JPH10185650A - Method and apparatus for measuring gas absorption amount of gas absorber - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To make it possible to measure the transition of the gas absorption function of a gas absorber over time with a low-cost configuration. SOLUTION: A graduated cylinder 1 is arranged in an inverted state with an opening part downward in a water tank 4 containing water 3, and a graduated cylinder 1 is provided.
The air is accommodated in the sample accommodating space 5 above the water 3 in the inside, and the oxygen absorber 2 is arranged in the sample accommodating space 5. By measuring the displacement, the oxygen absorption amount of the oxygen absorber 2 is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for measuring a gas absorption amount of a gas absorber applied to, for example, measurement of an oxygen absorption amount by an oxygen absorber.

[0002]

2. Description of the Related Art Conventionally, a gas absorber has been used for the purpose of absorbing a specific gas in, for example, a closed container. As such a gas absorber,
For example, an oxygen absorber that absorbs oxygen in a bag in which food is sealed is known. This oxygen absorber suppresses deterioration or the like of food due to oxygen. Such a gas absorber needs to maintain the gas absorption function for a certain period of time or more. Further, it is necessary to have a gas absorption capacity of a certain amount or more. For this reason, the oxygen absorption function of the manufactured gas absorber is appropriately measured.

[0003] As a method for measuring the gas absorption function of a gas absorber as described above, conventionally, a gas absorber is disposed in a closed container containing a gas to be measured, and the gas concentration in the closed container is measured by the oxygen concentration. A method of measuring a gas concentration meter such as a meter and obtaining a gas absorption function based on the measurement result is adopted. Further, as another method, a gas absorber is arranged in a closed container containing a gas to be measured in the same manner, and a gas absorbing function is performed based on a change in weight of the gas container caused by absorbing the gas. The required method is adopted.

[0004]

However, in the above-mentioned method using the conventional gas densitometer, a different gas densitometer must be prepared for each gas absorber that absorbs a different gas, and the method lacks versatility. It has become. As a result, the cost is increased. In addition, this method
Since the sampled gas goes out of the system and is lost every time the measurement is performed, the number of measurements cannot be increased, and as a result, there is a problem that data indicating a detailed temporal change of the gas absorption function cannot be obtained.

Further, in the method utilizing the change in weight of the gas absorber, since the change in weight is minute, it is difficult to accurately measure the gas absorption function of the gas absorber. Furthermore, it has a problem that it is difficult to measure the transition of the gas absorption function of the gas absorber over time.

[0006]

According to a first aspect of the present invention, there is provided a method for measuring a gas absorption amount of a gas absorber, comprising: a container having an opening at one end; Disposed in an inverted shape with the opening in the tank,
A gas, for example, air is accommodated in the space above the liquid in the container, and a gas absorber having an absorption function for the gas, for example, an oxygen absorber is arranged in the space, and the gas absorber absorbs the gas. The amount of gas absorption of the gas absorber is obtained by measuring the displacement of the liquid level in the container accompanying the operation.

According to the first aspect of the present invention, the amount of gas absorbed by the gas absorber can be known from the change in the liquid level in the container, so that the measurement of the amount of gas absorbed can be easily performed. Further, the apparatus for carrying out this method can be applied to various types of gas absorbers that absorb different kinds of gases, and has high versatility. Further, the transition of the gas absorption function over time can be easily measured.

According to a second aspect of the present invention, there is provided an apparatus for measuring a gas absorption amount of a gas absorber, comprising a cylindrical portion having a lower end portion opened at a lower portion, and a sample accommodating space connected to a space in the cylindrical portion. A plurality of measurement containers having an upper part, provided at a position below these measurement containers, containing a liquid, a liquid tank for immersing the lower end of the cylindrical portion of the measurement container in the liquid, Liquid level detecting means for detecting a position of the liquid surface at which a gas absorber disposed in the sample accommodating space is displaced in accordance with an operation of absorbing gas in a space above the liquid surface in the cylindrical portion; Storage means for storing the liquid level information sequentially obtained from the detecting means together with time information; and arithmetic means for calculating a change in the gas absorption amount in the gas absorber based on the liquid level information and the time information. It is characterized by:

According to the second aspect of the invention, when measuring the gas absorption amount of the plurality of gas absorbers, the lower end of the cylindrical portion of the measuring container is immersed in the liquid in the liquid tank. A predetermined gas is filled in the sample accommodation space and the space above the liquid in the cylindrical portion, and a gas absorber is disposed in the sample accommodation space. Such a state is set in a plurality of measurement containers. With such a setting, the gas absorbing operation of each gas absorber is started.

When the gas absorber absorbs the gas, the liquid level, that is, the liquid level rises accordingly. The displacement of the liquid level is sequentially detected by the liquid level detecting means. The liquid level information obtained by this is stored in the storage means together with time information indicating the time when each liquid level information is detected. The calculating means obtains a transition of the gas absorption amount in the gas absorber based on the liquid level information and the time information.

In the present gas absorption measuring device, data indicating the transition of the gas absorption of the gas absorber can be automatically obtained by the above operation. Therefore, for example, even when a long-time measurement operation is required such that the measurement time reaches midnight, measurement data can be easily obtained without imposing a heavy burden on the operator. Further, it is possible to obtain data indicating a detailed temporal change of the gas absorption amount.

According to a third aspect of the present invention, in the apparatus for measuring a gas absorption amount of a gas absorber according to the second aspect, the liquid level detecting means is shared by a plurality of the measuring vessels. To this end, a moving means for sequentially moving the liquid level detecting means to a position corresponding to the cylindrical portion of each measuring container is provided.

According to the third aspect of the present invention, the liquid level detecting means is shared by a plurality of measuring containers, so that a low cost configuration can be achieved.

According to a fourth aspect of the present invention, in the apparatus for measuring a gas absorption amount of a gas absorber according to the second aspect of the present invention, the cylindrical portion of the measuring container is transparent, and the liquid level detection is performed. The means scans the image taken by the imaging means for taking an image of the cylindrical portion, and changes in brightness from the lower side to the upper side of the image taken by the imager, and the amount of change becomes equal to or greater than a predetermined value. Determining means for determining the initial position as the liquid level.

According to the configuration of the fourth aspect, the judging means determines the position of the boundary between the dark portion where the liquid exists in the cylindrical portion and the light portion where the liquid does not exist in the cylindrical portion. It is determined that the position is at the liquid level. At this time, the determination unit scans the image captured by the imaging unit for a change in brightness from the lower side to the upper side, and determines the first position where the amount of the change is equal to or more than a predetermined value as the liquid level. ing. By determining the liquid level by such a method, it is possible to accurately determine the liquid level without being affected by the vertical positional relationship between the imaging means and the liquid level, the meniscus, and the like.

According to a fifth aspect of the present invention, in the apparatus for measuring a gas absorption amount of a gas absorber according to the fourth aspect of the present invention, the imaging means performs the scanning along three or more virtual lines. Then, the liquid level determination values in each line are compared with each other, and the liquid level is determined based on only similar determination values.

According to the fifth aspect of the present invention, any one of the lines is determined by the presence of foreign matter or bubbles on the liquid surface, or by the presence of water droplets on the inner wall surface of the cylindrical portion of the measuring container. Even if the determination value of the liquid level in the step becomes an abnormal value, the influence of the abnormal value is suppressed, and the liquid level can be accurately determined.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. In the present embodiment, the present invention is applied to a method for measuring the amount of oxygen absorbed by an oxygen absorber that absorbs oxygen. First, the principle of the oxygen absorption amount measuring method will be described with reference to FIGS.

In the measurement of the amount of oxygen absorption, as shown in FIG. 1, an oxygen absorber (gas absorber) 2 is disposed in an elongated container having an open end, for example, a measuring cylinder 1, and the measuring cylinder 1 is In an inverted state, it is placed in a water tank (liquid tank) 4 filled with water (liquid) 3. In this state, a sample accommodating space 5 filled with air (gas) is formed in the upper part of the measuring cylinder 1. The oxygen absorber 2 is accommodated in the sample accommodation space 5, and the oxygen absorber 2 is held, for example, by a wire so as not to contact the water 3.

In the above state, when oxygen in the sample accommodating space 5 is absorbed by the oxygen absorber 2, the water level of the measuring cylinder 1 rises by the volume of the absorbed oxygen. Therefore, the measuring cylinder 1
If the water level in the inside is measured and the measurement result is recorded in a graph, it is possible to know the transition of the oxygen absorbing function of the oxygen absorber 2 over time as shown in FIG. In the measurement shown in the figure, measurement is performed for 24 hours.

The above-described method can be similarly applied to the measurement of a gas absorber having a different gas to be absorbed, as long as a liquid in which the gas is insoluble is appropriately used instead of the water 3. Therefore, the above method has high versatility and can cope with various kinds of gas absorbers at low cost. In the above method, the amount of gas absorbed by the gas absorber appears as a change in water level. By reading this, the transition of the gas absorption function of the gas absorber can be easily measured.

Next, a gas absorption amount measuring apparatus using the above method will be described. The present gas absorption amount measuring apparatus includes the measuring mechanism 11 shown in FIGS. The measurement mechanism unit 11 includes a measurement cell (measurement container) 12 and an imaging unit 1
3, a backlight part 14, a water tank (liquid tank) 15, and a housing part 16 for holding these parts.

A plurality of the measuring cells 12 are arranged at one end of the measuring mechanism 11 in the longitudinal direction of the measuring mechanism 11.

Each measuring cell 12 has a sample box 21 on the upper surface side of the housing 16 and a cylinder 22 on the lower surface side. As shown also in FIGS. 5A and 5B, the sample box 21 has a fixing part 23 fixed on the housing part 16 and a lid part 24 which can be opened and closed with respect to the fixing part 23. ing. With the lid 24 closed, the sample box 21
Inside, a sample chamber (sample accommodation space) 25 for disposing the sample, that is, the oxygen absorber 2 is formed.

To make the lid 24 openable and closable,
Is connected to the fixed part 23 by a hinge 26. An adjust fastener 27 for locking the lid 24 on the fixing portion 23 is provided at a position opposite to the portion where the hinge 26 is provided. Further, in order to ensure the sealing property of the sample chamber 25, double O-rings 28 are provided on the upper surface of the fixing portion 23.

A gas inlet 25a is formed in the upper wall of the lid 24. The gas inlet 25a
A rubber stopper 29 is provided for closing a. Rubber stopper 2
A rubber stopper holder 30 is fixed on the top wall of the sample box 21 around the sample stopper 9.
Inside, a rubber stopper cap 3 for fixing the rubber stopper 29 is provided.
1 is fitted. The portion inside the rubber stopper cap 31 on the rubber stopper 29 is a space. A seal cap 3 is provided outside the rubber stopper holder 30 so as to cover the outer surfaces of the rubber stopper holder 30 and the rubber stopper cap 31.
2 are fitted. Further, the space between the seal cap 32 and the upper surface of the lid portion 24 is sealed by an O-ring 33.

The cylinder 22 is formed of a transparent material, for example, glass, and is provided on the lower surface of the fixing portion 23 of the sample box 21 in a hanging manner. A flange-shaped connecting portion 34 is provided at the upper end of the cylinder 22, and the connecting portion 34 is fixed to the lower surface of the fixing portion 23 via an O-ring (not shown). A through hole 35 is formed in the lower wall portion and the connection portion 34 of the fixing portion 23, and the space in the cylinder 22 and the sample chamber 25 communicate with each other through the through hole 35.

The water tank 15 is provided at a position below the measurement cell 12 in the housing section 16 and contains water 3 as a liquid suitable for gas absorbed by the oxygen absorber 2. This water 3
Are colored to facilitate determination of the water level.

The water tank 15 is provided with a handle 1 shown in FIG.
7 can be moved up and down to a predetermined ascending position and a descending position by rotating. When the water tank 15 is placed in the raised position, the lower end of the cylinder 22
Immersed in On the other hand, when the water tank 15 is disposed at the lowered position, the upper end of the water tank 15 is located below the lower end of the cylinder 22. Thereby, the water tank 15 or the measurement cell 1
2 can be taken out from the measurement mechanism 11 by sliding it horizontally.

The imaging section 13 is provided at a position facing the cylinder 22 in the housing section 16 and is for moving the CCD camera (imaging means) 41 and the CCD camera 41 in the direction in which the measuring mechanism section 11 is juxtaposed. Camera moving unit (moving means)
42. The CCD camera 41 has a fixed viewing angle, and captures an image existing within the viewing angle, converts the captured image into an electric signal, and generates image data.

The camera moving section 42 has a moving base 43 provided with a CCD camera 41 on the upper surface side, and has a fixed base 44 fixed to the housing section 16 below the moving base 43. . Between the movable base 43 and the fixed base 44, a slide mechanism 45 for supporting the movable base 43 and for smoothly moving the movable base 43 with respect to the fixed base 44 is provided. In addition, the moving base 43 is provided with a step motor 46 that is a driving source of the moving base 43. This step motor 46
The drive shaft is provided with a pinion 47, and this pinion 4
7 is engaged with a rack 48 provided on the fixed base 44. Further, the guide member 4 provided on the fixed base 44
The guide rail 50 provided on the movable base 43 is inserted into the 9 guide groove 49a. With this structure, the moving base 43, that is, the CCD camera 41 is guided so that the moving direction is appropriate. Furthermore, a CCD camera 4
The cable 51 connected to 1 is held on a cable holding member 52 attached to the housing 16.

The backlight unit 14 includes a CCD camera 41
In order to assist the imaging operation of the image of the cylinder 22 by the camera, the imaging unit 13 is provided at a position facing the imaging unit 13 via the cylinder 22. The backlight unit 14 includes two upper and lower rod-shaped backlights, for example, fluorescent lights.
a.14b. These backlights 14a
As shown in FIG. 4B, 14b has a length that covers the range in which the measurement cells 12 are arranged.

Further, the present gas absorption amount measuring apparatus includes a measurement data processing section 61 shown in FIG. The measurement data processing unit 61 includes a personal computer (hereinafter, referred to as a personal computer) 62, a display device 63, and a printer 64. The personal computer 62 has a CPU (Central Process).
ing Unit) 65, ROM (Read OnlyMe
mory) 66, a RAM (Random Access Memory) 67, a hard disk device (hereinafter referred to as an HDD) 68 as a storage means, and a keyboard 69.

The CPU 65 constitutes an operation means.
Together with the CD camera 41, a liquid level detecting means is constituted. The step motor 46 is controlled so that the image of the cylinder 22 in each measurement cell 12 is sequentially captured by the CCD camera 41 in the imaging unit 13. Also, the CPU 65
Is the cylinder 22 imaged by the CCD camera 41
Is displayed on the display device 63, and the water level in the cylinder 22 that changes according to the oxygen absorbing operation of the oxygen absorber 2 is determined based on the image. The change in the water level with the passage of time is used as data as H
DD68 is stored. Further, based on this data, the amount of oxygen absorbed by the oxygen absorber 2 is obtained, and the data indicating the change in the water level, that is, the change in the amount of oxygen absorbed is displayed on the display device 63 as a graph, for example, in response to an operator request. , Or by the printer 64.

The RAM 67 has an area for storing a control program and a storage area when the CPU 65 performs various control operations. The HDD 68 is an external storage device for the RAM 67, and functions as a storage area for various data. The keyboard 69 is for the operator to input various commands.

The above-mentioned water level determination operation by the CPU 65 is as follows.
It is performed in the following order. FIG. 7 shows the following operation (2).
To (5) are shown with these numbers. (1) The analog image signal (NTSC voltage signal, 1 V _PP ) obtained from the CCD camera 41 is converted into grayscale image data (8 bits, 256 gradations). (2) In the grayscale image data, the image is horizontally scanned at a position lower than the start water level to detect the position of the cylinder 22. (3) A predetermined number of points are set at horizontal positions in the image of the cylinder 22, and a virtual search line L in the vertical direction passing through these points is set.

(4) The image of the cylinder 22 is scanned along each of the search lines L, and a predetermined number of water level values are detected. (5) An abnormal value is removed from the predetermined number of water levels, and a final water level is obtained from the average of the remaining numerical values. The operation (1) converts the image data from the CCD camera 41 into 8-bit, 256-gradation image data (A / D conversion; analog-digital conversion). If the contrast of the image is insufficient, enhancement processing such as primary differentiation, secondary differentiation or template matching of the image data is performed as appropriate. If the water 3 is colored as described above and the brightness of the image is clear, this processing is unnecessary.

In the operation (2), the start water level is the water level at the start of the measurement of the oxygen absorption amount of the oxygen absorber 2, and this water level is set by the amount of air injected into the sample chamber 25 of the sample box 21. .

In the operation (3), the cylinder 2
2 is divided into (n-1) pieces at equal intervals, for example, an area of 1/3 of the entire width of the cylinder 22, and n search lines L
Set. Here, n is set to n = 5.

In the operation (4), the image of the cylinder 22, which has been processed into a gray-scale image, is scanned along a search line L from a fixed position below to an upper position, and the lightness is checked. Then, the start position of the change when the brightness change amount first exceeds the set value is determined to be the water surface, that is, the water level.

The change in the brightness is as shown in FIG.
The state shown in (b) or the state shown in (c) is obtained for the cylinder 22 shown in (a). In the figure, A indicates a dark area, C indicates a light area, and B indicates a change area from a dark area to a light area, that is, a brightness change area. (A)
Depends on the color of the water 3 and the intensity of the lighting,
This is the case where the light 3 is not sufficiently shielded by the water 3, and FIG. In addition to the above light shielding, (b) or (c) depending on the difference in meniscus
State. (B) is a case where a liquid that easily wets the inner wall surface of the cylinder 22 is used, that is, (a), and (c) is a liquid that hardly wets the inner wall surface of the cylinder 22. It is the case when doing.

When the change in brightness is shown in FIG. 8B, for example, in the brightness change area B, as shown in FIGS. 9 to 11, the vertical positional relationship between the water surface and the CCD camera 41 is determined. The form of change in lightness differs depending on the type.
9 to 11, (a) schematically shows an image of the cylinder 22 taken by the CCD camera 41, (b) shows the position of the water surface in the case of (a), and (c) shows the water surface. (D) shows the positional relationship with the CCD camera 41, and (d) shows the change in brightness when the image of (a) is scanned from a lower fixed position to an upper position.

FIG. 9 shows a case where the CCD camera 41 is at a position higher than the surface of the water 3 (a position higher than the case of FIG. 10). At this position of the CCD camera 41, since the water surface is imaged by the CCD camera 41,
A brightness change region B ₁ and brightness change region B ₂ occurs in (d).

FIG. 10 shows a case where the CCD camera 41 is located near the water surface and at a position slightly higher than the water surface.
In this case, as in the case of FIG. 9, the brightness change area B _1.
B ₂ occurs. However, these brightness change areas B ₁ and B ₂
Since the CCD camera 41 is close to the surface of the water, the brightness change in the area B1 has a different form from the brightness change in the brightness change areas B ₁ and B ₂ .

FIG. 11 shows a case where the CCD camera 41 is at the same position as the water surface or at a position lower than the water surface. In this case, only one brightness change area B (the area B ₂ in FIG. 9, the area B ₁ in FIG. 10, or the area B _{2 in} FIG. 10)
Corresponding).

[0046] Therefore, CPU 65 is the brightness change region B ₁ represents in the case of FIGS. 9 and 10, also in the case of FIG. 11 by the brightness change region B, and detects the water level.

The operation (5) is for preventing erroneous detection of the water level due to the presence of foreign matter or bubbles on the water surface or the attachment of water droplets to the inner wall surface of the cylinder 22. The above abnormal value is removed by the CPU 65 as follows.

For example, as shown in FIG. 7, it is assumed that five search lines L are set, and numerical values a to e are obtained as numerical values indicating the water levels by searching on each of the search lines L. . In this case, it is determined whether or not each of the five numerical values is similar to each of the other four numerical values, and the degree of coincidence of the five numerical values with the other numerical values is determined. The similarity between the numerical values is determined by measuring in advance how many pixels in the image correspond to the amount of undulation on the water surface when there is no obstruction such as a foreign substance or a water drop, and determining the difference between the two numerical values to be compared. It is similar when the number of pixels is equal to or less than the number of pixels. In the example of FIG. 7, since the numerical value d is an abnormal value, the determination result is as follows. In addition, ○
Indicates that it can be used as a numerical value for calculating the water level, and ×
Indicates that it cannot be adopted, that is, it is an abnormal value.

A: a ≒ b a ≒ c a ≠ d a ≒ e: matching degree 3 → ○ b: b ≒ a b ≒ c b ≠ d b ≒ e: matching degree 3 → ○ c: c ≒ ac b c ≠ d c ≒ e: Matching degree 3 → ３ d: d ≠ ad ≠ b d ≠ c d ≠ e: Matching degree 0 → × e: e ≒ a e ≒ b e ≒ c e ≠ d: Matching degree 3 → ○ Therefore, in the above example, numerical values a, b,
The water level is determined using c and e.

When the water level is obtained from the five numerical values as described above, the water level can be obtained based on the similarity between the numerical values, as shown in FIG. 12 (a). In the case of similarity, there are a case where four numerical values are similar as shown in FIG. 6B, and in the case where three numerical values are similar as shown in FIGS. Figures (e) and (f)
When only two numerical values are similar to each other as shown in FIG. Therefore, when there are two or less similar numerical values, it is impossible to determine the water level.

The operation of the gas absorption amount measuring apparatus having the above configuration will be described below. When measuring the oxygen absorption amount of the oxygen absorber 2, the water tank 15 is arranged at the raised position, and the lower end of the cylinder 22 is immersed in the water 3 of the water tank 15. In this state, the oxygen absorber 2 is disposed in the sample chamber 25 of the sample box 21 in the measurement cell 12. In this case, the lid 24 of the sample box 21 is opened and the oxygen absorber 2
Is disposed in the sample chamber 25, the lid 24 is closed, and the lid is fixed by the adjustment fastener 27. As a result, the space where the sample chamber 25 is connected to the inside of the through hole 35 and the water 3 in the cylinder 22 is in a sealed state.

In the present embodiment, the oxygen absorber 2
It is formed in a circular sheet shape and is held upright in the sample chamber 25. Further, since the present gas absorption amount measuring apparatus includes 20 sample boxes 21..., It is possible to simultaneously measure 20 oxygen absorbers 2.

Next, surplus intake air is sucked out from the sample chamber 25 or, if insufficient, air is injected to substantially adjust the water level in the cylinder 22 to a predetermined measurement start water level. Sample room 2
As shown in FIG.
Performed by That is, the air amount is adjusted by removing the seal cap 32 on the upper surface of the sample box 21 and piercing the rubber stopper 29 with the injection needle 72a into the sample chamber 25. At this time, the operator performs the above-described processing while observing the image of the cylinder 22 captured by the CCD camera 41 and displayed on the display device 63. Therefore, this processing can be easily performed.

The CCD camera 41 has a fixed viewing angle and a fixed vertical position. Therefore, the measurement start water level is set in consideration of the imageable range of the CCD camera 41 and the rise of the water level due to the oxygen absorption of the oxygen absorber 2.

Thereafter, the keyboard 69 is operated by the operator.
Is turned on, the gas absorption amount measuring device starts measuring the oxygen absorption amount of each oxygen absorber 2. In this measurement, the CCD camera 41 is
2 to sequentially move to a position facing each cylinder 22 and sequentially capture images of each cylinder 22. For example, the imaging cycle for one cylinder 22 is set to 10 minutes, and measurement for up to four days is possible.

The image data of each cylinder 22 for each imaging cycle is sequentially stored in the HDD 68, and the CPU 65 determines the water level in each case based on the image data as described above. Thus, as shown in FIG. 14, for each oxygen absorber 2, the data D ₁ showing changes in the oxygen absorption amount over time is obtained. Note that data D
_2, of the data D ₁ transition, an approximate data which is linearly approximated in a range indicating the designated value or more variation.

Further, the CPU 65 sets the data D ₁ , D ₂
(A) the time required until the start of the oxygen absorption operation, (b) the time required until the oxygen concentration reaches zero, and (c) the oxygen absorption rate. Is determined.

Here, there are the following methods for obtaining (a) and (b), for example. A linear approximation data D _2, 0 cc line, and each of the first over time the absorption initiation time of the change amount of absorption of the specified value at the time to process a specified time an intersection point between oxygen content lines, as well A method of obtaining each required time as the end of absorption when the amount of change in the amount of absorption within the specified time falls below the specified value for the first time, that is, as the time when the oxygen concentration reaches zero is shown in FIG. ) And (b) are as follows.

Method: (a) 3 hours 46 minutes, (b) 16 hours 00 minutes Method: (a) 2 hours 30 minutes, (b) 17 hours 50 minutes Also, (c) shows the slope of the approximate data D ₂ Ask from. As a result of FIG. 14, it was 3.2 (cc / h).

Further, in order to confirm the quality of the water level determination operation by the present gas absorption amount measuring apparatus, the results of reading by the present gas absorption amount measuring apparatus and the results of visual inspection by the operator were compared for each changed water level. Almost the same reading results were obtained. Thereby, high reliability of the present gas absorption amount measuring device could be confirmed. As described above, the present gas absorption amount measuring apparatus can automatically measure the gas absorption amount for a large number of oxygen absorbers 2. Even when time measurement is required, measurement data can be easily obtained without imposing a burden on the operator.

The imaging unit 13 is connected to a plurality of measurement cells 12.
, So that a low-cost configuration can be achieved. In addition, the determination of the water level in the cylinder 22 is determined by CC
The image captured by the D camera 41 is scanned from the lower side to the upper side for changes in brightness, and the first position where the amount of change is equal to or greater than a predetermined value is determined to be the liquid level. It is possible to accurately determine the water level without being affected by the vertical positional relationship with the lens and the meniscus.

Further, since the above determination is made on a plurality of search lines, the presence of foreign matter or bubbles on the liquid surface
Alternatively, even if the determination value of the liquid level on any of the search lines becomes an abnormal value due to, for example, water droplets adhering to the inner wall surface of the cylindrical portion of the measurement container, the influence of the abnormal value is suppressed. Thus, accurate liquid level determination is possible.
In the present embodiment, five search lines are set. However, if three or more search lines are set, the above-described determination operation can be performed.

In the above description, in the method of detecting the amount of oxygen absorbed by the oxygen absorber 2 based on a change in the water level, the water level is detected by directly capturing an image of the cylinder 22 indicating the water level with the CCD camera 41. The method has been described. However, as a method of detecting the water level,
In addition, the following method can be adopted.

One of the methods is to arrange a light-emitting device and a light-receiving device to face each other via a cylinder 22,
That is, the fact that the amount of shading by the water 3 changes with a change in the water level is used. Specifically, as shown in FIG. 15, a laser emission source 81 and a collimator lens 82 are arranged on one side of a cylinder 22, and a condenser lens 83 and a light receiving element 84 are arranged on the opposite side via the cylinder 22. The configuration is as follows. In this configuration, the laser light emitted from the laser emission source 81 is converted into parallel light by the collimator lens 82 and is irradiated on the cylinder 22. Then, light indicated by the width W, which is not shielded by the water 3, is focused on the light receiving element 84 by the focusing lens 83. In this case, the intensity of the output signal of the light receiving element 84 changes according to the amount of received light, that is, the water level that determines the width W. Therefore, the water level can be detected based on the intensity of the output signal of the light receiving element 84.

As another example of the above configuration utilizing the change in the light blocking amount due to the change in the water level, as shown in FIG. 16, a linear light source 85 and a linear light receiver 86 are arranged to face each other via a cylinder 22. There are things. As the linear light source 85, a fluorescent lamp, an LED array, or the like can be used. Further, as the linear light receiver 86, a CCD line sensor, a photodiode array, or the like can be used.

As another method for detecting the water level, as shown in FIG. 17, a light beam 87 emitted from a light beam emitting means (not shown) is incident on the cylinder 22 and the light beam 87 is generated on the wall surface of the cylinder 22 by the light beam 87. There is one that utilizes the fact that the position of the spot 88 changes depending on the water level. As shown in FIG. 18, the position of the light spot 88 can be detected by an imaging device such as a CCD camera 41, for example. Alternatively, as shown in FIG. 19, the light can be detected by the light receiving element array 89. In the light receiving element array 89, independent light receiving elements 89a are arranged linearly, and a signal is output from the light receiving element 89a at a position where the light flux 87 is incident.

Still another method for detecting the water level is shown in FIG.
As shown in FIG. 7, a scale 91 for reading a water level is attached to the wall surface of a rectangular cylinder 90 corresponding to the cylinder 22, and the scale 91 is imaged by an imaging device such as a CCD camera 41 to detect the water level. . The cylinder 22 can of course be used as the rectangular tube 90.
From the point that the imaging of the rectangular tube 90 can be performed better.
You are using

In the above-described method for detecting the water level, the structure for implementing the method, that is, the liquid level detecting means is the same as the structure shown in FIG. By moving the cylinders to each other, they can be commonly used without being provided for each cylinder 22. Further, the above-described methods for detecting the water level are all compatible with the measurement cell 12 shown in FIG. 3, but if this measurement cell 12 is changed, FIGS.
6 can also be adopted.

In the method shown in FIG. 21, for example, a laser or ultrasonic displacement meter 101 is provided in the sample chamber 25, and a change in the water level is read by the displacement meter 101. As the displacement meter 101, a commercially available product can be used.

In the method shown in FIG. 22, a pair of electrodes 102, 102 facing the outer wall surface of the cylinder 22 are provided, and a water level is detected based on a change in capacitance caused by a change in the water level between the electrodes 102, 102. Things.

In the method shown in FIG. 23, a float type level meter 103 is arranged in the cylinder 22, and a change in the water level is detected by a change in the position of the float 103a.

In the method shown in FIG. 24, the water level is detected by the electric resistance level meter 104. In the electric resistance type level meter 104, in the resistance circuit 104a arranged in the cylinder 22, the electrode portion immersed in the water 3 comes into contact with the water pressure, and the resistance value decreases as the water level rises. Thus, the water level can be detected.

In the method shown in FIG. 25, the water level is detected by the optical fiber probe 105. FIG.
As shown in (2), in the optical fiber probe 105, if the tip is not immersed in the water 3, the light is reflected at the tip and returns to the emission side. On the other hand, if the tip is immersed in the water 3, light is transmitted into the water 3 without being reflected. In this configuration, when only a single optical fiber probe 105 is provided in the cylinder 22, it is possible to detect the arrival of the water level at a predetermined position. In addition, when the plurality of optical fiber probes 105 are arranged such that the tips thereof are positioned stepwise in the vertical direction, a change in water level can be detected.

The method shown in FIG. 26 is similar to the method shown in FIG. 23, in which the pointer 107 is attached to the float 106 floating on the water 3 in the cylinder 22, and
The scale 108 is mounted on the plane of the cylinder 22, and the water level is read by the position of the pointer 107 on the scale 108.

The gas absorption amount measuring method and the gas absorption amount measuring apparatus can be applied not only to the oxygen absorber 2 shown in the above example but also to the measurement of the gas absorption amount by other gas absorbers. It is.

[0076]

As described above, the method for measuring the amount of gas absorbed by a gas absorber according to the first aspect of the present invention comprises the steps of: placing a container having an opening at one end in a liquid tank containing a liquid; Are arranged in an inverted manner with the gas container in a space above the liquid in the container, and a gas absorber having an absorption function for the gas is arranged in the space. It is configured to obtain a gas absorption amount of the gas absorber by measuring a displacement of a liquid level in the container due to a gas absorbing operation.

Thus, it is possible to easily measure the gas absorption amount of the gas absorber. Further, the apparatus for carrying out this method can be applied to various types of gas absorbers that absorb different kinds of gases, and has high versatility. Further, there is an effect that the transition of the gas absorption function over time can be easily measured.

The gas absorption amount measuring device for a gas absorber according to the second aspect of the present invention has a cylindrical portion having an open lower end at a lower portion, and a sample accommodating space connected to the space in the cylindrical portion. A plurality of measurement containers having an upper part, provided at a position below these measurement containers, containing a liquid, a liquid tank for immersing the lower end of the cylindrical portion of the measurement container in the liquid, Liquid level detecting means for detecting a position of the liquid surface at which a gas absorber disposed in the sample accommodating space is displaced in accordance with an operation of absorbing gas in a space above the liquid surface in the cylindrical portion; Storage means for storing the liquid level information sequentially obtained from the detecting means together with time information; and arithmetic means for calculating a change in the gas absorption amount in the gas absorber based on the liquid level information and the time information. Configuration.

As a result, data indicating the transition of the gas absorption amount of the gas absorber can be automatically obtained. Therefore, for example, even when a long-time measurement operation is required such that the measurement time reaches midnight, measurement data can be easily obtained without imposing a heavy burden on the operator. Further, there is an effect that data indicating a detailed temporal change of the gas absorption amount can be obtained.

According to a third aspect of the present invention, in the apparatus for measuring a gas absorption amount of a gas absorber according to the second aspect, the liquid level detecting means is shared by a plurality of the measuring vessels. For this purpose, a moving means for sequentially moving the liquid level detecting means to a position corresponding to the cylindrical portion of each measuring container is provided.

Thus, in addition to the effect of the second aspect of the present invention, since the liquid level detecting means is shared by a plurality of measurement vessels, a low-cost configuration can be achieved. Play.

According to a fourth aspect of the present invention, in the apparatus for measuring the amount of gas absorbed by a gas absorber according to the second aspect of the present invention, the cylindrical portion of the measuring container is transparent, and the liquid level is detected. The means scans the image taken by the imaging means for taking an image of the cylindrical portion, and changes in brightness from the lower side to the upper side of the image taken by the imager, and the amount of change becomes equal to or greater than a predetermined value. And a determination means for determining the first position as the liquid level.

Thus, in addition to the effect of the second aspect, the liquid level can be accurately determined without being affected by the vertical positional relationship between the imaging means and the liquid level and the meniscus. There is an effect that there is.

According to a fifth aspect of the present invention, in the apparatus for measuring the amount of gas absorbed by the gas absorber according to the fourth aspect of the present invention, the imaging means performs the scanning along three or more virtual lines. In this configuration, the liquid level determination values in each line are compared with each other, and the liquid level is determined based on only similar determination values.

As a result, the final determination value of the liquid level becomes abnormal due to the presence of foreign matter or bubbles on the liquid surface, or the presence of water droplets on the inner wall surface of the cylindrical portion of the measuring container. This has the effect of suppressing the situation and enabling accurate determination of the liquid level.

[Brief description of the drawings]

FIG. 1 is a perspective view showing the principle of a method for measuring a gas absorption amount of a gas absorber according to the present invention.

FIG. 2 is a graph showing changes in the amount of oxygen absorbed by the oxygen absorber measured by the method shown in FIG.

FIG. 3 is a longitudinal sectional view showing a measuring mechanism in the gas absorption amount measuring device according to the embodiment of the present invention.

4A is a schematic plan view of the measurement mechanism shown in FIG. 3, and FIG. 4B is a schematic side view of the measurement mechanism shown in FIG.

5A is a longitudinal sectional view of a sample box of the measurement cell shown in FIG. 3, and FIG. 5B is a plan view showing a state where a lid of the sample box is removed.

FIG. 6 is a block diagram showing a measurement data processing unit in the gas absorption amount measuring device according to one embodiment of the present invention.

FIG. 7 is an explanatory diagram of a water level determination operation by the measurement data processing unit shown in FIG.

8 is an explanatory diagram showing a relationship between a water level position in a cylinder shown in FIG. 3 and a change in lightness obtained by scanning a grayscale image of the cylinder.

FIG. 9 shows an image of the cylinder taken by the CCD camera, the position of the water surface, the positional relationship between the water surface and the CCD camera, and the image of the cylinder when the CCD camera shown in FIG. 3 is at a position higher than the water surface. FIG. 9 is an explanatory diagram showing a change in brightness in a case.

10 shows an image of a cylinder taken by a CCD camera, the position of the water surface, the water surface and C when the CCD camera shown in FIG. 3 is located near the water surface and at a position slightly higher than the water surface.
FIG. 4 is an explanatory diagram showing a positional relationship with a CD camera and a change in brightness when an image of a cylinder is scanned.

FIG. 11 shows a case where the CCD camera shown in FIG. 3 is at the same position as the water surface or at a position lower than the water surface.
FIG. 4 is an explanatory diagram showing a captured image of a cylinder by a D camera, a position of a water surface, a positional relationship between the water surface and the CCD camera, and a change in brightness when an image of the cylinder is scanned.

FIG. 12A shows a case where all five numerical values indicating the water level obtained by the search operation are similar in the operation of determining the water level in the measurement data processing unit shown in FIG. 6; FIG. 12B is an explanatory diagram when the four numerical values are similar, FIG. 12C is an explanatory diagram when the three numerical values are similar, and FIG. 12D is a similar three numerical values. FIG. 12 (e) is an explanatory diagram of another example where the two are similar, and FIG. 12 (f) is an explanatory diagram of another example where the two are similar.

FIG. 13 is an explanatory diagram of an operation of injecting air into a sample chamber for adjusting a water level in a cylinder shown in FIG. 3;

FIG. 14 is data showing measurement results of the oxygen absorption amount of the oxygen absorber shown in FIG. 3, and is a graph showing transition of the oxygen absorption amount with time of the oxygen absorber.

FIG. 15 is an explanatory diagram of a method of detecting a water level using a change in the amount of light shielding accompanying a change in the water level, instead of the method shown in FIG. 3;

FIG. 16 is an explanatory diagram showing another example according to the method shown in FIG. 15;

FIG. 17 is an explanatory diagram of a method for detecting a water level using a change in the light spot position of a light beam accompanying a change in the water level, which is an alternative to the method shown in FIG. 3;

18 is an explanatory diagram of a method for detecting a light spot position in the method shown in FIG.

19 is an explanatory diagram of another method for detecting a light spot position in the method shown in FIG.

FIG. 20 is an explanatory diagram of a method of reading a change in water level on a scale instead of the method shown in FIG. 3;

FIG. 21 is an explanatory diagram of a method for detecting a change in water level using a laser or ultrasonic displacement meter, which is an alternative to the method shown in FIG. 3;

FIG. 22 is an explanatory diagram of a method for detecting a change in water level based on a change in capacitance, which is an alternative to the method shown in FIG. 3;

FIG. 23 is an explanatory diagram of a method for detecting a change in water level using a float type level meter instead of the method shown in FIG. 3;

FIG. 24 is an explanatory diagram of a method of detecting a change in water level using an electric resistance level meter instead of the method shown in FIG. 3;

FIG. 25 (a) is an explanatory view showing a state before immersing the probe in water in a method of detecting a change in water level using an optical fiber probe instead of the method shown in FIG. 3, and FIG. () Is an explanatory diagram showing a state after the probe is immersed in water.

FIG. 26 is an explanatory diagram of a method for detecting a change in water level by using a float and a scale instead of the method shown in FIG. 3;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Measuring cylinder (container) 2 Oxygen absorber (gas absorber) 3 Water (liquid) 4 Water tank (liquid tank) 5 Sample accommodation space 11 Measurement mechanism unit 12 Measurement cell (measurement container) 13 Imaging unit 14 Backlight unit 15 Water tank (liquid tank) 21 Sample box 22 Cylinder (cylindrical part) 25 Sample chamber (sample accommodation space) 29 Rubber stopper 35 Through hole 41 CCD camera (imaging means, liquid level detecting means) 42 Camera moving part (moving means) 65 CPU (arithmetic means, liquid level detecting means) 67 RAM (storage means) 68 Hard disk drive (storage means)

Claims (5)

[Claims] 1. A container having an opening at one end thereof is disposed in an inverted manner in a liquid tank containing a liquid with the opening facing down, and a gas is stored in a space above the liquid in the container. Along with disposing a gas absorber having an absorption function for the gas in the space, and measuring the displacement of the liquid level in the container due to the gas absorption operation of the gas absorber,
A method for measuring a gas absorption amount of a gas absorber, wherein a gas absorption amount of the gas absorber is obtained. 2. A plurality of measurement containers having a cylindrical portion having an open lower end at a lower portion and a sample accommodation space connected to a space in the cylindrical portion at an upper portion, and a lower portion of the measurement containers. A liquid tank for storing a liquid, and immersing a lower end portion of the cylindrical portion in the measurement container in the liquid; and a gas absorber disposed in the sample storage space in the cylindrical portion. Liquid level detecting means for detecting the position of the liquid surface which is displaced in accordance with the operation of absorbing gas in the space above the liquid surface; and storage means for storing liquid level information sequentially obtained from the liquid level detecting means together with time information. And a calculating means for calculating a transition of the gas absorption amount in the gas absorber based on the liquid level information and the time information. 3. A moving means for sequentially moving the liquid level detecting means to a position corresponding to a cylindrical portion of each measuring container in order to share the liquid level detecting means with a plurality of the measuring containers. The apparatus for measuring a gas absorption amount of a gas absorber according to claim 2, further comprising: 4. A cylindrical portion of the measuring container is transparent, and the liquid level detecting means includes an image capturing means for capturing an image of the cylindrical portion, and a lower side of the image captured by the image capturing means. 3. The apparatus according to claim 2, further comprising a determination unit that scans a change in the brightness from above to an upper side, and determines a first position where the change amount is equal to or more than a predetermined value as a liquid level. Gas absorption amount measurement device for gas absorber. 5. The imaging means performs the scanning along three or more virtual lines, compares liquid level determination values in each line, and performs liquid level determination based on only similar determination values. The apparatus for measuring a gas absorption amount of a gas absorber according to claim 4, wherein the apparatus determines a position.