Search results
Results from the WOW.Com Content Network
The physical limitation of the ability of a thermometer to measure low temperature is the freezing point of the liquid used. Ethanol freezes at −114.9 °C (−174.82 °F). If an alcohol thermometer utilizes a combination of ethanol, toluene, and pentane, its lower temperature range may be extended to measure temperatures down to as low as − ...
A thermometer has two important elements: (1) a temperature sensor (e.g. the bulb of a mercury-in-glass thermometer or the pyrometric sensor in an infrared thermometer) in which some change occurs with a change in temperature; and (2) some means of converting this change into a numerical value (e.g. the visible scale that is marked on a mercury ...
Place the cylinder of the thermometer in melting ice made of pure water and mark the point where the fluid in the thermometer stabilises. This point is the freeze/thaw point of water. In the same manner mark the point where the fluid stabilises when the thermometer is placed in boiling water vapour.
A medical thermometer or clinical thermometer is a device used for measuring the body temperature of a human or other animal. The tip of the thermometer is inserted into the mouth under the tongue (oral or sub-lingual temperature), under the armpit (axillary temperature), into the rectum via the anus (rectal temperature), into the ear (tympanic temperature), or on the forehead (temporal ...
Such thermometers are usually calibrated so that one can read the temperature simply by observing the level of the fluid in the thermometer. Another type of thermometer that is not really used much in practice, but is important from a theoretical standpoint, is the gas thermometer. Other important devices for measuring temperature include:
Aqua regia (/ ˈ r eɪ ɡ i ə, ˈ r iː dʒ i ə /; from Latin, "regal water" or "royal water") is a mixture of nitric acid and hydrochloric acid, optimally in a molar ratio of 1:3. [b] Aqua regia is a fuming liquid. Freshly prepared aqua regia is colorless, but it turns yellow, orange or red within seconds from the formation of nitrosyl ...
Old thermometer in a pharmacy in Vienna, showing room temperature by Reaumur scale. Réaumur and Celsius scale on thermometer. Private collection, central Europe. The Réaumur scale (French pronunciation: [ʁeomy(ː)ʁ]; °Ré, °Re, °r), also known as the "octogesimal division", [1] is a temperature scale for which the melting and boiling points of water are defined as 0 and 80 degrees ...
A Celsius Galilean thermometer in two degree gradations. A risen orange orb denotes 24 °C. A Galileo thermometer (or Galilean thermometer) is a thermometer made of a sealed glass cylinder containing a clear liquid and several glass vessels of varying density. The individual floats rise or fall in proportion to their respective density and the ...