Why is a mercury thermometer used to measure body temperature, and to measure the temperature of the air of alcohol: explanation

Differences in alcohol and mercury thermometers.

Content

Scientists have long noticed that the physical properties of bodies significantly depend on the ambient temperature. It is on the change in these physical properties that thermometers are built. In this article we will talk about mercury as well as alcohol thermometers.

Why is a mercury thermometer use to measure body temperature?

Almost classic is the use of mercury thermometers to measure body temperature.

Why is a mercury thermometer use to measure body temperature:

This type of measuring device has been used for a long time and almost every resident of our country has.
The main advantage- this is Quick temperature measurement, as well as accessibility.
The thermometer is built on the fact that when the temperature rises, the mercury expands and rises along the capillary, which is attached to the scale.
Thanks to this, it is possible to measure body temperature, fix its fall or rise.

Street thermometers are mercury or alcohol?

To measure the ambient temperature, not mercury thermometers are used at all, but alcohol. Why can't you use mercury?

Street thermometers mercury or alcohol:

The fact is that mercury- this is Metal, the crystallization temperature of which is at -34 degrees. Accordingly, at a temperature below this value, the metal acquires a solid shape, so in no case will it drop below the temperature of -40 degrees, so it will be in a frozen state.
The most interesting thing is that several scientists took up work on the thermometer at once, so it is simply impossible to reliably say who was the first to invented this tool for measuring technology.
Scientists tried to melt butter, wine alcohol and a variety of liquids to come to some consensus. And only in 1723, Fahrenheit invented the device, which became suitable for use in everyday life.
He used a thin glass capillary, into which he immediately poured alcohol, which then replaced with mercury. At the same time, several temperatures were fundamental in its scale.

How does an alcohol thermometer differ from mercury?

In the 18th century, thermometers became quite popular means of measuring technology, but they were not used at all in medicine, but used for ordinary, natural needs, in order to measure the temperature of the surrounding air.

How the alcohol thermometer differs from the mercury:

Much later they began to use mercury thermometers to measure body temperature.
Please note that mercury freezes at a temperature of -39 degrees, it becomes solid.
Accordingly, it is not possible to measure the temperature of the surrounding air somewhere in the northern regions.
That is why to measure the ambient temperature began to use alcohol, which freezes below -100 degrees Celsius.

Mercury thermometer or alcohol: which is better?

In 2017, the Convention entered into force, according to which by 2020 many states undertake to minimize the use of mercury. This is due to the fact that it is a heavy metal that poisons the environment is a potentially harmful tool.

Mercury thermometer or alcohol is better:

That is why, after 2020, it will be quite difficult to purchase an ordinary mercury thermometer in a pharmacy.
However, now there is practically no need for them, since modern mothers who have young children very rarely use mercury thermometers.
This is due to potential danger. They were replaced by electronic devices, which are highly sensitive, and the rate of temperature determination.
Using electronic thermometers, you can measure the temperature in just a few seconds. In addition, they are absolutely safe.

Why is an alcohol thermometer used to measure air temperature?

Quite often, electronic thermometers have been used recently to measure temperature. They have proven themselves well. The principle of their work is significantly different from mercury or alcohol. There is no liquid inside, and the device itself responds to temperature change by special alloy.

With an increase in temperature, the resistance of the metal increases, which is fixed by a special sensor. Modern electronic thermometers work on sensors that respond to temperature change.

Why is an alcohol thermometer to measure the air temperature:

It is worth noting that the working range of mercury thermometers is small, but they gained their popularity due to high accuracy and small error. This is an ideal option if it is necessary to measure body temperature.
To measure the air temperature in standard conditions, alcohol thermometers are usually used. In most cases, alcohol thermometers are designed to reduce temperature to -100 degrees. However, there are conditions in which it is necessary to measure higher or low temperatures. To measure higher temperatures and low temperatures, propane, as well as kerosene, is used.
The essence of the work of these products is the same as that of an ordinary mercury thermometer. Inside the capillary, liquid is poured, which, when heated, increases in volume, ensuring the expansion and increase in the column indicators. When cooling the liquid, on the contrary, the column drops. It is worth considering that you should not experiment with mercury thermometers when measuring low temperatures.

At a temperature of about -34, mercury freezes, while becoming solid. However, when warming up, performance may be violated. Mercury can warm up with pieces, areas, as a result, you will receive voids or gaps. Therefore, try not to experience a mercury thermometer at minimal and maximum temperatures.