Indicator and concentration measurement system

Abstract

To provide an indicator allowing a user to easily determine concentration of gas.SOLUTION: A cylindrical container 12 includes an intake port 21 for taking external gas into the inside, on a lower bottom surface. A removal member 13 is stored in the container 12 and allowing the gas taken in from the intake port 21 to permeate. A removal agent is impregnated in the removal member 13 to adsorb first gas. A spacer 14 is stored in the container 12 and includes a ventilation part 41 through which the gas permeating the removal member 13 passes. A detection member 15 is stored in the container 12, disposed in close contact with the spacer 14, visually recognized through an upper bottom surface of the container 12, and exposed to the gas that has passed through the ventilation part 41. A detection agent is impregnated in the detection member 15 and reacts with second gas different from the first gas to change the color.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an indicator and a concentration measurement system for measuring the concentration of a specific gas contained in a sample gas. [Background technology]

[0002] Patent Document 1 discloses an indicator that measures and determines the concentration of a specific gas contained in a sample gas over a long period of time. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2005-345280 A Summary of the Invention [Problem to be solved by the invention]

[0004] With the indicator of Patent Document 1, it is difficult to determine whether or not the color has changed, and it is necessary to ask an expert for an assessment. The present invention aims to solve such problems, for example. [Means for solving the problem]

[0005] The gas concentration measuring system includes an imaging unit that images the detection member through the top bottom surface of the container of the indicator, an analysis unit that analyzes the image captured by the imaging unit to obtain the color of the portion of the detection member that is above the ventilation portion and the color of the portion above the portion other than the ventilation portion, and a calculation unit that calculates the concentration of the second gas contained in the external gas based on the difference between the two colors acquired by the analysis unit. The analysis unit may analyze the image captured by the photographing unit to determine a central part of the detection member as the part located above the ventilation part, and may determine a part located a predetermined distance from the center of the detection member as the part located above a part other than the ventilation part. The analysis unit may analyze a plurality of images captured by the imaging unit at different times. The calculation unit may calculate a concentration of the second gas contained in the external gas based on a difference in time when the imaging unit captured the plurality of images analyzed by the analysis unit and a change in the difference between the two colors in the plurality of images analyzed by the analysis unit. Effect of the Invention

[0006] The gas concentration can be calculated accurately by analyzing the image of the indicator. The discolored and undiscolored parts are photographed simultaneously and the concentration is calculated based on the color difference, so the effects of shooting conditions such as lighting and shooting angle can be eliminated and the gas concentration can be calculated easily. By analyzing images taken at different times and calculating the concentration based on the difference in the shooting times and the change in color difference, the concentration can be calculated accurately even if the exact time the indicator was installed is unknown. [Brief description of the drawings]

[0007] [Figure 1] FIG. 4 is a plan view showing an example of an indicator. [Diagram 2] FIG. 4 is a side cross-sectional view showing an example of an indicator. [Diagram 3] FIG. 4 is a bottom view showing an example of an indicator. [Figure 4] FIG. 4 is a plan view showing an example of a spacer. [Diagram 5] FIG. 11 is a plan view showing an example of a color change of an indicator. [Figure 6] FIG. 4 is a bottom view showing an example of a cover. [Figure 7] FIG. 4 is a side cross-sectional view showing an example of a cover. [Figure 8] FIG. 13 is a plan view showing an example of an indicator with a cover attached. [Figure 9] FIG. 13 is a plan view showing an example of an indicator with a cover attached. [Figure 10] FIG. 1 is a block diagram showing an example of a gas concentration measurement system. [Figure 11] FIG. 4 is a flow diagram showing an example of a concentration measurement process. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] The indicator 10 will be described with reference to FIGS. The indicator 10 is used in places where chemicals in the air need to be controlled, such as art galleries and museums, and changes color in response to specific chemicals. The indicator 10 includes, for example, a container 12, a removal member 13, a spacer 14, and a detection member 15.

[0009] The container 12 is, for example, in a flat, generally cylindrical shape, and is made of a transparent material that is impermeable to gas. The container 12 is provided with an intake port 21 on the lower bottom side for taking in external gas. Before use, the intake port 21 is sealed, for example, by a seal (not shown).

[0010] The removal member 13 is, for example, a substantially circular filter paper, and is housed in the container 12. The removal member 13 is permeable to the gas introduced into the container 12 via the intake port 21. The removal member 13 is impregnated with a remover. The remover reacts with chemical substances contained in the air that are different from the chemical substances to be detected by the indicator 10 and that adversely affect the discoloration of the indicator 10 (an example of a first gas). In this way, the removal member 13 adsorbs and removes such chemical substances from the gas that is taken into the container 12 from the inlet 21 and permeates the removal member 13. For example, when the indicator 10 detects ammonia, the remover includes, for example, an indicator (e.g., pH indicators such as thymol blue, cresol red, meta-cresol purple, bromophenol blue, bromothymol blue, phenol red, and p-xylenol blue), a basic substance (e.g., sodium hydroxide, sodium carbonate, calcium hydroxide, potassium hydroxide, and potassium carbonate), glycerin, methanol, and the like, and reacts with acetic acid, acetone, ethyl acetate, toluene, formaldehyde, and the like. Alternatively, when the indicator 10 detects organic acids, the remover may include, for example, an indicator (e.g., a pH indicator such as thymol blue, cresol red, meta-cresol purple, bromophenol blue, bromothymol blue, phenol red, p-xylenol blue, etc.), an acidic substance (e.g., sulfuric acid, sulfates, phosphoric acid, phosphates, acetic acid, acetates, etc.), glycerin, methanol, etc., and reacts with ammonia, acetone, ethyl acetate, toluene, formaldehyde, etc.

[0011] The spacer 14 is, for example, a substantially circular plate, and is housed in the container 12. The spacer 14 is disposed on the removal member 13, for example, in close contact with it. The spacer 14 has a ventilation part 41. For example, as shown in Fig. 4, the ventilation part 41 is a substantially circular opening and is provided in the substantially center of the spacer 14. The gas that has permeated the removal member 13 passes through the ventilation part 41, but the other parts do not allow the gas to pass through.

[0012] The detection member 15 is, for example, a substantially circular filter paper, and is housed in the container 12. The detection member 15 is disposed on the spacer 14, for example, in close contact therewith. The detection member 15 is impregnated with a detection agent. The detection agent changes color upon reacting with a chemical substance (an example of a second gas) that is to be detected by the indicator 10, among chemical substances contained in the air. For example, detection agents for detecting ammonia include, for example, indicators (e.g., pH indicators such as thymol blue, cresol red, meta-cresol purple, bromophenol blue, bromothymol blue, phenol red, and p-xylenol blue), acidic substances (e.g., sulfuric acid, sulfates, phosphoric acid, phosphates, acetic acid, acetates, etc.), glycerin, methanol, and the like. Furthermore, detection agents for detecting organic acids include, for example, indicators (e.g., pH indicators such as thymol blue, cresol red, meta-cresol purple, bromophenol blue, bromothymol blue, phenol red, and p-xylenol blue), basic substances (e.g., sodium hydroxide, sodium carbonate, calcium hydroxide, potassium hydroxide, and potassium carbonate), glycerin, and methanol. Due to the presence of the spacer 14, the removing member 13 and the detecting member 15 do not come into direct contact with each other, so that it is possible to prevent the removing agent and the detecting agent from being mixed together.

[0013] As shown in the figure, the detection element 15 is positioned just below the top surface of the transparent container 12, so that the color change of the detection agent can be visually confirmed by observing the detection element 15 through the top surface of the container 12.

[0014] When using the indicator 10, the indicator 10 is brought to a place where a chemical substance is to be detected, and the seal sealing the intake 21 is removed to allow outside air to flow into the indicator 10, and then the indicator 10 is installed. After a predetermined period of time (for example, four days) has elapsed, the color change of the detecting agent is visually observed through the top and bottom surfaces of the containers 12.

[0015] 5, the portion of the detection member 15 immediately above the ventilation section 41 of the spacer 14 (discolored region 51) is directly exposed to the gas that has passed through the ventilation section 41, so the detection agent impregnated in the detection member 15 reacts with the chemical substance and discolors. In contrast, the other portion (undiscolored region 52) is not in direct contact with the gas that has passed through the ventilation section 41, so the detection agent impregnated in the detection member 15 does not react with the chemical substance and does not discolor. In this way, the discolored area 51 and the undiscolored area 52 are adjacent to each other, with the boundary being the part corresponding to the edge of the ventilation section 41. Therefore, even if the concentration of the chemical substance in the gas is low and the degree of discoloration of the discolored area 51 is small, the discoloration of the discolored area 51 is easily visible.

[0016] Next, the cover 60 will be described with reference to FIGS. The cover 60 is attached to the indicator 10 when in use. The cover 60 is, for example, substantially cylindrical and is open on the bottom. The cover 60 is made of an opaque material and covers the indicator 10. The cover 60 has a flange 64 on the bottom. The flange 64 is provided with a fixing hole 65. A fixing member (not shown) for fixing the indicator 10 to a wall or the like is inserted into the fixing hole 65. The upper surface 63 of the cover 60 is placed over the upper surface of the container 12 of the indicator 10 .

[0017] An upper bottom surface 63 of the cover 60 is provided with a discolored portion 61 and an undiscolored portion 62 . The discolored viewing portion 61 and the undiscolored viewing portion 62 are, for example, openings through which the detection member 15 can be viewed. The discoloration visual recognition portion 61 has, for example, a substantially circular shape, and is provided in a portion of the spacer 14 corresponding to the ventilation portion 41 . The undiscolored visible portion 62 is, for example, substantially circular, and communicates with the discolored visible portion 61. The undiscolored visible portion 62 is provided in a portion of the spacer 14 that does not correspond to the ventilation portion 41.

[0018] 8, when the detection member 15 changes color with the cover 60 attached to the indicator 10, the discolored area 51 is visible through the discoloration viewing portion 61, and the undiscolored area 52 is visible through the undiscolored viewing portion 62. Therefore, by viewing the discoloration of the detection member 15 through the discoloration viewing portion 61 and the undiscolored viewing portion 62, the discoloration of the discolored area 51 can be easily viewed.

[0019] In addition, when the concentration of a chemical substance in the gas is high, and all of the detection agent contained in the discoloration area 51 corresponding to the ventilation section 41 of the spacer 14 reacts with the chemical substance, the chemical substance passes through the detection member 15 and reaches the part of the spacer 14 that does not correspond to the ventilation section 41, and the discoloration area 51 expands. As a result, as shown in FIG. 9, the discolored region 51 extends beyond the discolored visually recognizable portion 61 and reaches the undiscolored visually recognizable portion 62. Therefore, when the discolored region 51 extends beyond the discolored visually recognizable portion 61 and reaches the undiscolored visually recognizable portion 62, it can be determined that the concentration of the chemical substance has exceeded a predetermined allowable concentration.

[0020] In this way, indicator 10 can easily detect chemical substances in the gas based on the degree of color change of color change region 51 and the size of color change region 51.

[0021] The removal member 13 and the detection member 15 are produced, for example, as follows. First, the materials described above are mixed together to produce a large quantity (eg, 100 pieces) of remover / detector agent. Next, a predetermined amount of the produced removing agent / detecting agent is impregnated into the removing member 13 / detecting member 15 using a dropper or the like. This allows the amount of removing agent / detecting agent impregnated in the removing member 13 / detecting member 15 to be approximately constant, and the appearance of the indicator 10 can be made uniform. For example, the color of the detecting member 15 can be H * S * V * The variation in hue H in the color space can be suppressed to, for example, 2%.

[0022] Next, the gas concentration measuring system 70 will be described with reference to FIG. The gas concentration measurement system 70 measures the concentration of a chemical substance in a gas. The gas concentration measurement system 70 is configured, for example, by a mobile terminal device such as a smartphone, and a server device. The gas concentration measuring system 70 includes, for example, an imaging unit 71, an analysis unit 72, a calculation unit 73, and a display unit 74.

[0023] The photographing unit 71 photographs the detection member 15 of the indicator 10 using, for example, a camera of a mobile terminal device. The image photographed by the photographing unit 71 is transmitted to the analysis unit 72.

[0024] The analysis unit 72 receives the image captured by the image capturing unit 71 using, for example, a server device, and analyzes the received image. The analysis unit 72 analyzes the image to obtain the color of the discolored region 51 and the color of the undiscolored region 52. For example, the analysis unit 72 analyzes the image to extract the outline of the top surface of the container 12, calculates the position of the center of the detection member 15 in the image based on the extracted outline, and obtains the RGB value of the pixel at that position to obtain the color of the discolored region 51. Alternatively, the analysis unit 72 may obtain the RGB values ​​of multiple pixels including the surrounding pixels and calculate the average value. Furthermore, the analysis unit 72 calculates the scale of the image (the actual distance that one pixel in the image corresponds to) from the diameter (number of pixels) of the extracted contour and the actual diameter of the top bottom surface of the container 12. The analysis unit 72 calculates a position that is a predetermined distance away from the center position in the image based on the calculated scale. This distance is greater than the radius of the ventilation portion 41 of the spacer 14 and less than the radius of the detection member 15. Then, the RGB value of the pixel at that position is obtained to obtain the color of the undiscolored region 52. Alternatively, the RGB values ​​of multiple pixels including the surrounding pixels may be obtained and their average value may be calculated.

[0025] In the image, the outline of the top surface of the container 12 will be a perfect circle if the indicator 10 is photographed from directly above, but will be an ellipse if photographed from an oblique angle. In this case, the scale will differ depending on the orientation in the image, so for example, the scale of the image is calculated based on the major axis of the ellipse, and the RGB values ​​of the pixels located away from the center in the major axis direction are obtained.

[0026] The calculation unit 73 calculates the difference between the color of the discolored region 51 acquired by the analysis unit 72 and the color of the undiscolored region 52. For example, the calculation unit 73 calculates the difference between the R value, the G value, and the B value based on the RGB values ​​of the pixels of the discolored region 51 and the undiscolored region 52 acquired by the analysis unit 72, and calculates the square root of the sum of the squares of the calculated differences to calculate the difference between the two colors. Note that the calculation unit 73 calculates the difference between the RGB values ​​as a function of the L value, not the difference between the RGB values. * a * b * Alternatively, the values ​​may be converted into values ​​in other color systems, such as values ​​in a chromatic aberration measurement system, and the difference between the values ​​may be calculated. The calculation unit 73 calculates the concentration of the chemical substance contained in the air based on the calculated difference between the two colors.

[0027] The degree of discoloration of the detection element 15 is proportional to the product of the concentration of the chemical substance contained in the air and the time the detection element 15 is exposed to that air. Therefore, if the elapsed time from the time the sticker was removed and indicator 10 was placed to the time the photograph was taken by photographing section 71 is known, the concentration of the chemical substance contained in the air can be found. Alternatively, by having the photographing unit 71 take multiple images at different times and comparing the degree of discoloration of the detection member 15 in each image, the concentration of the chemical substance in the air can be determined even if the exact time when the indicator 10 was installed is not known.

[0028] In order to accurately obtain the color of discolored region 51, it is necessary to illuminate indicator 10 from a specified angle with lighting of a specified color temperature and illuminance. However, color errors in an image caused by differences in the color temperature, illuminance, irradiation angle, and shooting angle of the lighting are thought to be approximately the same at any position in the image, so if the concentration of a chemical substance is determined based on the difference in color between discolored area 51 and undiscolored area 52, the concentration of a chemical substance in the air can be correctly calculated even if the color of discolored area 51 is not accurately obtained.

[0029] The display unit 74 displays the concentration of the chemical substance calculated by the calculation unit 73 using, for example, a liquid crystal display device of a mobile terminal device.

[0030] The concentration measurement process 80 will now be described with reference to FIG. In a concentration measurement process 80, the gas concentration measurement system 70 measures the concentration of a chemical substance in the gas. The concentration measurement process 80 includes, for example, an imaging step 81, an analysis step 82, a calculation step 83, and a display step 84.

[0031] First, the process starts from the imaging step 81. In the photographing step 81, the photographing unit 71 photographs the detection member 15 of the indicator 10. After that, the process proceeds to the analysis step 82. In the analysis step 82, the image captured by the photographing section 71 in the photographing step 81 is analyzed by the analysis section 72 to obtain the colors of the discolored region 51 and the undiscolored region 52. After that, the process proceeds to the calculation step 83.

[0032] In a calculation step 83, the calculation unit 73 calculates the concentration of the chemical substance contained in the air based on the difference between the two colors acquired by the analysis unit 72 in the analysis step 82. Thereafter, the process proceeds to a display step 84. For example, the calculation unit 73 inputs the date and time when the indicator 10 was installed using a touch panel of a mobile terminal device or the like. The calculation unit 73 acquires the date and time when the image was captured from the attached information of the image captured by the capture unit 71 in the capture step 81. The calculation unit 73 calculates the elapsed time from installation to capture based on the input date and time of installation and the acquired date and time of capture. The calculation unit 73 calculates the product of the concentration of the chemical substance contained in the air and the exposure time based on the difference between the two colors acquired by the analysis unit 72 in the analysis step 82, and calculates the quotient by dividing the calculated product by the calculated elapsed time to calculate the concentration of the chemical substance.

[0033] When there are multiple images captured by the imaging unit 71, the concentration of the chemical substance may be calculated as follows. For example, the calculation unit 73 calculates the product of the concentration of a chemical substance contained in the air and the exposure time for each of the two images. The calculation unit 73 also acquires the shooting dates and times for each of the two images. The calculation unit 73 then calculates the quotient by dividing the difference between the calculated products by the difference between the acquired shooting dates and times, thereby calculating the concentration of the chemical substance. This makes it possible to calculate the concentration of the chemical substance without inputting the date and time when the indicator 10 was installed.

[0034] In a display step 84, the display unit 74 displays the concentration of the chemical substance calculated by the calculation unit 73 in the calculation step 83. Thereafter, the concentration measurement process 80 is terminated.

[0035] In this way, the image of the indicator 10 is captured and analyzed to calculate the concentration of the chemical substance, so that the concentration of the chemical substance can be calculated accurately. The discolored and undiscolored areas are photographed simultaneously and the concentration of the chemical substance is calculated based on the difference between the images, eliminating the effects of photography conditions such as lighting and photography angle.

[0036] The gas concentration measurement system described above comprises an imaging unit that images the detection member through the top bottom surface of the container of the indicator, an analysis unit that analyzes the image captured by the imaging unit to obtain the color of the portion of the detection member that is above the ventilation portion and the color of the portion above the portion other than the ventilation portion, and a calculation unit that calculates the concentration of the second gas contained in the external gas based on the difference between the two colors acquired by the analysis unit. The analysis unit may analyze the image captured by the photographing unit to determine a central part of the detection member as the part located above the ventilation part, and may determine a part located a predetermined distance from the center of the detection member as the part located above a part other than the ventilation part. The analysis unit may analyze a plurality of images captured by the imaging unit at different times. The calculation unit may calculate a concentration of the second gas contained in the external gas based on a difference in time when the imaging unit captured the plurality of images analyzed by the analysis unit and a change in the difference between the two colors in the plurality of images analyzed by the analysis unit.

[0037] The gas concentration can be calculated accurately by analyzing the image of the indicator. The discolored and undiscolored parts are photographed simultaneously and the concentration is calculated based on the color difference, so the effects of shooting conditions such as lighting and shooting angle can be eliminated and the gas concentration can be calculated easily. By analyzing images taken at different times and calculating the concentration based on the difference in the shooting times and the change in color difference, the concentration can be calculated accurately even if the exact time the indicator was installed is unknown.

[0038] The above-described embodiment is an example for facilitating understanding of the present invention. The present invention is not limited thereto, and includes various modifications, changes, additions, or deletions without departing from the scope defined by the appended claims. This can be easily understood by those skilled in the art from the above description. [Explanation of symbols]

[0039] 10 indicator, 12 container, 21 intake port, 13 removal member, 14 spacer, 41 ventilation section, 15 detection member, 51 discolored area, 52 undiscolored area, 60 cover, 61 discolored visual inspection section, 62 undiscolored visual inspection section, 63 upper bottom surface, 64 flange section, 65 fixing hole, 70 gas concentration measurement system, 71 photographing section, 72 analysis section, 73 calculation section, 74 display section, 80 concentration measurement process, 81 photographing process, 82 analysis process, 83 calculation process, 84 display process.

Claims

1. an indicator including a cylindrical container having an intake port on a bottom surface for taking in an external gas; a removal member housed in the container and permeable to the gas taken in from the intake port; a removal agent impregnated in the removal member and adsorbing a first gas; a spacer housed in the container and having a ventilation part through which the gas that has permeated the removal member passes; a detection member housed in the container and disposed in close contact with the spacer, visible through the top surface of the container and exposed to the gas that has passed through the ventilation part; and a detection agent impregnated in the detection member and changing color in response to a second gas different from the first gas; and an image taking unit for taking an image of the detection member through the top surface of the container. an analysis unit that analyzes the image captured by the image capture unit to acquire the color of the portion of the detection member that is above the ventilation portion and the color of the portion of the detection member that is above a portion other than the ventilation portion; a calculation unit that calculates a concentration of the second gas contained in the outside gas based on the difference between the two colors acquired by the analysis unit; A gas concentration measurement system comprising:

2. The detection member of the indicator is substantially disk-shaped, The ventilation portion of the indicator has a substantially circular shape centered on the central axis of the detection member, The analysis unit analyzes the image captured by the imaging unit, determines a central portion of the detection member as a portion above the ventilation portion, and determines a portion away from the center of the detection member by a predetermined distance as a portion above a portion other than the ventilation portion.

2. The gas concentration measurement system of claim 1.

3. The analysis unit analyzes a plurality of images taken by the photographing unit at different times, The calculation unit calculates the concentration of the second gas contained in the external gas based on a difference in time when the multiple images analyzed by the analysis unit were captured by the imaging unit and a change in the difference between the two colors in the multiple images analyzed by the analysis unit.

3. The gas concentration measurement system according to claim 1 or 2.

4. The indicator A cover is further provided for use by placing it on the upper bottom surface of the container, The cover is a color-change visual confirmation portion located above the ventilation portion for visually confirming a portion of the detection member located above the ventilation portion; an undiscolored visual confirmation portion located above a portion other than the ventilation portion for visually confirming a portion of the detection member that is above the portion other than the ventilation portion; The gas concentration measurement system according to claim 1 or 2, comprising:

Images