Device for collecting charged particles with the aid of an ionizer for purposes of analysis

(54)

PATENT HOLDER Rolf Nybom, Börjesons väg 42 161 55 Bromma SE

INVENTOR'S OFFICE NAME

Rolf Nybom, Bromma SE

Bäckström Leif Protector AB

Device for collecting charged particles for analysis by means of an air ionizer (56) (57)

CALLED PUBLICATIONS: - - SUMMARY:

The invention relates to a device for collecting ionizer 1, 5, 6, 7, which is equipped with a collector (4) for the capture of charged particles, from air or from other gas by means of said ions charged particles. These are then intended to be analyzed in a particle analysis analyzer set up for this purpose.

The feature of the invention is that it comprises an electrically conductive capture device 2 which is electrically coupled to the collector 4 of said ionizer 1.

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The numbers in brackets indicate international identification code, INID code. Letters in clamps indicate international document code.

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The invention relates to a device for collecting ion-emitted ionizer, which is equipped with a collector 10 for trapping charged particles, from air or from other gas by means of said ions charged particles. These trapped particles are then intended to be analyzed in a particle analyzer set up for this purpose.

Capturing small particles from air and / or other gases, for example mold spores, bacteria, viruses, dust, pollen, smoke, plant parts, fungal spores, allergens, particles from animals, etc. is usually difficult.

Using an ionizer, ie. an apparatus which generates and emits electrically charged ions to the air, and especially if said ionizer is additionally equipped with a collector which gives an opposite polarity to said ions, these electrically charged ions will adhere to existing in the air small particles and said electrically charged particles will thereby endeavor to collect on said collector. In this case, the few particles that are normally present in the air are collected and concentrated by the effect of the electrostatic field on the collector. These collected or clustered particles can then be removed from the collector, for example, by scraping, and inserted into a suitable analyzer, for example, a scanning electron microscope, for further analysis, for example, to determine the size, amount and species of the particles.

The above method has proven to be very successful in terms of achieved measurement results and subsequent analysis, but is in itself not well adapted or suitable for rational analysis work.

Examples of these are the cases where one wishes to make continuous ^: 35 aerial examinations for longer periods of time in a space, but each individual examination should include a shorter time, which assumes that a large number of ionizers are required and that each ionizer is submitted for analysis.

^: Another exemplary case is when you want to analyze the air in each individual room in a building with many etc., for example to check how efficient the air exchange really is in a building's individual room and / or to determine if any ^: contamination cures (for example, bacterial accumulations) in the channels of a filter or air conditioning system, which cases also require. 45 on a large number of ionizers, in fact one for each room, which ionizers are then each sealed and sent to an analysis center.

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In any such assay, the trapped particles must be scraped or otherwise appropriately removed from the ionizer collector prior to analysis and in such removal other particles may be accidentally added or particles removed from the sample without these other particles being included in the original sample; i.e. Scraping off particles from the ionizer prior to analysis is a source of error per se.

In principle, this known method is thus not adapted to and suitable for larger-scale sampling.

The above disadvantages have been eliminated and have been reduced by the device 15 of the present invention mentioned in the description introduction by including an electrically conductive capture device which is electrically connected to the collector of said ionizer. A particularly advantageous solution according to the present invention is about said capture. device is disposed exposed, preferably detachable relative to the collector of the ionizer, and if said capture device is formed substantially as a bowl and if said capture device is adapted to and arranged to be covered with a cover after completion of collection.

Other embodiments of the invention will be apparent from the appended claims and from the description below of various embodiments of the accompanying drawings, in which Fig. 1 is a perspective view of an ionizer having a first type of capture device, which is, however, shown somewhat separate from the normal position of the ionizer for to clarify the design of the ionizer collector 30 and the capture device; 2 Fig. 3 is a perspective view of a protective cap adapted to the first type of capture device; Fig. 3A shows in perspective view a second type of catching device with ears which is viewed obliquely from above;

Fig. 3B shows the catching device with ears according to Fig. 3A but seen from below; part of said third embodiment, viewed obliquely from above, fig.

Fig. 5B shows the remainder of said third embodiment in perspective view and seen from below, and Fig. 6 shows in perspective the first type according to Fig. 1 of the capturing device but seen from below.

An ionizer 1 of Fig. 1 comprises a box in which ^: required electrical and electronic circuits are housed. ionizer_: 1 may optionally be mains powered or battery operated. The circuitry of the electrical circuits is not part of the present invention and is a per se known technique, so they are not described in detail herein. At one end of said ionizer 1, a number of, preferably negative ions emitting means 5, 6, 7 are located and these are formed with

516 188 electrically and mechanically protective sleeves 5a, 6a, 7a, which surround and protect the ions emitting tips 5, 6, 7. It should be noted here that said tips 5, 6, 7 are directed away from the ionizer 1 and located far distance from a collector 4 built into the ionizer 1, which is given an electrical potential opposite to the emitting means 5, 6, 7. In addition, it should be noted that the operating surface of said collector 4 is relatively large and that in the embodiment shown here it is advantageously designed at least partially submerged in the ionizer 1.1 bottom of the collector 4, a preferably central recess 4a is located, whose task is primarily to control and electrically connect the collector 4 to the various capturing devices 2, 9, 13, 15, which can be used in the collector 4 of the ionizer.

Ionizer 1 works as follows. Ions, ie electric. charged, preferably negatively charged particles, are emitted from the tips 5, 6 and 7 in a direction away from the ionizer 1 and especially in a direction away from its collector 4 which has been given an electrical potential which tends to attract those from the tips 5. 6 and 7, the ions are emitted, which potential is preferably positive. As a result, said ions tend to migrate from the tips 5, 6 and 7 in a wide arc to the collector 4 of the electrostatic field generated between the tips 5, 6 and 7 and the collector 4, while said ions hit small particles in the air and these particles. is thereby also charged and influenced to follow the electrostatic field in the direction of the collector 4. Some of these charged particles 30 reach all the way to the collector 4, where they encounter an intercepting device 2 applied to the collector 4, the latter being located in the recess 4 intended for this purpose in the collector. Several particles from the air are gradually collected on the capture device 2 as ions are emitted from the tips 5, 6 and 7 and form accumulations 35 or so-called clusters of particles on the capture device 2. In addition to collecting particles from the air, the said in the movement of charged particles through the air up to the collecting device 2 also produces a certain, limited stirring of the air in a limited space (= room), which results in further particles being drawn into said movement. , why, the ionizer 1 has a stirring effect on the air, which in effect quickly - within, for example, an hour - can quickly ^: affect a whole mm of about 20 square meters to a relatively large extent.

The ionizer collector 4, for example, consists of an electrically conductive metal or of an electrically conductive plastic or has been provided with an electrically conductive coating and has been given an electrically active surface which, in relation to an intercepting device 2 for

516 188 particles are advantageous but not necessarily larger than the latter's active surface. The capture device 2 is adapted to be fixed in position when it is inserted into the upper side of the recess 4 for the recess, for example by means of a pin 3 projecting from its rear side, which is arranged to mechanically and electrically cooperate with a narrow recess 4a, carefully matched in size to said pin so that safe electrical contact is thereby created between the collector 4 of the ionizer and the capture device 2, allowing for simple removal of the capture device 2 from the collector 4 of the ionizer 1 after completion of the acquisition.

The FIG. 1 and the capturing device 2 shown in FIG. 6 is essentially formed as a bowl with easily graspable and exterior, e.g., sliding edge of the collector 4, whereby the capture device 2 can be easily and smoothly applied to the collector 4 of the ionizer 1 and removed therefrom without unnecessarily risking to affect in some material respect the particles that have accumulated on the upper side (= the bowl-shaped side) of the capture device 2 by essentially only gripping its projecting edge when moving the capture device 2 relative to the collector 4 of the ionizer 1. To reduce the risk of contamination even more, after the collection of particles, after the collection of particles but before removal from the collector 4 of the ionizer 1, the capture device 2 can be provided with a lid 8 carefully matched to the capture device, see fig. 2, which is adapted to snap around the edge of the capture device 2 and remain so during the removal of the capture device 2 from the collector 4 of the ionizer 1 and during further transport to an analytical instrument, for example an electron microscope or other suitable instrument, which may be on a completely different site and at a long distance from the site where ionizer 1 has been placed for conducting the present study.

Figures 3A and 3B illustrate a second embodiment of the ionizer 1's capture device and this second embodiment includes projecting ears 11, 12 projecting from the capture device which extend to be easy to grip relative to the collector 4. of the ionizer 1. Here, the shown lid, not shown, can - if desired or required - also be used in the present case to protect the collected particles and prevent contamination thereof. Upon completion of collection, the second embodiment of the capture device is removed from the collector 4 of the ionizer 1 and transferred to an analyzer, while a new capture device is inserted into the ionizer 1, and new particle capture is started, at the same or different location.

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In order to further improve the analysis work - as can be seen in particular from Figures 4A, 4B, 5A and 5B - a third embodiment of the capture device can be used. This third embodiment comprises a first portion 13 which is placed in electrical and mechanical contact via its central portion 14 with the collector 4 of the ionizer 1 via its central recess 4a, and a second portion 15 which has been given substantially less active surface than the first portion. 13 and which has been advantageously treated in advance to react primarily or solely to and that a particular type of particle or substance strikes its surface. One type of such treatment is referred to as the second portion 15 having been capped.

This makes it possible to capture and detect an extremely low concentration in the air of the particular type of particle or substance. Advantageously, the second portion 15 is made in size and design to fit exactly in and is adapted for the subsequent analyzing instrument, which may be, for example, an electron microscope.

Variations of the invention are of course possible within the scope of the appended claims.

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