thermometer - Types of thermometers, Specialist uses of thermometers

A device for measuring temperature. In household alcohol and mercury thermometers, heat causes the liquid in a reservoir to expand, forcing some of the liquid up a graduated tube. The graduations are fixed by calibration against known markers of chosen temperature scale. The first reliable mercury-in-glass thermometer was invented by Gabriel Fahrenheit in 1714.

The word thermometer is derived from two smaller word fragments: thermo from the Latin (or Greek) for heat and meter from Latin, meaning to measure.

The first thermometer was a thermoscope. In 1593, Galileo Galilei invented a rudimentary water thermometer (using the contraction of air to draw water up a tube). In 1714, Daniel Gabriel Fahrenheit invented the first mercury thermometer.This history of the thermometer, from its invention in the early seventeenth century (an achievement attributed to at least four scientists, including Galileo) through various changes and applications over the next three centuries, includes controversy about its invention, the story of different scales, from Fahrenheit and Celsius to the now-forgotten Reaumur, Delisle, and Christin scales, and the history of the gradual scientific then popular understanding of the concept of temperature. Not until 1800 did people interested in thermometers begin to see clearly what they were measuring, and the impetus for improving thermometry came largely from study of the weather -- the liquid-in-glass thermometer became the meteorologist's instrument before that of the chemist or physicist.

Types of thermometers

Thermometers have been built which utilise a range of physical effects to measure temperature. Most thermometers are originally calibrated to a constant-volume gas thermometer.

Mercury-in-glass thermometer Bi-metal mechanical thermometer Electrical resistance thermometer Galileo thermometer Infrared thermometer Liquid Crystal Thermometer Maximum minimum thermometer Reversing thermometer Silicon bandgap temperature sensor Six's thermometer Thermistor Thermocouple

Specialist uses of thermometers

Candy thermometer Meat thermometer Medical thermometer