Who was the first to create a modern thermometer? How was the thermometer invented? Absolute temperature scale

We all often use such a device as a thermometer in our lives, but few people know the history of its invention and improvement. It is generally accepted that the thermometer was invented by Galileo Galilei back in 1592. The design of the thermoscope (that’s what the thermometer was called then) was primitive (see figure below): a thin glass tube was soldered to a glass ball of small diameter and placed in a liquid.

Air in glass ball using a burner or simply rubbing it with the palms, it was heated, as a result of which it began to displace the liquid in the glass tube, thereby showing the degree of increase in temperature: the higher the air temperature in the glass ball became, the lower the water level in the tube dropped. An important role was played by the ratio of the volume of the ball to the diameter of the tube: by creating a thinner tube, it was possible to monitor more minor changes in temperature in the ball.

Subsequently, the design of Galileo's thermoscope was modified by one of his students, Fernando Medici. The basic idea remained the same, but Fernando made significant changes that made the thermoscope more similar to a modern mercury thermometer. A glass ball and a thin tube were also used (see figure above), but now the tube was soldered not from the bottom, but from the top, and the liquid was poured into the glass ball, while the top of the tube was open. Changing the temperature of the poured liquid (at that time wine alcohol was used) led to an increase in its level in the tube. Later, divisions were applied to the tube, i.e. The thermometer was first calibrated.

A lot of time has passed since then, and during this period the thermometer has been improved and modernized more than once. Recent advances in the fields of physics have enabled the development of new approaches to temperature measurement. Today, various digital thermometers have been created, which are based on the principle of changing the resistance of a substance with a change in temperature (electric thermometers) or the principle of changing the level of luminosity, spectrum and other quantities with a change in temperature (optical thermometers).

Today it is almost impossible to imagine life without a thermometer. Of course, you can find out about the temperature outside from the weather report. But how can you determine the heat level in a room, oven, drying chamber or greenhouse? There is no way to do this without a thermometer.

There are several types:

liquid;
mechanical;
gas;
electrical;
optical.

Liquid

The operating principle of such a device is based on the effect of expansion or compression of a liquid that fills a flask and changes its volume as its own temperature fluctuates. Usually, mercury or alcohol is poured into it, which subtly react to minimal changes in heat in the environment.

In medicine, mercury thermometers are usually used, but in meteorology they are filled with alcohol, since the mercury column can freeze at -38 degrees.

Mechanical

Operating principle of the device of this type is also based on expansion. But with its help, the temperature is determined depending on the expansion of the bimetallic strip or metal spiral.

These are characterized by high accuracy, they are reliable and easy to use.

As a separate independent model However, they are not used; they are usually used in automated systems.

Gas

The gas type temperature meter works on the same principle as the liquid device. It uses some inert gas as a working substance.

The advantage of this device is that it can measure temperatures approaching absolute zero, and its measurement range ranges from -271 to +1000 degrees. This is a rather complex device that is rarely used in laboratory measurements.

Electrical

The operation of such a measuring device is related to the dependence of the resistance of the conductor used on temperature. It is known that the resistance of any metals linearly depends on the level of their heat. More accurate measurements can be obtained by replacing metal conductors with semiconductors. However, semiconductors are practically not used in such devices, since the relationship between the characteristics of the semiconductor and the heat level cannot be expressed linearly and it is almost impossible to calibrate the instrument scale.

Copper usually acts as a conductor, showing temperature changes from -50 to +180 degrees. If we take another working metal, for example, platinum, then its temperature range will expand significantly and will be from -200 to +750 degrees. Such electrical thermal sensors are used in laboratories, at experimental stands or in production.

Optical

Optical instruments or pyrometers allow you to find out the temperature by the level of luminosity of a body, analysis of its spectrum and some other parameters. This is a non-contact device capable of measuring, with an accuracy of several degrees, the level of heat in a wide range - from 100 to 3000 degrees. Most often in practice we come across infrared household thermometers. Such thermometers are very convenient because they allow you to safely, quickly and accurately determine a person’s body temperature.

There are other, more complex temperature meters, such as fiber optic or thermoelectric. These are very sensitive instruments that give the most accurate measurement results with virtually no error.

Useful tips

Today there is not a single person who does not use such a device as a thermometer. At the moment it is a common occurrence. However, this was not always the case. Few people know what a long and difficult journey the thermometer had. The history of its appearance goes deep into the past.

The first thermometer, or rather thermoscope, was invented during the Renaissance in late XVI century. Its creator was none other than Galileo Galilei. The thermoscope was a glass ball to which a tube was soldered. Heating the ball with his hands and turning it, the Italian physicist lowered the free end of the glass tube into a bowl with colored water or wine. After the ball cooled, the volume of air it contained decreased significantly, and water rose through the tube. The difference between a thermoscope and a modern thermometer was that in Galileo's invention, instead of mercury, air expanded.

Almost simultaneously with Galileo, still not knowing about his discovery, Professor S. Santorio from the University of Padua created his own device with which it was possible to measure temperature human body.

The device was quite bulky and also had the shape of a ball and an oblong winding tube on which divisions were drawn. The free end of the tube was filled with colored liquid. In order to measure the temperature, a person had to take this ball into his mouth or warm it with his hands. Since Santorio’s device was very large, it was installed in the courtyard of the house.

In Europe at the beginning of the 15th century, very a large number of unique thermometers. For example, in the Netherlands, the so-called “Dutch” type of thermometer, which had two balls and a winding tube, was widespread. The lower ball was filled with liquid, and the upper ball was filled with air.

Invention of the first thermometer, the data of which was not determined by changes atmospheric pressure, occurred in 1641. Such a thermometer was created under the Holy Roman Emperor, Ferdinand II, who was not only a patron of the arts, but also the author of many instruments. Physicist Toricelli's experiments with barometers filled with mercury gave impetus to the improvement of the thermoscope, which was invented by Galileo. This device was simply turned over, colored alcohol was added to the ball and the upper end of the tube was sealed.

German physicist Otto von Guericke, exploring atmospheric air, invented a number of unique thermometers, including the largest, whose height was seven meters. This original thermometer was attached to the wall of the house. A large copper ball, covered with blue paint and decorated with gold stars, was filled with air. One elbow of the tube, welded from below, was partially filled with liquid, while the other remained open. In hot weather, the hot air in the glass ball pushed the liquid out of the tube, the float began to rise, and the angel fell down, thereby pointing to the corresponding division of the scale. The lowest division showed “great heat”, and the highest, seventh division showed “great cold”.

At that time, the single scale that we use today did not exist. Scientists for a long time could not find starting points, the distance between which would need to be divided evenly. They suggested taking into account, for example, the thawing points of ice and melted water. butter. After some time, more precisely in 1714, a more or less usable thermometer appeared. The creator of such a thermometer was the German physicist Gabriel Fahrenheit.

Initially, Fahrenheit created two alcohol thermometers, but thanks to them, only conditionally accurate measurements could be made. Then the physicist decided to use mercury in the thermometer. This invention turned out to be more successful. In thermometers he used several types of scales, the last of which was based on three established points. The first point was the temperature of the composition of water, ice and ammonia, which was marked 0 degrees, the second was the temperature of the mixture of water and ice, designated 32 degrees, and the third was the boiling point of water, which was 212 degrees. This scale was later named after its creator. The Fahrenheit scale is still used in the USA and England.

After 30 years, astronomer Anders Celsius began conducting experiments with a mercury thermometer to study the correlation between the melting point of snow and the boiling point from atmospheric pressure. Celsius came to the conclusion that it would be rational to divide the distance between points into 100 intervals. The number 100 marked the melting point of ice, and 0 the boiling point of water.

However, in 1860, the English scientist William Kelvin proposed a new model of the temperature scale. A temperature of -273 degrees Celsius corresponded to zero kinetic energy of the molecules. Since no substance could be cooled further, a temperature of -273 degrees is considered “absolute zero.” In William Kelvin's scale, zero was taken as the beginning, and each subsequent division was equal to an ordinary degree. This scale turned out to be very convenient, because with its help it was possible to fairly fully display all the phenomena that occur on Earth.

In medicine, thermometry began to be used much later than in technology. As early as 1861, Karl Gerhard believed that temperature measurement was a very difficult procedure to introduce into practice and regular use. After some time, these simple, but very necessary equipment- medical thermometers that worthily serve science and protect human health.

Original taken from biboroda in The history of the creation of the thermometer: how was the first thermometer invented?

On March 29, 1561, the Italian doctor Santorio was born - one of the inventors of the first mercury thermometer, a device that was an innovation for that time and which no person can do without today.

Santorio was not only a doctor, but also an anatomist and physiologist. He worked in Poland, Hungary and Croatia, actively studied the breathing process, “invisible evaporations” from the surface of the skin, and conducted research in the field of human metabolism. Santorio conducted experiments on himself and, studying the features human body, created many measuring instruments- a device for measuring the force of pulsation of arteries, scales for monitoring changes in human weight and - the first mercury thermometer.

Three inventors

It is quite difficult to say today who exactly created the thermometer. The invention of the thermometer is attributed to many scientists at once - Galileo, Santorio, Lord Bacon, Robert Fludd, Scarpi, Cornelius Drebbel, Porte and Salomon de Caus. This is due to the fact that many scientists simultaneously worked on creating a device that would help measure the temperature of air, soil, water, and humans.

There is no description of this device in Galileo's own writings, but his students testified that in 1597 he created a thermoscope - an apparatus for raising water using heat. The thermoscope was a small glass ball with a glass tube soldered to it. The difference between a thermoscope and a modern thermometer is that in Galileo's invention, instead of mercury, air expanded. Also, it could only be used to judge the relative degree of heating or cooling of the body, since it did not yet have a scale.

Santorio from the University of Padua created his own device with which it was possible to measure the temperature of the human body, but the device was so bulky that it was installed in the courtyard of a house. Santorio's invention had the shape of a ball and an oblong winding tube on which divisions were drawn; the free end of the tube was filled with tinted liquid. His invention dates back to 1626.

In 1657, Florentine scientists improved the Galileo thermoscope, in particular by equipping the device with a bead scale.

Later, scientists tried to improve the device, but all thermometers were air, and their readings depended not only on changes in body temperature, but also on atmospheric pressure.

The first liquid thermometers were described in 1667, but they burst if the water froze, so they began to use wine alcohol to create them. The invention of a thermometer, the data of which would not be determined by changes in atmospheric pressure, occurred thanks to the experiments of the physicist Evangelista Torricelli, a student of Galileo. As a result, the thermometer was filled with mercury, turned upside down, colored alcohol was added to the ball, and the upper end of the tube was sealed.

Single scale and mercury

For a long time, scientists could not find starting points, the distance between which could be divided evenly.

The initial data for the scale were the thawing points of ice and melted butter, the boiling point of water, and some abstract concepts like “a significant degree of cold.”

Thermometer modern form, most suitable for household use, with an accurate measurement scale was created by the German physicist Gabriel Fahrenheit. He described his method for creating a thermometer in 1723. Initially, Fahrenheit created two alcohol thermometers, but then the physicist decided to use mercury in the thermometer. The Fahrenheit scale was based on three established points:

the first point was equal to zero degrees - this is the temperature of the composition of water, ice and ammonia;
the second, designated 32 degrees, is the temperature of the mixture of water and ice;
the third, the boiling point of water, was 212 degrees.
The scale was later named after its creator.

Reference
Today, the most common is the Celsius scale, the Fahrenheit scale is still used in the USA and England, and the Kelvin scale is used in scientific research.
But it was the Swedish astronomer, geologist and meteorologist Anders Celsius who finally established both constant points - melting ice and boiling water - in 1742. He divided the distance between points into 100 intervals, with the number 100 marking the melting point of ice, and 0 the boiling point of water.

Today, the Celsius scale is used inverted, that is, the melting point of ice is taken as 0°, and the boiling point of water as 100°.

According to one version, the scale was “turned over” by his contemporaries and compatriots, the botanist Carl Linnaeus and the astronomer Morten Stremer, after the death of Celsius, but according to another, Celsius himself turned over his scale on Stremer’s advice.

In 1848, the English physicist William Thomson (Lord Kelvin) proved the possibility of creating an absolute temperature scale, where the reference point is the value of absolute zero: -273.15 ° C - at this temperature further cooling of bodies is no longer possible.

Already in the middle of the 18th century, thermometers became a trade item, and they were made by artisans, but thermometers came into medicine much later, in the middle of the 19th century.

Modern thermometers

If in the 18th century there was a “boom” of discoveries in the field of temperature measurement systems, today work is increasingly being carried out to create methods for measuring temperature.

The scope of application of thermometers is extremely wide and has special meaning For modern life person. A thermometer outside the window reports the temperature outside, a thermometer in the refrigerator helps control the quality of food storage, a thermometer in the oven allows you to maintain the temperature when baking, and a thermometer measures body temperature and helps assess the causes of poor health.
A thermometer is the most common type of thermometer, and it is the one that can be found in every home. However, mercury thermometers, which were once a brilliant discovery by scientists, are now gradually becoming a thing of the past as unsafe. Mercury thermometers contain 2 grams of mercury and have the highest accuracy in determining temperature, but you not only need to handle them correctly, but also know what to do if the thermometer suddenly breaks.
To replace mercury thermometers There are electronic or digital thermometers that operate on the basis of a built-in metal sensor. There are also special thermal strips and infrared thermometers.

Santorio was not only a doctor, but also an anatomist and physiologist. He worked in Poland, Hungary and Croatia, actively studied the breathing process, “invisible evaporations” from the surface of the skin, and conducted research in the field of human metabolism. Santorio conducted experiments on himself and, studying the characteristics of the human body, created many measuring instruments - a device for measuring the force of pulsation of arteries, scales for monitoring changes in human weight, and the first mercury thermometer.

Three inventors

Greenhouse thermometer, 1798. Photo: www.globallookpress.com

In 1657, Florentine scientists improved the Galileo thermoscope, in particular by equipping the device with a bead scale.

Later, scientists tried to improve the device, but all thermometers were air, and their readings depended not only on changes in body temperature, but also on atmospheric pressure.

Single scale and mercury

For a long time, scientists could not find starting points, the distance between which could be divided evenly.

The initial data for the scale were the thawing points of ice and melted butter, the boiling point of water, and some abstract concepts like “a significant degree of cold.”

A thermometer of a modern form, most suitable for household use, with an accurate measurement scale was created by the German physicist Gabriel Fahrenheit. He described his method for creating a thermometer in 1723. Initially, Fahrenheit created two alcohol thermometers, but then the physicist decided to use mercury in the thermometer. The Fahrenheit scale was based on three established points:

the first point was equal to zero degrees - this is the temperature of the composition of water, ice and ammonia;
the second, designated 32 degrees, is the temperature of the mixture of water and ice;
the third, the boiling point of water, was 212 degrees.

The scale was later named after its creator.

Today, the most common is the Celsius scale, the Fahrenheit scale is still used in the USA and England, and the Kelvin scale is used in scientific research.

But it was the Swedish astronomer, geologist and meteorologist Anders Celsius who finally established both constant points - melting ice and boiling water - in 1742. He divided the distance between points into 100 intervals, with the number 100 marking the melting point of ice, and 0 the boiling point of water.

Today, the Celsius scale is used inverted, that is, the melting point of ice is taken as 0°, and the boiling point of water as 100°.

Already in the middle of the 18th century, thermometers became a trade item, and they were made by artisans, but thermometers came into medicine much later, in the middle of the 19th century.

Modern thermometers

If in the 18th century there was a “boom” of discoveries in the field of temperature measurement systems, today work is increasingly being carried out to create methods for measuring temperature.

The scope of application of thermometers is extremely wide and is of particular importance for modern human life. A thermometer outside the window reports the temperature outside, a thermometer in the refrigerator helps control the quality of food storage, a thermometer in the oven allows you to maintain the temperature when baking, and a thermometer measures body temperature and helps assess the causes of poor health.

Mercury thermometers are being replaced by electronic or digital thermometers, which operate on the basis of a built-in metal sensor. There are also special thermal strips and infrared thermometers.