4 Temperature Measurements
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The units in the previous part of this section dealt with heat energy measurement. The answers we were calculating indicated an amount or quantity of heat. When measuring temperature we are not measuring quantity but instead we are gauging the intensity of the heat.
For example going outside on a day when it’s −10°C feels colder or much more intense that going outside on a day that is +20°C.
How much heat content would you think there is at −10°C? Honestly who cares? Just get inside and we can sort that out later.
If I were to ask you what units you generally associated with temperature what would you say?
I’m guessing most of you would respond with either Celsius or Fahrenheit. Those would be the two most common methods of describing the heat here in Canada and as Canada uses the metric system we would most likely be seeing the temperature in Celsius.
But have you ever heard of the Kelvin temperature scale or the Rankine temperature scale?
Well these temperature scales are based on what is known as “absolute temperature.”
If you go on the internet and look up absolute temperature you can get some pretty convincing definitions, some of which we might actually be able to comprehend. Basically, the absolute temperature scale starts at absolute zero and a simplified definition of absolution zero would be the following:
ABSOLUTE ZERO: The temperature at which all molecular movement ceases to exist.
As there is no molecular movement there is also no heat generated by the molecules.
If you want to know more about absolute zero check out the link: Absolute Zero (Wikipedia)
So what we start with are the Celsius scale which is the metric version of temperature and the Fahrenheit scale which is the imperial version. You might notice that when you are watching T.V. in Canada you will see much smaller temperature numbers than when you watch T.V. from a U.S. channel. This is due to the fact that if we took a temperature reading on the Fahrenheit scale and found a similar temperature on the Celsius scale the Celsius temperature reading would work out to be much smaller.
For example we could look at room temperature.
[latex]\Large \text{Metric} = {20}^{\circ} \text{ Celsius} \qquad \text{Imperial} = {68}^{\circ} \text{ Fahrenheit}[/latex]
On another note does anyone watch T.V. anymore or is it just the internet and Netflix? Anyway, back to Celsius and Fahrenheit.
What we want to do here is relate the metric and imperial scale with each other and then add the absolute scale equivalents. We’ll start with the boiling point of water.
Water boils at 100°C and 212°F. Note the letter “C” represents Celsius while the letter F represent Fahrenheit.
Next we find the freezing point of water. Water freezes at 0°C and at 32°F. We can put all those together into a small drawing.
We’ll go through how to go from Celsius to Fahrenheit and back in just a bit but before w