B+Smoke+Detectors

=__Isotope and Radioactivity__= = = =Name of radioactive isotope/electromagnetic radiation/scientist:= Smoke Detectors.

= = = = =Explanation of interesting facts: (how used/works/experiments/discoveries)=
 * 1) Most smoke detectors work either by optical detection (photoelectric) or by physical process (ionization), while others use both detection methods to increase sensitivity to smoke.
 * 2) Walter Jaeger tried to invent a sensor for poison gas but it failed. He lit a cigarette and was surprised to notice that a meter on the instrument had registered a drop in current.
 * 3) Smoke detectors are one of those amazing inventions that, because of mass production, cost practically nothing. You can get a smoke detector for as little as $7. And while they cost very little, smoke detectors save thousands of lives each year.
 * 4) The first smoke detector was made from strong fire resistant steel and was shaped like a beehive.
 * 5) The most common reasons for smoke alarms to not work when there is a fire is disconnected batteries, dead batteries, debris build up/obsrtuction and failure because of age.

=3 Advantages of using the radiation/benefits of discovery=

1. Household smoke detectors save many lives a year because of early detections. It gives the people inside the house more time to get out of there and your house won't have as much damage

2. Battery operated smoke alarm systems have test buttons to ensure it is working. Also, the are easy to install and aren't very expensive.

3. People feel safe in their home when the know that their family is protected.

=3 Disadvantages of using the radiation/discovery:= 1. The optical smoke detector takes 30 seconds longer to detect smoke than a ionization detector.

2. The Ionization detector is cheaper but it is more prone to false alarms then photoelectric.

3. Battery operated smoke detectors need to be checked every once in a while to make sure it is working properly.

=Is the radiation/discovery still used today? Explain=

Yes, smoke detectors are use today. There are many types of smoke alarms, each with different features. Alarms can be electrically connected, battery powered or a combination of both. Having the combination of both is mostly recommended. There are smoke alarms in 95% of houses in the US.

=References= www.philliesfireco.com/smoke_detectors_facts www.wikipedia.com www.ezinearticles.com

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