JP4665004B2 - Leak inspection apparatus and leak inspection method - Google Patents

Description

  The present invention relates to a leak inspection apparatus and a leak inspection method for inspecting a gas leak from an inspection object using a tracer gas (for example, helium gas).

  As a method for inspecting gas leakage from an inspection object (test body), the Japanese Industrial Standard (JIS) defines a helium leakage test method (see Non-Patent Documents 1 and 2). This helium leak test method is roughly classified into a vacuum method and a pressurization method. In the vacuum method, the inside of the test body is evacuated in advance, and the presence or absence of gas leakage is determined by detecting the leakage (intrusion) of helium gas from the outside into the test body. On the other hand, in the pressurization method, helium gas is sealed in advance in the test body, and the presence or absence of gas leakage is determined by detecting helium gas leaking from the test body to the outside. However, since products that are desired to be leak-checked are generally used in a state where the inside thereof is pressurized, a pressurizing method is generally used in many cases.

  Among the pressurizing methods, the “vacuum vessel method” is particularly common. The vacuum vessel method has an advantage that even a very small amount of He can be detected because helium gas leaking from a test specimen into a vacuum hood is detected. However, there is a drawback that a large-scale vacuum facility is required and the facility cost is high. Therefore, there is a need to adopt a leak inspection by a pressure integration method or a suction cup method that does not require expensive vacuum equipment.

  For example, in the pressure integration method, helium gas is sealed in the test body, and the test body is covered with a hood to create an airtight space in the outer adjacent area of the test body. Then, helium gas that has leaked to the outside of the specimen in the hood is accumulated in the hood for a certain period of time, and the concentration of helium gas (He) in the gas collected through the sniffer probe is measured. The presence or absence of gas leakage is determined based on the temporal change of (see Non-Patent Document 2).

  For example, as shown in FIG. 3, when a change in the concentration of helium gas is observed at a pace of 0.2 ppm (or higher) in 20 seconds after the start of the test, it is clearly determined that there is a leak. . On the other hand, if the change in the concentration of helium gas is less than 0.1 ppm even after 20 seconds from the start of the inspection, it is determined that there is no leakage. Even if the concentration of helium gas is slightly increased, it is determined that there is no leakage. The natural atmosphere contains about 5 ppm of helium, which penetrates from the outside of the hood to the inside. Thus, there is a possibility of disturbing the He concentration.

As a patent document disclosing a technique related to a leak inspection apparatus and method using a pressurization method, for example, Patent Document 1 can be cited.
JIS-Z2330 (type of helium leak test method) Annex 4 (Pressure integration method) and Annex 5 (Suction cup method (Suction cup method)) of JIS-Z2331 (2006) (Helium leak test method)) JP 2004-163223 A

  However, in the conventional pressurization integration method, it is difficult to accurately determine the presence or absence of gas leakage from the specimen in a short time. Specifically, as will be shown later as a comparative example, there is a problem that the detected value of the He concentration by the gas detector varies greatly every measurement time and is not stable. For this reason, in order to accurately determine the presence or absence of leakage, the inspection time is lengthened to some extent, and the tendency of temporal change in He concentration (whether it is close to the tendency without leakage or the tendency to leak) It was necessary to identify. That is, the instability of He concentration detection prolongs the inspection time required for each specimen.

  Also, in the conventional pressurized integration method and suction cup method, helium contained in the natural atmosphere at about 5 ppm or helium diffused after the previous leak test is a disturbing factor. There was a problem that it was difficult to distinguish from a small amount of helium leaking from the body. Due to the above circumstances, the pressure integration method and the suction cup method are not so much used in practice despite their existence.

  The present invention has been made in view of the above circumstances, and its purpose is to stabilize the detection of the tracer gas at the time of leak inspection based on the pressurization integration method or the suction cup method, and to detect the presence or absence of gas leakage in a relatively short time. An object of the present invention is to provide a leakage inspection apparatus and a leakage inspection method that can be accurately determined.

  The inventor of the present application has reexamined the conventional leakage inspection method using the pressurization method, and as a result, the gas detector increases as the airtightness of a space (monitoring space) defined by a covering member such as a hood that covers the inspection object increases. We have obtained the unexpected finding that the detection of tracer gas by the system becomes unstable. As a cause thereof, it is conceivable that a suction negative pressure is generated due to the airtightness of the monitoring space when the gas is sucked from the monitoring space to the gas detector. Therefore, by connecting the monitoring space to the external area via the communication path filled with the reference gas, the gas detector will intentionally break the airtightness of the monitoring space at the time of leak inspection, and the detection of the tracer gas by the gas detector is stabilized. The present invention was created based on the idea of making it possible.

The present invention relates to a leak inspection apparatus for inspecting gas leakage from an inspection object. The leak inspection apparatus includes a covering member capable of defining an airtight monitoring space in an outer adjacent region of the inspection object by covering all or a part of the inspection object, and a tracer gas inside the inspection object. Tracer gas supply means for supplying, a gas detector for detecting the concentration of the tracer gas, and the covering member for guiding the gas in the monitoring space defined by the covering member to the gas detector A sniffer probe attached to the communication space, and a communication path provided to connect the monitoring space to other external regions in order to supplement gas sucked from the monitoring space via the sniffer probe. Before starting the leak inspection, a reference gas is supplied from a reference gas supply source to the monitoring space and the communication path to purge the monitoring space and the communication path with the reference gas. Characterized in that it comprises a gas purging means. There are three preferred modes of the communication path.
In the first aspect, the communication path is a communication path provided so as to communicate the monitoring space with an “atmospheric open area separated from the covering member by a predetermined distance” as an external area other than the monitoring space. And the communication path is formed as a hose-like or tube-like tube, and the internal volume over the entire length of the communication path is detected from the monitoring space by the sniffer probe within a predetermined inspection time. It exceeds the volume of gas introduced to the vessel.
In the second aspect, the communication path is a communication path provided to communicate the monitoring space with a “downstream region of the gas detector” as an external region other than the monitoring space.
In the third aspect, the communication path is a communication path provided so as to communicate the monitoring space with a “gas supply source including a gas cylinder” as an external region other than the monitoring space.
The gas purge means supplies a reference gas from the reference gas supply source to the monitoring space (S) before the leak inspection starts, and purges the inside of the monitoring space with the reference gas ( 23) and a second gas purge means (26) for supplying a reference gas from the reference gas supply source to the communication passage (31) and purging the communication passage with the reference gas before starting the leak inspection. It is preferable that it consists of.

  The present invention also relates to a leak inspection method for inspecting a gas leak from an inspection object using the leak inspection apparatus. The leakage inspection method includes a covering step that covers an entire or part of the inspection object with a covering member to define an airtight monitoring space in an outer adjacent area of the inspection object, and a tracer gas supply unit. A tracer gas supply step for supplying the tracer gas into the inspection object in advance, and a reference for the monitoring space defined by the covering member and the communication path provided in the covering member by the gas purging means before starting the inspection. A gas purge step of supplying a reference gas from a gas supply source to purge the inside of the monitoring space and the communication passage with the reference gas, and a state in which the monitoring space is communicated with the other external region via the communication passage The tracer gas concentration in the gas guided from the monitoring space to the gas detector through the sniffer probe attached to the covering member And a measurement step of measuring over inspection time, based on the temporal change of the tracer gas concentration obtained in the measurement step, and judging the presence or absence of gas leakage from the test object.

  According to the leak inspection apparatus and the leak inspection method of the present invention, a sniffer is provided as a covering member capable of defining an airtight monitoring space in an outer adjacent region of the inspection object by covering all or part of the inspection object. In order to supplement the gas sucked out from the monitoring space through the probe, a covering member having a communication path that communicates the monitoring space with other external regions is used. Therefore, the tracer gas concentration in the gas guided from the monitoring space to the gas detector can be measured while maintaining the monitoring space in communication with the external region via the communication path. For this reason, when introducing gas from the monitoring space to the gas detector, excessive negative pressure generation in the introduction path is avoided, and as a result, gas communication between the monitoring space and the gas detector is extremely stabilized. Therefore, the detection of the tracer gas at the time of leak inspection is also stabilized, and it becomes possible to accurately determine the presence or absence of gas leak in a shorter time than in the past.

  In the leak inspection apparatus and leak inspection method of the present invention, not only the monitoring space but also the communication path can be purged by supplying a reference gas from a reference gas supply source before starting the leak inspection. Therefore, at the time of leak inspection, even if gas movement from the communication path to the monitoring space occurs due to gas introduction from the monitoring space to the gas detector, the gas entering the monitoring space from the communication path is the reference gas itself. Therefore, this cannot be a factor that disturbs the concentration of the tracer gas leaked from the inspection object into the monitoring space. Therefore, according to the leak inspection apparatus of the present invention provided with the gas purge means and the leak inspection method using the apparatus, it is possible to accurately determine the presence or absence of gas leak.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a leak inspection apparatus according to the present invention and a leak inspection method (leak inspection by a pressure integration method) using the apparatus will be described with reference to the drawings.

  As shown in FIG. 1, the leak inspection apparatus 10 of the present embodiment is installed in an inspection room R provided at one corner of a factory F1. The leak inspection apparatus 10 includes a base 11 installed on the floor of the inspection room R, and a hood 12 as a covering member placed on the base 11. The hood 12 is generally formed as a cylindrical body having a diameter of 35 cm and a height of 40 cm, and can be moved in the vertical direction by a hood lifting mechanism (not shown).

  During standby (that is, during non-inspection), the hood 12 is levitated and held at an upper standby position away from the placement surface 11a of the base 11. At that time, the inspection target T is horizontally transported by a transport mechanism 13 (manual transport roller in this example) installed on the base 11 and is at a predetermined inspection position (ie, a position directly below the hood 12 at the upper standby position). ) Can be set.

  On the other hand, by lowering the hood 12 after the inspection object T is set, the hood 12 is switched to the lower inspection position (position shown in FIG. 1) where the lower end of the hood 12 contacts the mounting surface 11a of the base. . As a result, the entire inspection target T is covered with the hood 12, and the monitoring space S is defined in the outer adjacent area of the inspection target T by the mounting surface 11 a of the base and the hood 12. This monitoring space S is basically an airtight space with the exception of communication with the outside via various lines to be described later.

  The leak inspection apparatus 10 includes a tracer gas supply means 14 for supplying helium gas as a tracer gas into the inspection target T. The tracer gas supply means 14 includes a helium gas cylinder 15, a coupler 16 (coupler), a gas supply path 18 that connects both of them and includes an opening / closing valve 17, and a coupler lifting / lowering mechanism (not shown). ).

  The leak inspection apparatus 10 further includes a gas detector 21 for detecting the concentration of the tracer gas (He gas). The gas detector 21 is installed outside the hood 12, and is connected to the hood 12 via a sniffer probe 22 attached to the ceiling portion of the hood 12. That is, the sniffer probe 22 is a “gas inlet” for guiding the gas in the monitoring space S defined by the hood 12 to the gas detector 21.

  As shown in FIG. 1, a plurality of types of air supply lines (pipings) are connected to the side wall and the ceiling wall of the hood 12. Specifically, an in-hood air blow line 23, an in-hood air release line 31, and an in-line air blow line 26 are provided.

  The air blow line 23 in the hood is a communication path that connects the hood 12 and a reference gas supply source (in this example, an atmosphere in another factory F2 outside the factory F1), and includes an on-off valve 24 and a reference gas supply. A compressor 25 (forced pumping means) for forcibly supplying the air of the source (F2) to the line 23 is provided. The air blow line 23 functions as a first gas purge means for supplying air as a reference gas into the hood 12 and purging the monitoring space S with air.

  Note that the “reference gas” is a gas that fills the inside of the hood 12 at the start of the leak inspection, and forms an atmosphere in which the leak of the tracer gas from the inspection target T can be detected. . A gas other than the tracer gas can be used as the reference gas, but a small amount of tracer gas (preferably 10 ppm or less) may be included in advance in the reference gas. In this embodiment, air, that is, normal air in nature (generally containing about 5 ppm of He) is used as the reference gas.

  The open air line 31 in the hood is a communication path that connects the hood 12 to an open air region (external region) that is separated from the side wall of the hood 12 by a predetermined distance (about 3.3 m in this example). In the present embodiment, the air release region is in the same examination room R. The atmosphere opening line 31 has a hood side opening end 32, an atmosphere side opening end 33, and a line branch point 34.

  The in-line air blow line 26 is a communication path that allows the line branch point 34 and the reference gas supply source (external factory F2) to communicate with each other. The on-off valve 27 and the air of the reference gas supply source are connected to the line 26. And a compressor 28 (forced pumping means) forcibly supplying the air to the vehicle. The air blow line 26 functions as a second gas purge means for supplying air as a reference gas to the atmosphere release line 31 in the hood and purging the inside of the line 31 with air.

  In the atmospheric open line 31 in the hood of the present embodiment, the ratio (L1) between the distance L1 from the line branch point 34 to the hood side opening end 32 and the distance L2 from the line branch point 34 to the atmosphere side opening end 33. / L2) is set to a predetermined ratio, and a diaphragm 35 is provided between the hood-side opening end 32 and the line branch point 34. The ratio of L1 / L2 and the inner diameter of the throttle 35 are set so that the air supplied to the line branch point 34 via the in-line air blow line 26 is supplied to the two opening ends 32 and 33 to the same extent. Has been.

  In this embodiment, the in-hood atmosphere release line 31 is formed by a hose-like or tube-like pipe. The atmospheric open line 31 has an internal volume over its entire length equal to or exceeding the volume of gas guided from the monitoring space S to the gas detector 21 by the sniffer probe 22 within a predetermined inspection time. Is formed.

  Further, as shown in FIG. 1, an exhaust pipe 41 with an open / close valve 42 is provided below the base 11. One end (upper end in the figure) of the exhaust pipe 41 opens into the monitoring space S in the hood 12, and the other end (lower end in the figure) opens into the inspection chamber R. Sometimes gas discharge from the monitoring space S to the outside is allowed.

  A plurality of agitation fans 43 are arranged in the upper area inside the hood 12. These agitation fans 43 are agitation means for convection of the gas in the hood 12 and maintaining the uniformity of the gas phase in the monitoring space S.

  Next, a leak inspection method using the leak inspection apparatus 10 will be described. In addition, although the inspection target T in this embodiment assumes the hydraulic pump motor for construction machines, it is not limited to this.

  As preparation before the start of the inspection, as shown in FIG. 1, the inspection object T is set at a predetermined inspection position on the base 11, and the hood 12 is arranged at the lower inspection position (position shown in FIG. 1). By covering the entire inspection target T with the hood 12 in this way, a monitoring space S is defined in the outer adjacent area of the inspection target T.

  After (or before) the monitoring space S is defined, the coupler 16 of the tracer gas supply means 14 is connected to the inspection object T, and the He gas enters the inspection object T from the helium gas cylinder 15 through the gas supply path 18. (Tracer gas) is supplied under pressure. Then, the inside of the inspection target T is filled with He gas having a predetermined pressure exceeding the atmospheric pressure (for example, 0.3 MPa = about 3 atm). When the internal pressure of the inspection object T reaches the predetermined pressure, the on-off valve 17 is closed.

  Subsequently, the open / close valve 42 of the exhaust pipe 41 is opened, and the open / close valve 24 of the in-hood air blow line 23 and the open / close valve 27 of the in-line air blow line 26 are opened under the condition that a gas escape path from the monitoring space S is secured. Both valves are opened, and the air from the external factory F2 is forcibly supplied to the hood 12 and the atmosphere release line 31. As a result, the purge space (gas phase replacement) is performed in the monitoring space S and the open air line 31 with the air as the reference gas.

  By this gas purge operation, the He concentration in the hood 12 (in the monitoring space S) changes as shown in the graph of FIG. That is, before the gas purge start time t1, He exceeding 12 ppm stays in the inspection room R as a result of the leak inspection up to the previous time, and the same amount of He is unavoidable in the hood 12 due to the influence. Remains. The purpose of the gas purge is to eliminate this dirty situation and return the monitoring space S to the initial state. As a result of the gas purge operation for a predetermined time t1 to t2 (about 20 seconds in this example), the He concentration in the hood 12 at the time t2 when the gas purge ends is reduced to the same level as the He concentration in the air existing in nature. In the present embodiment, the air containing about 5 ppm of He is regarded as a “reference gas”.

  At the end of the gas purge t2, the on / off valves 24, 27 of the two air blow lines 23, 26 are both closed to shut off the air supply, and the on / off valve 42 of the exhaust pipe 41 is closed to pass through the exhaust pipe 41. Block external communication. As a result, the monitoring space S is in a state of communicating with the atmosphere release area only through the atmosphere release line 31.

  In this embodiment, the time after the elapse of the predetermined time T from the gas purge end time t2 when the on-off valves 24, 27 and 42 are simultaneously closed is defined as the leak inspection start time t3. This time T (T = t3-t2) is a grace time for equalizing or stabilizing the He gas concentration in the hood 12 after the end of the gas purge. In this embodiment, T is set to 5 seconds. In this embodiment, the gas is taken from the monitoring space S through the sniffer probe 22 for about 60 seconds from the start of the leak test t3, and the He concentration in the gas is measured by the gas detector 21. The amount of change in He concentration obtained based on the measured value is shown by a solid line in the graph of FIG.

  In the present embodiment, for the same inspection object T, from setting of the inspection object T to a predetermined inspection position on the base 11 to pressurized supply of He gas, gas purge operation, and leakage measurement for about 60 seconds. A total of 5 measurement experiments were performed with 1 cycle (1 time). As a result, the results were shown as a solid line in the graph of FIG. 4 for all five times, and the change in He concentration at each measurement time was extremely stable. Note that the measurement result indicated by the solid line in FIG. 4 indicates that the inspection target T is “no leakage”.

[Comparative example]
As a leakage inspection apparatus of the comparative example, an apparatus (not shown) in which the atmosphere release line 31 was removed from the leakage inspection apparatus 10 of the above embodiment was prepared. Then, using the apparatus, five measurement experiments were performed on the same inspection target T in substantially the same procedure as in the above embodiment. In this comparative example, the monitoring space S is kept in a sealed state during the leak inspection (however, excluding communication by the sniffer probe 22), the apparatus and method of the comparative example conform to the conventional pressure integration method. Is.

  The measurement results of five times in the comparative example are indicated by broken lines (five) in the graph of FIG. As can be seen from FIG. 4, the results of the five measurements are not the same, and variation in the He concentration was observed for each measurement. In addition, one of the five measurements shows a change trend in which the change in the first 20 seconds from the start of the test slipped to the “leakage judgment line”. In order to make the determination, the change in density had to be observed for at least 40 seconds. In addition, three out of five measurements draw a change line that deviates significantly from the ideal line for determining no leakage (that is, the zero ppm horizontal line), so these are also judged as “no leakage”. In order to do that, it took some time.

  As described above, even when the inspection object T to be determined as “no leakage” is inspected, in the comparative example, the change in He concentration after the start of the leakage inspection is very unstable. A long inspection time (monitoring time) of, for example, 40 seconds or longer is required before the final determination of “none” is made. On the other hand, in this embodiment, since the change in He concentration is very stable immediately after the start of the leak test, the test time (monitoring time) until the final determination of “no leak” is made is longer than in the comparative example. It can be greatly shortened (for example, shortened to 10 seconds or less), and even if the inspection time is shortened, there is almost no risk of erroneous determination.

  Prior to the completion of the present invention, the influence of the position of the sniffer probe 22 on the hood 12 and the stirring ability of the stirring fan 43 was also examined. However, it has been experimentally confirmed that these factors hardly affect the stability (or instability) of the He concentration detection by the gas detector 21. As shown in the measurement results of the above embodiment and the comparative example, the greatest key for stabilizing the He concentration detection is the presence / absence of the open air line 31 in the hood 12.

  In the present embodiment, as the hood 12 capable of defining an airtight monitoring space S in the outer adjacent area of the inspection target T by covering the inspection target T, the monitoring space S is separated from the hood 12 into an open air area. A hood 12 having an open air line 31 communicating with the hood 12 was used. Accordingly, the tracer gas concentration in the gas guided from the monitoring space S to the gas detector 21 can be measured while maintaining the state where the monitoring space S is communicated with the atmosphere opening region via the atmosphere opening line 31. As a result, an excessive suction negative pressure is avoided when gas is introduced from the monitoring space S to the gas detector 21, and gas communication between the monitoring space S and the gas detector 21 is extremely stabilized. Therefore, the detection of the tracer gas at the time of leak inspection is also stabilized, and it becomes possible to accurately determine the presence or absence of gas leak in a shorter time than in the past.

  In the present embodiment, not only the monitoring space S of the hood 12 but also the atmosphere open line 31 can be purged by supplying air from the external factory F2 before starting the leak inspection. For this reason, even if gas movement from the atmosphere open line 31 to the monitoring space S occurs due to gas introduction from the monitoring space S to the gas detector 21 at the time of leak inspection, gas entering the monitoring space S at that time Since this is the air itself as the reference gas, this cannot be a factor that disturbs the concentration of He gas leaked from the inspection object T into the monitoring space S.

  In particular, in the present embodiment, the air release line 31 is formed as a hose-like or tube-like tube material, and the internal volume over the entire length of the line is within the predetermined and sufficient predetermined inspection time (for example, 10 seconds). The probe 22 is set to be equal to or exceeding the volume of the gas guided from the monitoring space S to the gas detector 21. Therefore, there is no possibility that gas other than the reference gas filled in the atmosphere release line 31 by the gas purge operation is mixed into the monitoring space S through the line 31 at the time of leak inspection. Therefore, according to the leak inspection apparatus 10 and the leak inspection method using the apparatus of the present embodiment, it is possible to accurately determine the presence or absence of gas leakage even though the monitoring space S is not completely airtight.

  [Modification] The present invention may be modified in the following manner.

  As the tracer gas, hydrogen gas, hydrogen sulfide gas, carbon dioxide gas, or the like may be used instead of helium gas (He). Further, instead of air, nitrogen gas, argon gas, carbon monoxide gas, methane gas, or the like may be used as the reference gas.

  In the above-described embodiment, the hood 12 is configured as a cylinder having a single wall. However, the hood 12 may be configured as a multiple-structured cylinder having multiple walls to increase the confidentiality of the hood itself.

  In the above embodiment, the end 33 of the line 31 as the “communication path” may be connected to the downstream side of the gas detector 21. In that case, the gas sucked by the sniffer probe 22 is returned into the hood 12 via the line 31. That is, the downstream area of the gas detector 21 corresponds to “an external area other than the monitoring space”. Even if comprised in this way, the effect | action and effect similar to the said embodiment are acquired.

  In the above embodiment, a gas supply source such as a gas cylinder may be connected to the end 33 of the line 31 as the “communication path”. In that case, a gas corresponding to the volume of the gas sucked by the sniffer probe 22 can be supplied into the hood 12 from the gas supply source via the line 31. That is, the gas supply source corresponds to “an external region other than the monitoring space”. Even if comprised in this way, the effect | action and effect similar to the said embodiment are acquired.

  Needless to say, the present invention can be applied not only to the pressure integration method of JIS-Z2331, but also to the suction cup method (suction cup method).

[Appendix] Other technical ideas and preferred components are listed below.
I. (Delete)
B. In the leak inspection apparatus described in the claims, the covering member is a hood used at the time of inspection by the pressure integration method or a suction cup used at the time of inspection by the suction cup method.
C. In the leak test apparatus or leak test method set forth in the appended claims, reference gas of the reference gas source is a air leakage inspection apparatus taken from the installed laboratory or isolated locations from inside the building The tracer gas concentration in the air is equal to the tracer gas concentration in nature.

The block diagram which shows the outline | summary of the leak test | inspection apparatus according to one Embodiment. A graph of gas concentration over time showing an outline of preparatory operations up to the start of a leak test. The graph which shows the time-dependent change of the gas concentration used as the criterion of the presence or absence of leak. The graph which shows the time-dependent change of the gas concentration in an Example and a comparative example.

Explanation of symbols

10 Leak Inspection Device 12 Hood (Coating Member)
14 Tracer gas supply means 21 Gas detector 22 Sniffer probe 23 Air blow line in hood (first gas purge means)
26 In-line air blow line (second gas purge means)
31 Atmospheric open line (communication passage)
F2 Reference gas supply source S at the time of gas purge Monitoring space T Inspection object R Inspection room

Claims (6)

A leakage inspection device for inspecting gas leakage from an inspection object (T),
A covering member capable of defining an airtight monitoring space (S) in an outer adjacent region of the inspection object by covering all or a part of the inspection object;
Tracer gas supply means (14) for supplying tracer gas to the inside of the inspection object;
A gas detector (21) for detecting the concentration of the tracer gas;
A sniffer probe (22) attached to the covering member to guide the gas in the monitoring space defined by the covering member to the gas detector;
In order to compensate for the gas sucked out from the monitoring space via the sniffer probe, the monitoring space is communicated with an atmosphere open area separated from the covering member as an external area other than the monitoring space by a predetermined distance. A communication path (31) provided
A reference gas supply source (F2);
Gas purge means (23, 26) for supplying a reference gas from the reference gas supply source to the monitoring space and the communication path and purging the monitoring space and the communication path with the reference gas before starting the leak inspection And comprising
The communication path is formed as a hose-like or tube-shaped pipe, and the internal volume over the entire length of the communication path is a gas guided from the monitoring space to the gas detector by the sniffer probe within a predetermined inspection time. Leakage inspection apparatus characterized by having a volume greater than A leakage inspection device for inspecting gas leakage from an inspection object (T),
A covering member capable of defining an airtight monitoring space (S) in an outer adjacent region of the inspection object by covering all or a part of the inspection object;
Tracer gas supply means (14) for supplying tracer gas to the inside of the inspection object;
A gas detector (21) for detecting the concentration of the tracer gas;
A sniffer probe (22) attached to the covering member to guide the gas in the monitoring space defined by the covering member to the gas detector;
In order to supplement the gas sucked out from the monitoring space via the sniffer probe, the monitoring space is provided to communicate with a downstream region of the gas detector as an external region other than the monitoring space. The communication path (31)
A reference gas supply source (F2);
Gas purge means (23, 26) for supplying a reference gas from the reference gas supply source to the monitoring space and the communication path and purging the monitoring space and the communication path with the reference gas before starting the leak inspection and, the Bei example,
The gas purge means includes
A first gas purge means (23) for supplying a reference gas from the reference gas supply source to the monitoring space (S) and purging the inside of the monitoring space with the reference gas before starting a leak inspection; and
Before starting the leak inspection, the communication path (31) includes a second gas purge means (26) for supplying a reference gas from the reference gas supply source and purging the communication path with the reference gas.
Leak inspection device characterized by that. A leakage inspection device for inspecting gas leakage from an inspection object (T),
A covering member capable of defining an airtight monitoring space (S) in an outer adjacent region of the inspection object by covering all or a part of the inspection object;
Tracer gas supply means (14) for supplying tracer gas to the inside of the inspection object;
A gas detector (21) for detecting the concentration of the tracer gas;
A sniffer probe (22) attached to the covering member to guide the gas in the monitoring space defined by the covering member to the gas detector;
In order to supplement the gas sucked out from the monitoring space via the sniffer probe, the monitoring space is provided so as to communicate with a gas supply source including a gas cylinder as an external region other than the monitoring space. A passage (31);
A reference gas supply source (F2);
Gas purge means (23, 26) for supplying a reference gas from the reference gas supply source to the monitoring space and the communication path and purging the monitoring space and the communication path with the reference gas before starting the leak inspection and, the Bei example,
The gas purge means includes
A first gas purge means (23) for supplying a reference gas from the reference gas supply source to the monitoring space (S) and purging the inside of the monitoring space with the reference gas before starting a leak inspection; and
Before starting the leak inspection, the communication path (31) includes a second gas purge means (26) for supplying a reference gas from the reference gas supply source and purging the communication path with the reference gas.
Leak inspection device characterized by that. The gas purge means includes
A first gas purge means (23) for supplying a reference gas from the reference gas supply source to the monitoring space (S) and purging the inside of the monitoring space with the reference gas before starting a leak inspection; and
Before starting the leak test, the communication path (31) is supplied with a reference gas from the reference gas supply source, and comprises a second gas purge means (26) for purging the communication path with the reference gas. The leak inspection apparatus according to claim 1 . A leak inspection method for inspecting a gas leak from an inspection object (T) using the leak inspection apparatus according to any one of claims 1 to 4,
A covering step of defining an airtight monitoring space (S) in an outer adjacent region of the inspection object by covering all or a part of the inspection object with a covering member;
A tracer gas supply step of supplying a tracer gas in advance into the inspection object by the tracer gas supply means (14);
Before starting the inspection, the gas purge means (23, 26) from the reference gas supply source (F2) to the monitoring space (S) defined by the covering member and the communication path (31) provided in the covering member. A gas purge step of supplying a reference gas to purge the inside of the monitoring space and the communication passage with the reference gas;
The monitoring space is connected to the gas detector (21) through the sniffer probe (22) attached to the covering member while keeping the monitoring space in communication with the other external region via the communication path. Measuring the concentration of the tracer gas in the introduced gas over a predetermined inspection time, and
A leakage inspection method, wherein the presence or absence of gas leakage from the inspection object is determined based on a temporal change in the tracer gas concentration obtained in the measurement step. Based on the temporal change of the tracer gas concentration in the monitoring space (S) defined by the covering member that covers the inspection object in advance, the tracer gas is sealed inside the inspection object (T). A leakage inspection method based on a pressure integration method or a suction cup method for inspecting gas leakage from an object,
As the covering member, a hose-like or tube-like communication path that communicates the monitoring space defined by the covering member with an air release region that is a predetermined distance away from the covering member as the other external region, The communication path (31) in which the internal volume over the entire length of the communication path is equal to or larger than the volume of gas guided from the monitoring space to the gas detector (21) by the sniffer probe (22) within a predetermined inspection time. While using the covering member provided,
A leak inspection method for measuring a tracer gas concentration in a gas led from the monitoring space to a gas detector while maintaining the monitoring space in communication with the external region via the communication path.

Images