The advantage of mercury thermometers as a filler, such as: Mercury does not wet the walls of the capillary tube, so that the measurement be careful. Mercury is easily seen as shiny. Mercury rapidly removes heat from an object being measured. Temperature range is wide enough mercury, because mercury freezes at a temperature of – 40 0C and boils at 360 0 C. The volume of mercury is changed regularly.
Mercury also has some disadvantages, among others:
- Mercury is expensive.
- Mercury can not be used to measure very low temperatures.
- Mercury including toxic substances so dangerous when the tube ruptured.
The advantage of using alcohol as a filler thermometers, among other things: Alcohol’s cheap. Alcohol is more rigorous, because for a small temperature rise of alcohol was experiencing a large volume changes. Alcohol can measure very low temperatures, because the freezing point of alcohol-1300C.
Disadvantages of using alcohol as a filler thermometers, among others:
- Wet the glass wall.
- Low boiling point (78 0C)
- Alcohol is a colorless, so it is necessary first to give the dye to be visible.
Why water is not used to fill the tube thermometer? The reason is because the water over the glass wall, a limited temperature range, small volume changes, a poor conductor of heat. (image source : http://arifansyah.wordpress.com/)