Thermometers without mercury are now widely used both in domestic conditions and in medical institutions. They gradually displace mercury thermometers, which have an increased degree of toxicity, as a result of which, if the protective shell is damaged, they can be harmful to human health. A similar medical device is available in every home. Its use helps to determine the deviation of body temperature from normal, which is a symptom of the onset of the disease.
Temperature measurement
The history of the appearance of thermometers goes into the distant past. The invention is attributed to the famous scientist Galileo. He himself did not leave any mention of such a device in his notes, but his students and contemporaries confirm the creation of a thermobaroscope. The development of the thermometer can be seen in the following chronology of events:
- 1597 - the advent of the invention under the name "thermobaroscope". It was a glass tube of small diameter with a ball that was soldered into its middle.
- 1657 - adding an improvised scale to a thermobaroscope and creating a vacuum inside it. This was done by Florentine scholars.
- 1667 - the first mention of such devices.
- 1703 - the French scientist Amonton improved the air thermometer.
- 1723 - thermometers appeared, the shape of which resembled the modern one. Fahrenheit succeeded, he opened the world to fill the device with mercury. On the scale of the invention there were three main temperature points.
- 1742 - Anders Celsius defined two temperature limits used to this day. This is the temperature of melting ice (0 degrees Celsius) and boiling water (100 degrees Celsius).
There have been many attempts to create the perfect thermometer. For example, Lord Bacon, Robert Fludd and several other scientists, in collaboration with them, spoke out about the primacy of the invention of an air thermometer. Also known is Santorio, a scientist from Italy, who was able to make a device designed to measure human body temperature. Its only minus was too large parameters. It should be noted Kelvin thermometer, which is widely used in the scientific field.
To date, there are many varieties of thermometers. They are used not only for medical purposes, but also in industry and everyday life. Using similar instruments, you can also measure the temperature of water or air.
Advantages and disadvantages of mercury thermometers
Such a device is a tube of small diameter, at the end of which there is a tank with mercury. All this is sealed in an impermeable shell, which prevents the penetration of toxic substances into the environment.
The advantages of mercury temperature meters include:
- ease of use;
- duration of operation;
- ubiquity of use (temperature determination by oral, rectal methods, in the axillary or inguinal region);
- high accuracy;
- reasonable price;
- simple disinfection.
When using such devices, it must be remembered that they must not be subjected to mechanical stress, including disinfection by boiling, since they are very fragile. A mercury device cannot be classified as a “safe thermometer” due to the toxicity of its contents, which makes this type of thermometer the most demanding of operating conditions. Disposal of such thermometers is necessary as “special waste”, be sure to provide hand protection and ventilate the room.
Temperature measurement with mercury thermometers takes quite a long time, it takes about 10 minutes. Therefore, such a thermometer for children whose age does not allow them to explain the need to sit quietly is not very suitable.
What are mercury free thermometers?
Thermometers for measuring body temperature can be different. The most common option is alcohol. Outwardly, they look like mercury, the only difference is only the color of the contents of the tank. Mercury is silver, and alcohol is dyed with red.
There are electronic and infrared thermometers; It is also necessary to note such a variety as a thermometer for young children, made in the form of a nipple.
Electronic thermometers
Such mercury-free thermometers have appeared on the drugstore shelves relatively recently. Such devices work due to the presence of a special sensor in them. Models of this kind may vary depending on the set of functions (impermeable housing, sound signals, memory, which records the data of several recent measurements, and the presence of sterile caps).
Mercury-free thermometer has the following advantages:
- security
- quick measurement;
- different variations of the appearance;
- the presence of a display;
- reasonable price;
- wide range.
Other characteristics and functions depend on the configuration of an individual device and its cost.
Among the shortcomings, a certain percentage of error can be noted, which varies depending on the place of application, and the need to hold the mercury-free thermometer under the arm for some time after the sound signal. For example, children do not have such patience. Do not forget about the regular change of batteries. If they are not at hand - the device can "sit down" at the most inopportune moment.
Modern alcohol thermometers
Thermometers without mercury included in this category are considered the most popular. Alcohol possess all the mercury merits, but unlike them are safe. They do not need batteries or other additional power. They represent a kind of compromise between obsolete and modern devices for measuring temperature.
The latest medical innovation is infrared thermometers. They are classified according to the place of impact. Thermometers can be contactless, aural or frontal. Application - strictly for its intended purpose. When creating these devices, the advantages of previous thermometer variations were taken into account and their disadvantages were eliminated. The result is a product characterized by:
- security
- almost instant measurement (no more than 5 seconds);
- small margin of error;
- ease of use;
- functionality.
Among the disadvantages: high price and the impossibility of rectal administration.
The best thermometers for children
Mercury-free baby thermometers for measuring body temperature are nipple-shaped. Your baby will not be bothered, and you can easily measure his temperature within 3-4 minutes, the values of which will be displayed on a special display. The color effect will allow you to immediately understand the condition of the child, since with deviations from the norm, the nipple acquires a red color, and when it remains green.
There are also thermal strips that are easy to carry. Most often they are used in special situations, for example, in nature or on a trip. In everyday life, they are not common, because they only record the fact of an increase in temperature, but do not give exact values.
In general, you can find a way to determine body temperature for each person in any conditions. You just need to make the right choice.