MEASURING HEAT INTENSITY

We have to measure the heat in order to acquire certain knowledge about heat. Our feelings cannot be use to measuring the degree heat an object because it is often mislead us.

In solid Object, the molecules attract to each other with more powerful and permanent position, so the vibration of the molecules just around a fixed point.

Liquid molecules can move a bit more freely from one place to another because the molecule is not in a fixed position. Liquid molecules attract each other, but not as strong as in solids object.Because it can move, liquid molecules can take the form corresponding to the shape of its container, although the gravity prevented to rising up to a certain level in the container.

On the gas, the molecules far from each other so that the intermolecular attraction is very small. gas molecules can move more freely than liquid molecules so it can fill the entire volume of the container.in solid Object, liquid object, or gas object when it becomes hotter then the objects will expand, and when it is colder, the objects will shrink.

This effect can be used as an effective tool for measuring the temperature, which is "the degree of heat" or "intense heat" of an object. The tool called the thermometer from the Greek word thermos meaning heat and meter meaning measure.

Famous Italian scientists from the beginning of the seventeenth century, Galileo Galilei was among those who first designed the device, a simple tool called termoskop.

This tool composed from a glass ball equipped with a long glass rod. then the glass ball were heated and the long glass rod are immersed in water in another vessel. At the time when air in the glass ball become cold, the air will shrink and the water will rise into the tank.

So this tool can be used to indicate changes in temperature,Galileo's termoskop has two main drawbacks. Termoskop does not have scale and therefore can only be shown if the temperature goes up or down. These devices are also sensitive to fluctuations in atmospheric pressure of cource is going to affect the rise or fall of water in the tank.

then they used water instead of air as the medium expansion and termoskop was replaced,water filled glass ball and some glass rod.

then the alcohol replaces the water, because alcohol isnt quickly frozen,Also they closed end of the rod so that alcohol does not evaporate.

Another improvement is the use of mercury, the mercury opaque, low freezing point and high boiling point and the volume change with temperature, so the mercury is best for this purpose.

Ordinary mercury thermometer is made by combining a glass ball with the bottom of a narrow hollow glass tube.then Mercury was inserted into the pipe through the hopper at the upper end of the pipe thermometer and bring to a boil and cooled, then sealed tube.