The primogenial thermometer in 1593 by the Italian scientist Galileo Galilei ( 1564 - 1642 ) invented. His lead off thermometer is a glass tube of one borderline of the exposure and the other stub with a immense walnut, glass thought Digital thermometer. Occasion lavish upon the glass mental picture heating, and then the glass tube into the water. With the change in temperature, the water in the glass tube will procedure up and down temperature changes and big and low temperature can be firm according to the number of moving.
Thermometer the role of thermal expansion and contraction, so this thermometer, by the external atmospheric pressure and other environmental factors, so the measurement error. Later, Galileo ' s students and other scientists, on the basis of repeated improvements, such as glass tube upside down, the liquid on the tube, the glass tube closed and so on. The more prominent is the thermometer manufactured by the Frenchman Bu Liao in 1659, his glass bubble volume is reduced, and temperature material to mercury, such a thermometer with the thermometer of the prototype. After Dutch Fahrenheit in 1709 the use of alcohol, the use of mercury in 1714 as the measurement of material, creating a more accurate thermometer. He observed that the water temperature, salt water and ice mixed in when the boiling temperature of water and ice mixed temperature; after repeated experiments and approval of the final temperature when the solidification of a certain concentration of salt water to 0 F, the solidification of pure water The temperature is 32, the standard atmospheric pressure, water boiling temperature of 212 on behalf of the Fahrenheit temperature, which is the Fahrenheit thermometer.
Fahrenheit while the Frenchman column Muir ( 1683 ~ 1757 ) also design and manufacture of a thermometer. He believes that the coefficient of expansion of mercury is too small, not so temperature material. He devotes himself to study the advantages of alcohol as a temperature material. He repeated practice found to contain 1 / 5 of water, alcohol, between the freezing temperature and the boiling temperature of water, the expansion of its volume is increased from 1000 volume units to 1080 units of volume. He therefore between freezing and boiling is divided into 80 parts, as its own thermometer temperature degree, this is the column ' s thermometer.
Fahrenheit made and then after 30 years, the Swedish camera Seoul Hughes in 1742 to improve the Fahrenheit thermometer scale, the boiling point of water as 0 degrees, the freezing point of water at 100 degrees. Later, his colleagues Shilemoer, two temperature values upside down, it becomes now the percentage of temperature, that is the Celsius temperature in indoor - outdoor thermometer. The relationship between Fahrenheit and Celsius temperature = 9 / 5 32 = 5 / 9 ( - 32 ).
British and American countries the use of Fahrenheit, the German multi - column ' s temperature, world scientific community and industrial and agricultural production, and most of China, France and other countries is more, in degrees Celsius.
