Alcohol thermometers: an overview of manufacturers and the best models

Now everyone knows alcohol thermometers. How did they arise, what kinds of these measuring devices exist at the given time and how do they apply?

The prototype of a modern thermometer

It is believed that the father of the thermometer was Galileo Galilei. At the end of the XVI century, he created some kind of modern instrument called a thermoscope. It consisted of a cone and a glass tube and was intended to determine the fact of a change in the temperature of the water. Scales of this device was not. Therefore, it was impossible to find out how much it had changed.

Then the device was perfected by adding a scale of beads, air was removed, turned upside down with a ball-shaped cone. Finally, water was replaced with wine alcohol. This was done by Florentine Torriceli. The innovation allowed to carry out measurements in frosty weather. After all, the water did not move along the scale when freezing. The glass vessel itself burst and became worthless. In addition, the alcohol thermometer did not depend on the pressure of the atmosphere. Several of the old Florentine thermometers have survived to this day and are in the Galilee Museum.

The fissions were applied to the tube with hot enamel, dozens of white, the rest black. The range was usually -10 to +40. The tube was filled with alcohol and sealed with sealing wax. The alcohol thermometers of one master showed the same values under the same conditions. But the divisions of each master were different. When trying to divide the scale into 100 or more parts, it was not possible to obtain the same values.

Fill the thermometer with mercury invented by G. Fahrenheit. He fixed the freezing point of the saline solution on the scale, 32 degrees Fahrenheit, 96 degrees - body temperature, 212 freezing of water. This thermometer was used until the middle of the XX century, and in the US continue to be used now.

Improvement of the thermometer

At the beginning of the XVIII century, Guillaume Amonton changed the measurement system. The Frenchman, who invented an alcohol thermometer, watched the change in the elasticity of the air, ignoring the pressure. In this case, the zero of the scale was the temperature, which is now called absolute zero. Another constant point in the thermometer was the boiling point of water. But the Frenchman, who invented the alcohol thermometer, did not take into account the effect of atmospheric pressure on the boiling point of water.

In appearance it was a siphon barometer with an open knee pointing upwards. From below there was a solution of potash, and from above oil. The reservoir was sealed.

Temperature measuring scales

This device is not very similar to modern alcohol thermometers for measuring temperature. At this time, many scientists worked on creating their own or improving existing models.

The device was perfected by another Frenchman. The alcohol thermometer of Reaumur had a scale from 0 to 80 degrees. The ice melted at 0 degrees, and the water was boiling at 80. He realized that mercury and alcohol expand in different ways, therefore, the scales for thermometers should be unequal. But his thermometers were big and inconvenient to use.

From the middle of the 18th century to the 20th, several important discoveries were made. Swede Anders Celsius accurately determined the boiling point of water by zero, and its freezing point was 100. It turned out that only the boiling point of ice depends on the atmospheric pressure, and it does not affect freezing. Therefore, the divisions were located just like this.

There is no exact data on who exactly turned the scale "upside down". Some say that it was Celsius himself. Other researchers attribute a change in the direction of the scale to Karl Linnaeus or Morten Strehmer.

The English scientist Calvin (William Thomson) created an absolute temperature scale from absolute zero, on the Celsius scale it is -273.15 degrees.

In the XVIII century, alcohol thermometers were widely distributed in Europe. They began to sell along with other goods. At that time, temperature scales were already known. Thus, M. Lomonosov proposed his own, with 150, and Lambert - a scale with 375 divisions, each of which was equal to a thousandth part of the expansion of air.

The XVIII century was marked by significant discoveries in the field of creation and improvement of measuring instruments, including alcohol thermometers.

At the end of the 20th century, new directions and instruments began to emerge, based on other principles of action.

Types of thermometers

• Liquid.
• Mechanical acts on the same principle, but instead of a liquid, bimetallic tapes or spirals are used.
• Electronic uses a change in the resistance of the metal under the influence of temperature. As a conductor, platinum wire or sputtering on ceramics is used. Measured from -200 ° C to 850 ° C.
• Optical ones are based on changing the level of the spectrum or other parameters. These include infrared body temperature meters that work without contact with a person.
• Manometric, expansion thermometers, pyrometric, thermoelectric.

Technical Thermometers

These include instruments based on all types of measurements. They differ in their increased adaptability to the conditions of use. These are agricultural, vibration-resistant and low-grade for a special chamber, for petroleum products and laboratory. They are used for installation in pipelines, various tanks, in the chemical and food industries, in particular, in beet processing in sugar.

They are also used in private homes to control the temperature in various containers.

They can be vertical and angular. The name depends on the type of its lower part: it's straight or angular.

The principle of action of alcohol technical thermometers is based on the fact that the working solution expands or contracts under the influence of temperature.

Before buying this measuring device you need to familiarize yourself with its characteristics.

Thermometer spirit technical can measure the temperature from -70 ° C to 600 ° C.

Thermometer alcohol to 100 degrees is not suitable for canning. So, jam is considered ready when its temperature reaches 106 ° С. It will help to measure its thermometer alcohol for canning TK-1 or TK-110 in a metal case.

Filling thermometers

Liquid thermometers were previously filled with mercury and alcohol. But mercury vapor is very dangerous for the body. They are formed if you break a thermometer. Therefore now mercury thermometers are practically not used.

Outdoor Thermometers

Now large street alcohol thermometers are becoming popular. Their length can reach 80 cm and more. They can decorate the wall of an office, store or bank. The frame made of valuable wood, plastic or metal looks rich and original. The scale of ceramic granite is strong and reliable.

Such street alcohol thermometer measures temperatures from -53 ° C to 51 ° C.

The thermometer "Vine leaves" of the German company TFA Dostmann GmbH is made of wrought iron. Can be used as external or internal. The length is 385 cm.

From German companies, Moller-Therm GmbH can be named. They make interior thermometers of high quality. Guarantee for them - 2 years.

Household street thermometers of small size are often used. They are attached to the window by Velcro or to the wooden parts of windows and doors with the help of screws. Popular street double-sided alcohol thermometers with Velcro with a scale that can be seen through the window glass. After all, in order to know the temperature on the street, you do not need to leave the apartment. One of the manufacturers is Penosil (Russia).

There are models with a plastic casing.

Measurement of water temperature

An alcohol thermometer can measure the temperature of the water in the bathing bath of the child. To do this, it must be sealed in a plastic case.

Many people are wondering whether it is possible to measure the temperature of water that boils with an alcohol thermometer. No, because alcohol boils at a lower temperature than water. But nevertheless there are specially calibrated and sealed thermometers with which you can do it. Therefore use an alcohol thermometer to 100 degrees Celsius. And for temperatures below zero it fits better than mercury. After all, mercury freezes at 39 degrees below zero. While alcohol can measure temperatures up to 70 degrees below zero.