Difference between revisions of "Thermometer"
(invented in 1714 by Gabriel Fahrenheit, who used mercury in a glass tube) |
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| − | A '''thermometer''' is a device for measuring [[temperature]]. The two simplest ways to do this both rely on the principle that hot things expand and cold things contract. A liquid such as colored alcohol or mercury can be placed in an evacuated glass tube. The expansion and contraction of the liquid indicates the temperature. A helical spring can also be used, | + | A '''thermometer''' is a device for measuring [[temperature]]. The two simplest ways to do this both rely on the principle that hot things expand and cold things contract. A liquid such as colored alcohol or mercury can be placed in an evacuated glass tube. The expansion and contraction of the liquid indicates the temperature, which can be read from a scale next to the expanded liquid. A helical spring can also be used, as in the common refrigerator thermometer. In such a refrigerator, the thermometer points at a scale. |
| − | The first useful thermometer was invented in 1714 by [[Gabriel Fahrenheit]], who used mercury in a glass tube graduated with 180 degrees between the freezing and boiling points of water ( | + | The first useful thermometer was invented in 1714 by [[Gabriel Fahrenheit]],<ref>[http://www.brannan.co.uk/thermometers/invention.html Who Invented the Thermometer?]</ref> who used mercury in a glass tube graduated with 180 degrees between the freezing and boiling points of water (32 °F and 212 °F). Modern scientists use the [[Celsius]] scale, graduated with 100 degrees between freezing and boiling (0 °C to 100 °C). |
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| + | ==Notes== | ||
| + | {{reflist}} | ||
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| + | [[Category:Measurements]] | ||
Latest revision as of 14:07, June 24, 2016
A thermometer is a device for measuring temperature. The two simplest ways to do this both rely on the principle that hot things expand and cold things contract. A liquid such as colored alcohol or mercury can be placed in an evacuated glass tube. The expansion and contraction of the liquid indicates the temperature, which can be read from a scale next to the expanded liquid. A helical spring can also be used, as in the common refrigerator thermometer. In such a refrigerator, the thermometer points at a scale.
The first useful thermometer was invented in 1714 by Gabriel Fahrenheit,[1] who used mercury in a glass tube graduated with 180 degrees between the freezing and boiling points of water (32 °F and 212 °F). Modern scientists use the Celsius scale, graduated with 100 degrees between freezing and boiling (0 °C to 100 °C).