sceince proget
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Name: Sada Joachim
Class: 4 Waldron
Teacher: Miss Burnette
Subject: Integrated Science
Due date: 01.May.2012
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I would like to express my special thanks of gratitude to my teacher Miss Burnette
as well as our principal Mrs Challenger who gave me the golden opportunity to do
this wonderful project on the topic temperature control, which also helped me in
doing a lot of Research and I came to know about so many new things. I am
really thankful to them. Secondly I would also like to thank my parents and
friends who helped me a lot in finishing this project within the limited time. I am
making this project not only for marks but to also increase my knowledge.
THANKS AGAIN TO ALL WHO HELPED ME.
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Acknowledgement
Introduction
Definition of temperature
Temperature measured
Types of thermometers
Features and principals of thermometers
Properties of liquid
Definition of humidity
Humidity measured
Effects of temperature and relative humidity on the body
Conclusion
Bibliography
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The term temperature control is used to describe the process
in which change of temperature of a space is measured or
otherwise detected, and the passage of heat energy into or out
of the space is adjusted to achieve a desired average
temperature.
This project is basically on temperature, what is, how it is
measured, the features and many more, just keep on reading I
know for a fact you will learn something new after today.
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Temperature is a measure of the average heat or thermal
energy of the particles in a substance. Since it is an average
measurement, it does not depend on the number of particles in
an object. In that sense it does not depend on the size of it.
For example, the temperature of a small cup of boiling water is
the same as the temperature of a large pot of boiling water.
Even if the large pot is much bigger than the cup and has
millions and millions more water molecules, it is still the same.
the pots of boiling water.
Temperature does not depend on the size or type of object.
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Many devices have been invented to accurately measure temperature. It all
started with the establishment of a temperature scale. This scale transformed the
measurement of temperature into meaningful numbers. In the early years of the
eighteenth century, Gabriel Fahrenheit created the Fahrenheit scale. He set the
freezing point of water at 32 degrees and the boiling point at 212 degrees. These
two points formed the anchors for his scale. Later in that century, around 1743,
Anders Celsius invented the Celsius scale. Using the same anchor points, he
determined the freezing temperature for water to be 0 degree and the boiling
temperature 100 degrees. The Celsius scale is known as a Universal System
Unit. It is used throughout science and in most countries. There is a limit to how
cold something can be. The Kelvin scale is designed to go to zero at this
minimum temperature.
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Alcohol Thermometer
Alcohol thermometer uses alcohol as the liquid to measure the temperature
variations. Alcohol expands when it absorbs temperature and contract in colder
temperatures. Most commonly used alcohol in these is ethanol, but different types
of alcohols can be used depending on the measured temperature and
environment in which the measurements are taken. The measurable temperature
range varies according to the used fluid inside the bulb. For example, boiling
point of ethanol is 80C and the freezing point is -115C. So in an alcohol
thermometer containing ethanol, -115C to 80C temperature variations can be
measured. Alcohol is a colourless, volatile fluid.
Mercury Thermometer
A small volume of silver colour mercury liquid is used inside the mercury
thermometer. Mercury is a highly toxic liquid; therefore, it should be handled with
care especially if the thermometer is broken. The freezing point of mercury is -
38.83 C and the boiling point is 357 C. Therefore, mercury thermometers are
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best at measuring higher temperatures than the lower temperatures. Thus, this is
widely used in laboratories to measure the temperature variations of chemical
reactions.
What is the difference between Alcohol Thermometer and Mercury
Thermometer?
Mercury thermometer has mercury inside the bulb as the temperature sensitive
fluid, and in alcohol thermometers, it is an alcohol.
Since alcohol is non-toxic, alcohol thermometers are much safer to use than
the mercury thermometers.
Alcohol thermometers can be used to measure very low temperatures. Since
mercury has a higher boiling point than alcohol, mercury thermometer can be
used to measure high temperatures.
Digital Thermometers
Digital thermometers use thermocouples or thermistors to sense the change in
temperature and display the temperature on a digital display. They are widely
used as clinical, outdoor and food thermometers. Infrared thermometers use the
infrared sensors to determine the temperature and have a digital display.
Outdoor ThermometersThe outdoor thermometers are used to measure the
temperature of the surrounding air. Wireless outdoor thermometers are very
popular these days.
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Food Thermometers
There are many food thermometers like the dial oven-safe thermometers, digital
instant thermometers, pop-up thermometers and disposable thermometers. The
dial oven-safe thermometers are used for thick foods and can be placed in the
food while you are cooking the food. However, the dial oven-safe thermometers
are not suitable for thin and watery foodstuffs. The digital instant thermometers
cannot be kept in the food while cooking. These thermometers read the
temperature within 10 seconds. The pop-up thermometers are used to measure
the temperatures of turkey and chicken. The disposable thermometer strips are
used to measure the temperature of food after they are cooked and they change
the colour according to the temperature. The colour of these thermometer strips
can be matched to a chart, which gives the corresponding temperature of food.
Celsius and Fahrenheit Thermometers
The Celsius thermometers use the Celsius (C) as the measurement unit and
Fahrenheit thermometers use Fahrenheit (F) as the temperature measurement
unit. Some thermometers have the measuring scales for both Celsius and
Fahrenheit. These thermometers give the reading in Celsius as well as
Fahrenheit.
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The thermometer has 5 basic parts which includes a scale, the bore, the bulb,
the steps and coloured alcohol known as mercury in the past.
The principals by which the work:
The scale of a thermometer: What is a thermometer scale? A thermometer scale
will give you a temperature reading of an object. Temperature is measured using
two different types of scales which include the Celsius scale and the Fahrenheit
scale. A thermometer scale will allow you to read the temperature in both the
Celsius degrees and the Fahrenheit degrees since most thermometers will consist
of both the Celsius scale and the Fahrenheit scale. Most countries use the
Celsius scale while the Fahrenheit scale is used in the USA.
The bore: the bore is the thin tube the goes through the centre of the whole
thermometer it is use as a passage way for the coloured alcohol/mercury.
The bulb: the bulb is a small chamber at the bottom for the thermometer which
house/contain the coloured alcohol/mercury.
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The coloured alcohol/mercury: is the liquid part of the thermometer which goes
up and down accord to the change in temper in otherto give the reading.
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It is able to stand tempers for 100 degrees Celsius and 0 degrees Celsius
without boiling of freezing, it is able to rise and drop accord to changes in
temperature.
It also has to be coloured, so you can read the etchings or markings properly,
and you can read the temperature.
The liquid also needs to be relatively cheap, so the factories can provide it and
make a profit.
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Humidity is a term for water vapour in the air, and can refer to any one of several
measurements of humidity. Formally, humid air is not "moist air" but a mixture of
water vapour and other constituents of air, and humidity is defined in terms of the
water content of this mixture, called the Absolute humidity. In everyday usage, it
commonly refers to relative humidity, expressed as a per cent in weather
forecasts and on household humidistats; it is so called because it measures the
current absolute humidity relative to the maximum. Specific humidity is a ratio of
the water vapour content of the mixture to the total air content. The water vapour
content of the mixture can be measured either as mass per volume or as a partial
pressure, depending on the usage.
In meteorology, relative humidity indicates the likelihood of precipitation, dew, or
fog. High relative humidity reduces the effectiveness of sweating in cooling the
body by reducing the rate of evaporation of moisture from the skin.
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There are various devices used to measure and regulate relative humidity. A
device used to measure relative humidity is called a psychrometer or hygrometer.
A humidistat is used to regulate the relative humidity of a building with a
dehumidifier. These can be analogous to a thermometer and thermostat for
temperature control.
Humidity is also measured on a global scale using remotely placed satellites.
These satellites are able to detect the concentration of water in the troposphere
at altitudes between 4 and 12 kilometres. Satellites that can measure water
vapour have sensors that are sensitive to infrared radiation. Water vapour
specifically absorbs and re-radiates radiation in this spectral band. Satellite water
vapour imagery plays an important role in monitoring climate conditions (like the
formation of thunderstorms) and in the development of future weather forecasts.
a hygrometer
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Humans are sensitive to humid air because the human body uses evaporative
cooling as the primary mechanism to regulate temperature. Under humid
conditions, the rate at which perspiration evaporates on the skin is lower than it
would be under arid conditions. Because humans perceive the rate of heat
transfer from the body rather than temperature itself, we feel warmer at a given
temperature when the relative humidity is high than when it is low.
For example, if the air temperature is 24 C (75 F) and the relative humidity is
zero per cent, then the air temperature feels like 21 C (69 F). If the relative
humidity is 100 per cent at the same air temperature, then it feels like 27 C (80
F). In other words, if the air is 24 C (75 F) and contains saturated water
vapour, then the human body cools itself at the same rate as it would if it were
27 C (80F) and dry.
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We all have use for a temperature control. It is for our own good, doing this
project I have learnt a lot and it taught me a little more about temperature and
humidity and the effect it can have on our bodies. You may not know it but we
use temperature control every day in everything that we do. So thanks for taking
your time and read my project I hope that u learnt a lot too.
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www.wikipedia.com/temperaturecontrol
www.wikipedia.com/humidity
www.answers.com
Macmillan cxc science series: Integrated science text book: Tania Chung-Harris
www.google.com/effectsofhumidityandtemperatureonthebody
Leon George: a pass high school student
http://www.wikipedia.com/temperaturecontrolhttp://www.wikipedia.com/temperaturecontrolhttp://www.wikipedia.com/humidityhttp://www.wikipedia.com/humidityhttp://www.answers.com/http://www.answers.com/http://www.google.com/effectsofhumidityandtemperatureonthebodyhttp://www.google.com/effectsofhumidityandtemperatureonthebodyhttp://www.google.com/effectsofhumidityandtemperatureonthebodyhttp://www.answers.com/http://www.wikipedia.com/humidityhttp://www.wikipedia.com/temperaturecontrol
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