History of thermometers. Types of modern temperature measuring instruments

People needed to measure the temperature of physical bodies and liquids from the very beginning of the development of civilized society. The history of the creation of thermometers begins several centuries ago. Let's find out what the first instruments of this purpose were. Who designed the thermometer scale? When was the first thermometer invented?

The 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 brings us back to the far 1597 year. 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 design, represented by a thin glass tube with a small ball sealed in the middle. During the measurements, the lower part of the thermobaroscope was subjected to heating. 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 movement of the ball.

Unfortunately, the scientist did not manage to refine the device. He never found his practical application. There was no scale of the thermometer. Therefore, using the device it was impossible to determine the exact numerical values of the temperature of the surrounding space or liquids. The only thing to which such a thermometer was found is the determination of the heating of a certain substance.

Refinement of the Galilean thermobaroscope

The history of the creation of thermometers did not end with Galileo's vain attempts to come up with a practical device. In 1657, 60 years after the first attempts and mistakes 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. Water in it was replaced with wine alcohol. Thus, the thermobaroscope began to function on the principle of expanding the liquid when the temperature parameters of the environment change.

Thermometer Santorio

In 1626, an Italian scientist named Santorio from Padua, who was a professor at a local university, created his own version of the thermometer. With his help, it became possible to measure the temperature of a person's body. However, the device did not find practical application, because it was extremely cumbersome. The device was so impressive that it was necessary to carry it out to the yard for measurements.

What was Santorio's thermometer? The device was made in the form of a ball connected to a sinuous, oblong tube. On the surface of the latter, the scale was divided. The free end of the tube was filled with a liquid substance with a dye content. When the tube was placed in a heated substance, the colored internal medium reached a certain value on the scale.

The invention of a single measurement scale

The history of creating thermometers includes not only attempts to develop an effective design of the thermometer, 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 alcohol in the bulb of thermometers of that time with mercury.

The scientist's scale was based on the presence of three reference points:

• The first corresponded to the zero temperature of the water;
• The second point on the scale corresponded to 32 degrees;
• The third was equal to the boiling point of water.

Finally, the Swedish physicist, meteorologist and astronomer Anders Celsius improved the scale of the thermometer. In 1742, during the experiments, he decided to divide the thermometer scale into 100 equivalent intervals. The upper figure corresponded to the temperature of the melting 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 in the measuring instruments in an inverted form. Thus, the upper index of 100 ^o now corresponds to the boiling point of water, and the lower one is taken at 0 ^o .

In the middle of the 19th century, the English physicist William Thomson proposed his version of the measurement scale, which is better known to a wider audience, like Lord Kelvin. He chose the temperature as the starting point for the measurements, which was -273 ° C. It is this parameter that excludes any movement in the molecules of physical objects. However, devices based on such a scale have found their application only in a scientific environment.

Types and devices of modern thermometers

The simplest kind of thermometer is an ordinary glass thermometer, which is now available in every home. However, such adaptations are gradually receding into the past. Since filling the flask with toxic mercury is not a very safe solution for domestic use.

At the present time digital devices are gradually beginning to be used as an alternative to mercury thermometers . The latter measure the ambient temperature through the operation of an integrated electronic sensor.

As for the latest inventions, they are infrared thermometers and disposable thermal strips. However, such devices have not yet found wide application.

Finally

So we found out who invented the thermometer, what kinds of devices of this category are available to users today. Finally I would like to note that the devices of this purpose are of particular importance for the modern person. The thermometer not only makes it possible to quickly determine the temperature of the body, but also lets you know how warm or cold it is outside. The thermometer, installed in the oven, helps to maintain the optimum cooking temperature, and a similar device in the refrigerator - control over the quality of food storage.