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Using Sound To Measure Temperature
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In physics, sound is a vibration that propagates as a
typically audible mechanical wave of pressure and displacement, through a
medium such as air or water. In physiology and psychology, sound is the
reception of such waves and their perception by the brain.
Sound can
propagate through compressible media such as air, water and solids as
longitudinal waves and also as a transverse waves in solids (see
Longitudinal and transverse waves, below). The sound waves are generated
by a sound source, such as the vibrating diaphragm of a stereo speaker.
The sound source creates vibrations in the surrounding medium. As the
source continues to vibrate the medium, the vibrations propagate away
from the source at the speed of sound, thus forming the sound wave. At a
fixed distance from the source, the pressure, velocity, and
displacement of the medium vary in time. At an instant in time, the
pressure, velocity, and displacement vary in space. Note that the
particles of the medium do not travel with the sound wave. This is
intuitively obvious for a solid, and the same is true for liquids and
gases (that is, the vibrations of particles in the gas or liquid
transport the vibrations, while the average position of the particles
over time does not change). During propagation, waves can be reflected,
refracted, or attenuated by the medium.
The behaviour of sound propagation is generally affected by three things:
A
relationship between density and pressure this relationship, affected
by temperature, determines the speed of sound within the medium.
The
propagation is also affected by the motion of the medium itself. For
example, sound moving through wind. Independent of the motion of sound
through the medium, if the medium is moving, the sound is further
transported.
The viscosity of the medium also affects the motion of
sound waves. It determines the rate at which sound is attenuated. For
many media, such as air or water, attenuation due to viscosity is
negligible.
When sound is moving through a medium that does not have
constant physical properties, it may be refracted (either dispersed or
focused).
1.2.STATEMENT OF PROBLEM:
The following forms the problems that necessitated the research of this project work.
i.The lapses found with other means of measuring temperature.
ii.The difficulties involved in using other means of measuring temperature.
iii.The high cost of other means of measuring temperature.
1.3.OBJECTIVE OF THE STUDY:
The following forms the objective of this study:
1.To
show that the use of sound for the measurement of temperature is faster
and more accurate than the other methods already known.
2.To determine temperature by measuring the speed of sound in air.
3.To
minimize the cost of measuring temperature using the other methods that
are expensive by introducing the measurement of temperature using
sound.
1.4.SIGNIFICANCE OF THE STUDY:
The significance of this
study is focused on its intent to portrait the essence of measuring
temperature using sound through showing its speed, accuracy, reliability
etc. this was achieved by using air as an example. Here, the
temperature of air was measured by measuring the speed of sound in air.
1.5.SCOPE OF THE STUDY:
This
project work only covers the measurement of temperature using sound
where an example was sited using the measurement of the temperature of
air using sound. This was achieved by measuring the speed of sound in
air. The researcher therefore wishes to state that at the time of this
research, the topic sited on the cover page was researched. Any other
discovery made or not covered by this research should be assumed to be
beyond the scope of this study.
CHAPTER ONE -- [Total Page(s) 3]
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ABSRACT - [ Total Page(s): 1 ]A method to measure the real time temperature distribution along an interferometer path based on the propagation of acoustic waves is presented. It exploits the high sensitivity of the speed of sound in air to the air temperature. In particular, it takes advantage of a special set-up where the generation of the acoustic waves is synchronous with the amplitude modulation of a laser source. A photodetector converts the laser light to an electronic signal considered as reference, while the incoming ... Continue reading---
