Editing Smoke detector (section)

== History ==
{{disputed section|date=September 2021}}

The first automatic electric fire alarm was patented in 1890 by [[Francis Robbins Upton]],<ref>{{Cite patent|country=US|number=436961|inventor=[[Francis Robbins Upton]]}}.</ref> an associate of [[Thomas Edison]].<ref name="party1">{{cite news |title= Birthday Party to Edison; Men Associated with Him in the Early 80s Organize the Pioneers |url= https://timesmachine.nytimes.com/timesmachine/1918/02/03/102977088.pdf |quote=Francis R. Upton of Newark, Mr. Edison's oldest associate, has been elected President of the Pioneers. |newspaper=[[The New York Times]] |date= February 3, 1918 |access-date= January 13, 2011 }}</ref> In 1902, George Andrew Darby patented the first European electrical [[heat detector]] in [[Birmingham]], [[England]].<ref>{{Cite patent|country=GB|number=190225805|title=An Electric Heat-indicator and Fire-alarm|inventor=George Andrew Darby}}.</ref><ref>{{cite book|last=Prosser|first=Richard|title=Birmingham Inventors And Inventions|year=1970|publisher=H.M. Patent Office (originally 1881) later published by S.R. Publishers 1970|isbn=0-85409-578-0}}</ref> In the late 1930s, Swiss physicist Walter Jaeger attempted to invent a sensor for poison gas.<ref name="nrc">{{cite web|url=https://www.nrc.gov/reading-rm/doc-collections/fact-sheets/smoke-detectors.html|title=NRC: Fact Sheet on Smoke Detectors|date=4 September 2013|website=NRC.gov|publisher=United States Nuclear Regulation Commission|access-date=9 June 2014|url-status=live|archive-url=https://web.archive.org/web/20140727144647/http://www.nrc.gov/reading-rm/doc-collections/fact-sheets/smoke-detectors.html|archive-date=27 July 2014}}</ref> He expected the gas entering the sensor to bind to ionized air molecules and thereby alter an electric current in a circuit of the instrument.<ref name="nrc" /> However, his device did not achieve its purpose as small concentrations of gas did not affect the sensor's conductivity.<ref name="nrc" /> Frustrated, Jaeger lit a cigarette and was surprised to notice that a meter on the instrument had registered a drop in current.<ref name="wallis">{{cite book |last=Wallis|first=Ian|date=1 November 2013|title=50 Best Business Ideas That Changed the World|url=https://books.google.com/books?id=WbgQAgAAQBAJ&q=duane+pearsall|publisher=Jaico Publishing House|isbn=978-81-8495-284-1|access-date=2014-11-20}}</ref> Unlike poison gas, the smoke particles from his cigarette were able to alter the circuit's current.<ref name="wallis" /> Jaeger's experiment was one of the developments that paved the way for the modern smoke detector.<ref name="wallis" /> In 1939, Swiss physicist Ernst Meili devised an ionization chamber device capable of detecting combustible gases in mines.<ref name="madehow">{{cite web|url=http://www.madehow.com/Volume-2/Smoke-Detector.html|title=How smoke detector is made|website=MadeHow.com|publisher=Advameg|access-date=9 June 2014|url-status=live|archive-url=https://web.archive.org/web/20140607111645/http://www.madehow.com/Volume-2/Smoke-Detector.html|archive-date=7 June 2014}}</ref> He also invented a [[cold cathode]] tube that could amplify the small signal generated by the detection mechanism so that it was strong enough to activate an alarm.<ref name="madehow" />

In 1951, ionization smoke detectors were first sold in the United States. In the following years, they were used only in major commercial and industrial facilities due to their large size and high cost.<ref name="madehow" /> In 1955, simple "fire detectors" for homes were developed,<ref>{{cite journal|last=Jones|first=Hilton Ira|date=April 1955|title=Peeps at Things to Come|url=https://books.google.com/books?id=5T8EAAAAMBAJ&q=home+fire+detectors+invented+1955&pg=PA37|journal=The Rotarian|publisher=Rotary International|volume=86|issue=4|access-date=2014-11-27|url-status=live|archive-url=https://web.archive.org/web/20180508184806/https://books.google.com/books?id=5T8EAAAAMBAJ&pg=PA37&dq=home+fire+detectors+invented+1955&hl=en&sa=X&ei=8qtzVOL_B8qpNu-DgqAK&ved=0CDAQ6AEwAA#v=onepage&q=home%20fire%20detectors%20invented%201955&f=false|archive-date=2018-05-08}}</ref> which detected high temperatures.<ref name="whitepaper" /> In 1963, The [[United States Atomic Energy Commission]] (USAEC) granted the first license to distribute smoke detectors that used radioactive material.<ref name="nrc" /> In 1965, the first low-cost smoke detector for domestic use was developed by [[Duane D. Pearsall]] and Stanley Bennett Peterson. It was an individual, replaceable, battery-powered unit that could be easily installed.<ref>{{Cite web|title=History of Smoke Detectors|url=https://thedailysecure.com/history-of-smoke-detectors/|access-date=2020-12-27|website=The Daily Secure|language=en-US}}</ref><ref>{{cite magazine|last=Ha|first=Peter|date=25 October 2010|title=Smoke Detector|url=https://content.time.com/time/specials/packages/article/0,28804,2023689_2026093_2023789,00.html|magazine=[[Time (magazine)|Time]]|publisher=[[Time Inc.|Time]]|issue=ALL-TIME 100 Gadgets|page=1|access-date=9 June 2014|url-status=live|archive-url=https://web.archive.org/web/20140714194451/http://content.time.com/time/specials/packages/article/0,28804,2023689_2026093_2023789,00.html|archive-date=14 July 2014}}</ref> The "SmokeGard 700"<ref>{{cite act|title=Voluntary Standards and Accreditation Act of 1977|number=S. 825 |language=en|date=1 March 1977|url=https://books.google.com/books?id=okjQAAAAMAAJ&q=smokegard+700+pearsall|access-date=24 July 2014}}</ref> was beehive-shaped, fire-resistant, and made of steel.<ref>{{cite web |author=David Lucht |date=1 March 2013 |title=Where Theres Smoke |url=http://www.nfpa.org/newsandpublications/nfpa-journal/2013/march-april-2013/features/where-theres-smoke |url-status=live |archive-url=https://web.archive.org/web/20151220185914/http://www.nfpa.org/newsandpublications/nfpa-journal/2013/march-april-2013/features/where-theres-smoke |archive-date=20 December 2015 |access-date=7 January 2016 |newspaper=Nfpa.org}} With picture of SmokeGard.</ref> The company began mass-producing these units in 1975.<ref name="wallis" /> Studies in the 1960s determined that smoke detectors respond to fires much faster than heat detectors.<ref name="whitepaper">{{cite tech report|title=White Paper: Home Smoke Alarms and Other Fire Detection and Alarm Equipment|number=1|institution=Public/Private Fire Safety Council|year=2006}}</ref>

The first single-station smoke detector was invented in 1970 and was brought out the next year.<ref name="whitepaper" /> It was an ionization detector powered by a single [[Nine-volt battery|9-volt battery]].<ref name="whitepaper" /> It cost about {{US$|125|1970}} and sold at a rate of a few hundred thousand units per year.<ref name="madehow" /> Several developments in smoke detector technology occurred between 1971 and 1976, including the replacement of cold-cathode tubes with [[solid-state electronics]]. This greatly reduced the detectors' cost and size and made it possible to monitor battery life.<ref name="madehow" /> The previous alarm horns which required special batteries were replaced with horns that were more energy-efficient and allowed the use of widely available batteries.<ref name="madehow" /> These detectors could also function with smaller amounts of radioactive source material, and the sensing chamber and smoke detector enclosure were redesigned to make the operation more effective.<ref name="madehow" /> The rechargeable batteries were often replaced by a pair of [[AA battery|AA batteries]] along with a plastic shell encasing the detector.

The photoelectric (optical) smoke detector was invented by Donald Steele and Robert Emmark from Electro Signal Lab and patented in 1972.<ref>{{Cite patent|country=US|number=3863076|status=patent|title=Optical Smoke Detector|pridate=1973-07-24|gdate=1975-01-28|invent1=Donald F. Steele|invent2=Robert B. Enemark}}</ref>

In 1995, the 10-year-lithium-battery-powered smoke alarm was introduced.<ref name="whitepaper" />