JP2007285951A - Pressure sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pressure sensor for surely detecting a pressure in an enclosed container in a simple composition by being simply installed to the enclosed container. <P>SOLUTION: The pressure sensor 1 comprises: a variable volume part 2 for changing a volume in response to the pressure of a liquid L being in contact with an outer shell by floating in the liquid L stored in the enclosed container 20, possessing the outer shell formed of a flexible film 13 and sealing a gas inside; and a contact detection part 4 for detecting the liquid by contacting by being provided upward from the upper face of the variable volume part 2. The pressure sensor 1 rises and falls in the liquid by accompanying the pressure in the container 20 while holding vertically standing or substantially vertically standing attitude by setting a centroid downward. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a pressure in a sealed container that stores a liquid and a pressure detection device that detects the pressure of the liquid.

As the pressure detection device as described above, as shown in FIG. 1 of Patent Document 1, a container containing liquid is provided with a pressure guiding tube for guiding pressure from the inside of the container to the outside of the container. A device that measures pressure by installing a pressure sensor or the like at the tip is known.
JP-A-7-286886

  However, in the case of the pressure detection device as described above, the pressure guiding tube must be fixedly attached to the container, and an attachment seat for the attachment is required. Further, since the mounting seat or the like must be provided in a container or the like, the structure becomes complicated and the mounting work becomes complicated. Furthermore, there is a problem in that the cost increases because the container must be specially processed separately. In particular, when it is desired to simply detect whether or not the pressure is within a predetermined range, the preparation of the apparatus takes too much time and the usability is poor.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a pressure detection device that can be easily mounted and can be easily measured.

  In order to solve the above-mentioned problems, the present invention has an outer shell formed of a flexible film in a pressure detection device that detects a pressure in a sealed container that floats in a liquid and stores the liquid. In addition, a gas is sealed in the inside thereof, and a variable volume part whose volume changes in accordance with the pressure of the liquid in contact with the outer shell is provided above the upper surface of the variable volume part and comes into contact with the variable volume part. A contact detection unit that detects the liquid, and is configured to float and sink in the liquid with the pressure in the container while maintaining a vertical or substantially vertical posture by setting the center of gravity downward. A pressure detection device is provided.

  According to such a configuration, since the outer shell of the variable volume portion is formed of a flexible film and the gas is sealed therein, the pressure of the liquid in contact with the outer shell is changed. For example, the membrane contracts and expands to change the volume of the variable volume portion. If the volume of the variable volume section changes, the buoyancy applied to the variable volume section changes, so that the variable volume section and the contact detection section provided above the upper surface of the variable volume section float and sink. Here, the contact detection unit detects the liquid by coming into contact with the liquid, and whether the contact detection unit is submerged in the liquid from the output of the contact detection unit or is in contact with the liquid. It is possible to determine the floating state such as whether it floats above the surface and is not in contact with the liquid. As described above, since the floating state changes depending on the pressure of the liquid, according to the detection result of the contact detection unit, it is possible to detect the pressure of the liquid, that is, the pressure in the sealed container in which the liquid is stored. It becomes possible.

  For example, when the pressure in the container is increased from the initial state where the contact detection unit is located above the liquid level (not in contact with the liquid), the pressure of the liquid increases at the same time. Since the volume decreases, the contact detection unit descends. At a certain point in time, the contact detection unit comes into contact with the liquid level, and the liquid is detected in the contact detection unit. Since the predetermined pressure in the container when the liquid is detected is known in advance from calculation or the like, the pressure in the container at the detection time is the predetermined pressure based on the detection result of the contact detection unit. Can be detected.

  In addition, since the device is configured to maintain an upright or substantially upright posture, it is possible to avoid an unexpected situation in which the device falls down and the contact detection unit and the liquid come into contact with each other. In addition, in this apparatus, only the cable such as the power supply supplied to the contact detection unit and the output line for guiding the detection result to the outside of the container need only be pulled out of the container as necessary. It only needs to be put in, and the installation work becomes very simple.

  In the present invention, it is preferable that the variable volume section includes a gas adjusting section that can adjust the amount of gas sealed in the variable volume section.

  According to such a configuration, the initial volume of the variable volume portion can be maintained in an optimal shape even when the initial pressure of the inside of the container, that is, the liquid changes. Moreover, the pressure which a contact detection part detects can be easily set and changed by changing the initial volume of a variable volume part suitably.

  In the present invention, it is preferable that the center of gravity of the variable volume portion is formed so as to be positioned below, a support column extending upward from the variable volume portion is provided, and the contact detection unit is provided on the support column. .

  According to such a configuration, the apparatus can be surely kept upright or in a substantially upright posture by the same simple principle as so-called spilling. Moreover, if the position which attaches a contact detection part to a support | pillar is changed, the pressure which a contact detection part detects can be set and changed easily.

  In the present invention, the contact detection unit includes a first contact detection unit provided above and a second contact detection unit provided below the first contact detection unit, the first contact detection When the pressure in the container is a preset reference pressure, the liquid level of the liquid is located between the first contact detection unit and the second contact detection unit. It is preferable to be configured as described above.

  According to such a configuration, the pressure detected by the first contact detection unit is set as the upper limit value, the pressure detected by the second contact detection unit is set as the lower limit value, and the pressure in the container is centered on the reference pressure. Whether it is within the lower limit can be easily monitored.

  As described above, according to the present invention, it is possible to provide a pressure detection device capable of reliably detecting the pressure in the container only by a simple operation of putting the device into the sealed container storing the liquid.

  FIG. 1 is a cross-sectional view of a pressure detection device according to an embodiment of the present invention set in a container, and FIG. 2 is a cross-sectional view of the pressure detection device.

  The airtight container 20 storing the liquid L is provided with a lid 21 at the top thereof, and the pressure detection device 1 is introduced into the container from the lid 21 and the cable 6 of the pressure detection device 1 described later. Is led out from a cable through hole 21 a provided in the lid 21. The cable through-hole 21a of the lid 21 is subjected to a predetermined sealing process so that the inside of the container 20 can be kept airtight.

  The pressure detection device 1 is attached to a hemispherical variable volume portion 2 capable of keeping the inside in an airtight state, a support column 3 protruding upward from a substantially upper center of the variable volume portion 2, and an upper side of the support column 3. The first contact sensor 4 (first contact detection unit) and the second contact sensor (second contact detection unit) 5 attached below the first contact sensor 4 are arranged in the upright or substantially upright posture according to the same principle as the so-called rising up. Configured to keep up.

  Specifically, the variable volume portion 2 is made of stainless steel, carbon steel, or the like and has a substantially circular upper surface disk portion 10 that forms the upper surface, and similarly, a lower surface disk that is made of stainless steel, carbon steel, or the like and forms the lower surface. And a base column 12 projecting from the lower surface disk unit 11 toward the upper surface disk unit 10. The upper surface disk unit 10, the lower surface disk unit 11, and the base column 12 are connected to each other. The frame is formed by fixing by welding or screwing. In addition, the weight of the lower surface disk portion 11 is set so that the center of gravity of the variable volume portion 2 is positioned below.

  Here, as described above, the upper surface disc portion 10 and the lower surface disc portion 11 are made of a material having a relatively heavy specific gravity such as stainless steel, and the center of gravity of the entire pressure detection device 1 is designed to be positioned at the lower portion. The pressure detection device 1 can maintain an upright or substantially upright posture based on a principle similar to that of so-called rising up.

  Further, a flexible film 13 such as a rubber film is disposed over the entire circumference between the upper surface disk part 10 and the lower surface disk part 11, and this film 13 is disposed on the upper surface disk part 10. And the outer shell of the lower surface disk part 11 is attached with an adhesive or the like, so that the outer shell of the variable volume part 2 is formed, and the airtightness inside the variable volume part 2 is maintained. This film 13 is provided with an adjustment hole (gas adjustment part) 13a that can inject gas from the outside and adjust the amount thereof, such as a so-called navel used to adjust the air of a soft tennis ball or the like. The gas is sealed in the variable volume portion 2 from the adjustment hole 13a.

  The support 3 is for supporting the contact sensors 4 and 5. The support column 3 is formed in a cylindrical shape by a stainless or carbon steel tube sealed at both ends so as to be hollow, and is designed to have a sufficiently low density. Moreover, this support | pillar 3 is comprised so that division | segmentation into several parts 3a, 3b (support upper and lower half part) is possible, and the upper surface disk part 10, the 2nd contact sensor 5, and the 2nd contact sensor 5 of the variable volume part 2 by these parts. Are connected to the first contact sensor 4. Therefore, the support position of each contact sensor 4 and 5 with respect to the variable volume part 2 can be changed by changing the length of this part. In addition, joining of each part 3a, 3b of the support | pillar 3 and the contact sensors 4 and 5 is mentioned later.

  The length, thickness, and the like of the support column 3 are set so that the entire center of gravity of the pressure detection device 1 is located at the bottom from the viewpoint of preventing the pressure detection device 1 from falling down, and detected by the contact sensors 4 and 5. It is set as appropriate based on the difference between the upper limit pressure and the lower limit pressure desired. In the present embodiment, the support column 3 is set to have a length substantially equal to the diameter of the upper surface disk portion 10 of the variable volume portion 2. And the 1st contact sensor 4 is attached to the front-end | tip part of this support | pillar 3, and the 2nd contact sensor 5 is attached to the substantially intermediate part.

  Each of the first contact sensor 4 and the second contact sensor 5 is a known contact type level meter, and may be, for example, an electrode type level meter, but here, a capacitance type level meter is used. Yes. That is, both of the contact sensors 4 and 5 include electrode probes 41 and 51, and insulators 42 and 52 that hold the base ends of the electrode probes 41 and 51 and have a ground electrode (not shown) disposed thereon. When the liquid as the measurement object comes into contact with the electrode probes 41 and 51, changes in the resistance value and the capacitance value between the electrode probes 41 and 51 and the ground electrode are detected, and ON and OFF are switched. It is configured. Therefore, the contact sensors 4 and 5 are configured to output a detection signal (switched to ON) when the target liquid is in contact with the electrode probes 41 and 51.

  The detection signals detected by these contact sensors 4 and 5 are configured to be output to a controller (not shown) via the cable 6. The cable 6 is a metal sheath type cable that has flexibility and has a predetermined number of signal lines arranged in an electrically insulated state. The cables 6 connected to the upper and lower contact sensors 4, 5 are bundled together and led out of the container 20 through the cable through hole 21 a of the lid 21 provided in the container 20. The cable through-hole 21a is subjected to a predetermined sealing process as described above.

  On the other hand, the insulators 42 and 52 are columnar bodies provided with flange portions 42a and 52a protruding outward at the tip portions, and are made of an insulating material such as pottery. A fitting hole (not shown) substantially corresponding to the diameter of the column 3 is provided in the lower part of the insulator 42 of the first contact sensor 4, and the tip end portion of the column 3 is fitted into the fitting hole in a tight state. Thus, the first contact sensor 4 is supported by the support column 3. In addition, fitting holes (not shown) corresponding to the diameter of the column 3 are also arranged on the upper and lower portions of the insulator 52 of the second contact sensor 5 in a straight line. The second contact sensor 5 is supported by the support column 3 by fitting the distal end portions of the lower half 3a in a tight state.

  Next, a method of using the pressure detecting device 1 and its operation will be described with reference to FIGS. 1 and 3 to 6. 1 and FIGS. 3 to 5 are explanatory views showing the use state of the pressure detection device 1, and FIG. 6 is a view showing the outputs of the contact sensors 4 and 5 according to the pressure in the container 20. FIG.

  First, as shown in FIG. 1, the pressure detection device 1 is put into the liquid L stored in the container 20. The cables 6 are bound to each other and drawn out of the container 20 through the cable through hole 21 a of the lid 21 of the container 20. In the initial state in which the pressure in the container 20 becomes the reference pressure P0, as shown in FIG. 3, the variable volume portion 2 is substantially hemispherical, and the liquid level of the liquid L is Gas is appropriately injected into the variable volume portion 2 from the adjustment hole 13a so as to be positioned between the second contact sensors 5, and the positions of the parts 3a and 3b of the column 3 are adjusted.

  In the initial state as described above, the first contact sensor 4 does not detect the liquid, and only the second contact sensor 5 detects the liquid. Therefore, the output of the first contact sensor 4 is OFF, and the second contact sensor 5 The output of is ON.

  When the pressure in the container 20, that is, the pressure of the liquid L rises from this initial state, as shown in FIG. 4, the outer shell film 13 of the variable volume portion 2 is pushed by the surrounding liquid pressure and contracts inward, making it variable. The volume of the volume part 2 decreases compared with the normal pressure (indicated by a virtual line). If the volume of the variable volume portion 2 decreases, the buoyancy applied to the variable volume portion 2 decreases, so that the pressure detection device 1 sinks into the liquid. On the other hand, as the pressure detection device 1 sinks, the volume of the column 3 that sinks in the liquid L increases, and buoyancy is applied to the increased volume, so that the column 3 sinks in the liquid of the variable volume portion 2 and the column 3. When the sum of the buoyancy applied to the portion and the second contact sensor 5 submerged in the liquid is balanced with the weight of the pressure detection device 1, the pressure detection device 1 stops. That is, the pressure detection device 1 sinks until the amount of decrease in the volume of the variable volume portion 2 caused by the pressure increase in the container 20 is equal to the amount of increase in the volume of the portion of the column 3 that sinks in the liquid L. Go. When the pressure in the container 20 rises to P2, for example, the first contact sensor 4 sinks in the liquid, and the output from the first contact sensor 4 is switched to ON. Since the second contact sensor 5 remains submerged in the liquid, both of the contact sensors 4 and 5 output ON, and from this output result, the pressure in the container 20 has risen to the pressure P2 or higher. Can be determined.

  Conversely, when the pressure in the container 20, that is, the pressure of the liquid L is decreased, the outer shell film 13 of the variable volume portion 2 expands outward, the volume of the variable volume portion 2 increases, and the pressure detection device 1 Surface. Then, as shown in FIG. 5, when the pressure in the container 20 decreases to, for example, P1, the second contact sensor 5 is lifted from the liquid level, and the output of the second contact sensor is switched from ON to OFF. Therefore, both the contact sensors 4 and 5 output OFF, and it can be determined from this output result that the pressure in the container 20 has decreased to the pressure P1 or less.

  As described above, the pressure detection device 1 floats and sinks according to the pressure in the container 20, that is, the pressure of the liquid L, and the outputs of the contact sensors 4 and 5 change. be able to. That is, it is possible to easily determine whether or not the pressure in the container 20 is within the preset upper and lower pressure limits P1 and P2, for example, using the pressure detection device 1.

  Here, the upper limit pressure P2 detected by the first contact sensor 4 and the lower limit pressure P1 detected by the second contact sensor 5 are the buoyancy of the portion below the contact sensors 4 and 5 and submerged in the liquid L. In other words, since the product of the volume of the portion submerged in the liquid L and the density of the liquid L is the pressure when the weight of the pressure detection device 1 is balanced, the pressure difference between the upper and lower pressure limits P2 and P1 to be detected is It can be adjusted by the volume of the support 3 and the weight of the support 3 existing between the first contact sensor 4 and the second contact sensor 5. Further, the upper and lower limit pressures P1 and P2 can be appropriately changed by adjusting the parts 3a and 3b of the support column 3 to adjust the fixing positions of the contact sensors 4 and 5.

  As described above, according to the pressure detection device 1 of the present embodiment, the variable volume portion 2 whose volume changes according to the pressure in the container 20, that is, the pressure of the liquid L, and the liquid L provided in the upper portion thereof are in contact with the liquid L. The first contact sensor 4 and the second contact sensor 5 for detecting that the pressure is detected, and the center of gravity of the pressure detection device 1 is set at the lower portion to maintain the upright or substantially upright posture. Since it is configured to float and sink with fluctuation, the pressure in the container 20, that is, the pressure of the liquid L can be ensured simply by putting the pressure detection device 1 into the liquid L stored in the sealed container 20. And can be easily detected.

  In particular, according to the present pressure detection device 1, it is not necessary to install a pressure guiding tube or the like in the container 20, and only the cable associated with the contact sensor needs to be pulled out.

  In addition, since the adjustment hole 13a is provided in the membrane 13 of the variable volume portion 2 so that the amount of gas in the variable volume portion 2 can be changed as appropriate, the variable volume portion can be used without depending on the initial pressure in the container 20. The initial shape of 2 can be kept optimal.

  Further, the first contact sensor 4 and the second contact sensor 5 are provided, and when the pressure in the container 20 becomes the reference pressure, the liquid level of the liquid L is between the first contact sensor 4 and the second contact sensor 5. It is possible to monitor whether or not the pressure in the container 20 is within a predetermined range across the normal pressure.

  The pressure detection device 1 described above is an embodiment of the device according to the present invention, and the specific configuration and the like of the device can be changed as appropriate without departing from the spirit of the present invention. Is described below.

  (1) Although the same type of sensor is used for the contact sensors 4 and 5 in the above embodiment, different types of sensors may be used for these contact sensors.

  (2) In the above embodiment, the variable volume portion 2 is hemispherical, but this shape is not particularly limited and may be hemispherical or conical.

  (3) In the above-described embodiment, the case where the first contact sensor 4 and the second contact sensor 5 are provided as the contact sensors has been described. However, one or more contact sensors may be provided depending on the application. .

It is a schematic sectional drawing shown in the state where one embodiment of a pressure sensing device concerning the present invention was stored in a container. It is sectional drawing of the same apparatus. It is explanatory drawing which shows the installation initial state of the apparatus. It is explanatory drawing which shows the state which the apparatus settled. It is explanatory drawing which shows the state which the apparatus floated. It is explanatory drawing which shows the pressure in an airtight container, and the output condition of each contact sensor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pressure detection apparatus 2 Variable volume part 3 Support | pillar 4 1st contact sensor (1st contact detection part)
5 Second contact sensor (second contact detector)
6 Cable 10 Upper disk part (upper surface)
11 Lower surface disk part 13 Membrane 13a Gas adjustment hole (gas adjustment part)
20 container (sealed container)

In the present invention, the contact detection unit includes a first contact detection unit provided above and a second contact detection unit provided below the first contact detection unit, the first contact detection When the pressure in the container is a preset reference pressure, the liquid level of the liquid is located between the first contact detection unit and the second contact detection unit. The first contact detection unit and the second contact detection unit float and sink with respect to the liquid level as the pressure in the container changes with respect to the reference pressure. It is preferable to do this.

In order to solve the above-mentioned problems, the present invention has an outer shell formed of a flexible film in a pressure detection device that detects a pressure in a sealed container that floats in a liquid and stores the liquid. In addition, a gas is sealed in the inside thereof, and a variable volume part whose volume changes in accordance with the pressure of the liquid in contact with the outer shell is provided above the upper surface of the variable volume part and comes into contact with the variable volume part. and a contact detecting unit that detects the liquid, upright by the center of gravity is set downward, to, while maintaining a substantially upright posture, which is configured to sink-float in the liquid in with the pressure in the vessel The contact detection unit includes a first contact detection unit provided above and a second contact detection unit provided below the first contact detection unit, and the first contact detection unit and the first contact detection unit The two-contact detection unit is a standard in which the pressure in the container is set in advance. The liquid level of the liquid in the container is positioned between the first contact detection unit and the second contact detection unit, and the first contact detection unit and the second contact When the pressure in the container changes, the detector moves up and down due to a change in buoyancy associated with the change in volume of the variable volume part, and the pressure in the container is set in advance to the reference pressure. When the first contact detection unit sinks below the liquid level when the pressure is higher than a predetermined value, the pressure inside the container is lower than the second predetermined value set in advance than the reference pressure. A pressure detection device is provided, wherein the second contact detection unit is arranged so as to float above a liquid surface .

According to the present invention , the variable volume portion has an outer shell formed of a flexible film and has a gas sealed therein, so that a change in pressure of the liquid in contact with the outer shell is accompanied. the membrane shrinks, the volume of its changes expands. And if the volume of the variable volume part changes in this way, the buoyancy applied to the variable volume part changes, so the floating state of the contact detection part provided above the variable volume part and the upper surface of the variable volume part Will change .
Here, since the contact detection unit can detect the liquid by contacting the liquid, whether the contact detection unit is submerged in the liquid based on the output of the contact detection unit or above the liquid level. Therefore, it is possible to detect the buoyancy applied to the variable volume part and the volume of the variable volume part, and thus the pressure change of the liquid.
In particular, in the present invention, the contact detection unit includes a first contact detection unit positioned above the liquid level of the liquid in the container in a state where the pressure in the container becomes a reference pressure, and the container in the above state. And a second contact detection unit that is positioned below the liquid level inside the first contact detection unit and the second contact detection unit, as the pressure in the container changes. When the pressure in the container moves up and down due to a change in buoyancy associated with the volume change of the variable volume part and the pressure in the container becomes higher than the reference pressure by a first predetermined value or more, the first contact detection part is below the liquid level. On the other hand, when the pressure in the container is lower than the reference pressure by a second predetermined value or more, the second contact detector is arranged so as to float above the liquid level. Based on the output of the first contact detector and the second contact detector, the pressure in the container becomes the reference pressure. Or by at most a first predetermined value or more than the second predetermined value if it can be determined.
That is, when the pressure in the container is at the reference pressure, the first contact detection unit does not detect the liquid level, only the second contact detection unit detects the liquid level, and the pressure in the container is The first contact detection unit detects the liquid level if the reference pressure is greater than or equal to the first predetermined value, and the second contact detection unit is liquid if the pressure in the container is less than or equal to the second predetermined value than the reference pressure. The face is not detected. Therefore, in a state where the first contact detection unit detects the liquid level, the pressure in the container is equal to or higher than the first predetermined value than the reference pressure, and the second contact detection unit does not detect the liquid level. Then, it can be determined that the pressure in the container is equal to or lower than the second predetermined value with respect to the reference pressure, and the pressure in the container is equal to or higher than the first predetermined value or lower than the second predetermined value with respect to the reference pressure. It is possible to easily monitor whether it is.

When the pressure in the container 20, that is, the pressure of the liquid L rises from this initial state, as shown in FIG. 4, the outer shell film 13 of the variable volume portion 2 is pushed by the surrounding liquid pressure and contracts inward, making it variable. The volume of the volume part 2 decreases compared with the normal pressure (indicated by a virtual line). If the volume of the variable volume portion 2 decreases, the buoyancy applied to the variable volume portion 2 decreases, so that the pressure detection device 1 sinks into the liquid. On the other hand, as the pressure detection device 1 sinks, the volume of the column 3 that sinks in the liquid L increases, and buoyancy is applied to the increased volume, so that the column 3 sinks in the liquid of the variable volume portion 2 and the column 3. When the sum of the buoyancy applied to the portion and the second contact sensor 5 submerged in the liquid is balanced with the weight of the pressure detection device 1, the pressure detection device 1 stops. That is, the pressure detection device 1 sinks until the amount of decrease in the volume of the variable volume portion 2 caused by the pressure increase in the container 20 is equal to the amount of increase in the volume of the portion of the column 3 that sinks in the liquid L. Go. Then, when the pressure in the container 20 rises to, for example, P2 (reference pressure P0 + first predetermined value) , the first contact sensor 4 sinks in the liquid, and the output from the first contact sensor 4 is switched to ON. Since the second contact sensor 5 remains submerged in the liquid, both of the contact sensors 4 and 5 output ON, and from this output result, the pressure in the container 20 has risen to the pressure P2 or higher. Can be determined.

Conversely, when the pressure in the container 20, that is, the pressure of the liquid L is decreased, the outer shell film 13 of the variable volume portion 2 expands outward, the volume of the variable volume portion 2 increases, and the pressure detection device 1 Surface. Then, as shown in FIG. 5, when the pressure in the container 20 decreases to, for example, P1 (reference pressure P0− second predetermined value) , the second contact sensor 5 is lifted from the liquid surface, and the output of the second contact sensor is increased. Switch from ON to OFF. Therefore, both the contact sensors 4 and 5 output OFF, and it can be determined from this output result that the pressure in the container 20 has decreased to the pressure P1 or less.

And while providing the 1st contact sensor 4 and the 2nd contact sensor 5, when the pressure in the container 20 becomes the reference pressure P0 , the liquid level of the liquid L is the 1st contact sensor 4 and the 2nd contact sensor 5 configured so as to be positioned between, the first contact sensor 4, the pressure in the container 20 becomes higher first predetermined value or more than the reference pressure P0, when the pressure within said vessel 20 becomes P2 When the second contact sensor 5 is arranged to sink below the liquid level, the pressure in the container 20 is lower than the reference pressure P0 by a predetermined value or more, and the pressure in the container 20 becomes P1. Therefore , it is possible to monitor whether or not the pressure in the container 20 is within a predetermined range with the reference pressure P0 interposed therebetween.

Claims (4)

In a pressure detection device that floats in a liquid and detects the pressure in a sealed container storing the liquid,
A variable volume portion having an outer shell formed of a flexible film, in which a gas is sealed, and the volume changes according to the pressure of the liquid in contact with the outer shell;
A contact detection unit that is provided above the upper surface of the variable volume unit and detects the liquid by contact;
By maintaining the center of gravity at a lower position and maintaining an upright posture or an upright posture,
A pressure detection device configured to float and sink in the liquid with the pressure in the container.   The pressure detection device according to claim 1, wherein the variable volume portion includes a gas adjustment portion capable of adjusting an amount of gas sealed in the variable volume portion.   The center of gravity of the variable volume portion is formed so as to be located below, and a support column extending upward from the variable volume portion is provided, and the contact detection unit is provided on the support column. Or the pressure detection apparatus of 2.   The contact detection unit includes a first contact detection unit provided above and a second contact detection unit provided below the first contact detection unit, and the first contact detection unit and the second contact When the pressure in the container is a preset reference pressure, the detection unit is configured such that the liquid level of the liquid is positioned between the first contact detection unit and the second contact detection unit. The pressure detection device according to claim 1, wherein

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