color of the illumination light, and can accurately find the gas leakage location. .

Brightness switching of illumination means The number of light sources provided in one illumination means 4 can be changed by turning off at least one light source. Thereby, the brightness (light quantity) of the illumination means 4 can be changed. For this purpose, a brightness switching means 63 for changing the brightness of the illumination means 4 can be provided.
Thereby, the operator can change the brightness of the illumination light at a desired timing, and can easily find the gas leak location accurately.

The brightness switching means 63 can be set so that automatic switching can be performed instead of manual switching. That is, the brightness switching control means 73 is configured to change the brightness of the illumination light according to the concentration of the gas to be detected detected by the determination means 9. For example, the brightness switching control means 73 is set so as to change the brightness of the illumination light when the concentration of the gas to be detected exceeds a predetermined threshold.
This automatic switching control may be executed in combination with the irradiation mode. For example, in at least one of the spot irradiation mode and the wide irradiation mode, the brightness switching control means 73 is configured to change the brightness of the illumination light in accordance with the concentration of the gas to be detected detected by the determination means 9. The illumination mode can change the brightness of illumination light not only in the above-described two modes but also in the side illumination mode.

  When the brightness switching control means 73 is configured in this way, the operator can know the leakage of the gas to be detected by recognizing the change in the brightness of the illumination light, and can accurately find the gas leakage location. .

[Another embodiment 1]
In the above-described embodiment, the mode switching from the wide irradiation mode to the spot irradiation mode is exemplified by using a plurality (four) of the illumination means 4. However, the present invention is not limited to this, and an illumination mode can be switched by providing a diaphragm mechanism (not shown) or the like in one illumination unit 4.
If the aperture mechanism is applied in this way, it is easy to arbitrarily set the irradiation range (area) in the spot irradiation mode, so that the irradiation range can be appropriately set according to the state of the part to be inspected. . Therefore, it becomes easy to recognize the gas leak location according to the state of the part to be inspected.

[Another embodiment 2]
The gas sampling unit 8 can be configured by a transparent member (not shown) through which irradiation light is transmitted, and can be configured to be able to irradiate illumination light from the tip of the transparent member. At this time, if the illumination means 4 is disposed adjacent to the transparent member at the base end portion of the gas sampling unit 8 on the gas detection device main body side, the irradiation light from the illumination means 4 is emitted from the transparent member. It penetrates the inside and is discharged from the tip portion 81. As a result, the irradiation light reaching the opposite side of the tip portion 81 of the gas sampling portion 8 can be irradiated from the tip portion 81, so that the illumination light can be reliably irradiated toward the tip portion 81 of the gas sampling portion 8. It becomes the composition.

  The present invention can be applied to a gas detection device that detects gases such as flammable gas, malodorous gas, and volatile gas, and is particularly applicable to a gas detection device that may detect gas even in a dark place.

Schematic showing the appearance of the gas detector of the present invention Conceptual diagram of the gas detector of the present invention Schematic diagram of gas detection element Schematic front view of the gas detector in each irradiation mode

Explanation of symbols

X Gas detection device 1 Gas detection element 3 Output detection unit 4 Illumination means 8 Gas sampling part 81 Tip portion 9 Discrimination means

Claims (10)

A gas detection element having a gas sensing unit provided in contact with the gas to be detected; an output detection unit for obtaining an output from the gas detection element; and a value of the gas to be detected based on a value obtained by the output detection unit. In a gas detection apparatus provided with a discriminating means for discriminating a concentration level and a gas sampling unit for sampling the gas to be detected from a part to be inspected as a gas detection target,
A gas detection apparatus provided with illumination means capable of irradiating illumination light toward at least one of a distal end portion of the gas sampling unit and its periphery.   2. The gas detection according to claim 1, wherein the illuminating unit has a spot irradiation mode for irradiating the vicinity of a tip portion of the gas sampling unit, and a wide irradiation mode for irradiating a wider range than an irradiation range in the spot irradiation mode. apparatus.   The gas detection apparatus according to claim 2, further comprising an irradiation mode setting unit that sets an irradiation mode of the illumination unit.   The gas detection apparatus according to claim 3, further comprising an irradiation mode switching control unit that switches an irradiation mode of the illumination unit according to the concentration of the detected gas detected by the determination unit.   The gas detection device according to any one of claims 1 to 4, wherein the illumination unit includes a color switching unit that changes a color of illumination light.   The gas detection apparatus according to claim 5, further comprising a color switching control unit that changes a color of illumination light in accordance with a concentration of the detected gas detected by the determination unit.   The gas detector according to any one of claims 1 to 6, wherein the illuminating means is provided with a brightness switching means for changing the brightness of the illumination light.   The gas detection apparatus according to claim 7, further comprising a brightness switching control unit that changes the brightness of the illumination light in accordance with the concentration of the detected gas detected by the determination unit.   The gas detection device according to claim 4, 6 or 8, wherein the detection mode of the detected gas can be changed according to the concentration of the detected gas detected by the determining means.   The gas sampling unit is configured with a transparent member through which irradiation light passes, and illumination light can be irradiated from a tip portion of the transparent member. The gas detector described.