•THERMOMETER GLASS• function -> It is a device used to measure the temperature with liquid in capillary coloum or glass• Kind of Types of glass thermometer Mercury thermometer Alcohol thermometer Mixed thermometer
THERMOMETER MERCURY• The mercury will freeze at a temperature of - 38.83 ° C (-37.89 ° F) and can only be used at temperatures above it. Mercury, unlike water, does not expand when frozen so it does not break the glass tube, making it difficult to observe when it freezes
1. Advantages from the mercury thermometer are: 1. Mercury can absorb / take the heat from the temperature measured something. 2. Mercury has properties that do not wet the medium of glass on the thermometer. 3. Mercury can be seen easily because of its shiny. 4. Mercury possesses expansion / expand a regular basis from the temperature to the temperature. 5. Mercury has a freezing point and boiling point range is remote, making it suitable for measuring high temperatures.
THERMOMETER ALCOHOLAlcohol thermometer is a thermometer which use the alcohol as amedium gauge, which is an alternative to mercury thermometerswith the same function. But it is not the same as the mercury in aglass thermometer. Contents are non-toxic and alcoholthermometer will evaporate fairly quickly.
Advantages of alcohol than mercurythermometers are:1) alcohol is more sensitive, because changes volume greater than mercury for the same temperature change. Thus, for the same temperature change, the change in length of mercury column larger,2) alcohol can measure extremely cold temperatures, for example, the temperature at the poles, because the freezing point of alcohol is very low at-112 C.
MIXED THERMOMETERSome companies use a mixture of gallium, indium, and tin(galinstan) instead of mercury.How Thermometers WorkIn general, how the thermometer is as follows: When thetemperature rises, the liquid in the bulb tube expands morethan the glass that covered it. As a result, a thin threadwhich fluid is forced into the capillaries. Conversely, whenthe temperature drops, the liquid and the liquid shrinks thintube that moves back down. The movement ends labeledthin liquid meniscus is read against a scale that indicatesthe temperature.
• Today, mercury thermometers are still widely used in the fields of meteorology, but use the other fields on the wane, because mercury is very toxic permanently on the system is fragile and some developed countries have condemned its use for medical purposes. Some companies use a mixture of gallium, indium, and tin (galinstan) instead of mercury.