JPH10170412A - Gas collecting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas collecting device wherein, without damaging a to-be- examined object, a to-be-inspected gas released from the to-be-examined object is collected. SOLUTION: A collection cover 12 is formed to hemispherical shape, in specified thickness, using a transparent material, and a introduction opening 14 for taking a purified air into the collection cover 12 and a discharge opening 16 which supplied the air containing a toxic gas in the collection cover 12 to a gas inspection device, are provided. At the periphery part of an opening part 12a of the collection cover 12, a packing 18 of soft rubber, etc., is attached, and the opening part 12a is pressed to the packing 18 on the inspecting surface of an object 20. The purified air introduced into the collection cover 12 from the introduction opening 14 is obtained by purifying the outside air with the catalyst in a pre-filter 24.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas collecting device used in a gas inspection device for collecting and analyzing a gas to be inspected in air and provided in a gas collecting portion.

[0002]

2. Description of the Related Art In recent years, in houses using new building materials, volatile organic compounds such as formaldehyde are radiated from the building materials.
This may become a harmful gas and adversely affect the human body. Ammonia gas generated from concrete or paint accelerates the deterioration of exhibits in museums and museums, and may cause product defects in clean rooms such as semiconductor manufacturing plants. In examining countermeasures against these harmful gas problems, it is extremely important to not only measure the concentration of harmful gas components in the air, but also to investigate the sources and clarify the gas emission rates.

Conventionally, various methods have been put to practical use for collecting and analyzing harmful gas in the air inside a building. However, an effective method for specifying the source and amount of emission (generation rate) has been used. There was no technology. Only JIS A 5980 "Particle Board" defines a method for measuring the amount of formaldehyde emission from wood-based building materials. In this method, the material to be investigated is cut into strips, placed in a sealed container (glass desiccator) together with distilled water in a dish, and left for a predetermined period of time to naturally dissolve formaldehyde in distilled water. And let them collect.

[0004]

However, in the conventional method for investigating harmful gas, the amount of formaldehyde emission per unit time can be detected by inspecting the collected distilled water. However, this method requires cutting a specimen from the material to be investigated. Since the specimen is cut in this way, the existing building cannot be damaged and inspected, resulting in a problem that the applicable range is extremely limited.

[0005] In view of the above-mentioned problems, it is an object of the present invention to provide a gas collecting device capable of collecting a gas to be inspected emitted from the object without damaging the object. And

[0006]

In order to achieve the above object, a gas collecting instrument according to the present invention is provided by pressing against a surface of an object to be inspected to cover an inspection area with a predetermined area in a sealed state. A collection cover for collecting the gas to be inspected spontaneously radiated from the inspection object; the collection cover has an inlet for introducing a reference gas into the collection cover; and a gas inlet for the inspection gas in the collection cover. An exhaust port for supplying the mixed reference gas to the gas inspection device is provided.

According to a second aspect of the present invention, there is provided a gas trapping device according to the present invention, wherein a resistance tube is provided at the discharge port to adjust a flow rate of a reference gas mixed with a gas to be inspected discharged from the trapping cover. Configuration.

The operation of the gas collecting device of the present invention having the above-described structure will be described below. In the gas collecting device according to the first aspect, the inside of the collecting cover is closed by pressing the collecting cover against the surface of the inspection target, and the gas to be inspected emitted from the inspection target can be confined in the collection cover. it can.
Then, the gas to be inspected collected in the collection cover is mixed with the reference gas taken in from the inlet and supplied to the gas inspection device from the outlet. Therefore, the gas inspection device only needs to separate and detect the gas to be inspected mixed with the reference gas, and can easily detect the amount of radiation per unit time of the object to be investigated without damaging the object to be investigated. .

Further, the gas collecting instrument of the present invention is configured such that a resistance tube is provided at the discharge port to adjust the flow rate of the reference gas mixed with the gas to be inspected discharged from the collecting cover. Therefore, when the reference gas inside the collection cover is sucked from the outlet, it is possible to prevent the negative pressure inside the collection cover from becoming excessively large. Therefore, it is possible to prevent the outside air from entering the inside of the collection cover from the sealed portion at the periphery of the opening of the collection cover, and to forcibly dissipate the gas to be inspected from the inspection target due to the outside air. Can be prevented, and the inspection accuracy of the gas to be inspected can be improved.

[0010]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. 1 and 2 show an embodiment of the gas collecting device of the present invention, FIG. 1 is a perspective view of the gas collecting device, and FIG. 2 shows the relationship between the length and the flow rate of a resistance tube used in the present embodiment. FIG.

That is, as shown in FIG. 1, the gas collecting device 10 of the present embodiment includes a collecting cover 12 formed of a transparent material in a hemispherical shape having a predetermined thickness. An inlet 14 for taking the purified air used as the air into the collection cover 12 and an outlet 16 for supplying the air containing the harmful gas in the collection cover 12 to a gas inspection device (not shown) are provided to face each other. ing. The gas inspection device forcibly sucks the air in the collection cover 12 by an air pump.

A packing 18 made of soft rubber or the like is attached to the periphery of the opening 12a of the collecting cover 12, and the opening 12a is formed on the surface of the object 20 to be investigated through the packing 18. It is pressed. Also,
A spirally wound capillary tube 22 is connected to the outlet 16 as a resistance tube, and the capillary tube 22 suppresses the flow rate of air caused by the suction of the air pump to a low speed.

The purified air introduced into the collection cover 12 through the inlet 14 is obtained by purifying the outside air through a catalyst filled in a pre-filter 24. In this case, as the catalyst filled in the pre-filter 24, activated carbon, porous polymer beads, molecular sieves, chemical filters and the like are appropriately selected and used according to the type of the gas to be measured. As shown by a two-dot chain line in FIG. 1, instead of the pre-filter 24, a gas bag 26 filled with purified air used as a reference gas or nitrogen gas that can be used as a reference gas is used. By connecting to the inlet 14, the reference gas in the gas bag 26 can be taken into the collection cover 12.

With the above configuration, the gas collecting device 10 of the present embodiment is constructed such that the capillary tube 22 connected to the outlet 16 of the collecting cover 12 is connected to a gas inspection device (not shown). The pre-filter 24 is connected to the inlet 14 of the collection cover 12 while the opening 12 a of the sample 12 is pressed against the inspection site of the target 20 to be investigated. At this time, the opening 12 of the collection cover 12
Since the soft packing 18 is provided in a, the opening 12a can be sealed by the packing 18 when the opening 12a is pressed against the surface of the inspection target 20. In addition, since the collection cover 12 is formed transparent, when the collection cover 12 is pressed against the inspection target 20, the installation state can be confirmed and the state of the surface of the inspection target 20 can be easily observed. .

When air is sucked from the outlet 16 by the air pump of the gas inspection device, the air purified by the pre-filter 24 from the inlet 14 by the amount of the sucked air flows from the inlet 14 into the collection cover 12. Incorporated in. At this time, the harmful gas radiated from the investigation target 20 is collected in the sealed collection cover 12, and the collected harmful gas is mixed with the purified air taken in from the introduction port 14, and is mixed with the exhaust port 16. From the gas inspection device. Then, the air sucked for a predetermined time by the air pump is collected by a gas inspection device, and the inspection of the harmful gas contained in the collected air is quantitatively analyzed by a chemical method.

At this time, the amount of harmful gas emission from the portion covered by the collection cover 12 can be obtained by the following equation. Gas emission amount = amount of collected gas / (opening area of collection cover x collection operation time)

In the present embodiment, a capillary tube 22 is connected to the outlet 16 of the collecting cover 12 to add resistance to the flow of air sucked from the inside of the collecting cover 12 to the gas inspection device, thereby increasing the flow rate. Is reduced, it is possible to prevent the negative pressure inside the collection cover 12 from becoming excessively high when the air inside the collection cover 12 is sucked from the outlet 16. Therefore, although the packing 18 is provided around the periphery of the opening 12a of the collection cover 12 to seal it, outside air can be prevented from entering the collection cover 12 from the sealed portion due to excessive negative pressure. In addition, it is possible to prevent the harmful gas from being forcibly dissipated by the invading outside air, and to improve the accuracy of gas inspection.

As shown in FIG. 2, by appropriately selecting the inner diameter and length of the capillary tube 16, the flow velocity of the air can be arbitrarily set at a low speed and stably. FIG. 2 shows a tube made of polytetrafluorocarbon (trade name: Teflon) and a capillary tube 2
2 shows the result of measuring the relationship between the length and the flow rate when used as 2.

The capillary tube 22 is connected to the outlet 1
6 is shown, but the present invention is not limited to this. If there is a possibility that a measurement error may occur due to the gas to be measured adsorbed inside the capillary tube 22, the capillary tube 22 is connected to the air pump of the gas inspection device. It may be connected to the downstream side.

Therefore, the gas collecting device 10 of the present embodiment is
By simply pressing the collection cover 12 against the surface of the inspection target 20, the harmful gas can be collected and inspected by the gas inspection device, so that it is not necessary to cut out the test piece from the inspection target 20. For this reason, it is possible to easily measure the amount of gas emission at an arbitrary portion even in an existing building after the construction, in addition to the material inspection before the construction.

In addition, building materials are often used in combination of different materials. For example, even in the case of a combination in which an adhesive is applied to concrete and a finishing material is stuck, the building material is actually used in a state where it is constructed. Measurement is very useful for investigating gas emission phenomena. Further, conventionally, the concentration of harmful gas in a building is detected only as an average concentration in a large space. However, by using the trapping gas appliance 10 of the present embodiment, the harmful gas concentration is radiated from individual materials. Since it is possible to investigate the amount of gas per unit area, it is easy to consider measures to prevent harmful gases.

By the way, the inlet 1 of the collecting cover 12
4, a case is described in which a pre-filter 24 is connected so that the purified outside air is introduced into the collection cover 12. However, instead of the pre-filter 24, a gas bag 26 is used.
In the case where is used, the gas in the gas bag 26 is taken into the collection cover 12 as the air is sucked from the outlet 16.

[0023]

As described above, in the gas collecting device according to the first aspect of the present invention, a collecting cover is provided for pressing against the surface of the object to be investigated, and the reference gas is introduced into the collecting cover. Since a mouth and a discharge port for supplying a reference gas mixed with the gas to be inspected to the gas inspection device were provided, the trapping cover was pressed against the surface of the inspection target to collect the gas in the collection cover. The gas to be inspected can be mixed with the reference gas taken in from the inlet and supplied to the gas inspection device from the outlet. Therefore, by simply pressing the collection cover against the surface of the object to be inspected, the gas to be inspected emitted from the object to be inspected can be collected and inspected by the gas inspection device, so that the specimen is cut out from the object to be inspected. There is no need. For this reason, it is possible to easily measure the amount of gas emission at an arbitrary portion even in an existing building after the construction, in addition to the material inspection before the construction. In addition, even when the survey target is a composite of heterogeneous materials, measurement can be performed in the actual construction state, and gas per unit area released from individual materials in the constructed building Since the amount can be investigated, it is extremely useful for investigating gas emission phenomena.

According to a second aspect of the present invention, there is provided a gas collecting device, wherein a resistance tube is provided at the outlet to adjust a flow rate of a reference gas mixed with a gas to be inspected discharged from the collecting cover. With this configuration, it is possible to prevent the negative pressure in the collection cover from being excessively increased when the internal reference gas is sucked from the outlet. Therefore, it is possible to prevent outside air from entering the inside of the collection cover from a sealed portion around the opening edge of the collection cover, and to prevent the inspection target gas from being forcibly dissipated by the outside air. This provides various excellent effects that the inspection accuracy of the gas to be inspected can be improved.

[Brief description of the drawings]

FIG. 1 is a perspective view of a gas collecting device according to an embodiment of the present invention.

FIG. 2 is a characteristic diagram showing the relationship between the length and the flow rate of a resistance tube used in the gas collecting device according to one embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Gas collection apparatus 12 Collection cover 14 Inlet 16 Outlet 18 Packing 20 Survey target 22 Capillary tube (resistance tube)

Claims (2)

[Claims] 1. A collection cover that presses against a surface of a subject to be inspected to cover an inspection site with a predetermined area in a hermetically sealed state, and that collects a gas to be inspected spontaneously radiating from the subject to be inspected. A gas inlet, for introducing a reference gas into a collection cover, and an outlet for supplying a reference gas mixed with a gas to be inspected in the collection cover to a gas inspection device. Appliances. 2. The gas collecting apparatus according to claim 1, wherein a resistance tube is provided at the outlet to adjust a flow rate of a reference gas mixed with a gas to be inspected discharged from the collecting cover. Appliances.