阅读说明：本技术 流量测量单元以及使用了该流量测量单元的气量计 (Flow rate measurement unit and gas meter using same ) 是由 杉山正树 片瀬博昭 永沼直人 于 2018-05-10 设计创作，主要内容包括：利用流量测量部(11)和截止阀(14)来构成流量测量单元(10),所述流量测量部(11)具有包括被测量流体的导入部(12a)和导出部(12b)在内的直管状的测量流路(12),所述截止阀(14)具有形成于导入部(12a)的阀座(17)和用于抵接于阀座(17)的阀芯(15)。通过将具有所述那样的结构的流量测量单元(10)用于气量计,从而无论气量计的形状如何,都能够进行稳定的流量测量,并且通过使流量测量部(11)与截止阀(14)一体化,从而能够简化气量计的构造,并且能够实现小型化。(A flow rate measurement unit (10) is configured by a flow rate measurement unit (11) and a shut-off valve (14), wherein the flow rate measurement unit (11) has a straight tubular measurement flow path (12) including an introduction section (12a) and a discharge section (12b) of a fluid to be measured, and the shut-off valve (14) has a valve seat (17) formed in the introduction section (12a) and a valve body (15) for abutting against the valve seat (17). By using the flow rate measurement unit (10) having the above-described structure for a gas meter, stable flow rate measurement can be performed regardless of the shape of the gas meter, and by integrating the flow rate measurement unit (11) and the shutoff valve (14), the structure of the gas meter can be simplified and the gas meter can be miniaturized.)

1. A flow measuring unit, wherein,

the flow rate measurement unit includes:

a flow rate measurement unit having a straight tubular measurement flow path including an introduction portion and a discharge portion of a fluid to be measured; and

and a shut-off valve having a valve seat formed in the introduction portion and a valve body configured to abut against the valve seat.

2. Flow measuring unit according to claim 1,

the shutoff valve includes a cylindrical portion that protrudes from the introduction portion and has an opening portion, and a drive device that drives the valve element fixed inside the cylindrical portion.

3. Flow measuring unit according to claim 2,

the driving device is a structure which utilizes a motor and a linear motion mechanism to move the valve core, the linear motion mechanism converts the rotary motion of the motor into linear motion,

the opening, the rotating shaft of the motor, the introduction portion, and the discharge portion are arranged substantially linearly.

4. A gas meter, wherein,

the gas meter includes:

a body comprising a gas meter inlet and a gas meter outlet for a fluid to be measured; and

a flow rate measuring unit according to any one of claims 1 to 3,

the lead-out portion is hermetically connected to the gas meter outlet.

5. A gas meter, wherein,

the gas meter includes:

a main body in which a gas meter inlet and a gas meter outlet for a fluid to be measured are arranged substantially linearly; and

a flow rate measuring unit according to any one of claims 1 to 3,

the lead-out portion is hermetically connected to the gas meter outlet.

6. A gas meter, wherein,

the gas meter includes:

a main body in which a gas meter inlet and a gas meter outlet for a fluid to be measured are arranged substantially linearly; and

a flow rate measuring unit according to any one of claims 1 to 3,

the opening portion is hermetically connected to the gas meter inlet.

7. A flow measuring unit, wherein,

the flow rate measurement unit includes:

a flow rate measurement unit having a straight tubular measurement flow path including an introduction portion and a discharge portion of a fluid to be measured; and

and a shut valve formed in the lead-out portion.

8. Flow measuring unit according to claim 7,

the stop valve includes: a cylindrical portion having one end connected to the lead-out portion and an outlet portion at the other end; a valve seat provided at an outlet portion of the cylindrical portion; a valve element configured to abut against the valve seat; and a drive device that drives the valve element fixed inside the cylindrical portion.

9. Flow measuring unit according to claim 8,

the driving device is a structure which utilizes a motor and a linear motion mechanism to move the valve core, the linear motion mechanism converts the rotary motion of the motor into linear motion,

the outlet section, the rotation shaft of the motor, the introduction section, and the discharge section are arranged substantially linearly.

10. A gas meter, wherein,

the gas meter includes:

a body comprising a gas meter inlet and a gas meter outlet for a fluid to be measured; and

a flow rate measuring unit according to any one of claims 7 to 9,

the outlet portion is hermetically connected to the gas meter outlet.

11. A gas meter, wherein,

the gas meter includes:

a main body in which a gas meter inlet and a gas meter outlet for a fluid to be measured are arranged substantially linearly; and

a flow rate measuring unit according to any one of claims 7 to 9,

the outlet portion is hermetically connected to the gas meter outlet.

12. A gas meter, wherein,

the gas meter includes:

a main body in which a gas meter inlet and a gas meter outlet for a fluid to be measured are arranged substantially linearly; and

a flow rate measuring unit according to any one of claims 7 to 9,

the introduction portion is hermetically connected to the gas meter inlet.

Technical Field

The present invention relates to a flow rate measurement unit for measuring a flow rate of a fluid such as a gas, and a gas meter incorporating the flow rate measurement unit.

Background

As for a flow meter such as a gas meter, a so-called electronic meter using an ultrasonic wave or a flow sensor is put to practical use, and as an application thereof, a flow rate measurement unit capable of individually measuring a flow rate and a gas meter using the flow rate measurement unit are proposed.

The gas meter incorporates a shutoff valve as a protective function member for monitoring the flow rate of the gas and shutting off the gas in the case of an abnormality.

Fig. 13 shows the gas meter as described above, and a flow rate measurement unit 403 is housed in a gas meter 400 having an inlet 401 and an outlet 402. A shutoff valve 405 is connected to the inlet 401, and the gas entering from the inlet 401 is diffused into the body of the gas meter 400 through a passage in the shutoff valve 405. The gas that is the fluid to be measured diffused in the main body of the gas meter 400 flows in from the inlet 403a of the flow rate measuring unit 403 and flows out from the outlet 403b connected to the outlet pipe 404 (see, for example, patent document 1).

As another embodiment, a gas meter 500 as shown in fig. 14 is also proposed. The gas meter 500 is configured such that a shutoff valve 502 and a flow rate measurement unit 503 are externally attached to a middle portion of a straight pipe-shaped pipe 501 (see, for example, patent document 2).

Disclosure of Invention

However, in the gas meter described in patent document 1, since the flow rate measurement unit 403 and the stop valve 405 are separated from each other, the gas diffused into the gas meter 400 through the stop valve 405 flows into the flow rate measurement unit 403 from each direction, and therefore, the inflow state of the gas flowing into the flow rate measurement unit 403 is difficult to be constant due to the influence of the shape and size of the inside of the gas meter 400, and it is necessary to optimize the shape, the flow rate coefficient, and the like of the flow rate measurement unit 403 one by one in accordance with the shape of the body of the gas meter.

In the case of the gas meter described in patent document 2, an opening 501a for attaching the flow rate measurement unit 503 and an opening 501b for attaching the shutoff valve 502 are formed in the pipe 501. Therefore, there is a problem that the gas meter is difficult to be miniaturized. Alternatively, it is necessary to ensure airtightness against gas leakage in the openings 501a and 501b, respectively, and therefore there is a problem that the sealing structure is complicated.

The invention provides a flow rate measuring unit which has a shut-off function, can perform stable flow rate measurement regardless of the shape of a built-in gas meter, and can realize miniaturization of the gas meter.

The flow rate measurement unit of the present invention includes: a flow rate measurement unit having a straight tubular measurement flow path including an introduction portion and a discharge portion of a fluid to be measured; and a shut valve having a valve seat formed in the introduction portion and a valve body configured to abut against the valve seat.

With this configuration, since the flow of the gas from the stop valve to the measurement flow path is constant, stable flow measurement can be performed regardless of the shape of the gas meter, and the gas meter can be downsized by integrating the flow measurement unit and the stop valve.

Further, a flow rate measurement unit of the present invention includes: a flow rate measurement unit having a straight tubular measurement flow path including an introduction portion and a discharge portion of a fluid to be measured; and a shut valve formed in the lead-out portion.

With this configuration, since the flow of the gas flowing through the shutoff valve is constant, stable flow rate measurement can be performed regardless of the shape of the gas meter, and the gas meter can be downsized by integrating the flow rate measurement unit and the shutoff valve.

Drawings

Fig. 1 is a side view of a flow rate measurement unit according to embodiment 1 of the present invention.

Fig. 2 is a sectional view of a flow rate measurement unit according to embodiment 1 of the present invention.

Fig. 3 is a sectional view of a gas meter using a flow rate measurement unit according to embodiment 1 of the present invention.

Fig. 4 is a sectional view of another gas meter using the flow rate measurement unit according to embodiment 1 of the present invention.

Fig. 5 is a sectional view of another gas meter using the flow rate measurement unit according to embodiment 1 of the present invention.

Fig. 6 is a main portion sectional view of fig. 5.

Fig. 7 is a side view of a flow rate measurement unit according to embodiment 2 of the present invention.

Fig. 8 is a sectional view of a flow rate measurement unit according to embodiment 2 of the present invention.

Fig. 9 is a sectional view of a gas meter using a flow rate measurement unit according to embodiment 2 of the present invention.

Fig. 10 is a sectional view of another gas meter using the flow rate measurement unit according to embodiment 2 of the present invention.

Fig. 11 is a sectional view of another gas meter using the flow rate measurement unit according to embodiment 2 of the present invention.

Fig. 12 is a main portion sectional view of fig. 11.

Fig. 13 is a cross-sectional view of a gas meter using a conventional flow rate measurement unit.

Fig. 14 is a sectional view of a gas meter using another conventional flow rate measurement unit.

Detailed Description

Hereinafter, a flow rate measurement unit according to an embodiment of the present invention and a gas meter using the flow rate measurement unit will be described with reference to the drawings. The same components are denoted by the same reference numerals. The components already described are not described again. The embodiments described below do not limit the present invention.

In this specification, a gas meter is connected to a pipe for transporting a fluid and measures the flow rate of the fluid flowing through the pipe. The gas meter is equipped with a flow rate measurement unit that measures the flow rate of the fluid. That is, the flow measuring unit is provided as a component of the gas meter. Hereinafter, first, a detailed configuration of the flow rate measurement unit will be described, and then, a gas meter equipped with the flow rate measurement unit will be described.

(embodiment 1)

Fig. 1 is an external side view of a flow rate measurement unit according to embodiment 1. Fig. 2 is a sectional view of the flow rate measurement unit of embodiment 1.

The flow rate measuring unit 11 constituting the flow rate measuring unit 10 is formed of a measuring flow path 12 and a flow rate measuring block 13, the measuring flow path 12 having an introduction portion 12a and a discharge portion 12b of gas as a fluid to be measured, and the flow rate measuring block 13 measuring a flow rate of the gas flowing through the measuring flow path 12.

The flow rate measurement unit 11 uses a measurement method using ultrasonic waves. Specifically, the time during which, for example, an ultrasonic wave transmitted from one ultrasonic transceiver 13a into the measurement channel 12 propagates through the gas, is reflected by the inner wall 12c of the measurement channel 12 facing the one ultrasonic transceiver 13a, and further propagates through the gas until the ultrasonic wave is received by the other ultrasonic transceiver 13b is measured using the pair of ultrasonic transceivers 13a and 13b provided in the flow rate measurement module 13. Then, the flow velocity of the gas is obtained from the time, and finally the flow rate of the gas is obtained.

A shutoff valve 14 is provided upstream of the measurement channel 12. The shutoff valve 14 includes a valve body 15, a drive device 19 for the valve body 15, a valve seat 17 formed in the introduction portion 12a, and a cylindrical portion 18 for holding the drive device 19. The valve element 15 is moved by the driving device 19 to abut against the valve seat 17, thereby shutting off the gas.

The driving device 19 includes a motor 16 and a linear motion mechanism, the motor 16 includes a stator 16a, a rotor 16b, and a rotary shaft 16c, and the driving device 19 moves the valve body 15 by converting rotation of the rotary shaft 16c into linear motion by screwing a female screw 15a of the valve body 15 to a male screw 16d provided at a tip end of the rotary shaft 16 c.

Here, the cylindrical portion 18 may be integrally molded with the measurement flow path 12 by resin, or the cylindrical portion 18 may be separately molded by resin and bonded to the measurement flow path 12. Further, a passage through which the gas passes is formed as a gap between the inner wall 18a of the cylindrical portion 18 and the outer periphery of the driving device 19, and the gas is introduced into the measurement flow path 12 through a path as indicated by an open arrow. An opening 18b is formed at the gas inlet of the cylindrical portion 18, the driving device 19 is inserted into the cylindrical portion 18 through the opening 18b, and the flange 16e of the driving device 19 is fixed to the fixing portion 18c of the cylindrical portion 18 by screws or the like, not shown.

As described above, since the flow rate measurement unit 10 according to the present embodiment has the shutoff function, the flow rate measurement unit 10 can be incorporated into a gas meter to measure and shut off the fluid. Further, by positioning the valve body 15 in the vicinity of the upstream of the introduction portion 12a of the measurement flow path 12, the gas flows uniformly into the measurement flow path 12 due to the flow rectification effect achieved by the valve body 15, and therefore, stable flow rate measurement can be performed.

Even if the flow state of the gas flowing into the flow rate measurement unit 10 varies depending on the size and shape of the internal space of the gas meter, the influence on the flow rate measurement can be reduced by the flow rectification effect of the valve body 15, and 1 flow rate measurement unit 10 can be used for gas meters of various shapes.

Fig. 3 shows a cross-sectional view of a gas meter 100 in which the flow rate measurement unit 10 is assembled, the flow rate measurement unit 10 is built in a gas meter main body 103 having a gas meter inlet 101 and a gas meter outlet 102, and the opening 18b is connected to a connection member 104 connected to the gas meter inlet 101. In this configuration, gas as a fluid to be measured flows out from the gas meter inlet 101 through the coupling member 104, passes through the flow rate measurement unit 10, and flows out from the gas meter outlet 102, as indicated by hollow arrows indicated by broken lines.

As described above, the flow rate measurement unit 10 according to the present embodiment is incorporated in a gas meter, and a gas meter with a shutoff function can be easily realized.

Fig. 4 shows a gas meter 200 incorporating another example of the flow rate measurement unit 10 of the present embodiment. As shown in fig. 4, a flow rate measurement unit 10 is incorporated in a gas meter main body 203 in which a gas meter inlet 201 and a gas meter outlet 202 are linearly arranged, and a lead-out portion 12b of the flow rate measurement unit 10 is directly and airtightly connected to the gas meter outlet 202 via a mounting member 20.

With the gas meter 200 configured as described above, the gas meter main body can be further downsized as compared with the gas meter 100 shown in fig. 3. Further, the gas meter can be attached to the middle of the linear pipe, and the degree of freedom of installation is improved.

Fig. 5 shows a gas meter 300 incorporating another example of the flow rate measurement unit 10 of the present embodiment. As shown in fig. 5, a coupling member 30 for coupling the gas meter inlet 301 is connected to the opening 18b of the flow rate measurement unit 10. A gas meter outlet 302 is provided on a surface of the gas meter 300 opposite to the surface on which the gas meter inlet 301 is provided. Fig. 6 is a main-part sectional view of fig. 5 showing a state in which the coupling member 30 and the gas meter inlet 301 are joined to the flow rate measurement unit 10. As shown in fig. 6, the flow rate measurement unit 10 and the connection member 30 are hermetically connected to each other by an O-ring 31, and the connection member 30 and the gas meter inlet 301 are hermetically connected to each other by an O-ring 32.

With the gas meter 300 configured as described above, the gas meter main body can be further downsized as compared with the gas meter 100 shown in fig. 3. Further, the gas meter can be attached to the middle of the linear pipe, and the degree of freedom of installation is improved.

(embodiment 2)

Fig. 7 is an external side view of the flow rate measurement unit 40 of embodiment 2. Fig. 8 is a sectional view of the flow rate measurement unit of embodiment 2.

The flow rate measuring unit 41 constituting the flow rate measuring means 40 is formed of a measuring flow path 42 and a flow rate measuring block 43, the measuring flow path 42 having an introduction portion 42a and a discharge portion 42b of gas as a fluid to be measured, and the flow rate measuring block 43 measuring a flow rate of the gas flowing through the measuring flow path 42.

The flow rate measurement unit 41 uses a measurement method using ultrasonic waves. Specifically, the time during which, for example, an ultrasonic wave transmitted from one ultrasonic transceiver 43a into the measurement flow path 42 propagates through the gas, is reflected by the inner wall 42c of the measurement flow path 42 facing the one ultrasonic transceiver 43a, and then propagates through the gas until the ultrasonic wave is received by the other ultrasonic transceiver 43b is measured using the pair of ultrasonic transceivers 43a and 43b provided in the flow rate measurement module 43. Then, the flow velocity of the gas is obtained from the time, and finally the flow rate of the gas is obtained.

A shutoff valve 44 is provided downstream of the measurement flow path 42. The shutoff valve 44 includes a valve body 45, a drive device 49 for the valve body 45, a valve seat 47 formed in an opening portion 48d, and a cylindrical portion 48 connected to the lead-out portion 42 b. The valve body 45 is moved by the driving device 49 to abut on the valve seat 47, thereby shutting off the gas.

The driving device 49 includes a motor 46 and a linear motion mechanism, the motor 46 includes a stator 46a, a rotor 46b, and a rotary shaft 46c, and the driving device 49 moves the valve body 45 by converting rotation of the rotary shaft 46c into linear motion by screwing a female screw 45a of the valve body 45 to a male screw 46d provided at a tip end of the rotary shaft 46 c.

Here, an opening 48d is formed at the gas inlet of the cylindrical portion 48, the driving device 49 is inserted into the cylindrical portion 48 from the opening 48d, and the flange 46e of the driving device 49 is fixed to the fixing portion 48c of the cylindrical portion 48 by screws or the like, not shown.

The connection between the cylindrical portion 48 and the flow rate measurement portion 41 is performed in an airtight manner using a lead-out portion 42b having a shape matching the opening portion 48d and a sealing member such as an O-ring, not shown. Further, a passage through which the gas passes is formed as a gap between the inner wall 48a of the cylindrical portion 48 and the outer periphery of the driving device 49, and the gas passing through the measurement flow path 42 flows out from the opening portion 48d through the gap.

As described above, since the flow rate measurement unit 40 according to the present embodiment has the shutoff function, the flow rate measurement unit 40 can be incorporated into a gas meter to measure and shut off the fluid.

Even if the flow state of the gas flowing into the flow rate measurement unit 40 varies depending on the size and shape of the internal space of the gas meter, the influence on the flow rate measurement can be reduced by the flow rectification effect of the valve body 45, and 1 flow rate measurement unit 40 can be used for gas meters of various shapes.

Fig. 9 shows a cross-sectional view of a state in which the flow rate measurement unit 40 is assembled to the gas meter 110, the flow rate measurement unit 40 is built in a gas meter main body 113 having a gas meter inlet 111 and a gas meter outlet 112, and the opening portion 48b is connected to a connecting member 114 connected to the gas meter outlet 112. In this configuration, gas, which is a fluid to be measured, passes through the flow rate measurement unit 40 from the gas meter inlet 111 and flows out from the gas meter outlet 112 via the coupling member 114, as indicated by hollow arrows indicated by solid lines and broken lines.

As described above, the flow rate measurement unit 40 of the present embodiment is incorporated in a gas meter, and a gas meter with a shut-off function can be easily realized.

Fig. 10 shows a gas meter 210 incorporating another example of the flow rate measurement unit 40 of the present embodiment. As shown in fig. 10, a flow rate measurement unit 40 is incorporated in a gas meter main body 213 in which a gas meter inlet 211 and a gas meter outlet 212 are linearly arranged, and an opening portion 48d of the flow rate measurement unit 40 is directly and airtightly connected to the gas meter outlet 212. Fig. 11 is a main part sectional view of fig. 10 showing a state in which the gas meter outlet 212 and the flow rate measurement unit 40 are joined together. As shown in fig. 11, the flow rate measurement unit 40 and the gas meter outlet 212 are hermetically connected by an O-ring 51.

With the gas meter 210 formed by the above structure, the gas meter main body can be further downsized as compared with the gas meter 110 shown in fig. 9. Further, the gas meter can be attached to the middle of the linear pipe, and the degree of freedom of installation is improved.

Fig. 12 shows a gas meter 310 incorporating another example of the flow rate measurement unit 40 of the present embodiment, and the introduction portion 42a of the flow rate measurement unit 40 and the gas meter inlet 311 are connected together by a coupling member 60. A gas meter outlet 312 is provided on a surface of the gas meter 310 opposite to the surface on which the gas meter inlet 311 is provided.

With the gas meter 310 configured as described above, the flow rate measurement unit 40 of the present embodiment is directly connected to the gas meter inlet 311, and the gas meter body can be further downsized as compared with the gas meter 110 shown in fig. 9. Further, the gas meter can be attached to the middle of the linear pipe, and the degree of freedom of installation is improved.

As described above, the flow rate measurement unit disclosed in claim 1 includes: a flow rate measurement unit having a straight tubular measurement flow path including an introduction portion and a discharge portion of a fluid to be measured; and a shut valve having a valve seat formed in the introduction portion and a valve element abutting against the valve seat.

With this configuration, it is possible to perform stable flow rate measurement regardless of the shape of the gas meter, and it is possible to reduce the size of the gas meter by integrating the flow rate measurement function by the fluid measurement unit and the shutoff function by the shutoff valve.

The flow rate measuring unit disclosed in claim 2 may be configured such that, in particular, in addition to the flow rate measuring unit disclosed in claim 1, the shutoff valve includes a cylindrical portion that protrudes from the introduction portion and has an opening portion, and a driving device that drives a valve body fixed inside the cylindrical portion.

The flow rate measuring unit disclosed in claim 3 may be configured such that the drive device moves the valve body by using a motor and a linear motion mechanism that converts a rotational motion of the motor into a linear motion, and the opening portion, the rotary shaft of the motor, the introduction portion, and the discharge portion are arranged substantially linearly, particularly in addition to the flow rate measuring unit disclosed in claim 2.

The gas meter disclosed in 4 may include: a body comprising a gas meter inlet and a gas meter outlet for a fluid to be measured; and a flow rate measurement unit according to any one of claims 1 to 3, wherein the lead-out portion is hermetically connected to the gas meter outlet.

The gas meter disclosed in claim 5 may further include: a main body in which a gas meter inlet and a gas meter outlet for a fluid to be measured are arranged substantially linearly; and a flow rate measurement unit according to any one of claims 1 to 3, wherein the lead-out portion is hermetically connected to the gas meter outlet.

The gas meter disclosed in claim 6 may further include: a main body in which a gas meter inlet and a gas meter outlet for a fluid to be measured are arranged substantially linearly; and a flow rate measurement unit according to any one of claims 1 to 3, wherein the opening portion is hermetically connected to the gas meter inlet.

The flow rate measurement unit disclosed in 7 includes: a flow rate measurement unit having a straight tubular measurement flow path including an introduction portion and a discharge portion of a fluid to be measured; and a shut valve formed in the lead-out portion.

With this configuration, the flow rate measurement function by the fluid measurement unit and the shutoff function by the shutoff valve are integrated, whereby the gas meter can be downsized.

The flow rate measurement unit disclosed in claim 8 may be the flow rate measurement unit disclosed in claim 7, wherein the shutoff valve includes: a cylindrical portion having one end connected to the lead-out portion and an outlet portion at the other end; a valve seat provided at an outlet portion of the cylindrical portion; a valve element for abutting against the valve seat; and a drive device that drives the valve element fixed inside the cylindrical portion.

The flow rate measuring unit disclosed in 9 may be configured such that, particularly in addition to the flow rate measuring unit disclosed in 8, the drive device moves the valve body by using a motor and a linear motion mechanism that converts a rotational motion of the motor into a linear motion, and the outlet portion, the rotary shaft of the motor, the introduction portion, and the discharge portion may be arranged substantially linearly.

The gas meter disclosed in claim 10 may further include: a body comprising a gas meter inlet and a gas meter outlet for a fluid to be measured; and a flow rate measurement unit according to any one of the 7 th to 9 th publications, wherein the outlet portion is hermetically connected to the gas meter outlet.

The gas meter disclosed in claim 11 may include: a main body in which a gas meter inlet and a gas meter outlet for a fluid to be measured are arranged substantially linearly; and a flow rate measurement unit according to any one of the 7 th to 9 th publications, wherein the outlet portion is hermetically connected to the gas meter outlet.

The gas meter disclosed in claim 12 may further include: a main body in which a gas meter inlet and a gas meter outlet for a fluid to be measured are arranged substantially linearly; and a flow rate measurement unit according to any one of the 7 th to 9 th publications, wherein the introduction portion is hermetically connected to the gas meter inlet.

Industrial applicability

The measuring unit of the present invention can realize the miniaturization of the gas meter with the cut-off function by the built-in cut-off valve.

Description of the reference numerals

10. 40, a flow rate measurement unit; 11. 41, a flow rate measuring section; 12. 42, a measurement flow path; 12a, 42a, an introduction part; 12b, 42b, a lead-out part; 14. 44, a stop valve; 15. 45, a valve core; 16. 46, a motor; 17. 47, valve seat; 18. 48, a cylindrical portion; 18b, 48d, an opening; 19. 49, a driving device; 48b, an outlet portion; 100. 110, 200, 210, 300, 310, gasometer; 101. 111, 201, 211, 301, 311, gasometer inlet; 102. 112, 202, 212, 302, 312, gasometer outlet.