CN215263377U

CN215263377U - Gas purity calibration device

Info

Publication number: CN215263377U
Application number: CN202121324806.8U
Authority: CN
Inventors: 孙跃; 李俊博; 黄林; 祖俊洁; 蒋森
Original assignee: China General Nuclear Power Corp; CGN Power Co Ltd; China Nuclear Power Operation Co Ltd
Current assignee: China General Nuclear Power Corp; CGN Power Co Ltd; China Nuclear Power Operation Co Ltd
Priority date: 2021-06-15
Filing date: 2021-06-15
Publication date: 2021-12-21
Anticipated expiration: 2031-06-15

Abstract

The utility model relates to a gas purity calibration equipment. The gas purity calibration device comprises a switching valve, a standard air injection channel, a protective gas injection channel, a hydrogen injection channel and a measuring instrument; the standard air injection channel is communicated with a first interface of the switching valve, the protective gas injection channel is communicated with a second interface of the switching valve, the hydrogen injection channel is communicated with a third interface of the switching valve, and the switching valve is communicated with the measuring instrument through a pipeline; and the measuring instrument is communicated with the first interface, the second interface and the third interface in sequence through the switching valve. The utility model provides a measuring instrument switches on with first interface, second interface and third interface in proper order through the diverter valve for the protective gas that gets into from the second interface is located all the time and lets in between air and the hydrogen, thereby can sweep air and hydrogen in switching valve, measuring apparatu and the gas circuit between the two, has avoided the possibility of hydrogen and air contact in the system, reduces the risk of hydrogen explosion, improves the security of device operation.

Description

Gas purity calibration device

Technical Field

The utility model relates to a gas monitoring technology field especially relates to gaseous purity calibration equipment.

Background

The hydrogen purity monitoring devices used by the hydrogen supply system of the base generator are all heat conduction cell type measuring instruments, and are periodically calibrated in a mode of sweeping multiple gases in turn. In the process of calibrating the hydrogen purity monitoring device, the hydrogen with known purity needs to be calibrated, but in the prior art, the hydrogen is easy to contact with air, so that the hydrogen explosion risk exists, and serious potential safety hazards exist.

SUMMERY OF THE UTILITY MODEL

Therefore, it is necessary to provide a gas purity calibration apparatus for solving the technical problem that hydrogen is easily contacted with air and has a risk of hydrogen explosion in the calibration process in the prior art.

A gas purity calibration device, comprising:

the device comprises a switching valve, a standard air injection channel, a protective gas injection channel, a hydrogen injection channel and a measuring instrument;

the standard air injection channel is communicated with a first interface of the switching valve, the protective gas injection channel is communicated with a second interface of the switching valve, the hydrogen injection channel is communicated with a third interface of the switching valve, and the switching valve is communicated with the measuring instrument;

and the measuring instrument is communicated with the first interface, the second interface and the third interface in sequence through the switching valve.

In one embodiment, the switching valve includes a valve handle and a valve body having a valve cavity; the valve handle is rotationally connected with the valve body, and the measuring instrument is communicated with the valve cavity;

the valve handle of the through valve rotates relative to the valve body, and the first interface, the second interface and the third interface can be respectively communicated with the valve cavity;

the second interface is arranged between the first interface and the third interface.

In one embodiment, the gas purity verifying device further comprises a first gas cylinder filled with standard air, and an opening of the first gas cylinder is connected to one end of the standard air injection channel, which is far away from the first interface;

the gas purity calibration device also comprises a second gas cylinder filled with protective gas, and an opening of the second gas cylinder is connected to one end, far away from the second interface, of the protective gas injection channel;

the gas purity checking device further comprises a third gas cylinder filled with hydrogen, and an opening of the third gas cylinder is connected to one end, far away from the third interface, of the hydrogen injection channel.

In one embodiment, the gas purity calibration device further comprises a pressure reducing valve, and the pressure reducing valve is arranged on a gas path of the measuring instrument communicated with the switching valve.

In one embodiment, the gas purity calibration device further comprises a first pressure gauge, and the first pressure gauge is arranged on a gas path where the pressure reducing valve is communicated with the switching valve.

In one embodiment, the gas purity calibration device further comprises a second pressure gauge, and the second pressure gauge is arranged on a gas path where the pressure reducing valve is communicated with the measuring instrument.

In one embodiment, the gas purity calibration device further comprises a flow regulator, and the flow regulator is arranged on a gas path where the pressure reducing valve is communicated with the measuring instrument.

In one embodiment, the gas purity verifying unit further comprises a flow display, and the flow display is arranged on a gas path where the flow regulator is communicated with the measuring instrument.

In one embodiment, the standard air injection channel, the protective gas injection channel and the hydrogen injection channel are respectively provided with a one-way valve.

In one embodiment, the standard air injection channel, the shielding gas injection channel and the hydrogen injection channel are provided with connectors.

The utility model has the advantages that:

the embodiment of the utility model provides a gas purity calibration equipment, including diverter valve, standard air injection passageway, protective gas injection passageway, hydrogen injection passageway, measuring instrument; the standard air injection channel is communicated with a first interface of the switching valve, the protective gas injection channel is communicated with a second interface of the switching valve, the hydrogen injection channel is communicated with a third interface of the switching valve, and the switching valve is communicated with the measuring instrument through a pipeline; and the measuring instrument is communicated with the first interface, the second interface and the third interface in sequence through the switching valve. The utility model provides a measuring instrument among the gas purity calibration equipment passes through the diverter valve in proper order with first interface, second interface and third interface switch on, make the gas that awaits measuring that lets in measuring instrument at every turn only one, and the protective gas that gets into from the second interface lies in all the time and lets in between air and hydrogen, thereby can be to the switching valve, the measuring instrument with and air and hydrogen in the gas circuit between the two sweep, the possibility of the contact of hydrogen in the system with the air has been avoided, the risk of hydrogen explosion has been reduced, the security of improving the device operation.

Drawings

Fig. 1 is a schematic view of a gas purity calibration apparatus provided by an embodiment of the present invention.

Reference numerals: 100-a switching valve; 110 — a first interface; 120-a second interface; 130-a third interface; 140-closed mouth; 150-way valve handle; 160-a valve body; 200-standard air injection channel; 210-a first gas cylinder; 220-a first one-way valve; 230-a first joint; 300-a shielding gas injection channel; 310-a second gas cylinder; 320-a second one-way valve; 330-a second joint; 400-a hydrogen injection channel; 410-a third gas cylinder; 420-a third one-way valve; 430-a third joint; 510-a pressure reducing valve; 520-a first pressure gauge; 530-a second pressure gauge; 540-flow regulator; 550-a flow display; 560-air outlet.

Detailed Description

In order to make the above objects, features and advantages of the present invention more comprehensible, embodiments of the present invention are described in detail below with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein, as those skilled in the art will be able to make similar modifications without departing from the spirit and scope of the present invention.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", and the like, indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for convenience of description and simplicity of description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore, should not be construed as limiting the present invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," and "fixed" are to be construed broadly and may, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.

In the present application, unless expressly stated or limited otherwise, the first feature may be directly on or directly under the second feature or indirectly via intermediate members. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

It will be understood that when an element is referred to as being "secured to" or "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and the like as used herein are for illustrative purposes only and do not denote a unique embodiment.

Referring to fig. 1, fig. 1 shows a schematic diagram of a gas purity calibration apparatus in an embodiment of the present invention, and the gas purity calibration apparatus provided in an embodiment of the present invention includes a switching valve 100, a standard air injection channel 200, a shielding gas injection channel 300, a hydrogen injection channel 400, and a measuring instrument; the standard air injection channel 200 is communicated with the first interface 110 of the switching valve 100, the shielding gas injection channel 300 is communicated with the second interface 120 of the switching valve 100, the hydrogen injection channel 400 is communicated with the third interface 130 of the switching valve 100, and the switching valve 100 is communicated with the measuring instrument through a pipeline; the measuring instrument is sequentially communicated with the first interface 110, the second interface 120 and the third interface 130 through the switching valve 100. The utility model provides a measuring instrument among the gas purity verifying attachment passes through diverter valve 100 in proper order with first interface 110, second interface 120 and third interface 130 switch on, make the gas that awaits measuring that lets in measuring instrument at every turn only one, and the protective gas that gets into from second interface 120 is located all the time and lets in between air and hydrogen, thereby can be to diverter valve 100, the measuring instrument with and air and hydrogen in the gas circuit between the two sweep, the possibility of the contact of hydrogen in the system and air has been avoided, the risk of hydrogen explosion has been reduced, the security of improving the device operation. In addition, due to the fact that multiple gases to be measured need to be repeatedly purged for multiple times during each calibration, air, protective gas and hydrogen can enter the measuring instrument sequentially from the first interface 110, the second interface 120 and the third interface 130 due to the arrangement of the switching valve 100, repeated disassembly and assembly of the joint pipeline during replacement of the gases to be measured can be avoided, the possibility that the joint pipeline is aged and the sealing performance is reduced in the repeated disassembly and assembly process is avoided, and the risk of gas leakage is reduced.

In one embodiment, the switching valve 100 includes a valve handle 150 and a valve body 160 having a valve cavity; the valve handle 150 is rotationally connected to the valve body 160, and the measuring instrument is communicated with the valve cavity; the valve handle 150 rotates relative to the valve body 160, and can respectively communicate the first port 110, the second port 120 and the third port 130 with the valve cavity; the second interface 120 is provided between the first interface 110 and the third interface 130.

Specifically, the valve handle 150 is rotated relative to the valve body 160 to enable one of the first port 110, the second port 120, and the third port 130 to communicate with the valve body 160. The valve handle 150 can only rotate from the position on the valve body 160 where the first port 110 and the valve cavity are connected to each other, to the position where the second port 120 and the valve cavity are connected to each other, to the position where the third port 130 and the valve cavity are connected to each other, to the position where the second port 120 and the valve cavity are connected to each other, and to the position where the first port 110 and the valve cavity are connected to each other. That is, the valve handle 150 cannot rotate from the position on the valve body 160 where the first port 110 communicates with the valve cavity to the position where the third port 130 communicates with the valve cavity, or from the position on the valve body 160 where the third port 130 communicates with the valve cavity to the position where the first port 110 communicates with the valve cavity. Due to the arrangement, the protective gas entering the valve cavity from the second interface 120 is always located between the introduced hydrogen and the air, so that the protective gas entering from the second interface 120 can sweep the air and the hydrogen in the gas circuit among the switching valve 100, the measuring instrument and the air circuit between the switching valve and the measuring instrument, the possibility of contact between the hydrogen and the air in the system is avoided, the risk of hydrogen explosion is reduced, and the operation safety of the device is improved.

It should be noted that, in the whole process of detecting the gas to be detected, the purities of the hydrogen and the shielding gas are known, and the introduced air is standard air, which is the detection of the purity of the nitrogen in the standard air. And the last time, the air is needed to be introduced, so that after the measurement is finished, the air channels among the switching valve 100, the measuring instrument and the measuring instrument are filled with air, and therefore when the switching valve 100, the measuring instrument and other devices are disassembled, detected or replaced, the air flowing out of the air channels can meet the breathing requirements of workers, and the possibility of suffocation is avoided. In addition, the gas to be measured introduced for the first time cannot be hydrogen, so that the reaction between the hydrogen entering from the third interface 130 and the air in the gas path among the switching valve 100, the measuring instrument and the switching valve 100 and the measuring instrument is avoided, the risk of hydrogen explosion is reduced, and the operation safety of the device is improved. Preferably, the shielding gas is carbon dioxide, which is a common gas, so that cost can be saved. The shielding gas may be helium, etc., as long as the reaction of hydrogen is not required.

Further, the valve body 160 is further provided with a closing port 140 communicated with the valve cavity, the closing port 140 is arranged between the first interface 110 and the third interface 130, when the calibration of the gas purity calibration device is finished, and the through valve handle 150 is rotated to the position of the closing port 140 of the valve body 160, the valve cavity is closed, the gas to be measured cannot flow into the measuring instrument, and preparation is made for the next calibration.

In one embodiment, the gas purity verifying device further comprises a first gas cylinder 210 filled with standard air, wherein an opening of the first gas cylinder 210 is connected to one end of the standard air injection passage 200 away from the first interface 110; the gas purity verifying device further comprises a second gas cylinder 310 filled with shielding gas, wherein an opening of the second gas cylinder 310 is connected to one end, far away from the second interface 120, of the shielding gas injection channel 300; the gas purity verifying apparatus further includes a third gas cylinder 410 filled with hydrogen, and an opening of the third gas cylinder 410 is connected to an end of the hydrogen injection passage 400 remote from the third port 130. The arrangement of the first gas cylinder 210, the second gas cylinder 310 and the third gas cylinder 410 enables continuous air, carbon dioxide and hydrogen to enter the switching valve 100, and then enter the measuring instruments in sequence to calibrate the measuring instruments. The contents of air, carbon dioxide and hydrogen filled in the first gas cylinder 210, the second gas cylinder 310 and the third gas cylinder 410 are high, so that repeated disassembly of the standard air injection channel 200, the protective gas injection channel 300 and the hydrogen injection channel 400 can be avoided, the possibility of aging and reduction of sealing performance of a joint pipeline in the repeated disassembly and assembly process is avoided, and the risk of gas leakage is reduced.

Specifically, the opening of the first gas cylinder 210, the opening of the second gas cylinder 310 and the opening of the third gas cylinder 410 are all provided with a switch valve, when one or more of the standard air injection channel 200, the protective gas injection channel 300 and the hydrogen injection channel 400 leaks gas, the switch valves corresponding to the openings of the first gas cylinder 210, the second gas cylinder 310 and the third gas cylinder 410 can be closed in time, so that the waste of energy is avoided, and the danger of hydrogen explosion caused by the leakage of hydrogen into the air is avoided.

In one embodiment, check valves are disposed on the standard air injection passage 200, the shielding gas injection passage 300, and the hydrogen injection passage 400. Specifically, the standard air injection passage 200 is provided with a first check valve 220, the shielding gas injection passage 300 is provided with a second check valve 320, and the hydrogen injection passage 400 is provided with a third check valve 420. The arrangement of the first one-way valve 220 can prevent the gas in the gas path between the switching valve 100 and the measuring instrument from being mixed with the standard air in the standard air injection channel 200, thereby affecting the content of the nitrogen in the standard air flowing into the measuring instrument, and affecting the nitrogen concentration measuring structure, thereby inaccurate calibration of the measuring instrument. In addition, the mixing of hydrogen with air in the switching valve 100, the meter and the air path therebetween can be avoided, and the possibility of danger is eliminated. The second check valve 320 and the third check valve 420 are disposed in the same manner as the first check valve 220, and therefore, are not described again.

In one embodiment, joints are provided on the standard air injection passage 200, the shielding gas injection passage 300, and the hydrogen gas injection passage 400. Specifically, the first cylinder 210 is opened with a first connector 230 connected to the standard air injection passage 200, the second cylinder 310 is opened with a second connector 330 connected to the shielding gas injection passage 300, and the third cylinder 410 is opened with a third connector 430 connected to the hydrogen gas injection passage 400. The first connector 230 is provided to facilitate the connection between the standard air injection channel 200 and the opening of the first air bottle 210, and to facilitate the detachment from the standard air injection channel 200 after the standard air in the first air bottle 210 is exhausted, so as to replace the first air bottle 210. The second joint 330 and the third joint 430 are disposed in the same manner as the first joint 230, and therefore, the description thereof is omitted. Preferably, the first joint 230, the second joint 330 and the third joint 430 are all quick joints.

In one embodiment, the gas purity calibration apparatus further includes a pressure reducing valve 510, and the pressure reducing valve 510 is disposed on a gas path of the measuring instrument communicating with the switching valve 100. Because the pressure in the gas cylinder is generally very high, the gas to be measured flowing out of the gas cylinder has higher pressure, and the high-pressure gas is dangerous and easily causes harm to human bodies. The pressure reducing valve 510 is arranged to make the gas to be measured flowing into the measuring instrument from the switching valve 100 in a normal pressure state, so that the measuring instrument can measure the gas to be measured conveniently, and the accuracy of measurement of the gas to be measured is improved. The pressure reducing valve 510 is provided on the gas path through which the measuring instrument communicates with the switching valve 100, so that the number of the pressure reducing valves 510 can be reduced, and the cost can be saved. In another embodiment, a pressure reducing valve 510 is provided on each of the standard air injection passage 200, the shielding gas injection passage 300, and the hydrogen gas injection passage 400. With such an arrangement, damage to the switching valve 100 due to high-pressure gas to be measured can be avoided.

In one embodiment, the gas purity calibration apparatus further includes a first pressure gauge 520, and the first pressure gauge 520 is disposed on a gas path connecting the pressure reducing valve 510 and the switching valve 100. The first pressure gauge 520 is provided to detect the pressure of the gas to be measured flowing into the pressure reducing valve 510, so that the gas to be measured flowing into the measuring instrument is in a normal pressure state by setting the pressure reducing value of the pressure reducing valve 510. In one embodiment, the gas purity calibration apparatus further comprises a second pressure gauge 530, and the second pressure gauge 530 is disposed on a gas path connecting the pressure reducing valve 510 and the measuring instrument. The second pressure gauge 530 is used to measure the pressure of the gas to be measured flowing into the measuring instrument. Since the standard air, the carbon dioxide and the hydrogen are respectively contained in the first air cylinder 210, the second air cylinder 310 and the third air cylinder 410, the pressure of the standard air, the carbon dioxide and the hydrogen flowing out from the first air cylinder 210, the second air cylinder 310 and the third air cylinder 410 are different, and the arrangement of the second pressure gauge 530 can detect whether the pressure of the gas to be detected flowing into the measuring instrument is normal pressure, so that the pressure reducing valve 510 can be adjusted in time, the pressure of the gas to be detected flowing into the measuring instrument is consistent, and the accuracy of detecting the purity of the gas to be detected is improved.

In one embodiment, the gas purity calibration apparatus further comprises a flow regulator 540, and the flow regulator 540 is disposed on a gas path where the pressure reducing valve 510 and the measuring instrument communicate. The flow regulator 540 is used for regulating the gas to be measured flowing into the measuring instrument, so that the flow of the gas to be measured flowing into the measuring instrument is stable, the gas to be measured is in a relatively stable range, and the inaccurate detection of the purity of the gas to be measured by the measuring instrument due to the unstable flow of the gas to be measured is avoided. In one embodiment, the gas purity verification apparatus further comprises a flow display 550, and the flow display 550 is disposed on the gas path where the flow regulator 540 communicates with the measurement instrument. The flow display 550 is used to display the flow of the gas to be measured flowing into the measuring instrument, thereby facilitating the flow regulator 540 to regulate the stability of the flow of the gas to be measured flowing into the measuring instrument.

Specifically, the gas outlet 560 is provided on the gas path of the flow regulator 540 connected to the measuring instrument, and the gas outlet 560 is connected to the measuring instrument, so that the gas to be measured can flow into the measuring instrument from the gas outlet 560 for purging. Further, be equipped with the fourth on the gas outlet 560 and connect, the setting that the fourth connects to be convenient for with the installation in dismantlement of measuring instrument, thereby be convenient for be connected with multiple measuring instrument. Preferably, the fourth joint is a quick joint.

In one embodiment, the gas purity verifier device further includes a housing for protecting components within the gas purity verifier device. Wherein the shell is panel beating fretwork design, when losing weight, can also guarantee intensity. And the design of fretwork for when taking place gas leakage among the gas purity calibration equipment, the leakage gas can in time be discharged away, avoids gathering in the shell, thereby leads to dangerous emergence.

In one embodiment, the outsides of the first gas cylinder 210, the second gas cylinder 310 and the third gas cylinder 410 are coated with a buffer material, the buffer material is used for fixing the first gas cylinder 210, the second gas cylinder 310 and the third gas cylinder 410, and on the other hand, when the first gas cylinder 210, the second gas cylinder 310 and the third gas cylinder 410 move, the buffer material can play a role in buffering, so that the first gas cylinder 210, the second gas cylinder 310 and the third gas cylinder 410 are prevented from colliding with each other and causing danger. Preferably, the cushion is a hard sponge. In one embodiment, the bottom of the housing is provided with a brake universal wheel, thereby facilitating adjustment of the gas purity calibration device in any direction.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only represent some embodiments of the present invention, and the description thereof is specific and detailed, but not to be construed as limiting the scope of the present invention. It should be noted that, for those skilled in the art, without departing from the spirit of the present invention, several variations and modifications can be made, which are within the scope of the present invention. Therefore, the protection scope of the present invention should be subject to the appended claims.

Claims

1. A gas purity calibration device, comprising:

the device comprises a switching valve (100), a standard air injection channel (200), a protective gas injection channel (300), a hydrogen injection channel (400) and a measuring instrument;

the standard air injection channel (200) is communicated with a first interface (110) of the switching valve (100), the protective gas injection channel (300) is communicated with a second interface (120) of the switching valve (100), the hydrogen injection channel (400) is communicated with a third interface (130) of the switching valve (100), and the switching valve (100) is communicated with the measuring instrument;

the measuring instrument is communicated with the first interface (110), the second interface (120) and the third interface (130) in sequence through the switching valve (100).

2. The gas purity verifier device of claim 1, wherein the switch valve (100) comprises a switch valve handle (150) and a valve body (160) having a valve cavity; the valve handle (150) is rotationally connected with the valve body (160), and the measuring instrument is communicated with the valve cavity;

the valve handle (150) rotates relative to the valve body (160) and can respectively communicate the first interface (110), the second interface (120) and the third interface (130) with the valve cavity;

the second interface (120) is arranged between the first interface (110) and the third interface (130).

3. The gas purity verifier device of claim 1, further comprising a first gas cylinder (210) containing standard air, the first gas cylinder (210) having an opening connected to an end of the standard air injection passage (200) remote from the first port (110);

the gas purity verifying device further comprises a second gas cylinder (310) filled with shielding gas, and an opening of the second gas cylinder (310) is connected to one end, away from the second interface (120), of the shielding gas injection channel (300);

the gas purity verifying device further comprises a third gas cylinder (410) filled with hydrogen, and an opening of the third gas cylinder (410) is connected to one end, away from the third interface (130), of the hydrogen injection channel (400).

4. A gas purity calibration device according to claim 3, further comprising a pressure reducing valve (510), wherein said pressure reducing valve (510) is provided on a gas path of said gauge communicating with said switching valve (100).

5. The gas purity verifying unit of claim 4, further comprising a first pressure gauge (520), wherein the first pressure gauge (520) is disposed on a gas path connecting the pressure reducing valve (510) and the switching valve (100).

6. The gas purity verification apparatus according to claim 5, further comprising a second pressure gauge (530), wherein the second pressure gauge (530) is disposed on a gas path where the pressure reducing valve (510) and the measuring instrument communicate.

7. The gas purity verification apparatus according to claim 5, further comprising a flow regulator (540), wherein the flow regulator (540) is provided on a gas path where the pressure reducing valve (510) and the measuring instrument communicate.

8. The gas purity verification apparatus according to claim 7, further comprising a flow display (550), wherein the flow display (550) is disposed on a gas path of the flow regulator (540) in communication with the measurement instrument.

9. The gas purity verifying unit according to any one of claims 3 to 8, wherein check valves are provided on the standard air injection passage (200), the shielding gas injection passage (300), and the hydrogen gas injection passage (400).

10. The gas purity verifying unit according to any one of claims 3 to 8, wherein joints are provided on the standard air injection passage (200), the shielding gas injection passage (300), and the hydrogen gas injection passage (400).