Indication value reading device and indication value reading method

Abstract

To read the concentration of a detection object by a detector tube without variation.SOLUTION: An indicated value reading device pertaining to an embodiment reads a memory of a detector tube having a detection agent that changes colors reacting with a detection object substance and a glass tube filled with the detection agent, which the detection object substance passes through, the indicated value reading device comprising memory detection means, boundary detection means and read means. The memory detection means detects the memory attached to the glass tube from an image of the detector tube. The boundary detection means detects a boundary line between a detection agent that has reacted with the detection object substance among the detection agents and other detection agents on the basis of the degree of discoloration of the detection agent. The read means reads the indicated value of the detector tube from a positional relation between the memory detected by the memory detection means and the boundary line detected by the boundary detection means.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] An embodiment of the present invention relates to an indication value reading device and an indication value reading method. [Background technology]

[0002] Factories and experimental facilities that handle hazardous substances are required by laws such as the Industrial Safety and Health Act to periodically measure the working environment. Examples of hazardous substances contained in the working environment include lead, mercury, and formaldehyde. To detect these types of hazardous substances, for example, a detector tube is used. A detector tube is mainly composed of a detector agent that reacts with the substance to be detected and a glass tube in which the detector agent is enclosed (for example, see Patent Document 1).

[0003] In measurements using a detector tube, the concentration of harmful substances in the work environment is detected according to the degree of discoloration of the detector agent sealed in the glass tube. The user of the detector tube can read the concentration of harmful substances according to the positional relationship between the boundary between the discolored part of the detector agent and the rest of the part and the markings on the glass tube. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2014-92487 A Summary of the Invention [Problem to be solved by the invention]

[0005] By using a detector tube, the user of the detector tube can measure the concentration of harmful substances in the work environment. However, the boundary between the part where the detector agent has changed color and the rest of the part is not necessarily a straight line. Also, if the color of the detector agent changes gradually, it may be difficult to identify the boundary line. Therefore, the measurement results using a detector tube may vary due to the user's sensitivity and skill.

[0006] The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to read the indicated value of a detector tube uniquely and without variation. [Means for solving the problem]

[0007] In order to solve the above problems, the indication value reading device of the first invention is a device for reading the memory of a detector tube having a detector agent that changes color upon reacting with a substance to be detected, and a glass tube in which the detector agent is sealed and through which the substance to be detected passes, and is equipped with a memory detection means, a boundary detection means, and a reading means. The memory detection means detects the memory attached to the glass tube from an image of the detector tube. The boundary detection means detects the boundary between the detector agent that has reacted with the detection target substance and the other detector agent based on the degree of discoloration of the detector agent. The reading means reads the indicated value of the detector tube from the positional relationship between the memory detected by the memory detection means and the boundary detected by the boundary detection means.

[0008] The second invention relates to a method for reading indications of a detector tube having a detector agent that changes color upon reacting with a substance to be detected, and a glass tube in which the detector agent is sealed and through which the substance to be detected passes. The method for reading the indicated value includes the steps of acquiring an image of the detector tube, detecting a marking attached to the glass tube from the image of the detector tube, detecting the boundary between the detector agent that has reacted with the object to be detected and the other detector agent based on the degree of discoloration of the detector agent, and reading the indicated value of the detector tube from the positional relationship between the detected marking and the boundary line. [Brief description of the drawings]

[0009] [Figure 1] 1 is a block diagram of an indication value reading device according to an embodiment of the present invention. [Diagram 2] FIG. [Diagram 3] FIG. 3 is a cross-sectional view of a detector tube. [Figure 4] FIG. [Diagram 5]4 is a flowchart showing a process executed by the indication value reading device. [Figure 6] 4 is a flowchart showing a process executed by the indication value reading device. [Figure 7] FIG. 13 shows an image of a detector tube. [Figure 8] FIG. 10 is a diagram illustrating a detected memory. [Figure 9] FIG. 2 shows a frame defined on an image of a detector tube. [Figure 10] FIG. 13 illustrates an example of a filter. [Figure 11] FIG. 13 is a diagram for explaining filtering. [Figure 12] FIG. [Figure 13] FIG. 13 is a diagram showing a screen displaying, as an example, a calculation result of an indication value. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, the present embodiment will be described with reference to the drawings. In the description, a coordinate system consisting of an X-axis, a Y-axis, and a Z-axis which are mutually orthogonal will be appropriately used.

[0011] 1 is a block diagram of an indication value reading device 10 according to the present embodiment. The indication value reading device 10 is a device that reads indication values ​​shown in the memory of a detector tube. The detector tube is used to detect the concentration of harmful substances contained in the environment, such as formaldehyde.

[0012] 2 is an example of a plan view of a detector tube 100 that is the reading target of the indication reading device 10. The detector tube 100 is, for example, a detector tube for detecting harmful substances in the air.

[0013] As shown in FIG. 2, the detector tube 100 is a member whose longitudinal direction is the X-axis direction, and includes a glass tube 110 and a detecting agent 130 filled inside the glass tube 110.

[0014] Glass tube 110 is made of, for example, quartz glass, and is a cylindrical member with its longitudinal direction along the X-axis. The length of glass tube 110 (dimension along the X-axis) is about 10 cm, and the inner diameter is about 2 to 3 mm. Two ends 110a, 110b of glass tube 110 are sealed, isolating the internal space of glass tube 110 from the external space.

[0015] A small diameter section 110c, which is shaped so that the inner and outer diameters are small, is formed about 20 mm away from the end 110b of the glass tube 110. Also, a mark M and an arrow A1 pointing in the direction from the end 110b to the end 110a are printed on the surface of the glass tube 110. The mark M includes a zero line L1 indicating that the concentration of the detection target is zero.

[0016] Fig. 3 is a cross-sectional view showing an XZ cross section of the detector tube 100. As shown in Fig. 3, inside the glass tube 110, a plug 120 made of Teflon (registered trademark), a detecting agent 130, a molecular sieve 140, and a cotton plug 150 are arranged.

[0017] The plug 120 is made of a fluororesin that has excellent chemical resistance. The plug 120 has air permeability due to the fluororesin that is the material of the plug 120 being made porous. The plug 120 is shaped into a sphere with a radius slightly smaller than the inner diameter of the glass tube 110, and its position in the X-axis direction is determined by abutting against the inner wall surface of the small diameter portion 110c.

[0018] The detecting agent 130 is composed of a reactant that changes color by chemically reacting with the detection target substance, and a support that supports this reactant. As the support, a chemically stable granular material with a uniform size and shape is used. As the support, for example, silica sand with an average particle size of 100 to 180 μm is used. For this reason, the image of the detecting agent 130 is visually recognized as a mosaic pattern with non-uniform colors.

[0019] The molecular sieve 140 is a crystalline zeolite and functions as a desiccant, and the cotton plug 150 is a member made of cotton.

[0020] 2, the above-mentioned plug 120, detecting agent 130, molecular sieve 140, and cotton plug 150 are filled in the order of plug 120, detecting agent 130, molecular sieve 140, and cotton plug 150 from end 110a of glass tube 110. The detecting agent 130 is filled between plug 120 and molecular sieve 140, and its length in the X-axis direction is about 70 mm.

[0021] When using the above-mentioned detector tube 100, both ends 110a, 110b of the glass tube 110 are cut at the positions shown by the dashed lines in Fig. 2. As a result, openings 100a, 100b are formed at both ends of the glass tube 110 as shown in Fig. 4, and a gas such as air containing a substance to be detected (a gas to be detected) can pass through the inside of the glass tube 110 through these openings 100a, 100b.

[0022] In the detector tube 100, when the target gas passes through the inside of the glass tube 110 in the direction indicated by the arrow A1, the detecting agent 130 changes color in accordance with the concentration of the target substance contained in the target gas.

[0023] 4, the discoloration of the detecting agent 130 occurs from the upstream side to the downstream side of the glass tube 110. Therefore, the length of the discolored region 130a where the detecting agent 130 has discolored corresponds to the concentration of the detection target substance contained in the detection target gas.

[0024] Returning to Fig. 1, the indication value reading device 10 is realized by installing software on a terminal such as a tablet, a smartphone, etc. The indication value reading device 10 includes a CPU (Central Processing Unit) 51, a main memory device 52, an auxiliary memory device 53, an operation device 54, a display device 55, a camera 56, an interface 57, and a bus 58 that connects the above-mentioned components.

[0025] The CPU 51 executes the processes described below in accordance with the programs stored in the auxiliary storage device 53 .

[0026] The main storage device 52 includes a RAM (Random Access Memory) etc. The main storage device 52 is used as a working area for the CPU 51.

[0027] The auxiliary storage device 53 has a non-volatile memory such as a ROM (Read Only Memory), a semiconductor memory, etc. The auxiliary storage device 53 stores applications executed by the CPU 51, various parameters, and the like.

[0028] The operation device 54 is composed of, for example, a touch panel or a pointing device such as a mouse.

[0029] The display device 55 is a liquid crystal display and constitutes a GUI (Graphical User Interface) in cooperation with, for example, a touch panel constituting the operation device 54. The user of the indication value reading device 10 can give desired instructions to the CPU 51 by operating the operation device 54 while looking at the display device 55.

[0030] The camera 56 is equipped with an imaging element such as a CCD (Charge Coupled Device) sensor.

[0031] The interface 57 includes a wireless LAN interface, etc. The indication value reading device 10 can be connected to a network 60 such as the Internet via the interface 57.

[0032] Next, the operation of the indication value reading device 10 configured as described above will be described. Figures 5 and 6 are flowcharts showing a series of processes executed by the indication value reading device 10. When an instruction to start an application constituting the indication value reading device 10 is given via the operation device 54, the CPU 51 starts the application and executes a predetermined program.

[0033] First, the CPU 51 waits for input of the type of the detector tube 100 from the user (step S101). The type of the detector tube 100 is indicated, for example, by the model number of the detector tube to which the specifications of the detector tube 100 are linked. When the type is input (step S101: Yes), the CPU 51 accepts input of the temperature (step S102). Here, the temperature is the temperature in the working environment when the working environment is measured by the detector tube 100.

[0034] When a temperature is input (step S102: Yes), the CPU 51 judges whether the input temperature is within a preset temperature range (step S103). The temperature range is determined according to the type of the detector tube 100, and means the temperature range in which the detector tube 100 can be used.

[0035] If the input temperature is not within the preset temperature range (step S103: No), the CPU 51 resets the input temperature and waits for another input of temperature (step S102).On the other hand, if the input temperature is within the preset temperature range (step S103: Yes), the CPU 51 waits for the input of image information of the detector tube 100 (step S104).

[0036] Here, when an image of the detector tube 100 is captured by the camera 56 by the user of the indication value reading device 10, the CPU 51 acquires image information indicating that image (step S104: Yes).

[0037] When photographing the detector tube 100, it is desirable to photograph the detector tube 100 so that memory M is located in the center of the field of view of the camera 56 and the entire memory of the detector tube 100 shown in Figure 2 fits within the field of view. In addition, it is desirable to photograph the detector tube 100 so that only the lines excluding the numbers attached to memory M fit within the field of view of the camera 56.

[0038] When the CPU 51 acquires the image information, it cuts out an image to be used for reading the indication value from the image shown in the image information (step S105). Fig. 7 shows the cut-out image P1. In the image P1, the memory M is located at the center. In addition, a margin α1 is secured between the 0 line L1 and the outer edge of the image P1.

[0039] Next, the CPU 51 detects the memory M as an object from the image P1 (step S106). Fig. 8 is a diagram showing a schematic diagram of the detected memory M. The memory M is recognized by the CPU 51 as lines M0 to M7. The CPU 51 checks whether the number of memory lines defined in the specifications associated with the type of the detector tube 100 matches the number of the detected lines M0 to M7 (step S107).

[0040] If the number of memory lines does not match the number of lines M0 to M7, the CPU 51 determines that it is not possible to detect all memory lines (step S107: No).The CPU 51 then outputs an error message and ends the process.On the other hand, if the number of memory lines matches the number of lines M0 to M7, the CPU 51 determines that it has detected all memory lines (step S107: Yes), and adjusts the rotation angle of the image (step S108).

[0041] As can be seen from FIG. 8, the rotation angle of the image is adjusted by detecting the angle θ between the Y-axis indicating the up-down direction of image P1 and lines M0 to M7 detected from image P1, and rotating image P1 so that the magnitude of this angle θ is equal to or smaller than a threshold value.

[0042] Next, the CPU 51 detects the boundary between the discolored detecting agents 130 and the non-discolored detecting agents 130 from the image of the detecting agents 130 included in the image P1, and calculates the indicated value of the detecting tube 100 (step S109). In step S109, the CPU 51 executes a series of processes shown in the flowchart of FIG.

[0043] First, the CPU 51 sets a detection area for detecting the instruction value from the image P1 (step S201). As shown in FIG. 9 as an example, the CPU 51 defines a frame F1 including all memory lines of the memory M except the 0 line L1. The position of the frame F1 in the Y-axis direction is defined by the upper and lower ends of the memory lines of the memory M. The position of the frame F1 in the X-axis direction is defined to include the 0 line L1 and to include an area, for example, 1.5 memories away from the memory line farthest from the 0 line L1. The area surrounded by the frame F1 becomes the detection area.

[0044] Next, the CPU 51 sets a sample area (step S202). A portion of the image P1 in which the detecting agent 130 is not discolored or is as little discolored as possible is set as the sample area. It is preferable to set the sample area in the detection area defined by the frame F1, which is the farthest from the zero line L1. The larger the area of ​​the sample area, the more preferable it is. However, if the area of ​​the sample area is large, the sample area may overlap with the printed matter on the surface of the detector tube 100, or may be affected by the distortion of the outer edge of the cylindrical glass tube 110 during shooting. For this reason, a square frame F2 having sides 60% of the length of the frame F1 in the Y-axis direction is defined, and the area defined by the frame F2 is set as the sample area. The CPU 51 sets the frame F2 so that it is located at the +X side end of the detection area surrounded by the frame F1 and the center is located in the center of the frame F1 in the Y-axis direction.

[0045] Next, the CPU 51 creates a filter (step S203). Fig. 10 is a diagram showing an example of the filter FL1. The filter FL1 is for removing an image of the detecting agent 130 that has not changed color from the detection region surrounded by the frame F1, thereby reducing the amount of data in the reading process of the indicated value.

[0046] As shown in FIG. 8 and other figures, the detecting agent 130 does not have a clearly separated boundary between a region where discoloration has occurred (discolored region) and a region where discoloration has not occurred (primary color region). For example, as shown in FIG. 9, the detecting agent 130 discolors in a gradational manner from the 0 line L1 toward the +X direction. Therefore, the image of the detecting agent 130 includes a region R1 consisting of the detecting agent 130 that has completely discolored, a region R2 consisting of detecting agents 130 with different degrees of discoloration mixed therein, and a region R3 consisting of the detecting agent 130 that has hardly discolored at all. Therefore, the CPU 51 creates a filter FL1 to exclude the portion with a small degree of discoloration.

[0047] Specifically, the CPU 51 extracts an area having a color tone equivalent to that of the sample area surrounded by frame F2 from the detection area surrounded by frame F1, and creates a filter FL1 shown in Fig. 10. In the filter FL1, the areas shown in black in the figure indicate discoloration areas where discoloration has occurred, and the other areas indicate primary color areas where discoloration has not occurred.

[0048] Next, the CPU 51 uses a filter FL1 to filter the detection region (step S204). Fig. 11 is a diagram showing a schematic diagram of filtering. As shown in Fig. 11, filtering is performed to extract a region Q1 obtained by excluding the primary color region from the detection region surrounded by the frame F1.

[0049] Next, the CPU 51 performs image processing on the region Q1 (step S205). Specifically, the CPU 51 performs threshold processing to generate a binary image P2 in which, for example, discolored regions are shown in white and primary color regions are shown in black. Note that the regions excluded by the filter FL1 are processed as primary color regions.

[0050] Fig. 12 is a diagram showing the binary image P2 and a characteristic curve. As can be seen from Fig. 12, the CPU 51 integrates the luminance of pixels arranged in the Y-axis direction of the binary image P2, column by column, and calculates a characteristic curve showing the relationship between the integrated value obtained for each column and the position of each column in the X-axis direction (step S206). The characteristic curve shows a sharp change in value before and after a boundary line appearing on the detecting agent 130.

[0051] Next, the CPU 51 identifies the point where the value shown on the characteristic curve has changed in the +X direction by more than the threshold as the position of the boundary line appearing on the detecting agent 130 (step S207). In Fig. 12, the position of the boundary line is indicated by a straight line LS1. The threshold value can be determined based on the result of learning the positions of the characteristic curve and the boundary line.

[0052] Next, CPU 51 calculates an indication value indicated by memory M and the boundary line from the positional relationship between the X coordinate of the boundary line indicated by straight line LS1 in image P1 and the X coordinate of each of the memory lines constituting memory M (step S208). After calculating the indication value, CPU 51 ends the indication value calculation process shown in Fig. 5 (step S109) and displays the indication value calculation result on display device 55 (step S110).

[0053] Fig. 13 is a diagram showing a screen 55a that displays an example of the calculation result of the indicated value. As shown in Fig. 13, the CPU 51 displays the indicated value as a read value (step S110). The CPU 51 also displays the image P1 and the shooting date associated with the image P1 as the measurement date, as well as the shooting location. Furthermore, the CPU 51 also displays a correction value for the read value based on the temperature of the measurement environment. The correction value is calculated, for example, based on the difference between the temperature of the work environment in which the detector tube 100 is used and a reference temperature.

[0054] As described above, in the indication reading device 10 according to this embodiment, the indication value of the detector tube 100 can be obtained by photographing the detector tube 100. Therefore, compared to reading the indication value of the detector tube 100 visually, it is possible to read it without being influenced by the senses or skills of the user. Therefore, the read value of the detector tube 100 can be read uniquely without variation.

[0055] In this embodiment, the amount of data used for image processing can be reduced by filtering the detection area using the filter FL1 (step S204). Therefore, even if the specifications of the terminal such as a smartphone are low, it becomes possible to read the indication value without stress.

[0056] In this embodiment, a portion of the image P1 in which the detecting agent 130 is not discolored or is discolored as little as possible is set as a sample region, and the image of the sample region is used to create the filter FL1. Therefore, the image of the detecting agent 130 in which no discoloration has occurred can be effectively removed by using the filter FL1.

[0057] For example, it is possible to prepare the filter FL1 in advance, but the color of the detecting agent 130 of the detector tube 100 varies from lot to lot even for the same type. In this embodiment, a sample area is set and a filter FL1 is generated each time the indicated value is read. Therefore, regardless of the color variation of the detecting agent 130 that constitutes the detector tube 100, the amount of data can be accurately reduced.

[0058] In this embodiment, as shown in Fig. 13, the read value is displayed together with the captured image P1, etc. Therefore, the user of the indication value reading device 10 can compare the image P1 with the read value. This makes it possible to roughly check the reliability of the read value.

[0059] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-mentioned embodiments. For example, in the above-mentioned embodiments, as shown in Fig. 9, a frame F1 is defined whose size in the vertical direction (Y-axis direction) is determined by memory lines constituting a memory M. However, the present invention is not limited to this, and in the case where the memory lines are long in the Y-axis direction, the size of the frame F1 in the Y-axis direction may be about 60% of the size of the detector tube 100 in the Y-axis direction.

[0060] The size of the frame F1 in the X-axis direction is specified to include the 0 line L1 and an area 1.5 memory units away from the memory line farthest from the 0 line L1. This is just an example, and the frame F1 does not necessarily have to be specified to include an area 1.5 memory units away from the memory line farthest from the 0 line L1. For example, the size of the frame F1 can be determined appropriately depending on the type of detector tube 100 and the type of detector agent used. If the frame F1 becomes large, the calculation area becomes large, so it is preferable to specify the frame F so that it includes as many images as necessary of the detector agent in its original color without changing color even if the detector agent changes color to the full scale of the memory M.

[0061] The detector tube 100 shown in the above embodiment is an example. The detector tube to be read by the indication value reading device 10 can be of any type or detect any object, as long as the indication value is indicated by the boundary between discolored and undiscolored detecting agents. The number of memory lines of the memory M may be, for example, eight or more, depending on the object to be detected.

[0062] In the above embodiment, an RGB image made up of red, green, and blue pixels obtained by the camera 50 is used as the image P1. However, the present invention is not limited to this, and the characteristic curve may be calculated after the image P1 is converted into an HSV image.

[0063] In the indication reading device 10 according to this embodiment, for example, as shown in FIG. 13, the user can write comments in the memo field of the screen 55a.

[0064] Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and spirit of the invention, and are included in the scope of the invention and its equivalents described in the claims. [Explanation of symbols]

[0065] 10. Indicator reading device 50 Camera 51 CPU 52 Main memory 53 Auxiliary storage device 54 Operating device 55 Display device 55a Screen 56 Camera 57 Interface 58 Bus 60 Network 100 Detector tube 100a,100b opening 110 Glass tube 110a,110b end 110c small diameter section 120 Stopper 130 Detecting Agent 130a Discolored area 140 Molecular Sieve 150 Cotton plug M Memory α1,α2 margin F1, F2 frames FL1 Filter L1 0 line L2 limit line P1 Image P2 binary image Q1 area R1~R3 ​​area

Claims

1. A detector tube reading device having a detector agent that reacts with a detection target substance to change color, and a glass tube in which the detector agent is enclosed and through which the detection target substance passes, a memory detection means for detecting a memory attached to the glass tube from an image of the detector tube; a boundary detection means for detecting a boundary between the detecting agent that has reacted with the detection target substance and the other detecting agents based on the degree of discoloration of the detecting agent; a reading means for reading an indication of the detector tube based on a positional relationship between the memory detected by the memory detection means and the boundary line detected by the boundary detection means; Equipped with The boundary detection means An indication value reading device that identifies and extracts an area defined by the memory from the image, and detects the boundary line based on an extracted image showing the identified area.

2. The boundary detection means 2. The indication value reading device according to claim 1, wherein the boundary line is detected based on a characteristic curve obtained by integrating the feature amounts of pixels constituting the extracted image in a direction perpendicular to the arrangement direction of the memory included in the extracted image.

3. 3. The indication value reading device according to claim 2, wherein the characteristic amount is a luminance of a pixel.

4. The boundary detection means 4. The indication reading device according to claim 3, wherein the characteristic curve is obtained based on a binary image obtained by binarizing the extracted image.

5. the memory includes a zero line indicating that the concentration of the detection target substance is zero; The boundary detection means obtaining the color of the detecting agent that has not reacted with the detection target from a region of the extracted image that is furthest from the zero line; The indication reading device according to claim 1 , wherein the boundary line is detected from the extracted image in which areas having the same color as the color of the unreacted detecting agent have been excluded.

6. A method for reading an indication of a detector tube having a detecting agent that reacts with a detection target substance and changes color, and a glass tube in which the detecting agent is enclosed and through which the detection target substance passes, comprising the steps of: The indication value reading method includes: acquiring an image of the detector tube; detecting a mark attached to the glass tube from the image of the detector tube; detecting a boundary line between the detecting agent that has reacted with the detection target substance and the other detecting agent based on the degree of discoloration of the detecting agent; and reading an indication of the detector tube from the detected positional relationship between the memory and the boundary line, The step of detecting the boundary line includes identifying and extracting an area defined by the memory from the image, and detecting the boundary line based on an extracted image showing the identified area.

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