JP4979635B2 - Airtightness determination device and airtightness determination method - Google Patents

Description

  The present invention relates to an airtightness determining device and an airtightness determining method for determining an airtight state of a sealed container.

  According to the results of the investigations so far, when the air conditioner of the switch that opens and closes the electric circuit of the power circuit / power device can be kept airtight, it is extremely unlikely to cause problems such as rusting and partial discharge. I know it. For this reason, by detecting the initial hermetic breakage, it becomes possible to suppress the electrical accident of the switch and to prolong the life by the initial repair. In view of this, an apparatus capable of detecting the inundation state inside the switch by an acoustic emission (AE) method by hitting sound has been developed and verified. The AE technique uses the fact that the frequency of sound changes when water accumulates, and detects inundation based on the change in AE frequency. There is also a device for inspecting the flooding inside the switch using ultrasonic waves. Patent Document 1 discloses an ultrasonic immersion detection device.

Patent Document 2 discloses a method of measuring an insulation resistance of a low-voltage circuit in a switch and determining a flooded state inside the switch according to the measured value.
Japanese Patent No. 3233858 JP 2000-46894 A

  However, the device based on the AE technique is capable of detecting an initial hermetic breakdown state easily and accurately when the switch is hot, because it is difficult to detect a small amount of moisture or is complicated and expensive. There is a problem that can not be. In addition, the ultrasonic water immersion detection device has a problem that it is difficult to detect without a water immersion amount of about 3 mm or more, and a sprayed state (moisture adhesion) cannot be detected.

  The present invention has been made in view of the above problems, and a main object thereof is to easily and accurately determine an airtight state of a sealed container.

In order to solve the above problems, the present invention is an airtightness determining device for determining the presence or absence of water in the inside of a sealed container, wherein the means for heating the outer surface of the sealed container and the inside of the sealed container are submerged. In this state, the temperature change according to the heating of the outer surface of the sealed container is detected in advance and stored, and the temperature change according to the heating of the outer surface of the sealed container to be determined whether there is water immersion is detected. And means for determining the presence or absence of water immersion based on the detected temperature change and a temperature change in a state where the inside of the sealed container is not submerged.
According to this configuration, it is possible to easily and accurately determine the flooded state of the sealed container.

Further, the present invention is an airtightness judging device for judging the presence or absence of water in the inside of the sealed container, the means for heating the outer surface of the sealed container, and a temperature change according to the heating of the outer surface of the sealed container. Means for detecting, and means for determining that there is moisture when the detected temperature change is reduced after the start of heating.
According to this configuration, the fact that the temperature of the outer surface decreases after the start of heating is due to the heat of vaporization due to the evaporation of moisture, and thus indicates the presence of moisture. According to this, it is possible to easily and accurately determine the flooded state of the sealed container.

Further, the present invention is an airtightness determination device, based on the detected temperature change, a means for specifying a time from the start of heating until the temperature change starts to increase, and based on the specified time And a means for determining the degree of water content inside the sealed container.
According to this configuration, it is possible to easily grasp the degree of water content inside the sealed container.

The present invention is also an airtightness determining device, wherein when the outer surface of the sealed container is heated, an air discharge pipe for discharging air leaking from the inside of the sealed container to the outside, and air is discharged from the air discharge pipe. And a means for notifying that the user is present.
According to this configuration, it is possible to determine whether or not the airtight state of the sealed container is maintained before determining whether or not the sealed container is flooded. It will be good.

  Further, the present invention is an airtightness determining device, characterized in that the means for notifying that the air is discharged from the air discharge pipe is a gas flow meter, a soap solution, or an underwater bubble confirmation device.

  The present invention includes an airtight determination method. In addition, the problems disclosed in the present application and the solutions thereof will be clarified by the column of the best mode for carrying out the invention and the drawings.

  According to the present invention, it is possible to easily and accurately determine the airtight state of the sealed container.

  Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings. The airtightness determination apparatus and the airtightness determination method according to the embodiment of the present invention heat the outer surface of a sealed container that has not been submerged in advance, detect and store temperature changes at that time, and then determine whether there is water immersion. The outer surface of the sealed container to be determined is heated, the temperature change at that time is detected, and the presence or absence of water in the target sealed container is determined based on both temperature changes. According to this, the airtight state of the sealed container can be determined easily and accurately.

≪Air switch structure and overview≫
In the present embodiment, an air switch is taken up as an example of a sealed container. An air switch is a large-sized device that opens and closes an electric circuit during normal operation of a power circuit / power device. In particular, air is sealed and stored inside the switch. An example of the structure of an air switch is disclosed in Japanese Patent Laid-Open No. 10-334775.

  FIG. 1 is a diagram illustrating an appearance of an air switch. Fig.1 (a) shows the example installed in the utility pole. FIG.1 (b) shows the example of the switch of a top cover. FIG.1 (c) shows the example of the switch of a lower surface cover.

  FIG. 2 is a diagram showing a configuration of an airtightness determination device 20 for diagnosing the presence and extent of air release from the air switch 1. In the sectional view of the air switch 1, a packing 4 is provided between the main body 2 and the lid 3, and the air switch 1 is sealed by the packing 4, in other words, the inner side and the outer side. The air flow between them is blocked. The packing 4 is obtained by processing various materials such as silicon rubber, urethane rubber, and butyl rubber. Next, an air passage 5 is provided between the main body 2 and the lid 3 in a portion corresponding to the outside of the container as viewed from the packing 4, and a seal 6 is attached to the outside of the air passage 5 to be sealed. The air passage 5 is a tube for securing a passage of air that leaks due to deterioration of the packing 4 or the like, and for example, a spring, a pore tube, or the like is used. For the seal 6, clay or tape is used.

  One end of the air discharge pipe 7 passes through the air passage 5, and a gas flow meter 8, a soap solution 9, and an underwater bubble confirmation device 10 are installed at the other end of the air discharge pipe 7. The gas flow meter 8 is provided with a forward / reverse counter so that the flow direction and flow rate of air can be understood, and the air temperature and humidity can be measured. The soap liquid 9 is filled in the other end of the air discharge pipe 7 and, when air comes out from the air passage 5 to the air discharge pipe 7, bubbles are formed into bubbles, thereby notifying air leakage (no airtightness). The underwater foam check device 10 is obtained by submerging the other end of the air release pipe 7 in water, and when air comes out from the air passage 5 to the air release pipe 7, it becomes an underwater foam, thereby causing air leakage. Notify (no airtightness). Although the gas flowmeter 8 is of course, the flow rate of the air can be confirmed visually by using the soap solution 9 and the underwater bubble confirmation device 10.

As an example of the air switch 1, the main body 2 uses SUS304L as a material and has a thickness of 2.0 mm. The internal pressure is 0.00 kg / cm ² G (G: gauge pressure = absolute pressure−atmospheric pressure). The estimated approximate value of the internal volume is 0.3 m (D) × 0.3 m (H) × 0.5 m (L) ≈0.05 m ³ . The following shows the thermal properties of the substance.

  The airtight breakage of the air switch 1 occurs almost entirely from the surface of the seal 6 between the main body 2 and the lid 3, and the following two are the main causes. One is that the lower part (especially the four corners) of the surface of the seal 6 where moisture is difficult to escape at the welded part of the main body 2 (the adhesion of the paint is weak due to residual stress) is most corroded, and this corrosion progresses and becomes airtight. Loss of function. However, when the main body 2 of the air switch 1 was made of mild steel, it was necessary to make an inspection object. However, since it has been changed to SUS material, it is considered that such hermetic failure does not occur. The other is that a compression set (which is said to leak at a strain of 10 to 20%) due to aged elasticity deterioration of the packing 4 (particularly, four corners) is generated and the hermetic function is lost.

  FIG. 3 is a flowchart showing a method for diagnosing an airtight state and a flooded state in the air switch 1. This diagnosis method may be performed by an operator using each device, or may be performed by a computer such as a notebook PC acquiring data from each device.

  First, the airtight state in the air switch 1 is diagnosed (S301). In the diagnosis of the airtight state, when the air temperature in the air switch 1 is increased, the internal pressure increases if the airtightness is maintained. Use the fact that it leaks out of the vessel or the air temperature inside the vessel is difficult to rise. In order to raise the air temperature in the air switch 1, the outer surface of the air switch 1 is heated by the heater W adjuster H (see FIG. 1C). In addition, natural measurement by the temperature difference between morning and noon in summer, negative pressure measurement by cooling in summer, measurement by blowing hot air and cold air, etc. can be considered.

  In order to detect the air leaking outside the apparatus, the equipment configuration shown in FIG. 2 is used. In this case, by using the gas flow meter 8, the soap liquid 9 or the underwater bubble confirmation device 10, not only the presence or absence of an airtight state, but also the degree of air leakage in the case of no airtightness (for example, divided into three stages) ) Visual diagnosis is also possible. The air temperature in the chamber is measured by attaching a thermocouple thermometer M to the outer surface of the air switch 1 (see FIG. 1C).

  If the airtight diagnosis result indicates that the airtightness is airtight (“airtight” in S302), it is determined to be normal (S303), and the diagnosis is terminated.

  On the other hand, if the result of the airtight diagnosis indicates that the airtightness is not airtight (“no airtight” in S302), there is a possibility that the inside of the device is inundated, so the inundated state in the device is diagnosed (S304). Focusing on the fact that a small amount of moisture (to the extent that it adheres to the inner surface of the vessel) is easily evaporated in order to diagnose the flooded state, the heat of vaporization (heat transfer surface) Detects the occurrence of temperature drop phenomenon). For water that exceeds the degree of water adhesion, the degree of water immersion (for example, several mm or more) is determined by the time it takes for the heat transfer surface to decrease in temperature and increase in temperature. can do.

  Specifically, as shown in FIG. 1 (c), first, the heater W controller H is installed on the bottom (lower surface cover) of the air switch 1, and the thermocouple thermometer M is connected to the air switch 1. Install at various locations on the outer surface. Next, heating is performed by the heater W controller H, and at that time, a temporal temperature change of each portion is measured by a thermocouple thermometer M. Then, the presence or absence of moisture and the degree of water immersion are determined from the measurement results. As the determination method, there are a method of checking the data of the measurement result itself, and a method of comparing the data of the measurement result with the data when there is no moisture measured in advance. In addition, the simulation experiment of the inundation diagnosis and the result will be described later.

  If the infiltration diagnosis result indicates no moisture (“No moisture” in S305), it is determined that the initial hermetic failure has occurred (S306), the lid 3 is tightened (S307), and the airtight state is diagnosed again. (S301). In the tightening of the lid 3, the tightening force of the lid 3 is adjusted, or the thickness of the packing 4 is increased by 10 to 20%.

  Next, when the result of the inundation diagnosis indicates that there is adhering moisture (“There is adhering moisture” in S305), it is determined that the hermetic breakdown has occurred for about one season (S308), and the inside of the vessel is first dried (S309). After that, the lid is tightened again (S307), and the airtight state is diagnosed again (S301).

  Further, when the inundation diagnosis result indicates the inundation number mm (“infiltration number mm” in S305), it is determined that repair is necessary at an early stage (S310), and after the repair, the airtight state is diagnosed again (S301).

  Further, if the inundation diagnosis result indicates that the inundation number is larger than the number of inundation mm (“greater than inundation number mm” in S305), it is determined that the repair is urgently required (S311), and after the repair, the airtight state is diagnosed again (S301).

≪Mock experiment and results≫
FIG. 4 is a diagram (cross-sectional view) showing an equipment configuration of an experiment simulating the bottom of the air switch 1. A SUS plate having the same thickness (about 2 mm) as the main body 2 of the air switch 1 is installed horizontally. Next, a water storage frame capable of storing water is provided on the inner surface side of the air switch 1. Then, a lamp heater H1 with an AL shade and thermocouple thermometers M1 to M6 (No. 1 to 6) are provided on the outer surface side, and a thermocouple thermometer M7 ( No. 7) is provided. The thermocouple thermometers M1 to M6 are arranged on a straight line at intervals of 1 cm in a direction away from the vicinity of the lamp heater H1. Although not shown in the drawing, the temperature data from the slidac that applies voltage (for example, 30 V) to the lamp heater H1 and the temperature data from the thermocouple thermometers M1 to M7 are sequentially input and stored, and the temperature from the data logger. It is assumed that a notebook PC (Personal Computer) or the like for inputting data and displaying a temporal change (trend) of temperature is also provided. In addition, these device configurations indicate the configuration of the airtightness determination device 21 for determining the inundation inside the air switch 1.

  FIG. 5 is a graph showing a result of the simulation experiment, that is, a temporal change in the outer surface temperature of the air switch 1 and shows temperature changes in the four cases according to the moisture content on the inner surface of the container. The elapsed time (minutes) from the start of heating is taken on the horizontal axis of each graph, and the outer surface temperature (° C.) of the air switch 1 is taken on the vertical axis. From the center to the lower part of each figure, changes in temperature measured by thermocouple thermometers M1 to M7 (No. 1 to 7) are shown. From the upper left to the lower right, no. The order is 7, 1, 2, 3, 4, 5, 6. And the graph which expanded the vertical axis | shaft is shown by the upper part of each figure so that the mode of the temperature change immediately after a heating start may be recognized notably.

  FIG. 5A shows a temperature change when the inner surface is dry air. In this case, since there is no moisture on the inner surface, the temperature does not decrease. In the graph of 6, the temperature stays constant for a while immediately after heating, and the temperature rises after about 2 minutes. Comparing the graphs, it can be seen that the longer the distance between the lamp heater H1 and the thermocouple thermometer M, the longer the time until the temperature starts to rise. According to this, the determination that the water immersion diagnosis result (S305) in FIG. 3 is “no moisture” is performed when the slope of the temperature change immediately after the start of heating is zero or positive.

  FIG. 5 (b) shows the temperature change when the inner surface is adhering to moisture. In this case, since the surface is deprived of heat of vaporization due to evaporation of moisture by heating, the surface temperature temporarily decreases. Then, after the inner surface is sequentially dried from the side closer to the lamp heater H1, the temperature rises with the same inclination as in the case of dry air in FIG. According to this, the presence or absence of slight moisture adhesion can be diagnosed by determining whether or not the slope of the temperature change graph immediately after the start of heating is negative.

  FIG.5 (c) shows a temperature change in case an inner surface is 1-2 mm of water immersion. In this case, like the water adhesion in FIG. 5 (b), the surface temperature temporarily decreases and eventually increases. However, the time from the start of heating to the temperature rise varies depending on the degree of moisture immersion. In other words, the degree of moisture immersion can be diagnosed based on the time required until the temperature rises. In addition, although there is no water in the measurement location of the thermocouple thermometer M7 (No. 7) which is just above the lamp heater H1 shown in FIG. 4, if the inside of the water storage frame is flooded, it will be affected by the water temperature. .

  FIG.5 (d) shows a temperature change in case an inner surface is 4-5 mm water immersion. In this case, as compared with the 1-2 mm water immersion in FIG. 5C, the depth of the water immersion increases, so it takes time until the outer surface temperature rises. And the temperature itself which raises with the increase in the amount of water immersion is suppressed low.

  According to the graphs of FIGS. 5B to 5D, when the infiltration diagnosis result (S305) in FIG. 3 is determined to be “attachment” or “immersion”, the slope of the temperature change immediately after the start of heating is negative. For example, no. If the time from the start of heating 6 to the temperature rise is within 2 minutes, it is determined as “water adhesion”, and if the time is 2 to 3 minutes, it is determined as “immersion number mm”, and the time is 3 If it is greater than or equal to minutes, it is determined that “larger than the number of submerged mm”. In this case, the time from the start of heating to the temperature rise may be determined by the operator by looking at the temperature change displayed on the notebook PC display, or the notebook PC sequentially acquires temperature data from the thermocouple thermometer M. Then, a program that is stored in the HDD and that specifies the timing at which the gradient of the temporal change in temperature becomes positive may be operated on the memory of the notebook PC.

  In addition, according to the result of another experiment conducted with carbon steel, it was found that the temperature in the uniform sprayed state is likely to decrease at the start of heating as compared to the state where it is not uniform and partially submerged. Moreover, in the case of carbon steel, since the thermal conductivity was large compared with the SUS board, it turned out that the fall of temperature is small at the time of a heating start.

  Separately from the method of determining for each graph as described above, the graph of dry air (temperature change in a non-immersed state) in FIG. 5A measured in advance and the graph of the diagnosis target (temperature change) are compared. You may make it determine by doing. When measuring the data in advance, it is divided into measurement conditions such as the manufacturer, model, material type and measurement position of the air switch 1 and the temperature change data is acquired in detail under the outside air temperature. For example, it is useful to store in a storage device such as a hard disk drive (HDD) of a notebook PC. In this case, it is assumed that a program that the notebook PC sequentially acquires temperature data from the thermocouple thermometer M and stores it in the HDD is operated on the memory of the notebook PC. And the temperature change of a diagnostic object is compared with the temperature change in the state which is not flooded on the same measurement conditions, For example, in the same position and the same time (elapsed time from a heating start) in the outer surface of the air switch 1 Judged from the temperature difference. That is, if the temperature difference is equal to or greater than a predetermined value, it is determined that the vehicle is in a flooded state. Further, a plurality of predetermined values serving as a reference may be set, and the amount of water immersion may be determined as a stepwise numerical range (for example, moisture adhesion, water immersion 1 to 2 mm, water immersion 3 to 4 mm, etc.).

  FIG. 6 is a diagram illustrating a configuration example of the airtightness determining device 22. The airtight determination device 22 is a device in which a planar heater H2 and a plurality of thermocouple thermometers M are fixed to a bottom surface of a container having a length of 15 cm, a width of 10 cm, and a depth of 3 cm by a spring. Rubber is applied to the edge of the container, and the inside of the container is filled with silica wool. If the main body 2 is a SUS material, the inside of the container is evacuated, but if the main body 2 is mild steel, a magnet can be used. For example, a 100 V power source or a lithium battery (about 30 to 40 W output) is used as the power source of the planar heater H2. In addition, a data logger and a notebook PC are connected to the thermocouple thermometer M, and temperature data is stored, a flood determination result is displayed, and the like. The results of the inundation determination are, for example, normal (airtight [dry air]), attention level 1 (with adhering moisture [low]), attention level 2 (with adhering moisture [high]), abnormal level 1 (inundation [1-2 mm) ], Abnormal level 2 (water immersion [2 to 4 mm]), abnormal level 3 (water immersion [greater than 4 mm]) and the like.

  Although the embodiment of the present invention has been described above, in order to make the data logger and notebook PC shown in FIG. 6 function, the program executed by the processing unit (CPU) is recorded on a computer-readable recording medium, It is assumed that the airtightness determination apparatus 22 according to the embodiment of the present invention is realized by causing a computer to read and execute the recorded program. Note that the program may be provided to the computer via a network such as the Internet, or a semiconductor chip or the like in which the program is written may be incorporated in the computer.

  According to the embodiment of the present invention described above, it is possible to realize an airtightness judgment device that is easy to handle and inexpensive as an on-site diagnostic tool, so that the cost associated with airtightness judgment inside the air switch 1 can be reduced. Can be reduced. Next, the reliability of the air switch 1 can be ensured by performing the air tightness determination inside the air switch 1 at any time using the air tightness determination device. In particular, since it is possible to detect an initial hermetic breakdown (a small amount of moisture), the life of the air switch 1 can be extended, which is very useful.

<< Other embodiments >>
Although the best mode for carrying out the present invention has been described above, the above embodiment is intended to facilitate understanding of the present invention and is not intended to limit the present invention. The present invention can be changed and improved without departing from the gist thereof, and equivalents thereof are also included in the present invention. For example, the following embodiments can be considered.

(1) In the above embodiment, the thermocouple thermometer M is arranged in a straight line in the simulation experiment to measure the outer surface temperature of the air switch 1, but the outer surface of the air switch 1 ( For example, one thermocouple thermometer M may be arranged at the bottom of the position No. 6 to measure the temperature change. According to this, it is possible to efficiently measure the temperature change and diagnose the flooded state. (2) In the above embodiment, the thermocouple is measured by a simulation experiment to measure the outer surface temperature of the air switch 1. Although the thermometers M are arranged in a straight line, the thermocouple thermometers M may be arranged in a distributed manner so as to cover the entire outer surface of the air switch 1 so as to measure the temperature change. According to this, it is possible to grasp the moisture distribution in the entire inner surface of the air switch 1. In that case, the thermocouple thermometer under the place where there is a water drop on the inner surface senses the evaporation of moisture, once decreases, and shows a unique temperature change that rises thereafter.

(3) In the above embodiment, the air switch 1 is shown and described as an example of a sealed container, but other switches such as a gas switch and a vacuum switch may be used.

(4) In the above-described embodiment, the method of comparing the temperature change in a state where the water is not submerged and the temperature change of the diagnosis target is mentioned, but another comparison may be performed. For example, the side and bottom of the air switch 1 are heated at the same time with two detectors, and the temperature is measured and compared, and the side and bottom of the air switch 1 are sequentially detected with one detector. A method of measuring and judging can be considered. According to this, it is possible to perform a comparison in a state where the environmental conditions of the outside world are the same.

It is a figure which shows the external appearance of an air switch, (a) shows the example installed in the utility pole, (b) shows the example of the switch of a top cover, (c) shows the example of the switch of a bottom cover Show. It is a figure which shows the structure of the airtight determination apparatus 20 for diagnosing the presence or absence and the extent of discharge | release of the air from the air switch 1. It is a flowchart which shows the diagnostic method of the airtight state in the air switch 1 and a flooded state. It is a figure (sectional drawing) which shows the apparatus structure (structure of the airtight determination apparatus 21) of the experiment which simulated the bottom part of the air switch 1. FIG. It is a graph which shows the time change of the outer surface temperature of the in-air switch 1, (a) shows a temperature change when an inner surface is dry air, (b) shows the case where an inner surface is moisture adhesion. A temperature change is shown, (c) shows a temperature change when the inner surface is 1 to 2 mm of water immersion, and (d) shows a temperature change when the inner surface is a water immersion of 4 to 5 mm. It is a figure which shows the structural example of the airtight determination apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Air switch 2 Main body 3 Lid 4 Packing 5 Air passage 6 Seal 7 Air discharge pipe 8 Gas flow meter 9 Soap liquid 10 Underwater bubble confirmation instrument 20, 21, 22 Airtightness determination apparatus M, M1-7 Thermocouple thermometer H Heater W controller H1 Lamp heater H2 Planar heater

Claims (10)

An airtight judgment device for judging the presence or absence of water in the inside of a sealed container,
Means for heating the outer surface of the sealed container;
Means for detecting and storing in advance a temperature change according to the heating of the outer surface of the sealed container in a state where the inside of the sealed container is not submerged;
Means for detecting a temperature change in response to the heating of the outer surface of the sealed container to be determined whether there is water immersion;
Means for determining the presence or absence of water immersion based on the detected temperature change and a temperature change in a state where the inside of the sealed container is not submerged;
An airtightness determining device comprising: An airtight judgment device for judging the presence or absence of water in the inside of a sealed container,
Means for heating the outer surface of the sealed container;
Means for detecting a temperature change according to the heating of the outer surface of the sealed container;
Means for determining the presence of moisture when the detected temperature change is reduced after the start of heating;
An airtightness determining device comprising: The airtight determination device according to claim 2,
Based on the detected temperature change, means for specifying a time from the start of the heating until the temperature change starts to rise;
Means for determining the degree of water content inside the sealed container based on the specified time;
An airtightness determining device further comprising: It is an airtight determination apparatus as described in any one of Claims 1 thru | or 3, Comprising:
When the outer surface of the hermetic container is heated, an air discharge pipe for discharging air leaking from the inside of the hermetic container; and
Means for notifying that air is discharged from the air discharge pipe;
An airtightness determining device further comprising: It is an airtight determination apparatus of Claim 4, Comprising:
Means for notifying that air is discharged from the air discharge pipe,
An airtightness determining device, characterized by being a gas flow meter, a soap liquid, or an underwater bubble confirmation device. An airtight judgment method for judging the presence or absence of water in the sealed container,
In a state where the inside of the sealed container is not submerged, the step of heating the outer surface of the sealed container in advance and detecting a temperature change according to the heating;
Heating the outer surface of the sealed container to be determined whether there is water immersion, detecting a temperature change according to the heating;
Determining the presence or absence of water immersion based on the detected temperature change and the temperature change in a state where the inside of the sealed container is not submerged;
An airtight judgment method characterized by executing An airtight judgment method for judging the presence or absence of water in the sealed container,
Heating the outer surface of the sealed container and detecting a temperature change according to the heating;
Determining the presence of moisture when the detected temperature change is reduced after the start of heating; and
An airtight determination method comprising: The airtight determination method according to claim 7,
Based on the detected temperature change, specifying the time from the start of the heating until the temperature change starts to rise,
Determining a degree of moisture content inside the sealed container based on the specified time;
Is further executed. An airtight determination method according to any one of claims 6 to 8, comprising:
Heating the outer surface of the sealed container, and determining whether air is discharged from the inside of the sealed container according to the heating; and
Detecting the temperature change when air is discharged from the inside of the sealed container to the outside;
An airtight judgment method characterized by executing The airtight determination method according to claim 9,
In the step of determining whether air is discharged from the inside of the sealed container to the outside,
An airtightness judging method using a gas flow meter, a soap liquid, or an underwater bubble confirmation device.

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