People have needed to measure the temperature of physical bodies and liquids from the very beginning of the development of a civilized society. The history of the creation of thermometers begins several centuries ago. Let's find out what the first devices for this purpose were? Who developed the thermometer scale? When was the first thermometer invented?
First thermometer
The progenitor of the modern thermometer is a rather primitive device known as a thermobaroscope. The history of the creation of thermometers of this category takes us back to the distant 1597. It was at this time that the famous scientist Galileo Galilei conducted his experiments aimed at developing a device for measuring the temperature of a liquid.
The first thermometer was nothing more than a construction, represented by a thin glass tube with a small ball sealed in the middle. During measurements, the lower part of the thermobaroscope was subjected to heating. Then the tube was placed in water. After a few minutes the airstructure was cooled, which led to a decrease in pressure and movement of the ball.
Unfortunately, the scientist did not manage to finalize the device. It never found its 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 was determining the heating of a certain substance.
Refining Galileo's thermobaroscope
The history of the creation 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 shortcomings 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 eliminated the dependence of the obtained measurement results on atmospheric pressure.
Later this device was also improved. The water in it was replaced with wine alcohol. Thus, the thermobaroscope began to function on the principle of liquid expansion when the ambient temperature changes.
Santorio thermometer
In 1626, an Italian scientist named Santorio from the city of Padua, who served as a professor at the 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 has not found practical application,because it was extremely cumbersome. The device was so impressive in size that it had to be taken out into the yard to take measurements.
What was the Santorio thermometer? The device was made in the form of a ball connected to a winding, oblong tube. On the surface of the latter contained divisions of the scale. The free end of the tube was filled with a liquid substance containing a dye. When the tube was placed in a heated substance, the colored internal environment reached one or another value on the scale.
Invention of a single measurement scale
The history of the creation 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 area was the success of the German physicist Gabriel Fahrenheit. It was he who in 1723 decided to replace the alcohol in the flask of thermometers of that time with mercury.
The scientist scale was based on the presence of three reference points:
- the first corresponded to zero water temperature;
- the second point on the scale corresponded to 32 degrees;
- third - 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 experiments, he decided to divide the thermometer scale into 100 equal 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.day. However, today it is installed in measuring instruments upside down. Thus, the upper figure of 100o now corresponds to the boiling point of water, and the lower one is taken as 0o.
In the middle of the 19th century, the English physicist William Thomson, who is better known to a wide audience as Lord Kelvin, proposed his version of the measuring scale. He chose temperature as the starting point for measurements, which was equal to -273oС. It is this indicator that excludes any movement in the molecules of physical objects. However, devices based on such a scale have found their application only in the scientific community.
Types and devices of modern thermometers
The simplest type of thermometer is a regular glass thermometer, which is now available in every home. However, such devices are gradually becoming a thing of the past. Since filling the flask of the device with toxic mercury is not a very safe solution for domestic use.
Currently, digital devices are gradually being used as an alternative to mercury thermometers. The latter measure the ambient temperature using the built-in electronic sensor.
As for the latest inventions, they are infrared thermometers and disposable thermal strips. However, such devices have not yet found wide application.
In closing
So we found out who invented the thermometer, what types of devicesof this category are available to users today. Finally, I would like to note that devices for 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 outside. A thermometer installed in the oven helps to maintain the optimal cooking temperature, and a similar device in the refrigerator helps control the quality of food storage.
