Gabriel Daniel Fahrenheit

1995/09/01 Azkune Mendia, Iñaki - Elhuyar Fundazioa Iturria: Elhuyar aldizkaria

• Biografiak

German physicist born in Dantzig (present-day Gdansk of Poland) on May 14, 1686. Still young, he emigrated to Amsterdam for business studies, despite being a manufacturer of meteorological devices.

Until then the invented thermometers were not exact. Liquid thermometers were already in use. It can be liquid, alcohol, its blends and water. But those thermometers were not very good either. Since alcohol boils at low temperature, it did not measure high temperatures. Alcohol and water mixtures were better in the problem mentioned, but their volume was variable depending on the different temperatures.

In 1714 Fahrenheit discovered that he replaced alcohol with mercury. In practice he was also able to test it on the thermometer, but first he had to find the method of cleaning mercury so that it would not stick to the thin tube of the thermometer. Mercury could measure both high and low temperatures.

In addition, mercury expanded and contracted more evenly. Therefore, the thermometer scale could be divided into smaller units. Newton suggested in 1701 to divide the interval between the freezing point and the normal temperature of the human body into twelve equal parts. Fahrenheit, however, mixed salt with water to make its freezing point lower.

This point was rated with a 0. He then distributed the difference between this point and normal body temperature in 96 degrees. So the thermometer was so precise. The thermometer was then reconditioned with the boiling point at 212 degrees and the freezing point at 32 degrees. On the Fahrenheit scale, the temperature of the human body is 98.6 degrees.

It was the first precise thermometer. Fahrenheit discovered that the boiling point of the water was constant. He also experimented with other liquids and found that under normal conditions each liquid had its boiling point. He also found that the boiling point varied depending on the pressure.

Currently the Fahrenheit scale is used in Britain, the United States, Canada, South Africa and New Zealand. Elsewhere a scale invented by Celsius a quarter of a century later is used. The relationship between both scales is as follows:

F = [(9/5)°C] + 32.

Fahrenheit died on 16 September 1736 in The Hague, Netherlands.