Tuesday, October 4, 2011

Unique thermometer

The inventor of the thermometer is considered to be Galileo. Galileo studied at this time of Heron of Alexandria, which has already described a similar device, but not for measuring degrees of heat, but to raise the water by heating.

The invention of the thermometer is also credited to Lord Bacon, Robert Fludd, Sanktoriusu, Scarpa, Cornelia Drebbelyu (Cornelius Drebbel), Porte de Salomon and Kaus, writing, and later part of who had personal intercourse with Galileo. All of these thermometers were air and consisted of a vessel with a tube containing air, separated from the atmospheric column of water, they changed their testimony, and from changes in temperature and from changes in atmospheric pressure.

Thermometers with a liquid are described for the first time in in 1667."Essays of the Academy of Natural experiences Cimento the city where they were referred to as objects, have long produced skilled craftsmen, who are called «Confia», a warming fire blown glass on the lamp, and maketh him out of the amazing and very gentle products. First, these thermometers are filled with water, and they burst when it freezes, use this alcohol wine began in the opinion of the Grand Duke of Tuscany Ferdinand II. Florentinckie thermometer not only depicted in «Saggi», but a few copies have survived to our time in Galilean Museum, Florence, and their preparation is described in detail.

First, the master had to make a division on the tube, thinking of her and the relative size of the ball: the division of the molten enamel deposited on a heated tube to tube, every tenth was designated a white point, and the other black. Usually done by 50 divisions, such that when snow melts alcohol does not fall below 10, but the sun did not rise above 40. Good masters made such thermometers are so fortunate that all thermometers showed the same under the same conditions, but nobody has been able to achieve, if the tube were separated by 100 or 300 ppm to obtain greater sensitivity. Filled thermometers by means of heating up the ball and dropping the tube in the alcohol, but were finishing filling with glass funnel with a finely drawn-out end, free access to a fairly wide receiver. After adjusting the amount of fluid, the tube was sealed with wax, called "Hermetic".

In 1703 Amontons (Guillaume Amontons) in Paris, has improved the air thermometer, measuring no extension, and increase elasticity of the air, reduced to the same volume at different temperatures podlivaniem mercury to the open elbow, barometric pressure and changes in this are taken into account . Zero on such a scale had to be "that a considerable degree of cold," in which the air loses all its elasticity (ie the modern absolute zero) and the second fixed point - the temperature of boiling water. The influence of atmospheric pressure at the boiling point was not yet known Amonton, and his air thermometer has been released from water-gas, so the data from its absolute zero is obtained at 239,5 ° centigrade scale today. Another air thermometer Amonton very imperfectly executed, was independent of changes in atmospheric pressure: he represented the siphon barometer, an open knee which was continued upward, filled with the first strong solution of potash, oil and ended with the top sealed tank with air.
The modern form of thermometer attached Fahrenheit and described his method of cooking in 1723, initially he also filled his pipe with alcohol, and only at the end turned to mercury. Zero of its scale, he put the mixture at a temperature of snow, with ammonia or sodium chloride, but at "starting freezing" it put 32 °, and 96 ° at the temperature of a healthy human body, the mouth or under the arm. Later, he found that water boils at 212 ° C and this temperature was always the same distance at the same barometer.

Finally found the two fixed points, melting ice and boiling water, the Swedish physicist Celsius in 1742, but initially it was set at 0 ° at the boiling point and 100 ° at the freezing point, and take back the designation only on the advice of M. Stormer. Surviving copies of Fahrenheit differ thoroughness.

Work Reaumur in 1736, though, and led to the establishment of 80 ° of the scale, but were rather a step back against what has already made Fahrenheit: Reaumur was huge and awkward to use, and its method of division into degrees inaccurate and fiddly.
After Fahrenheit and Reaumur thermometer manufacturing business into the hands of artisans, as the thermometers have been the subject of trade

Share

Twitter Delicious Facebook Digg Stumbleupon Favorites More