• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Smoke Alarms Assignment In this CDA I will be explaining how smoke alarms work, there are two types of smoke alarms, Ionisation smoke detectors and Photoelectric smoke detectors

Extracts from this document...

Introduction

CDA

In this CDA I will be explaining how smoke alarms work, there are two types of smoke alarms, Ionisation smoke detectors and Photoelectric smoke detectors, I will be explain what they both do and will compare them using a table to show the differences.  I will be also explaining what Americium is and Half-life is and what they do. Most people don’t know where and when smoke alarms are often used now a days and I’ll be explain that also.

Basic description:

Two basic types of smoke detectors are sold for residential use.



The photoelectric smoke detector: 

Uses an optical beam to search for smoke so when the smoke particles cloud the beam, a photoelectric cell senses the decrease in light intensity and triggers an alarm. This type of detector reacts most quickly to 
smoldering fires but no flame that release relatively large amounts of smoke.image00.jpgimage01.jpg

Ionisation smoke detector:

All smoke detectors have two basic parts: the sensors and the electronic horn that emits sound. These devices also require a power source, which is usually a 9-volt battery or 120-volt house current. Ionization-type detectors have an ionizing chamber with two electrically charged plates, and a minute amount of radioactive material is in between the plates. The radioactive material ionizes the air in the chamber, which results in current flow between plates.

...read more.

Middle

298

304

294

299

Number of alpha

76

104

126

102

Radiation with aluminium in the way

176

152

158

162

Number of beta

122

146

136

135

Number of gamma

176

152

158

162

% of alpha= 76/401 x100=25.4%

% of beta = 135/401 x 100= 33.6%

% of gamma = 162/401 x 100= 40.4%

Am 241 should be an alpha emitter

We did this to find out if there was more than one type of radiation coming out of the smoke alarms. The number of gamma radiation is the highest and there is least is alpha. I also found out that with paper in the way of radiation the number decreases

HOW TO MAKE IT MORE VALID: you can use accurate instruments which will make it more accurate.

TO MAKE IT MORE RELIABLE:  you will need to repeat the results with the same person

How long do smoke alarms last? What is the half-life of Am? Describe what manufacturers are trustworthy, are they valid? – The two types, their reliability, safety, cost:

Smoke alarms are cheap, easy to get hold of and, used properly, they really are lifesavers. There’s no excuse for not having one.

The photo-detector however, when there is smoke entering the chamber, the Smoke alarms are usually contained in areas of high risk from fire and smoke. They are warning device that detects smoke at the early stages of a fire. It sounds a piercing alarm to warn you.    

Many people that die in house fires are asleep at the time.

...read more.

Conclusion

Background radiation:

Background radiation resulting from cosmic rays and natural radioactivity is always present. Background radiation may also exist because of radioactive substances in other parts of a building (e.g., building material

Half-life:

The time in which the radioactivity usually associated with a particular isotope is reduced by half through radioactive decay

Ionising radiation:

Ionizing radiation is radiation with enough energy so that during an interaction with an atom, it can remove tightly bound electrons from the orbit of an atom, causing the atom to become charged or ionized.

Mutation

A permanent change in the genetic material that may alter a trait or characteristic of an individual, or manifest as disease, and can be transmitted to offspring.

Radioactivity

The radiation, including alpha particles, nucleons, electrons, and gamma rays, emitted by a radioactive substance.

Radon Gas: Radon is a naturally occurring gas produced when uranium breaks down into "radium".  The radium breaks further down to form a radioactive gas called radon

Bibliography

http://www.thefreedictionary.com/alpha+particle

http://www.picsearch.com/index.cgi?start=41&size=1p&width=1003&q=smoke%20alarms

http://www.ehow.com/about_5089815_different-kinds-smoke-detectors.html

http://www.thefreedictionary.com/Beta+particles

http://amazing-space.stsci.edu/resources/explorations/groundup/lesson/glossary/term-full.php?t=gamma_rays

http://medical-dictionary.thefreedictionary.com/background+radiation

http://medical-dictionary.thefreedictionary.com/half-life

http://www.who.int/ionizing_radiation/about/what_is_ir/en/index.html

http://encyclopedia2.thefreedictionary.com/Radioactivity

http://www.answers.com/topic/radon

http://www.answers.com/topic/radioactivity#ixzz1GrnMCIRz

...read more.

This student written piece of work is one of many that can be found in our GCSE Radioactivity section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related GCSE Radioactivity essays

  1. Marked by a teacher

    Is nuclear power the future? Should we build more nuclear power stations in ...

    4 star(s)

    This is an often overlooked part of nuclear power. According to CND 'it has taken the lives of many miners all over the world causing environmental contamination, cancers and nuclear waste.'[11] Uranium mining is also polluting, so nuclear power is not as clean as it may seem. Since uranium is mined using open pit mining, it devastates large areas of the landscape.

  2. Peer reviewed

    Ionisation smoke alarms use an ionisation chamber and a source of ionising radiation to ...

    3 star(s)

    Once the particles have attached themselves onto the ions they have effectively shut off the electric current.[7] The circuit in the detector spots this straight away and triggers the alarm. Ionisation smoke alarms are strong at detecting low levels of smoke.

  1. Radioactivity Experiments: To determine the penetrating power and the range in air of the ...

    Textbooks name the range of air for alpha particles as 5-6 cm but this graph comes short of this limit with the last count measured at 1.5 cm. Beta Distance (cm) Corrected counts per min Counts per minute (original data)

  2. Heat in the kitchen

    Metals are good conductors of thermal energy. Substances that do not allow thermal energy to move through them easily are called insulators. Air and plastics are insulators. Convection The particles in liquids and gases can move from place to place.

  1. Nuclear medicine is a field of medicine that uses radioactive substances to diagnose and ...

    Another type of treatment is called brachytherapy destroys cells by placing a radioisotope directly into the tumour, either by a manual implant or by using a device called a remote after loader. A small wire containing radioactive material is inserted into the tumour.

  2. Should radioactive smoke alarms be a compulsory purchase?

    One advantage is that it is cheaper-this is an advantage because high cost might put people, especially less well off people, off buying an alarm which could ultimately cost lives. Another advantage is that these alarms are quick to detect fast flaming fires (such as chip pan fires)

  1. SHOULD MORE NUCLEAR POWER STATIONS BE BUILT IN BRITAIN?

    http://www.politics.co.uk/news/energy/scientists-critiicise-nuclear-plants-$483804.htm Reliability of source: quite memorable quote for being said as it has opened a new question - is nuclear power sustainable? The group is made from 17 members who all agree with the quote. Clear to understand that they think nuclear power may become a mistake.

  2. Radiation: are mobile phones unsafe? Mobiles use electromagnetic radiation in order to send and ...

    http://www.cancerhealth.org/Brain_cancer.html This is a clear piece of evidence for microwave radiation performing "the heating effect". Mobile phones can cause biological damage through this heating effect, causing effects such as headaches, earaches, short-term memory loss, tingling and burning sensations, blurring of vision, numbing and disturbed sleep.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work