In the habitual speech of the word "thermometer" and "thermometer" became synonyms. Calling one, mean the second and vice versa. However these two concepts, though have some similarities, are not identical. The thermometer and the thermometer - not the same.
Thermometer or thermometer
Obviously, it is necessary to begin with what in general is the thermometer. In that case it is necessary to remember his primogenitor – the device created in 1597 by Galilei and the thermoscope called by it. The device was a glass tube with a hollow ball. The end of a tube fell to the vessel filled with water. The ball slightly heated up. In process of its cooling the water level in a tube rose. It was worth heating a ball again, water level began to fall.
Sixty years later the Florentine scientists the device was improved. It received a scale, from a tube pumped out air, and it allowed to receive more correct results of measurements. Over time the ball removed to the lower part of a tube, and the tube was soldered. Water was also replaced with the tinted alcohol, and the device with finding of a habitual look received and the familiar name was received by the thermometer.
Today call the thermometer practically any device for measurement of temperature of any body, water, air and so on. Thermometers are gas, optical, infrared, liquid, electric and mechanical. Now more and more popular are electric thermometers which are substantially safer more conveniently than mercury analogs. The principle of their action is based on change of conduction resistance which is followed by temperature change of the environment. Infrared thermometers which do not demand direct contact with a human body at all are in also increasing demand. In a number of the countries they already became widespread, in particular in medical institutions.
Or nevertheless thermometer?
If with thermometers all is rather clear, then a question — what is the thermometer - remained open. As it became clear, this word has two radically differing values. Actually, the thermometer is nothing but the colloquial term from a word degree, and he means the same thermometer. It is applied only in informal conversation. But there is also the second value, highly specialized, but not less capacious. The thermometer - the special lever intended for thin adjustment of accuracy of operation of the mechanism in the mechanical clock. The turn of this lever changes a tension of a clockwork spring to a certain corner or degree and by that defines effort on the driving mechanism that in turn sets a certain speed of rotation. Thus the accuracy of operation of the clockwork is also set.