JP6444781B2 - Gas detection device and control method thereof - Google Patents

Description

  In the present invention, a gas flow path for introducing a gas to be detected is provided, a gas detection unit including a gas detection element is provided in the gas flow path, and the gas to be detected is circulated through the gas flow path to be led to the gas detection element. The present invention relates to a gas detection device provided with a gas flow device and a control method thereof.

  In recent years, in order to measure the concentration of the gas to be detected in a wide concentration range from low concentration to high concentration by such a gas detection device, or to specify the type of trace component gas in the detection target gas, in particular, It is considered to use a gas detection element having a high gas detection performance for a low concentration gas. Further, it is known that such a gas detection element generally has a case where the detection accuracy for detecting the gas to be detected may be lowered by exposure to a high concentration gas.

  However, when the gas detection element described above is used in such a form, when the gas to be detected contains a high concentration of the gas to be detected, the gas detection element is exposed to the gas to be detected at a high concentration, and the gas detection element is detected. There is a possibility that the accuracy of the element is lowered and the gas detection element is deteriorated.

  Patent Document 1 discloses a gas for measuring the concentration of a combustible gas by switching a low-concentration side gas detection unit having a catalytic combustion type gas sensor and a high-concentration side gas detection unit having a heat conduction type gas sensor by a switching means. A detection device is described. Thereby, it was supposed that the gas detection element corresponding to the density | concentration of the combustible gas which should be measured can be selected automatically.

Japanese Patent No. 3929845

  In the gas detection device described in Patent Literature 1, when switching and controlling the detection results of the low concentration side gas detection unit and the high concentration side gas detection unit, the detection result may suddenly rise or fall, The gas concentration detection result may not change smoothly.

  Accordingly, an object of the present invention is to provide a gas detection device capable of displaying the detection result of the gas concentration so that the detection result of the gas concentration does not change suddenly when switching the detection result of the low concentration side gas detection unit and the high concentration side gas detection unit. There is to do.

  The first characteristic configuration of the gas detection device according to the present invention for achieving the above object is that a low-concentration side gas detection unit suitable for detecting a low-concentration detected gas because of a large change in output at a low concentration, A detected gas detected by the low-concentration side gas detection unit, and a high-concentration side gas detection unit suitable for detecting a detected gas at a higher concentration side than the low-concentration side gas detection unit According to the concentration of the low-concentration side gas detection unit and the high-concentration side gas detection unit. The detection result of the low-concentration side gas detection unit is displayed when the concentration of the detected gas detected by the unit is less than the first predetermined concentration, and when the concentration is higher than the second predetermined concentration higher than the first predetermined concentration, the high The detection result of the concentration side gas detection unit is displayed, and When the concentration is equal to or higher than a predetermined concentration and lower than the second predetermined concentration, a value obtained by multiplying the detection result of the low concentration side gas detection unit by a first predetermined ratio and the detection result of the high concentration side gas detection unit are The point is that control is performed so as to display a corrected density value obtained by adding the value obtained by multiplying the ratio by the second predetermined ratio, which is 100%.

  According to this configuration, the three concentrations of the gas to be detected detected by the low concentration side gas detector are less than the first predetermined concentration, the second predetermined concentration or more, and the first predetermined concentration or more and less than the second predetermined concentration. The control unit can control the detection results so that the display results of the detection results in the gas detection units are different. That is, when the concentration is lower than the first predetermined concentration that is the lowest concentration range, the detection result of the low concentration side gas detector is displayed as it is, and when the concentration is higher than the second predetermined concentration that is the highest concentration range, the high concentration is displayed. The detection result of the side gas detector is displayed as it is. In addition, when the intermediate density range is equal to or higher than the first predetermined density and lower than the second predetermined density, a corrected density value is displayed.

  The corrected concentration value is a concentration value that includes the detection result of the low concentration side gas detection unit by the first predetermined ratio and the detection result of the high concentration side gas detection unit by the second predetermined ratio. When the concentration value is inserted between the detection result of the portion and the detection result of the high concentration side gas detection portion, the detection results of both can be smoothly connected. Therefore, in the gas detection device of this configuration, when the detection results of the low concentration side gas detection unit and the high concentration side gas detection unit are switched and controlled, the detection result of the gas concentration can be displayed so as not to change suddenly. .

  A second characteristic configuration of the gas detection device according to the present invention is that the control unit is based on a detection output value of the low concentration side gas detection unit when the first predetermined concentration or more and less than the second predetermined concentration. A value obtained by multiplying the low-concentration-side converted concentration value converted by the concentration by the first predetermined ratio and a high-concentration-side converted concentration value converted based on the detection output value of the high-concentration-side gas detection unit are multiplied by the second predetermined ratio. The corrected density value obtained by adding the two values is displayed.

  According to this configuration, in this configuration, when the concentration is equal to or higher than the first predetermined concentration and lower than the second predetermined concentration, the low concentration side converted concentration converted based on the detection output value that is the raw data detected by each gas detection unit It is possible to calculate and display the corrected density value by performing the above-described calculation by multiplying the value and the high density side converted density value by a predetermined ratio.

  A third characteristic configuration of the gas detection device according to the present invention is that the control unit has a first detection output value of the low-concentration side gas detection unit when the first predetermined concentration or more and less than the second predetermined concentration. The control is performed to display the corrected concentration value obtained by concentration conversion after adding the value obtained by multiplying the predetermined ratio and the value obtained by multiplying the detection output value of the high concentration side gas detection unit by the second predetermined ratio. .

  According to this configuration, after the first predetermined concentration or higher and lower than the second predetermined concentration, after performing the above operation of multiplying the detection output value, which is raw data detected by each gas detection unit, by a predetermined ratio, and adding up Then, the corrected density value in terms of density can be calculated and displayed.

  The characteristic configuration of the control method of the gas detection device according to the present invention is that the change in output at low concentration is large, so that a low concentration side gas detection unit suitable for detecting a low concentration detected gas, and the low concentration side gas A high-concentration side gas detection unit suitable for detecting a detection gas at a higher concentration side than the detection unit, and according to the concentration of the detection gas detected by the low-concentration side gas detection unit, A control method of a gas detection device for switching and controlling which detection result of the low-concentration side gas detection unit and the high-concentration side gas detection unit is to be displayed, which is detected by the low-concentration side gas detection unit When the gas concentration is lower than the first predetermined concentration, the detection result of the low concentration side gas detection unit is displayed. When the gas concentration is higher than the second predetermined concentration, the detection result of the high concentration side gas detection unit is displayed. , Above the first predetermined concentration and below the second predetermined concentration A value obtained by multiplying the detection result of the low-concentration side gas detection unit by a first predetermined rate, and a second predetermined rate that is 100% in combination with the detection result of the high-concentration side gas detection unit and the first predetermined rate. The correction density value obtained by multiplying the value obtained by multiplying by and the control value is controlled to be displayed.

  According to this configuration, the three concentrations of the gas to be detected detected by the low concentration side gas detector are less than the first predetermined concentration, the second predetermined concentration or more, and the first predetermined concentration or more and less than the second predetermined concentration. In the above, it is possible to control so that the display mode of the detection result in each gas detection unit is different. That is, when the concentration is lower than the first predetermined concentration that is the lowest concentration range, the detection result of the low concentration side gas detector is displayed as it is, and when the concentration is higher than the second predetermined concentration that is the highest concentration range, the high concentration is displayed. The detection result of the side gas detector is displayed as it is. In addition, when the intermediate density range is equal to or higher than the first predetermined density and lower than the second predetermined density, a corrected density value is displayed.

  The corrected concentration value is a concentration value that includes the detection result of the low concentration side gas detection unit by the first predetermined ratio and the detection result of the high concentration side gas detection unit by the second predetermined ratio. When the concentration value is inserted between the detection result of the portion and the detection result of the high concentration side gas detection portion, the detection results of both can be smoothly connected. Therefore, in the control method of the gas detection device of this configuration, when the detection results of the low concentration side gas detection unit and the high concentration side gas detection unit are switched and controlled, the gas concentration detection result does not seem to change suddenly. Can be displayed.

It is the schematic which shows the gas detection apparatus of this invention. A graph showing the results when city gas is detected by the gas detection device of the present invention and the conventional gas detection device (the correction concentration value is not displayed) when the concentration of the city gas is gradually increased from 0 to 1000 ppm. It is.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
The gas detection device of the present invention samples the gas to be detected and measures the concentration of the gas to be detected.

  As shown in FIG. 1, the gas detection device X of the present invention has a low concentration gas detection unit 50 suitable for detecting a low concentration gas to be detected because the change in output at a low concentration is large, and a low concentration A high-concentration side gas detection unit 30 suitable for detecting a detection gas at a higher concentration side than the side gas detection unit 50, and the concentration of the detection gas detected by the low-concentration side gas detection unit 50 Accordingly, a control unit 60 that switches and controls which of the detection results of the low concentration side gas detection unit 50 and the high concentration side gas detection unit 30 is displayed is provided.

  In the present embodiment, a delay unit 40 that causes a gas flow delay is provided, and a low-concentration side gas detection unit 50 is disposed downstream of the delay unit 40, and a high-concentration side gas detection unit 30 is disposed upstream of the delay unit 40. The case will be described.

  The high-concentration side gas detection unit 30 and the low-concentration side gas detection unit 50 are disposed in the gas flow path 10 for introducing the gas to be detected, and a pump P is disposed downstream of the low-concentration side gas detection unit 50. They are connected via a path 10. A flow rate detection unit 70 that detects the gas flow rate is disposed downstream of the pump P. By operating the pump P, the atmospheric gas and the gas to be detected are sucked and discharged from the gas exhaust port 13 through the gas inlet portion 11, the high concentration side gas detection portion 30, the low concentration side gas detection portion 50, and the like. In the present embodiment, a case will be described in which a dilution unit 80 for diluting the sampled detected gas is provided on the upstream side of the high-concentration side gas detection unit 30.

(High concentration side gas detector)
Although the high concentration side gas detection part 30 in this embodiment demonstrates the case where a contact combustion type gas detection element is used, it is not limited to this. The catalytic combustion type gas detection element has a gas detection performance suitable for detecting a gas to be detected at a higher concentration side than a semiconductor type gas detection element (low concentration side gas detection unit 50) described later.

  The catalytic combustion type gas detection element is provided with a combustion catalyst part as a gas sensitive part in which a noble metal catalyst such as platinum is supported on a sintered metal oxide such as alumina on a noble metal wire such as platinum. By causing the combustible gas to be detected to contact and burn with the noble metal catalyst, the temperature change that occurs during the combustion is detected as a change in the resistance value of the noble metal wire. The combustion heat of the combustible gas is proportional to the concentration of the combustible gas and is almost linear up to LEL, and the resistance value of the noble metal wire is proportional to the combustion heat, so the change value of the resistance of the noble metal wire due to the combustion of the combustible gas is By measuring, the concentration of the combustible gas can be measured.

(Delay part)
In this embodiment, the delay unit 40 that causes a gas flow delay is described as a gas flow delay caused by forming a flow path in a coil shape, but the present invention is not limited to this. For example, if the flow path is provided with a long portion instead of the coiled flow path, the delay time can be ensured by increasing the distance that the gas to be detected moves. In this case, the delay time can be easily changed by changing the length of the long portion. In addition, if a large-diameter buffer portion is provided instead of the coiled flow path, a delay time corresponding to the volume can be secured by changing the volume of the buffer portion.

  By providing the delay unit 40 in this way, compared with the case where the delay unit 40 is not provided, the gas to be detected passes from the high concentration side gas detection unit 30 to the low concentration side gas detection unit 50. Time can be intentionally delayed.

(Low concentration side gas detector)
Although the low concentration side gas detection part 50 in this embodiment demonstrates the semiconductor type sensor using a hot-wire type semiconductor type gas detection element, it is not limited to this, The semiconductor type sensor containing a thin film type semiconductor type sensor Other sensors can also be used.
The semiconductor-type gas detection element is configured to detect changes in heat conduction and electrical conductivity due to gas adsorption on the metal oxide semiconductor surface with electrodes, for example, noble metal wires such as platinum, palladium, platinum-palladium alloy, A gas sensitive part is provided which is formed by applying a metal oxide semiconductor mainly composed of a metal oxide such as indium oxide, tungsten oxide, tin oxide, zinc oxide, etc., drying and sintering.
The semiconductor gas detection element configured as described above has a large change in output at a low concentration and is highly sensitive, and a gas component having a large molecular weight in the combustible gas exhibits high sensitivity.

  In this embodiment, a case where a catalytic combustion type gas detection element is used as the high concentration side gas detection unit 30 and a hot wire type semiconductor gas detection element is used as the low concentration side gas detection unit 50 has been described. In the gas detection element, a part of the detection gas detection characteristics of each other overlap. By applying such a set of gas detection elements, it is possible to provide a gas detection device that can reliably detect a gas to be detected from a high concentration to a low concentration.

(Control part)
The control unit 60 switches which detection result of the low concentration side gas detection unit 50 or the high concentration side gas detection unit 30 is displayed according to the concentration of the gas to be detected detected by the low concentration side gas detection unit 50. Control. The detection result can be displayed by a display unit 90 such as a digital type or an analog type.

  Specifically, the control unit 60 displays the detection result of the low concentration side gas detection unit 50 when the concentration of the gas to be detected detected by the low concentration side gas detection unit 50 is less than the first predetermined concentration. When the second predetermined concentration is higher than the first predetermined concentration or higher, the detection result of the high concentration side gas detector 30 is displayed, and when the first predetermined concentration is higher than the second predetermined concentration and lower than the second predetermined concentration, the low concentration side gas is detected. The value obtained by multiplying the detection result of the unit 50 by the first predetermined ratio and the value obtained by multiplying the detection result of the high-concentration side gas detection unit 30 by the second predetermined ratio which is 100% together with the first predetermined ratio. Control to display the corrected density value.

  The first predetermined ratio and the second predetermined ratio can be variously set so that the sum thereof is 100%. For example, when the first predetermined ratio is 20%, the second predetermined ratio is 80%, and when the first predetermined ratio is 60%, the second predetermined ratio is 40%. Thus, the “corrected concentration value” of the present invention is a concentration value calculated (combined) based on the detection output values actually measured by the plurality of gas detection units.

  In this configuration, the concentration of the gas to be detected detected by the low concentration side gas detection unit 50 is in three ranges of less than the first predetermined concentration, the second predetermined concentration or more, and the first predetermined concentration or more and less than the second predetermined concentration. The control unit 60 can control the detection results so that the display results of the gas detection units are different. That is, when the concentration is lower than the first predetermined concentration which is the lowest concentration range, the detection result of the low concentration side gas detection unit 50 is displayed as it is, and when the concentration is higher than the second predetermined concentration which is the highest concentration range, the detection result is high. The detection result of the concentration side gas detection unit 30 is displayed as it is. In addition, when the intermediate density range is equal to or higher than the first predetermined density and lower than the second predetermined density, a corrected density value is displayed.

  The high-concentration side gas detection unit 30 and the low-concentration side gas detection unit 50 have a case in which the detected gas detection characteristics of each other overlap each other, so that the intermediate concentration range is equal to or higher than the first predetermined concentration and lower than the second predetermined concentration. In both, the detection output can be obtained in both the high-concentration side gas detection unit 30 and the low-concentration side gas detection unit 50.

  Since the correction concentration value is a concentration value that includes the detection result of the low concentration side gas detection unit 50 by the first predetermined ratio and the detection result of the high concentration side gas detection unit 30 by the second predetermined ratio, When the detection result of the gas detection unit 50 and the detection result of the high-concentration side gas detection unit 30 are inserted as concentration values, both detection results can be smoothly connected. Therefore, in this configuration, when the detection results of the low-concentration side gas detection unit 50 and the high-concentration side gas detection unit 30 are switched and controlled, it is possible to display the detection result of the gas concentration so that it does not change suddenly.

  When the detection result of the low concentration side gas detection unit 50 is displayed when the concentration is less than the first predetermined concentration, the high concentration side gas detection unit 30 can be in an activated state. Further, when the detection result of the high concentration side gas detection unit 30 is displayed when the second predetermined concentration or higher, the low concentration side gas detection unit 50 is preferably in an inactivated state. The inactivated state may be that the power supplied to the low concentration side gas detection unit 50 is turned off or the voltage supplied to the low concentration side gas detection unit 50 is reduced.

  As described above, the control unit 60 determines the detection result of either the high concentration side gas detection unit 30 or the low concentration side gas detection unit 50 according to the concentration of the gas to be detected detected by the low concentration side gas detection unit 50. In order to control whether to display or not, if it is an aspect such as a microcomputer that can acquire any detection result for the low concentration side gas detection unit 50 and the high concentration side gas detection unit 30 according to the concentration of the gas to be detected Good.

  In addition, the control unit 60 may include a concentration calculation unit that calculates a detected gas concentration based on detection output values detected by the high concentration side gas detection unit 30 and the low concentration side gas detection unit 50. The density value calculated at this time becomes the converted density value. When the high-concentration side gas detection unit 30 continuously detects the gas to be detected that is higher than or equal to the alarm level, the control unit 60 sends an alarm signal to the alarm unit (not shown) so that the alarm unit issues an alarm. It is also possible to control it. Furthermore, the control unit 60 may control the operation of the dilution unit 80 and the opening / closing of the branching units 21 and 22 based on the output detected by the high concentration side gas detection unit 30 (described later).

  The case where the “detection result” of each gas detection unit in the present embodiment is “a converted concentration value converted into a concentration based on a detection output value detected by each gas detection unit” will be described. That is, the control unit 60 converts the concentration based on the detection output value of the low concentration side gas detection unit 50 when the concentration of the detected gas detected by the low concentration side gas detection unit 50 is less than the first predetermined concentration. (Conversion concentration value) is displayed, and when the concentration is equal to or higher than the second predetermined concentration, a value (conversion concentration value) obtained by converting the concentration based on the detection output value of the high concentration side gas detection unit 30 is displayed.

  Further, the control unit 60 converts the first predetermined ratio to the low concentration side converted concentration value converted based on the detection output value of the low concentration side gas detection unit 50 when the concentration is equal to or higher than the first predetermined concentration and lower than the second predetermined concentration. And the corrected concentration value obtained by adding the value obtained by multiplying the value obtained by multiplying the value by the second predetermined ratio to the high concentration side converted concentration value converted based on the detection output value of the high concentration side gas detection unit 30. To control.

  In this configuration, when the concentration is equal to or higher than the first predetermined concentration and lower than the second predetermined concentration, the low concentration side converted concentration value and the high concentration side converted based on the detection output value that is the raw data detected by each gas detection unit. It is possible to calculate and display a corrected density value by performing the above-described calculation by multiplying the density value by a predetermined ratio.

  The dilution of the gas to be detected can be performed by the dilution unit 80. That is, the control unit 60 controls the operation of the dilution unit 80 in accordance with the concentration of the detected gas detected by the catalytic combustion type gas detection element.

  The dilution unit 80 may be configured to provide a dilution gas for diluting the gas to be detected. Specifically, the diluting unit 80 is provided with an orifice 81 in the branch channel 10a branched by the branching means 20 (21, 22) that branches the gas channel 10, and provided with the air introduction unit 12 on the downstream side thereof. An air introduction pipe 10b is connected, and the air introduction interruption can be switched freely. Note that the dilution section 80 may be provided with a discharge path for discharging excess air. For example, a three-way valve can be used as the branching unit 20, but the branching unit 20 is not limited to such a mode.

  The dilution rate of the gas to be detected in the dilution unit 80 can be set as appropriate. However, the gas dilution rate of the dilution unit 80 may be determined in advance by the control unit 60 and the concentration of the gas to be detected after dilution may be obtained. For example, it is possible to obtain the detected gas concentration based on the measured measured gas concentration after dilution. For example, if the dilution rate is set to 20 times, the catalytic combustion type gas detection element whose detection limit is about 5 vol% can detect up to 100 vol%.

[Another embodiment 1]
In the above-described embodiment, the “detection result” is “converted concentration value converted in concentration based on the detection output value detected by each gas detection unit”. However, the present invention is not limited to this mode, and the “detection result” in the case where the concentration is equal to or higher than the first predetermined concentration and lower than the second predetermined concentration may be “detected output value detected by each gas detection unit”.

  That is, in the present embodiment, when the control unit 60 is equal to or higher than the first predetermined concentration and lower than the second predetermined concentration, the control unit 60 multiplies the detection output value of the low concentration side gas detection unit 50 by the first predetermined ratio, Control is performed to display a corrected concentration value obtained by converting the concentration after adding the value obtained by multiplying the detection output value of the concentration side gas detection unit 30 by the second predetermined ratio.

  In this configuration, when the concentration is equal to or higher than the first predetermined concentration and lower than the second predetermined concentration, the calculation is performed by multiplying the detection output value, which is raw data detected by each gas detection unit, by a predetermined ratio, and then the concentration is added. The converted corrected density value can be calculated and displayed.

[Another embodiment 2]
In the above-described embodiment, two gas detection units are provided, and the high concentration side gas detection unit 30 is a mode suitable for detecting a gas to be detected at a higher concentration side than the low concentration side gas detection unit 50. Furthermore, it is good also as an aspect which provided the additional detection part suitable for detecting the to-be-detected gas of the higher concentration side than the high concentration side gas detection part 30 (not shown). Even in this case, depending on the density range, the density display is performed based on the detection result of which detection unit, and the correction density value is calculated by changing the ratio by which the detection result of each detection unit is multiplied. The same effect as the form can be obtained.

  As such an additional detection unit, for example, a gas heat conduction type gas detection element can be used, but is not limited thereto. When three detection units are provided in this way, detection is performed at a low concentration (low concentration side gas detection unit 50), a high concentration (high concentration side gas detection unit 30), and a higher concentration (additional detection unit). Gas can be detected. Also in this case, the control provided with the delay unit 40 can be performed.

  The additional detection unit can be disposed in an additional flow path connected between the delay unit and the low-concentration side gas detection unit 50, for example. In this case, the control unit 60 flows down the detected gas sampled in either the low concentration side gas detection unit 50 or the additional detection unit according to the concentration of the detection gas detected by the high concentration side gas detection unit 30. Can be controlled.

  In the three detection units described above, the additional detection unit and the high-concentration side gas detection unit 30 partially overlap in their respective detectable ranges, and the high-concentration side gas detection unit 30 and the low-concentration side gas detection unit 50 have their respective detection ranges. What overlaps a part of each detection target gas detection characteristic should just be selected so that a part of detectable range may overlap.

[Example 1]
Examples of the present invention will be described.
In the gas detection device X of the present invention, a catalytic combustion type gas detection element was used as the upstream gas detection unit 30, and a hot-wire semiconductor type gas detection element was used as the downstream gas detection unit 50.
The contact combustion type gas detection element is suitable for detecting a combustible gas (for example, city gas) of about 1000 ppm to 5 vol% (50000 ppm). On the other hand, the hot-wire semiconductor gas detection element is suitable for detecting a combustible gas of about 10 to 1000 ppm.

  In this example, when the concentration of the city gas was gradually increased from 0 to 1000 ppm, the city gas was detected by the gas detection device X of the present invention and the conventional gas detection device (the correction concentration value is not displayed). The concentration of city gas was increased from around 22 seconds, and the flow rate was adjusted to 1000 ppm around 40 seconds.

  In the gas detection device X of the present invention, the control unit 60 is configured such that the detected gas concentration detected by the low concentration side gas detection unit 50 is equal to or higher than the first predetermined concentration (400 ppm) and lower than the second predetermined concentration (900 ppm). And a value obtained by multiplying the low concentration side converted concentration value converted based on the detection output value of the low concentration side gas detection unit 50 by the first predetermined ratio and the detection output value of the high concentration side gas detection unit 30. Control was performed so as to display a corrected density value obtained by adding a value obtained by multiplying the high density side converted density value by the second predetermined ratio. The first predetermined ratio and the second predetermined ratio are shown in Table 1.

  The results are shown in FIG. In the conventional gas detection device, when the detection output value of the low concentration side gas detection unit 50 is less than 800 ppm, the detection output value of the low concentration side gas detection unit 50 is displayed. 30 detection output values were displayed. As a result, in the vicinity of 31 to 35 seconds in which the detection results of the low-concentration side gas detection unit 50 and the high-concentration side gas detection unit 30 are switched and controlled, the detection result of the gas concentration rapidly increases from a rising tendency to a substantially constant concentration value. It was recognized that it changed.

  On the other hand, in the gas detection device X of the present invention, the control is performed so that the corrected concentration value is displayed when the concentration is equal to or higher than the first predetermined concentration (400 ppm) and lower than the second predetermined concentration (900 ppm). In the vicinity of 31 to 35 seconds in which the detection result of the high-concentration side gas detection unit 30 is switched and controlled, the gas concentration detection result can be displayed as a gently rising curve, and it was recognized that it did not change rapidly.

  The present invention can perform so-called wide-range detection, and the gas type to be detected is not particularly limited, and is provided with a gas flow path for introducing a gas to be detected, and the gas flow path is provided with a gas flow path. The present invention can be used for a gas detection apparatus provided with a gas detection unit provided with a detection element, and provided with a gas flow device that distributes a gas to be detected through a gas flow path to guide the gas detection element, and a control method thereof.

X gas detection device 30 high concentration side gas detection unit 50 low concentration side gas detection unit 60 control unit

Claims (4)

Because the change in output at low concentration is large, a low-concentration gas detection unit suitable for detecting a low-concentration gas to be detected and a detection gas at a higher concentration than the low-concentration gas detection unit are detected. A high-concentration side gas detection unit suitable for
A control unit for switching and controlling which of the detection results of the low concentration side gas detection unit and the high concentration side gas detection unit is displayed according to the concentration of the gas to be detected detected by the low concentration side gas detection unit; Prepared,
In the control unit, the concentration of the detected gas detected by the low concentration side gas detection unit is
When the concentration is less than the first predetermined concentration, the detection result of the low concentration side gas detection unit is displayed,
When the second predetermined concentration is higher than the first predetermined concentration, the detection result of the high concentration side gas detection unit is displayed, and
When the first predetermined concentration is higher than the second predetermined concentration and less than the second predetermined concentration, the detection result of the low concentration side gas detection unit is multiplied by the first predetermined ratio, and the detection result of the high concentration side gas detection unit is A gas detection device that controls to display a corrected concentration value that is a sum of a value obtained by multiplying a first predetermined ratio and a second predetermined ratio that is 100%. When the control unit is equal to or higher than the first predetermined concentration and lower than the second predetermined concentration,
Concentration conversion based on a value obtained by multiplying the low concentration side converted concentration value converted based on the detection output value of the low concentration side gas detection unit by a first predetermined ratio and the detection output value of the high concentration side gas detection unit The gas detection device according to claim 1, wherein the corrected concentration value obtained by adding the second predetermined ratio to the high concentration side converted concentration value is controlled to be displayed. When the control unit is equal to or higher than the first predetermined concentration and lower than the second predetermined concentration,
Concentration conversion after adding a value obtained by multiplying the detection output value of the low concentration side gas detection unit by a first predetermined ratio and a value obtained by multiplying the detection output value of the high concentration side gas detection unit by a second predetermined ratio The gas detection device according to claim 1, wherein control is performed to display the corrected concentration value. Because the change in output at low concentration is large, a low-concentration gas detection unit suitable for detecting a low-concentration gas to be detected and a detection gas at a higher concentration than the low-concentration gas detection unit are detected. A high-concentration side gas detection unit suitable for
A gas detection device that switches and controls which of the detection results of the low-concentration side gas detection unit and the high-concentration side gas detection unit is displayed according to the concentration of the gas to be detected detected by the low-concentration side gas detection unit Control method,
The concentration of the gas to be detected detected by the low concentration side gas detector is
When the concentration is less than the first predetermined concentration, the detection result of the low concentration side gas detection unit is displayed,
When the second predetermined concentration or higher, the detection result of the high concentration side gas detection unit is displayed, and
When the first predetermined concentration is higher than the second predetermined concentration and less than the second predetermined concentration, a value obtained by multiplying the detection result of the low concentration side gas detection unit by the first predetermined ratio and the detection result of the high concentration side gas detection unit are The control method of the gas detection apparatus which controls to display the correction | amendment density | concentration value which added together the value which multiplied the 2nd predetermined ratio which is set to 100% combining one predetermined ratio.

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