GB2019642A - Ionization smoke detector - Google Patents

Ionization smoke detector

Info

Publication number
GB2019642A
GB2019642A GB7845803A GB7845803A GB2019642A GB 2019642 A GB2019642 A GB 2019642A GB 7845803 A GB7845803 A GB 7845803A GB 7845803 A GB7845803 A GB 7845803A GB 2019642 A GB2019642 A GB 2019642A
Authority
GB
United Kingdom
Prior art keywords
chamber
radioactive material
air
support
radioactive
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
GB7845803A
Other versions
GB2019642B (en
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Isotec Industries Ltd
Original Assignee
Isotec Industries Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Isotec Industries Ltd filed Critical Isotec Industries Ltd
Publication of GB2019642A publication Critical patent/GB2019642A/en
Application granted granted Critical
Publication of GB2019642B publication Critical patent/GB2019642B/en
Expired legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G08—SIGNALLING
    • G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
    • G08B17/00—Fire alarms; Alarms responsive to explosion
    • G08B17/10—Actuation by presence of smoke or gases, e.g. automatic alarm devices for analysing flowing fluid materials by the use of optical means
    • G08B17/11—Actuation by presence of smoke or gases, e.g. automatic alarm devices for analysing flowing fluid materials by the use of optical means using an ionisation chamber for detecting smoke or gas
    • G08B17/113—Constructional details
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J41/00—Discharge tubes for measuring pressure of introduced gas or for detecting presence of gas; Discharge tubes for evacuation by diffusion of ions
    • H01J41/02—Discharge tubes for measuring pressure of introduced gas or for detecting presence of gas
    • H01J41/08—Discharge tubes for measuring pressure of introduced gas or for detecting presence of gas with ionisation by means of radioactive substances, e.g. alphatrons

Landscapes

  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Business, Economics & Management (AREA)
  • Emergency Management (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Other Investigation Or Analysis Of Materials By Electrical Means (AREA)
  • Fire-Detection Mechanisms (AREA)
  • Measurement Of Radiation (AREA)

Abstract

In an electronic smoke sensing and alarm device, a dual ionization chamber arrangement comprises a single source of radioactive material and first and second chambers separated by a common electrically conductive electrode. A portion of the radioactive material ionizes the air in the first chamber and another portion of the radioactive material ionizes the air in the second chamber. This arrangement provides an accurate control on the current flow through each chamber. A single source 36 of radioactive material, eg. Americium 241 or Nickel 63, may be disposed on a support 38 which is located on the partition 16 separating the two chambers 28 and 30 so that approximately the same amount of radioactive material is exposed in each chamber. The source and its support may be various shapes. Alternatively, the partition itself may be made up of a radioactive substance. <IMAGE>
GB7845803A 1978-04-19 1978-11-23 Ionization smoke detector Expired GB2019642B (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CA301,975A CA1109570A (en) 1978-04-19 1978-04-19 Dual ionization chamber

Publications (2)

Publication Number Publication Date
GB2019642A true GB2019642A (en) 1979-10-31
GB2019642B GB2019642B (en) 1982-12-15

Family

ID=4111341

Family Applications (1)

Application Number Title Priority Date Filing Date
GB7845803A Expired GB2019642B (en) 1978-04-19 1978-11-23 Ionization smoke detector

Country Status (4)

Country Link
CA (1) CA1109570A (en)
DE (1) DE2851820A1 (en)
GB (1) GB2019642B (en)
SE (1) SE7812025L (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20120146798A1 (en) * 2009-07-08 2012-06-14 Michael Dziekan Method of utilizing ionization chambers to detect radiation and aerosolized radioactive particles

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3041137C2 (en) * 1980-10-31 1984-09-20 Siemens AG, 1000 Berlin und 8000 München Capacitive gas detector

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20120146798A1 (en) * 2009-07-08 2012-06-14 Michael Dziekan Method of utilizing ionization chambers to detect radiation and aerosolized radioactive particles

Also Published As

Publication number Publication date
DE2851820A1 (en) 1979-10-31
CA1109570A (en) 1981-09-22
GB2019642B (en) 1982-12-15
SE7812025L (en) 1979-10-20

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Legal Events

Date Code Title Description
PCNP Patent ceased through non-payment of renewal fee