How A Thermometer Works
March 15, 2008 Thermomether fo me is a good friend of mine..why? it is because it helps me a lot to monitor my or your temperature. Wether if it is hot or cold.It is very useful to the hospital without it their job would much harder. Aside from being useful it can be a one of the best tools at our home.There are many kinds of it.But do ever wonder how it works? or should I say do you know how to use it.Well, this post might be helpful for you…try to read it.^_^
When you look at a regular outside bulb thermometer, you’ll see a thin red or silver line that grows longer when it is hotter. The line goes down in cold weather.
This liquid is sometimes colored alcohol but can also be a metallic liquid called mercury. Both mercury and alcohol grow bigger when heated and smaller when cooled. Inside the glass tube of a thermometer, the liquid has no place to go but up when the temperature is hot and down when the temperature is cold.
Numbers are placed alongside the glass tube that mark the temperature when the line is at that point.
The other type of common thermometer is a "spring" thermometer. A coiled piece of metal that is sensitive to heat is used. One end of the spring is attached to the pointer. As the air heats, the metal expands and the pointer moves higher. As the air cools, the metal contracts and the pointer moves lower. Typically, these type of thermometers are less accurate than bulb or digital thermometers.
