[en] This invention relates to detectors of the ionization type for detecting airborne particulate matter and, in particular, to the construction of an ionization chamber for such a detector. This invention may be used for detecting a variety of materials, such as dust, fog and the like, but is particularly useful for detecting combustion products such as smoke. The smoke detector ionization chamber has two electrodes connected to a source of electric power; means defining access openings for enabling air flow into and out of the chamber; and means for causing ionization within the chamber. It has control structure means within the chamber in the path of the airflow cooperating with the electrodes to establish within the chamber an electric field having a higher intensity close to the access openings and a lower intensity in the remainder of the chamber without significantly impairing the flow of neutral particles into the chamber. The control structure reduces airflow velocity within the chamber without adversely affecting the access of airborne particles to the chamber

[en] In the Philippines, ICSDs had been in use before the regulatory body was established. They have been installed in private houses, commercial establishments, public buildings, hotels, airports, hospitals, schools, cinemas and other public places. In the Philippines smoke detectors are a fire safety requirement and need to be installed before a building is occupied. Smoke detectors may be ionizing or photoelectric and even dual mode, but the most common smoke detectors available in the country are ICSDs. There are no manufacturers of ICSDs in the Philippines and they are not exported. All smoke detectors available in the market are imported by several companies. These were distributed through retail sales or bulk order for use in large buildings; they are installed by individual consumers for residential use only if instructions are provided on how to install them. For buildings requiring several hundreds of ICSDs, these are installed by authorized workers (typically, the contractor is engaged by the owner of the building). After 10 years of service life, as recommended by the manufacturers, ICSDs are removed from service by the consumer or other authorized workers (demolition contractors, safety officers, etc.). Ionization smoke detectors are available in hardware stores, some of which are located in shopping malls.

[en] In China, there are ICSD manufacturers, ICSD importers and ICSD exporters. The manufacturing of ICSDs requires approval by the regulatory body. Imported and exported ICSDs are required to be registered with the regulatory body. Therefore, the number of ICSDs in China is well known to the regulatory body. ICSDs are often installed in public and crowded places such as warehouses, shopping centres, hotels, museums, libraries, movie theatres and so on. ICSDs have also been installed in living areas (households). The service life of ICSDs is generally 5–10 years in China. In the past, ICSDs represented about 70% of all smoke detectors in China but currently the market for ICSDs is decreasing, especially since 2014. Photoelectric detectors are gradually replacing ICSDs. In the past the national repository charged the users for the collection of disused ICSD. Since 2017, the government has requested that the national repository receive disused ICSDs cost free. The most common ICSD radionuclide is 241Am. The use of other radionuclides requires approval by the regulatory body. So far, there have been no incidents or accidents due to the use of ICSDs that have impacted the national policy.

[en] ICSDs are an important component of fire safety systems in Canada. Both ICSDs and non‑radioactive smoke detectors are important components which contribute to the effectiveness of overall fire safety systems. Canada presently does not have any manufacturers or large‑scale exporters of ICSDs. As such, Canada is an importer of any ICSDs which are in use. The Canadian nuclear regulatory regime provides specific exemptions to regulation for ICSDs which meet certain performance criteria related to the ICSD’s radiation safety. These exemptions do not apply to the initial importers/distributors or any manufacturers of ICSDs in Canada. Distribution of exempted ICSDs within Canada is generally performed through retail sales channels. Installation and removal of these exempted ICSDs can be performed by consumers or their contractors. The distribution, installation and removal of any ICSD which does not meet regulatory requirements for exemption are required to be performed by an entity licensed and authorized by the Canadian Nuclear Safety Commission. As the disposal of most ICSDs in Canada is exempted from regulation by the nuclear regulator, a current estimate of the number of ICSDs is unknown. However, recent inventory levels at sites licensed to import, distribute or possess non‑exempt ICSDs totalled an inventory of approximately 260 000 units. Although the service life of ICSDs are specified by the manufacturer, ICSDs have approximately a 10–15 year recommended period of use.

[en] Albania does not have any ICSD manufacturers, importers or exporters. The import of ICSDs is prohibited and there is a ban on their use. A campaign to determine the number and types of ICSDs in Albania indicated that there are only a few ICSDs in the country, but their origins were not determined. Based on available information, ICSDs were never distributed or installed in Albania, except for the few mentioned above. Therefore, the guidance provided in Annex 1 is not applicable (i.e. a report on where and how were they installed, how were they removed from service, how were they collected and what is the recommended service life).

[en] The variety of gas locations in the country, makes that the gas that will be distributed by the net of present gas pipeline a very different composition, what bears to that these they behave in a different way during its use. In this work the main characteristics of the combustion are calculated for the Colombian gases, basically the properties of the combustion and the characteristics of the smoke, as basic information for the design and operation of the gas teams and their certification. These properties were calculated with the special help software for combustion developed by the authors

[en] An ionization-type particle detector is described that has an insulating base which mounts an inner electrode provided with a source of ionizing radiation which directs a generally conical beam perpendicularly away from the base; an intermediate cylindrical electrode symmetrically disposed around the inner electrode which has an open upper end through which the radiation beam exists from a compensation zone defined by the inner and intermediate electrodes; and an outer cup-shaped electrode symmetrically disposed about the intermediate electrode and which defines therewith a sensing zone into which radiation enters from the top opening in the intermediate electrode. The sensing zone is divided by the envelope of the radiation beam into an upper bipolar region and a lower unipolar region. The height and diameter of the intermediate electrode is selected relative to that of the outer electrode such that a decrease in ionization current between the intermediate and outer electrodes in the presence of smoke is attributable approximately 75% to a decrease in ionization flowing in the unipolar zone and approximately 25% to a decrease of current flowing in the bipolar zone. Slots in the outer electrode are configured such that air enters tangentially to avoid turbulence. The slots do not extend below a point equal to approximately the height of the intermediate electrode thereby blocking substantially the entirety of the compensation zone and approximately 50% of the unipolar region of the sensing zone from direct air flow paths via the slots. Full and partial blocking of the type described coupled with tangential air introduction enhances the insensitivity of the detector to variations in environmental air velocity

[en] Amendments to the Executive Order no. 154 of March 6th, 1990, on smoke detectors and consumer products containing radioactive substances are that, in the case of import of smoke detectors containing radioactive substances from a member country of the European Economic Community (EEC), the existing legislation as found in the Council of the European Communities' statutory order no. 93/1493/Euratom of June 8th, 1993 on transport of radioactive materials between member states is to be referred to. In the case of import of smoke detectors containing radioactive substances from a country not a member of the EEC the decisions of the (Danish) National Board of Health found in the boards executive order no. 546 of June 23rd, 1993 on transport of radioactive substances are to be referred to. Annex 4 is annulled. (AB)

[en] In Thailand, there are no ICSD manufacturers or exporters. There are ICSD importers. Currently, all radioactive materials need authorization. Each importer and user needs to declare the total amount of radioactive material for each consignment to the regulatory body. However, not all authorized importers have reported ICSD distribution to the regulator, therefore records of the distribution of radioactive material are incomplete. ICSDs were normally installed in institutions, hotels, subway station, factories etc. ICSDs were installed either by consumers or authorized workers. In addition, ICSDs were removed from service either by consumers or companies. There are no designated collection points for disused ICSDs. Consumers or companies collect disused ICSDs and inform the regulatory body Office of Atoms for Peace (OAP). The OAP informs the Radioactive Waste Management Center (RWMC), a part of the Thailand Institute of Nuclear Technology (TINT), a public organization. The RWMC is authorized to manage disused ICSDs and generators pay a service charge. Currently ICSDs are stored. Since ICSDs are only partially under regulatory control, the number of ICSDs in service may be difficult to determine. There is no recommended in‑service lifetime for ICSDs.

[en] In the Syrian Arab Republic, there are no ICSD manufacturers or exporters. There are ICSD importers that require authorization. ICSDs are normally installed by consumers or authorized workers in institutions, hotels, hospitals, power stations, etc. In the old days, not all authorized importers had reported ICSD distribution to the regulatory body; therefore, ICSD inventories are currently incomplete. Approximately, 580 ICSDs of five different types and models have been collected and stored at the Central Waste Management Facility for the last 10 years.