Full Name: Fahrenheit
Scale Factor: 1
The degree Fahrenheit (represented as ° F) is a temperature scale proposed by Daniel Gabriel Fahrenheit in 1724. The scale establishes the freezing and boiling temperatures of water, 32°F and 212°F, respectively. The method used is similar to the definition for the degree Celsius (°C).
There are many versions of the story of how Fahrenheit achieved that temperature scale. According to himself, in the article he wrote in 1724, he determined three temperature points. The zero point is determined by placing the thermometer in a mixture of ice, water and ammonium chloride. This is a type of refrigerating mixture, which is stabilized at a temperature of 0°F. It then puts the mercury thermometer or alcohol in the mixture and the liquid is left in the thermometer obtains its lowest point. The second point is at 32°F with the mixture of water and ice, this time without salt. The third point, 96°F, is the level of the liquid in the thermometer when put in the mouth or under the arm (axillary). Fahrenheit noted that by using this scale could boil mercury near 600 degrees.
Another theory is that Fahrenheit established 0° F and 100° F in the scale to record the lowest temperatures and he was able to measure their own body temperature, when in a state of slight fever. He took the lowest temperature was measured in the harsh winter of 1708-1709 in the city Danzig (now Gdansk in Poland), near -17.8 ° C, as the zero point.
A variant of this version is that the mixture of ice, salt and water registered on the Fahrenheit scale, he obtained in his laboratory and he took the higuest from his body temperature at 96°F.
Fahrenheit wanted to abolish negative temperatures that the Reaumurer scale. He fixed his own body temperature at 96 ° F (although the scale had to be recalibrated to normal body temperature, which is close to 96.8 ° F, equivalent to 36 ° C), divided the scale in twelve sections and subsequently each of these sections into 8 equal subdivisions resulting in a scale of 96 degrees. Fahrenheit noted that on this scale the freezing point of water was at 32 ° F and the boiling point to 212 ° F.