JP2007255939A - Instrument of measuring suspended particulate matter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve remarkable enhancement of measurement sensitivity and analysis performance without causing troubles such as hole breakage by appropriately and reasonably making proper use of a filter between short-time specifications and long-time specifications, with the filter having a layered structure comprising a porous film and a reinforcing layer. <P>SOLUTION: The filter 1 comprises the porous film 15 and the permeable reinforcing layer 16 layered thereon. A collection time switching means 27 is provided allowing switched use between collection time in a first state of use wherein the permeable reinforcing layer 16 is positioned on the upstream side of the flowing direction of a sample gas and collection time in a second state of use wherein the porous film 15 is positioned on the upstream side of the flowing direction of a sample gas. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to suspended particulate matter that is present in the atmosphere and adversely affects human health, particularly the respiratory organs, such as exhaust from automobile exhaust pipes and factory chimneys. Matter (hereinafter, abbreviated as SPM), and a suspended particulate matter measuring device used for analyzing components.

  In measuring the concentration and component analysis of SPM in the atmosphere, generally, a sample gas containing SPM is continuously sucked from the atmosphere, and the sucked sample gas is passed from one side of the filter to the other side. The SPM in the sample gas is collected so as to form a measurement spot on the filter, and the concentration of SPM is measured by irradiating the measurement spot with radiation such as β rays and detecting the amount of transmitted radiation. Or a suspended particulate matter measuring device that analyzes components by fluorescent X-ray analysis (XRF) or the like.

  Conventionally, as a filter used for the SPM measurement as described above, a single glass fiber or a porous film made of a fluororesin has been generally used.

Among them, a filter made of a single glass fiber cannot be made uniform in thickness, and the amount of radiation absorbed by the glass fiber is large. Therefore, the amount of transmission differs for each measurement spot, which is an error factor. Further, when the filter is made into a tape shape, in order to give a breaking strength (particularly tensile strength) that can withstand continuous use, the thickness must be increased (about 360 μm or more), and the weight is also increased. It must be (7mg or more). However, as the tape thickness increases, the amount of radiation absorbed by the glass fiber increases, so the minimum detection sensitivity (2σ) is 5 μg / m ³ or more, and it is difficult to detect low-concentration SPM with high sensitivity. Further, the glass fiber has a hygroscopic property of adsorbing moisture at the time of dew condensation, which causes an instruction error. Furthermore, since glass fiber has many components, it has many problems such as impractical use for component analysis of elements and ions in a state of being collected in a filter.

  On the other hand, in the case of a filter made of a single porous film made of a fluororesin, an error is likely to occur because the hygroscopicity due to moisture adsorption at the time of condensation is greater than that of glass fiber. In addition, since the chargeability is very large and it is easy to generate static electricity, when the filter is taped, the filter tape is moved and moved along a fixed path so that it is sequentially fed from the supply reel and taken up by the take-up reel. However, in the state set in the reel holder of the measuring device that continuously collects SPM and measures the concentration by irradiation, etc., the surrounding SPM is caused by static electricity generated on the filter tape wound around the supply reel. Since the SPM is attracted and attached, and the SPM is directly collected on the upper surface of the filter tape, when the filter tape is taken up and moved to move to the next measurement, the SPM collected at the measurement spot is filtered. It adheres strongly to the tape, and therefore SPM analysis cannot be performed accurately and accurately. In addition, since the porous film made of fluororesin has a lower tensile strength than glass fiber, it is necessary to increase the thickness in order to have a breaking strength that can withstand the use of the continuous measurement device as described above. Therefore, the weight (density) also increases, and the moisture absorption rate that causes measurement errors also increases. In addition, the charging half-life is also increased, and there is a problem that the required release property of the collected SPM is deteriorated at the time of component analysis such as ICP or ion chromatography that must be taken out of the filter. .

  In order to solve the problem that the strength is reduced if the filter made of a single glass fiber or a porous film made of a fluorine-based resin as described above is thinned, the present applicant A filter for measuring suspended particulate matter composed of a film and a breathable reinforcing layer laminated on the porous film has been developed and a patent application has already been filed (see Patent Document 1 below). The suspended particulate matter measurement filter according to the patent application can reduce the thickness of the filter itself compared to the above-mentioned glass fiber alone or a porous film alone made of a fluororesin. It is possible to improve the component analysis accuracy, and to provide a tensile strength that can sufficiently withstand the use of continuous measurement by laminating a breathable reinforcing layer.

JP 2004-205491 A

  By the way, in the suspended particulate matter measurement, for example, as defined in JIS and USEPA, sample gas is passed through the filter for 1 hour (when the component analysis of SPM collected by suction through the measurement spot is performed ( (Hereinafter referred to as a short-time specification) and when the sample gas is sucked through the filter for a long time of more than 1 hour and less than 24 hours to measure the concentration and component analysis of the SPM collected in the measurement spot ( In the suspended particulate matter measuring device according to the above-mentioned patent application by the applicant, there is a case where a hole is broken when the measurement time is long. .

  The present invention has been intensively researched based on the above-described knowledge, and the purpose of the invention is to provide a porous film and a reinforcing layer that have successfully solved the problems of a filter made of a single glass fiber or a porous film. Airborne particles that can achieve significant improvements in measurement sensitivity and component analysis performance without causing troubles such as broken holes by properly and rationally using laminated filters for short-time specifications and long-term use The object is to provide an object measuring apparatus.

    In order to achieve the above object, a suspended particulate matter measuring device according to the present invention allows a sample gas sucked from the atmosphere to pass from one side of a filter to the other side and be included in the sample gas in the filter. The suspended particulate matter collecting chamber section for collecting suspended particulate matter and forming a measurement spot, and the concentration measurement of the suspended particulate matter collected in the measurement spot in this chamber section and / or In the suspended particulate matter measuring apparatus having a measurement unit for performing component analysis, the filter is composed of a laminated structure of a porous film made of a fluororesin and a breathable reinforcing layer laminated on the porous film. The collection time in the first use state in which the breathable reinforcing layer of the filter is located on the one surface side, and the second use in which the porous film is located on the one surface side Collecting time switching means that can be used switching between collection time in state is characterized in that is provided.

  According to the present invention having the above-described characteristic configuration, the amount of radiation absorption can be reduced and the thickness can be made uniform by using a filter having a laminated structure of a porous film made of a fluororesin and a reinforcing layer. Since the fluororesin is used, the transmitted radiation intensity for each measurement spot can be made uniform. In addition, while the thickness of the filter itself is very thin, it is possible to ensure that its tensile strength is sufficient to withstand continuous measurement. By using such a thin filter, radiation transmission is possible. By increasing the amount, the minimum detection sensitivity (2σ) can be significantly improved (decreased), and low-concentration SPM can be measured with high sensitivity. Also, the hygroscopicity of the entire filter including the reinforcing layer is very low, and even if dew condensation occurs, it does not absorb and retain moisture, there is no alteration due to moisture absorption, and compared to a filter made of a porous film made of a fluororesin alone. In the case of component analysis in which the collected SPM must be taken out of the filter, such as IPC or ion chromatography, for example, and the marked concentration measurement sensitivity is significantly improved and there is no adhesion of SPM due to the generation of static electricity. It is also excellent in the release property of the collection SPM, and the component analysis performance can be improved.

  In addition, when using a filter having many advantages as described above, the filter in the first use state and the second use state can be attached, so that a breathable reinforcing layer is provided upstream of the sample gas flow direction. It is possible to collect SPM in the sample gas with a porous film located in the middle of the wall thickness instead of the surface of the filter by switching the collection time in the first use state located by the collection time switching means. In addition, when the filter is made into a tape shape, when the filter tape is moved and moved, the collected SPM is transferred to the filter tape part other than the measurement spot or the peripheral part of the tape traveling path, such as a radiation source or a detector. Switch the collection time in the second usage state where the porous film is positioned upstream of the sample gas flow direction to prevent adhesion. By switching in steps, the porous film that collects a lot of SPM is firmly supported by the reinforcing layer, and the measurement spot part of the porous film is greatly deformed or broken. Thus, it is possible to always achieve a remarkable improvement in the concentration measurement sensitivity and the component analysis performance by properly and rationally using both the front and back surfaces of the filter according to the SPM collection time.

  In the suspended particulate matter measuring device according to the present invention, as described in claim 2, the collection time setting in which the collection time in the first use state and the second use state of the filter can be set and changed separately. Of course, it is desirable to provide means.

  Moreover, in the suspended particulate matter measuring device according to the present invention, as described in claim 3, when the filter is formed in a tape shape, the filter tape is arranged on one side side from the center position in the width direction of the filter tape. It is preferable that the measurement spot is formed so as to be displaced along the predetermined route so as to be movable. In this case, since it is possible to secure a wide margin in the side portion of the measurement spot in the filter tape, the filter tape is separated in units of the measurement spot and is gripped by hand or tweezers, and other components such as ICP. When setting the analyzer, it is possible to eliminate contamination caused by a hand or tweezers or the like touching the measurement spot collection SPM by mistake. In addition, when extracting the collected SPM from the measurement spot of the separated filter tape portion, the separated filter tape portion is rounded and placed in a test tube or beaker. At this time, the SPM can be obtained by using a wide margin portion as a margin. Can be rounded and fixed in a state where it does not overlap the measurement spot being collected, and the influence of contamination can be further reduced.

  In particular, by setting the diameter of the measurement spot formed by being displaced to the one side from the center position in the width direction of the filter tape is set to be smaller than the standard diameter (about 16 mm), for example, about 11.5 mm, the margin portion. As described above, when the separation filter tape portion is gripped and set in another component analyzer, the separation filter tape portion is rolled up and placed in a test tube or the like to collect the SPM. The influence of contamination during extraction can be further reduced. In addition, by attaching a needle hole or a mark by printing to the margin part, when using another detector such as XRF following the suspended particulate matter measuring apparatus according to the present invention, the needle hole It is possible to improve the detection accuracy of other detectors by effectively using the mark and mark for accurate positioning with respect to the other detectors.

  Further, in the suspended particulate matter measuring apparatus according to the present invention, when a filter tape having a measurement spot diameter smaller than the standard diameter as described above is used, β as the radiation source as described in claim 4 It is desirable to use a radiation source and plastic scintillation as the detector. In this case, an improvement in measurement accuracy can be achieved by using plastic scintillation with less noise while minimizing the radiation dose that is undesirable in the interpersonal environment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the present embodiment, a description will be given of a filter formed in a tape shape (hereinafter referred to as a filter tape).
FIG. 1 is a schematic configuration diagram of the entire suspended particulate matter (SPM) measuring apparatus according to the present invention. The SPM measuring device 20 is fed out from the supply reel 2 set in the reel holder 2A, and is wound on a take-up roll 3 that is set on the reel holder 3A and driven to rotate via a motor 18. , 3 and the filter tape 1 stretched so as to be able to run and move in a predetermined length unit at regular intervals along a fixed path via the idle roller 4 with the filter retainer 4a and the two tension rollers 5 and 6. An introduction pipe 7 for sample gas G containing SPM sucked from the atmosphere by the sampling pump 17 is connected to one side of the movement path so that the filter tape 1 can move toward and away from the filter tape 1 via an actuator 19 such as a cylinder. A movable measurement chamber section (collection measurement chamber section) 8 is arranged.

  In the measurement chamber section 8, when the measurement section, that is, the sample gas G passes through the filter tape 1 from the one surface (upper surface) side to the other surface (lower surface) side, the SPM in the sample gas G is stored. A β-ray source (radiation source) 9 that irradiates β-rays to a measurement spot 10 (to be described later) formed by collection is provided, and on the other side of the travel movement path of the filter tape 1 A β-ray detector 11 composed of, for example, a proportional counter is arranged to detect β-rays transmitted through the measurement spot 10 and output a signal corresponding to the intensity.

  A thin plate-like member 12 is disposed between the β-ray source 9 and the filter tape 1 in a state of being fixedly supported by the chamber 8. This thin plate-like member 12 is clearly shown in FIG. Four or more exhaust holes 13 and 14 are formed. By passing the sample gas G through the exhaust holes 13 and 14, the SPM in the sample gas G is collected to form the measurement spot 10 described above. Like to do.

  The filter tape 1 has a length of about 21 m, for example, and a width W of about 4 cm, for example. Further, as clearly shown in FIG. 3, the filter tape 1 includes a porous film 15 made of a fluororesin such as tetrafluoroethylene resin, and a breathable reinforcing layer 16 laminated on the porous film 15. It is composed of

  The reinforcing layer 16 is made of polyethylene, polyethylene terephthalate, nylon, polyester, polyamide, or a laminate of polyethylene and polyethylene terephthalate, or a combination of two or more of the above, and a non-hygroscopic nonwoven fabric. It is comprised and is laminated | stacked and integrated with the said porous film 15 by appropriate means, such as affixing and sewing.

The porous film 15 of the filter tape 1 has a thickness in the range of 3 to 35 μm, and more preferably a filter weight in the range of 0.1 to 1.2 mg / cm ² .

  The laminated structure of the filter tape 1 is wound such that the reinforcing layer 16 is positioned inside the porous film 15 when wound around the supply reel 2, and the porous film 15. Are prepared so as to be wound so as to be located inside the reinforcing layer 16. The suspended particulate matter (SPM) measuring apparatus 20 according to the present invention is configured so that these filter tapes can be attached, and the former is set in the reel holder 2A, which is shown in FIG. As shown in FIG. 4B, the filter tape 1 is set in the first use state in which the breathable reinforcing layer 16 is located upstream of the sample gas G in the ventilation direction, and the latter is set in the reel holder 2A. ), The filter tape 1 is configured to be switchable to a second use state in which the porous film 15 is located upstream of the sample gas G in the ventilation direction.

  On the other hand, a pump driver 21 that controls the operation of the sampling pump 17, a reel motor driver 22 that controls the operation of the take-up reel drive motor 18, an actuator driver 23 that controls the operation of the actuator 19, and the drivers 21, 22, 23. Are input to the operation program memory 24 for controlling the operation in a preset order, the detection signal from the β-ray detector 11 and the measurement signal from the flow rate measuring unit 30 of the sample gas, and the concentration calculation or component analysis of the SPM is performed. An arithmetic control unit 26 such as a dedicated or general-purpose computer having a processing unit 25 has an SPM collection time due to the operation of the sampling pump 17 when the filter tape 1 is in the first use state, for example, JIS, USEPA. 1 hour as stipulated in When the filter tape 1 is switched to the second use state, the SPM collection time can be switched, for example, in two stages so that the SPM collection time by the operation of the sampling pump 17 is, for example, 1 hour or more and less than 24 hours Collection time switching means 27 and collection time setting means 28A, 28B are provided which can change the collection times of the first use state and the second use state separately.

  The SPM measuring operation by the SPM measuring apparatus 20 configured as described above can be performed in a short time (one hour specification) for component analysis specified in JIS and USEPA, and in a long time exceeding 1 hour and less than 24 hours. The description will be divided into long-term specifications for measuring the concentration and analyzing the components of the SPM collected by suction through the sample gas.

For short-time specifications:
(1-1) The supply reel 2 wound with the filter tape 1 wound so that the reinforcing layer 16 is positioned on the inner side of the porous film 15 is set on a reel holder 2A, and is fed out from the supply reel 2. When the tip of the filter tape 1 is fixed to the core of the take-up reel 3 set on the reel holder 3A side through the idle roller 4 and the two tension rollers 5 and 6, and when the operation of the apparatus is started, the reel is read from the operation program memory 24. When the operation signal is transmitted to the motor driver 22, the take-up reel 3 is rotationally driven via the reel motor 18, whereby the filter tape 1 follows a fixed path including between the measurement chamber 8 and the β-ray detector 11. The vehicle is moved and stopped by a predetermined length unit.

  (2-1) Next, after the actuator 19 is actuated by transmission of an operation signal from the operation program memory 24 to the actuator driver 23 and the measurement chamber 8 moves closer to the filter tape 1 side, the pump driver 21 is moved. After the sampling pump 17 is activated and the sample gas G containing SPM sucked from the atmosphere is introduced into the measurement chamber 8 through the introduction pipe 7, the sample gas G is as shown in FIG. The air-permeable reinforcing layer 16 on the upper surface side of the filter tape 1 is sequentially passed through the porous film 15 on the lower surface side (first use state). This state is maintained for the specified time (1 hour) switched by the collection time switching means 27, and the upper surface of the porous film 15 where the SPM in the sample gas G is the thick intermediate portion of the filter tape 1. And the measurement spot 10 is formed on the filter tape 1.

  (3-1) Subsequently, the β-ray source 9 irradiates the measurement spot 10 with β-rays, and the intensity of β-rays transmitted through the measurement spot 10 is detected by the β-ray detector 11 to detect the detection signal. And the measurement signal from the flow rate measuring unit 30 of the sample gas is input to the arithmetic processing unit 25, and the arithmetic processing unit 25 performs an operation using the detected β-ray intensity and a predetermined arithmetic expression, thereby SPM concentration analysis is performed.

  (4-1) After the SPM concentration analysis is performed as described above, the actuator 19 is activated by the transmission of the operation signal from the operation program memory 24 to the actuator driver 23, and the measurement chamber 8 is filtered by the filter tape. Then, the take-up reel 3 is rotated again via the reel motor 18 by the transmission of the operation signal from the operation program memory 24 to the reel motor driver 22, whereby the filter tape 1 is moved. It is moved to the take-up reel 3 side by a predetermined length unit, and the operations (2-1) and (3-1) are repeated on the filter tape 1 to perform a predetermined concentration analysis continuously.

  In the case of short-time specifications consisting of the operations (1-1) to (4-1) described above, the SPM in the sample gas G is not in the reinforcing layer 16 on the surface side of the filter tape 1 but in the middle of the tape thickness. Is collected by the porous film 15 positioned at the position of the filter tape 1 so that when the filter tape 1 travels, the collected SPM is filtered around the filter tape part other than the measurement spot 10 or the peripheral part of the tape travel path, such as the β-ray source 9 or There is no transfer adhesion to the detector 11 or the like. Therefore, the predetermined analysis performance can always be maintained in a high state.

For long-time specifications:
(1-2) The supply reel 2 on which the porous film 15 is wound so that the porous film 15 is positioned on the inner side of the reinforcing layer 16 is set on a reel holder 2A, and the filter tape 1 is fed out from the supply reel 2. When the tip of the filter tape 1 is fixed to the core of the take-up reel 3 set on the reel holder 3A side through the idle roller 4 and the two tension rollers 5 and 6, and when the operation of the apparatus is started, the reel is read from the operation program memory 24. When the operation signal is transmitted to the motor driver 22, the take-up reel 3 is rotationally driven via the reel motor 18, whereby the filter tape 1 follows a fixed path including between the measurement chamber 8 and the β-ray detector 11. The vehicle is moved and stopped by a predetermined length unit.

  (2-2) Next, the actuator 19 is actuated by transmission of an operation signal from the operation program memory 24 to the actuator driver 23 to move the measurement chamber 8 closer to the filter tape 1 side. After the sampling pump 17 is activated and the sample gas G containing SPM sucked from the atmosphere is introduced into the measurement chamber 8 through the introduction pipe 7, the sample gas G is as shown in FIG. The porous film 15 on the upper surface side of the filter tape 1 is sequentially passed through the breathable reinforcing layer 16 on the lower surface side (second use state). This state is switched by the collection time switching means 27, and the specified time (1 hour to less than 24 hours) longer than the first use state is maintained, so that the SPM in the sample gas G is on the upper surface side of the filter tape 1 The measurement spot 10 is formed on the filter tape 1 by being collected on the upper surface of the porous film 15.

  (3-2) Subsequently, the β-ray source 9 irradiates the measurement spot 10 with β-rays, and the intensity of the β-rays transmitted through the measurement spot 10 is detected by the β-ray detector 11 to detect the detection signal. And the measurement signal from the flow rate measuring unit 30 of the sample gas is input to the arithmetic processing unit 25, and the arithmetic processing unit 25 performs an operation using the detected β-ray intensity and a predetermined arithmetic expression, thereby SPM concentration measurement is performed.

  (4-2) After the SPM concentration measurement is performed as described above, the actuator 19 is activated by the transmission of the operation signal from the operation program memory 24 to the actuator driver 23, and the measurement chamber 8 is filtered by the filter tape. Then, the take-up reel 3 is rotated again via the reel motor 18 by the transmission of the operation signal from the operation program memory 24 to the reel motor driver 22, whereby the filter tape 1 is moved. A predetermined concentration is obtained by SPM collection over a long period of time by moving to the take-up reel 3 side in a predetermined length unit and repeating the operations (2-2) and (3-2) with respect to the filter tape 1. Measurements are made continuously.

In the case of long-time specifications consisting of the operations (1-2) to (4-2) described above, the porous film 15 that collects a large amount of SPM is firmly supported by the reinforcing layer 16. Therefore, the measurement spot 10 portion of the porous film 15 is not greatly deformed or broken, and a predetermined mass concentration or component analysis can be performed very accurately and accurately. it can.
In addition, it was confirmed that by providing the porous film 15 on the upper surface side, it was possible to collect SPM in one measurement spot 10 over a long period of time without causing breakage as compared with the first use state. did it.

  Further, in both the short-time specification and the long-time specification, the filter tape 1 having a laminated structure of the porous film 15 made of a very thin fluorine resin having a thickness of 3 to 35 μm and the breathable reinforcing layer 16 is used. By using it, it is possible to ensure sufficient tensile strength so that the filter tape 1 as a whole does not break during continuous measurement. Further, by using the porous film 15 having a very thin thickness within a range where sufficient tensile strength can be ensured, not only can the distribution of the collected SPM and the β-ray intensity be made uniform, but also β The amount of transmitted light is also increased, which makes it possible to significantly improve (decrease) the minimum detection sensitivity (2σ) and measure even a fine SPM with a small particle size with high sensitivity.

  Further, the hygroscopic property of the entire tape 1 including the reinforcing layer 16 is very low and moisture is not adsorbed and retained even if dew condensation occurs, so that the measurement sensitivity can be increased without deterioration due to moisture absorption. Furthermore, since it has a laminated structure with the reinforcing layer 16, the chargeability is very low compared to a filter tape made of a porous film 15 made of a fluororesin alone, and no SPM adheres due to generation of static electricity. Combined with the effect of properly and rationally using both the front and back surfaces of the filter tape 1 according to the SPM collection time, it is possible to further improve the predetermined concentration measurement sensitivity and component analysis performance.

  As described above, by using the filter tape 1 having the laminated structure of the porous film 15 made of a very thin fluorine resin having a thickness in the range of 3 to 35 μm and the breathable reinforcing layer 16, the collection and concentration of SPM are performed. Even in this continuous measurement, it is possible to ensure sufficient tensile strength so that the filter tape 1 does not break. In addition, since the porous film 15 having a very thin thickness is used as long as sufficient tensile strength can be ensured, the β-ray transmission amount is also increased, thereby significantly improving the minimum detection sensitivity (2σ). It is possible to measure (decrease) low-concentration SPM with high sensitivity. Further, since the fluororesin has a small amount of radiation (β-ray) absorption and can have a uniform thickness, the radiation intensity transmitted through each measurement spot 10 can be made uniform.

Incidentally, the test results conducted by the present inventor regarding the influence of the thickness of the porous film on the concentration measurement sensitivity and the component analysis performance will be described below.
Specimen Example product → Laminated structure of porous film made of ethylene tetrafluoride resin and breathable reinforcing layer
Comparative example products 1, 2 → Porous film made of tetrafluoroethylene resin Basic specifications and characteristics As shown in Table 1 Performance comparison As shown in Table 2

  In addition, an Example goods is a filter of the laminated structure of a porous film and a breathable reinforcement layer as above-mentioned. On the other hand, Comparative Examples 1 and 2 are filters made of only a porous film. In addition, since the thickness of the porous film having a thickness of 3 to 35 μm in the weight in Table 1 is insufficient for the porous film alone, the weight of the entire filter provided with the reinforcing layer on the porous film is shown. Yes.

  As is clear from the above test results, the sample product (filter) has a larger amount of sample gas ventilation and less pressure loss than the comparative sample products 1 and 2, and has a short charging half-life and static electricity. Occurrence is very low, moisture absorption is 0%, almost no hygroscopicity, β-ray transmission amount is about 2 to 4 times higher, so it has excellent mass concentration measurement sensitivity and can greatly improve measurement accuracy, It was confirmed that the collected SPM was excellent in releasability and effective in improving the performance of analyzing components such as elements and ions.

  In the above embodiment, the diameter D of the measurement spot 10 formed on the filter tape 1 is a standard 16 mmφ as shown in FIG. 5A, and the β-ray source 9 is a β-ray source. Although a description has been given of the case where the amount is 100 μCi and the proportional counter 11a having a large detection effective area is used as a detector, instead of this, as shown in FIG. 5B, the measurement spot diameter D1 is about 11.5 mmφ. The β-ray source amount may be 60 to 75 μCi, and the plastic scintillation 11b may be used as a detector.

  In this case, as the filter tape 1 is thinned, the distance between the β-ray source 9 and the detector 11b is reduced from L to L1, and the amount of β-ray source is reduced as the measurement spot diameter is reduced from D to D1. Can be reduced from 100 μCi to 60 to 75 μCi, so that not only an improvement effect in the interpersonal environment can be obtained, but it is also possible to use a plastic scintillation 11b instead of the proportional counter 11a having a large noise Thus, the measurement sensitivity and analysis performance can be further improved.

  Moreover, in the said embodiment, as shown to (A) of FIG. 6, what the measurement spot 10 with the diameter D (16 mm) is formed in the width direction center position of the filter tape 1 whose width W is about 4 cm is demonstrated. However, instead of this, as shown in FIG. 6B, a measurement spot 10 having a diameter D1 (11.5 mm) is formed at a location displaced from the center position in the width direction of the filter tape 1 to one side. As described above, the filter tape 1 may be stretched so as to be able to travel along the fixed path.

  In this case, since it is possible to ensure a wide margin (17.5 mm) 1a at one side of the measurement spot 10 in the filter tape 1, the filter tape 1 is adjacent as shown in FIG. When the measurement tape 10 is separated between the measurement spots 10 and 10 and the separated filter tape portion 1A is gripped by a gripping portion H such as a hand or tweezers and set in another component analyzer such as an ICP, the gripping portion H such as a hand or tweezers is Contamination due to erroneously touching the collection SPM of the measurement spot 10 can be eliminated. Further, when extracting the collected SPM from the measurement spot 10 of the separated filter tape portion 1A, as shown in FIG. 8, the separated filter tape portion 1A is rounded and put into an extraction container 30 such as a test tube or a beaker. At this time, by using the wide blank portion 1a as a margin, it can be rounded and fixed without overlapping the measurement spot 10 where the SPM is collected, and the influence of contamination is reduced even when the collected SPM is extracted. be able to.

  Further, in the case of the filter tape 1 shown in FIG. 6B, various analytical devices such as XRF and Fourier transform are provided following the SPM measuring device 20 by attaching a needle hole or a mark 31 by printing to the blank portion 1a. When other detectors such as an infrared spectrophotometer (FTIR) and a mass spectrometer (MS) are attached and used, the mark 31 is detected by, for example, an optical sensor (not shown), so that the other detectors can be detected. It is possible to improve the detection accuracy of other detectors by effectively using for accurate positioning.

  Furthermore, it is preferable to use the SPM measuring device 20 of the present invention in combination with weather devices such as anemometer, anemometer, solar radiation meter, temperature / humidity meter, barometer, rain gauge, soil moisture meter and the like. In this case, when aspirating the sample gas from the atmosphere, the sampling start signal is sent only when the preset weather conditions are met, and sampling is automatically stopped when the meteorological conditions are not met. Concentration measurement and component analysis can be performed with resolution.

  Furthermore, in the above embodiment, the specifications such as the thickness and weight of the porous film 15 and the breathable reinforcing layer 16 constituting the filter tape 1 have been described in detail. However, the present invention is limited to the specifications. In short, what is necessary is that the porous film 15 and the breathable reinforcing layer 16 are laminated.

  In the above embodiment, the filter is formed in a tape shape. However, the present invention is not limited to this, and as shown in FIGS. 9A and 9B, for example, a disc is used. It is also possible to form a filter 1A having a shape and use it for batch measurement.

  Furthermore, in the above-described embodiment, the SPM concentration measurement is performed by β-ray transmission in the measurement unit. However, the present invention is not limited to this, and for example, concentration measurement is performed by light scattering and electron beam transmission. May be. Although not shown in the figure, the component analysis of SPM can be performed instead of the concentration measurement or by providing, for example, XRF, FTIR, flow injection (FIA), MS, etc. continuously with the concentration measurement.

It is a schematic block diagram of the whole apparatus which shows embodiment of the suspended particulate matter measuring device which concerns on this invention. It is an expansion perspective view of the principal part explaining the formation operation of the measurement spot to the filter tape used for an apparatus same as the above. It is an expanded sectional view of the filter tape in the A section of FIG. (A) is a figure explaining the use condition of the filter tape at the time of short time specification, (B) is a figure explaining the use condition of the filter tape at the time of long time specification. (A) is the relationship between the filter tape, radiation source and detector used in the embodiment, and (B) is a schematic cross section of the main part showing the relationship between the filter tape, radiation source and detector used in the other embodiments. FIG. (A) is the specification of the measurement spot formed on the filter tape used in the embodiment, and (B) is an outline of the main part for explaining the specification of the measurement spot formed on the filter tape used in the other embodiments. It is a top view. It is a schematic plan view of the principal part explaining the state which isolate | separated the filter tape of the specification shown in (B) of FIG. 6 per measurement spot. It is a figure explaining the state which cut | disconnects the used filter tape shown to (B) of FIG. 6 in a measurement spot unit, and puts it into the collection SPM extraction container. (A), (B) is explanatory drawing of the use condition of another disk shaped filter which can be used for the measuring apparatus of this invention.

Explanation of symbols

1 Filter tape 1A Disc filter 9 β-ray source (radiation source)
DESCRIPTION OF SYMBOLS 10 Measuring sbot 11 Detector 11a Proportional counter 11b Plastic scintillation 15 Porous film made of fluororesin 16 Breathable reinforcement layer 20 SPM measuring device 27 Collection time switching means 28A, 28B Collection time setting means G Sample gas

Claims (4)

A suspended particulate matter that forms a measurement spot by passing a sample gas sucked from the atmosphere from one side of the filter to the other side and collecting the suspended particulate matter contained in the sample gas in the filter. In the suspended particulate matter measuring apparatus having a collection measurement chamber portion and a measurement portion that performs concentration measurement and / or component analysis of the suspended particulate matter collected at the measurement spot in the chamber portion,
The filter is composed of a laminated structure of a porous film made of a fluorine-based resin and a breathable reinforcing layer laminated on the porous film,
Switching between the collection time in the first use state in which the air-permeable reinforcing layer of the filter is located on the one surface side and the collection time in the second use state in which the porous film is located on the one surface. An apparatus for measuring suspended particulate matter, characterized in that a possible collection time switching means is provided.   The suspended particulate matter measuring device according to claim 1, further comprising collection time setting means capable of setting and changing the collection time in the first use state and the second use state of the filter.   The said filter is tape-shaped, The said collection measurement chamber is comprised so that it may displace to the one side side from the width direction center position of the said tape-shaped filter, and it is comprised. The suspended particulate matter measuring device described. The suspended particulate matter measuring device according to any one of claims 1 to 3, wherein the radiation source constituting the measurement unit is a β-ray source, and the detector is plastic scintillation.

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