Prepared by: Ahmad Aso Abdullah Date:27 th Nov.
2024
Supervised by: Ms. Mayassa Sirwan
Thermometers: Tools for Measuring
Temperature
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introduction
What is a thermometer? an instrument for measuring and indicating temperature, typically
one consisting of a narrow, sealed glass tube marked with graduations and having at one
end a bulb containing mercury or alcohol which extends along the tube as it expands.
There Are Alternative Options to Alcohol and Mercury:
1. Galinstan: A safer, non-toxic alternative to mercury, made of gallium, indium, and tin. It is
used in high-precision thermometers.
2. Gas Thermometers: Use gas pressure changes to measure temperature in scientific
instruments.
3. Digital Components: found in electronic thermometers, they use resistance or electrical
changes to measure temperature accurately.
4. Infrared Sensors: Used in modern digital thermometers to measure heat without contact.
These four materials are the best alternatives, so why aren't they more common? Why don’t
more people use them in daily life?
"The reason is that it's a lot simpler than you think. There are many reasons for that, but the
most common ones are..."
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The reasons why they are not common:
1. Cost and Availability
2. Handling Challenges
3. Public Awareness and Transition Time
4. Durability Issues
Although money was not the problem for all of them but for [Galinstan] is another story
[Galinstan] is a mix of gallium, indium, and tin. It's non-toxic and behaves like mercury but is
safer for the environment. So it is much better then mercury but the problem is it’s really rear
and expensive that is why it’s not common in our world
But for the others money is not much of a problem like [Gas Thermometers] it’s cheaper than
the others but the problem with this one is it’s hard to use it and difficult to measure with it and
in some cases it’s expensive
But the best one of them all is [Digital Thermometers] the only problem with it is it does not last
as long as mercury thermometers other then that it’s safe and it gives you the precise number
we are looking for, it is mostly used for medical reasons.
But why don’t more people use them if they’re better in every way? Well, it’s actually because
people aren’t used to them, just like our grandparents didn’t like new technology.
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Just because it is not common among us that is why it is not being used more often on daily
bases.
But perhaps [Infrared Sensors] has the most uses of them all.
Detecting Abnormal Temperatures. ...
Scanning Equipment Malfunctioning. ...
Identifying Finished Product Anomalies. ...
Measuring Temperature in Hard-to-Reach Places. ...
Measuring Temperature in Dangerous Systems.
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types of thermometers
1. Liquid-in-glass thermometers
2. Thermocouple Thermometers
3. Bimetallic Strip Thermometers
4. Digital Thermometers
5. Gas Thermometers
Ther are a lot more then these 5 thermometers, there are approximately {25} thermometers but these
are the ones we’re going to talk about.
Why are there so many thermometers?
Each type of thermometer has specific applications, advantages, and limitations. The choice depends on
factors like the required temperature range, accuracy, response time, and the environment in which it
will be used.
EX 1: {Liquid-in-glass thermometers} Liquid-in-glass thermometers are traditional thermometers
that use a liquid sealed inside a glass tube to measure temperature the 2 most common ones are
[alcohol & mercury ]
EX2: {Thermocouple Thermometers} A thermocouple is a device for measuring temperature. It
comprises two dissimilar metallic wires joined together to form a junction. When the junction is heated
or cooled, a small voltage is generated in the electrical circuit of the thermocouple which can be
measured, and this corresponds to temperature.
EX3:Bimetal thermometers are thermometers based on the functional principle that metals expand
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differently depending on the change in temperature.
EX4: {Digital Thermometers} there is almost a dozen digital thermometers but the best one of them is
[digital rectal thermometers] why is it the most common one?
Accuracy: digital rectal thermometers are the most accurate at measuring core temperature. However,
rectal thermometers are predominantly used to measure the temperatures of infants and toddlers up to
three years old.
EX5: [Gas Thermometers] The ideal gas thermometer is used for measuring temperatures less than 1
degree Kelvin. Pyrometer is used for measuring temperature of gas. As, we cannot make contact with
the gas, pyrometer, which measures temperature from distance, is used.
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