People needed to measure the temperature of physical bodies and fluids from the very beginning of the development of a civilized society. The history of thermometers begins several centuries ago. Let's find out what were the first devices of this purpose? Who developed the thermometer scale? When was the first thermometer invented?
First thermometer
The progenitor of a modern thermometer is a rather primitive device, known as a thermobaroscope. The history of the creation of thermometers in this category brings us back to the distant year 1597. It was at this time that his experiments aimed at developing a device for
measuring the temperature of a liquid were carried out by the famous scientist Galileo Galilei.
The first thermometer was nothing more than a design, represented by a thin glass tube with a small ball sealed in the middle. During measurements, the lower part of the thermobaroscope was heated. Then the tube was placed in water. After a few minutes, the air in the structure was cooled, which led to a decrease in pressure and the movement of the ball.
Unfortunately, the scientist was not able to modify the device. He never found his practical application. There was no thermometer scale. Therefore, using the device it was impossible to determine the exact numerical indicators of the temperature of the surrounding space or liquids. The only thing such a thermometer turned out to be suitable for is the determination of the heating of a certain substance.
Finalization of the Galileo thermobaroscope
The history of thermometers did not end with Galileo's futile attempts to come up with a practical device. In 1657, 60 years after the first trial and error of the inventor, his work was continued by a group of scientists from Florence. They managed to eliminate the main disadvantages of the thermobaroscope, in particular, to introduce a gradation scale into the device. Moreover, Florentine scientists created a vacuum in a sealed glass tube, which excluded the dependence of the obtained measurement results on atmospheric pressure.
Later, this device was further developed. The water in it was replaced with wine alcohol. Thus, the thermobaroscope began to function according to the principle of expansion of the liquid with a change in the temperature parameters of the environment.
Santorio Thermometer
In 1626, an Italian scientist by the name of Santorio from the city of Padua, who served as a professor at a local university, created his own version of the thermometer. With its help, it became possible to measure the temperature of the human body. However, the device did not find practical application, since it was extremely bulky. The device was so impressive that for measurements it had to be taken out into the yard.
What was a Santorio thermometer? The device was made in the shape of a ball connected to a winding, elongated tube. On the surface of the latter contained the division of the scale. The free end of the tube was filled with a dye-containing liquid substance. When the tube was placed in a heated substance, the colored internal medium reached one or another value on the scale.
The invention of a single measurement scale
The history of thermometers includes not only attempts to develop an effective thermometer design, but also work on the creation of an objective measuring scale. One of the most successful experiments in this field was a success for the German physicist Gabriel Fahrenheit. It was he who in 1723 decided to replace the alcohol in the thermometer flask of that time with mercury.
The scientist’s scale was based on the presence of three reference points:
- the first corresponded to a zero indicator of water temperature;
- the second point on the scale corresponded to 32 degrees;
- the third was equal to the boiling point of water.
The Swedish physicist, meteorologist and astronomer Anders Celsius finally improved the scale of the thermometer . In 1742, during the experiments, he decided to divide the scale of the thermometer into 100 equivalent intervals. The upper indicator corresponded to the melting temperature of ice, and the lower one corresponded to the boiling point of water. The Celsius scale is used in thermometers to this day. However, today it is installed upside down in measuring instruments. Thus, the upper indicator of 100 about now corresponds to the boiling point of water, and the lower is taken as 0 about .
In the mid-19th century, an English physicist William Thomson, who is better known to a wide audience as Lord Kelvin, proposed his version of the measuring scale. He chose the temperature as the starting point for measurements, which was -273 . This indicator excludes any movements in the molecules of physical objects. However, devices based on such a scale found their application only in the scientific community.
Types and devices of modern thermometers
The simplest
type of thermometer is an ordinary glass thermometer, which today is available in every home. However, such devices are gradually becoming a thing of the past. Since filling the flask with toxic mercury is not a very safe solution for domestic use.
Currently, as an alternative to mercury thermometers , digital devices are gradually beginning to be used. The latter measure the ambient temperature due to the operation of the built-in electronic sensor.
As for the latest inventions, they are infrared thermometers and disposable thermal strips. However, such devices have not yet been widely used.
Finally
So we found out who invented the thermometer, what types of devices in this category are available to users today. In conclusion, I would like to note that devices of this purpose are of particular importance for modern man. The thermometer not only makes it possible to quickly determine body temperature, but also allows you to find out how warm or cold it is on the street. A thermometer installed in the oven helps to maintain optimal cooking temperatures, and a similar device in the refrigerator helps control the quality of food storage.