Thermometer, which choice, why and cheaper?

November 2, 2021

The thermometer is an instrument that has evolved since its creation, with which medicine innovated; When it was created, its name came from two Greek terms “Thermos” and “metron” that together mean heat measurement and that is exactly what the thermometer is responsible for, measuring temperatures.

The thermometer was created in 1714 and since that year it has been adapted to multiple needs that have arisen, whether in medicine, biology or in everyday household use.

Thermometers have advanced to the point that today you can find many types, all ideal for any need that someone may present and each one has different applications and because of this it is almost a necessity to know them in depth.

Digital thermometer

Digital thermometers work with transducer devices that communicate the tense impulses they receive through small circuits that convert the variations obtained into numbers and display them on a small digital screen .

Some digital thermometers have an integrated circuit that is accompanied by a thermistor such as the LM35 which can be adapted through a microcontroller and set the temperature in degrees Fahrenheit or Celsius. These circuits can be seen hidden under the data sheet of each thermometer.

Each digital thermometer comes with different specifications, therefore it is not guaranteed that the thermometer works in optimal conditions when it is exposed to environmental temperatures very different from those that are integrated in its user manual where its electronic components and their scale graduation are discussed. .

Something to take into account when taking the temperature with a digital thermometer is that depending on the area of ​​the body to which it is exposed, it must be conditioned to give the correct temperature and avoid mistakes that could possibly occur.

Mercury thermometer

The mercury thermometer is the most traditional, almost the same one that was created in 1714 (only with slight changes over time), and its function is to measure temperatures in different materials. This type of thermometer is the one that is most commonly found in homes and these inside have a liquid that contracts or expands according to the temperature, that is, according to whether it is a low temperature or a high temperature respectively. In general, the liquid inside these thermometers is mercury, although in some cases it can also be colored alcohol .

The mercury thermometer works with a glass bulb that prevents the temperature and radiation of the environment from affecting its temperature measurement, that is, the thermometer completely isolates itself from the air temperature and concentrates only on the object it is measuring. specifically.

These thermometers in Spain have been banned for sale due to accidents where the thermometer has broken and cases of intoxicated due to the mercury inside have been seen ; However, it is estimated that the possibility of being poisoned with mercury is quite low due to the small amount of this element in its interior and in addition to the very rare that it turns out to be broken in the mouth of a person.

Baby thermometer

To calculate the temperature in infants, it is advisable to look for thermometers that adapt to them, and the way to obtain it is through their armpit so that possible accidents are avoided and also without causing discomfort to the little one.

Having the correct thermometers in your home to measure this type of temperature is ideal when you have a little one in your home, especially in cases where they get sick easily and you need to check their condition constantly and effectively.

Another method to calculate the temperature of babies is rectally only when they are small, when they grow a little more this can make them uncomfortable and cause them to move, which turns out to be fatal as it would cause the thermometer to break. Likewise, if this method is carried out, in babies it is more effective and once the thermometer is finished it must be removed, washed and disinfected complying with normal health measures.

It is not recommended that the temperature be measured orally in children since this method is unhygienic, it is not so reliable and in addition to this the temperature of the mouth can be conditioned by what the child has ingested, even if it was a cold food or hot. Likewise, this method presents a risk in relation to the possible rupture of the thermometer that it is preferable to avoid.

Laboratory thermometer

Laboratory thermometers have the ability to measure temperatures from -10 ° V to 200 ° C , this makes them one of the thermometers with a wider temperature range. Inside they have a liquid that expands when the temperature increases, in this case it is alcohol dyed red so that it can be much more attractive and it is easy to distinguish the temperature mark.

Unlike mercury thermometers, these do not isolate themselves from the ambient temperature and raise the mark when they are in a hot environment and lower it when they are in a cold one; they also do not have the ability to maintain the temperature mark if they move away from what is being measured.

The laboratory thermometer can be used with substances in full boil, provided that it does not collide with any edge of the container and that it is not more than half the depth of the substance. During the time the temperature is being measured, the thermometer should not be removed as its temperature will change.

These thermometers must have constant maintenance , they must be calibrated, you can by yourself if you have experience, if that is not the case, it is advisable to take the thermometer to an expert who can calibrate it when it has been used for a long time. On the other hand, it should always be completely clean at the time of use and if you are going to change from one substance to another it should be washed in advance.

Infrared thermometer (Laser thermometer)

The infrared thermometer or non-contact thermometer sometimes mistakenly called a laser thermometer because of the light it emits, is capable of measuring temperature through a beam of black light  that can emit a considerable distance. The laser built into this thermometer only has the function of targeting the object whose temperature is to be calculated, but it does not have the ability to measure it.

This thermometer can also be called a pyrometer, this name is because it does not measure temperature literally, but calculates thermal radiation and transforms it into a number that can be seen.

The laser thermometer allows to calculate the light energy of an object in more specific terms and its detector converts this energy into an electrical signal . Temperature measurement with a laser thermometer has a great advantage since it can be applied to moving objects, in a vacuum or even if it is surrounded by an electromagnetic field.

The laser thermometer can be used to calculate temperatures of vacuum packed products, ovens, electrical circuits, hot spots in fires, mechanical equipment, precisely control the temperature change of some material, measure human temperature and even measure the temperature of clouds to calculate storms.

Kitchen thermometer

This thermometer is a necessary tool for anyone who loves cooking, be it an amateur chef or a professional one, none denies the usefulness of the kitchen thermometer when preparing dishes of excellent quality and being able to control each step of their cooking.

Kitchen thermometers are the perfect utensil to ensure that each dish you prepare has the ideal temperature and that at all times you can maintain a perfect cooking for whatever you cook.

These thermometers have evolved into different types that are adapted to different types of cooking; there are those that are used in liquids, in fryers, ovens or grills, in addition to there are also multifunction thermometers that focus on more than one type of specific cooking.

Using a kitchen thermometer is essential mainly because it is the only reliable way to ensure that everything you actually cook is properly cooked. Especially in the case of poultry and meat, the thermometer plays an essential role in allowing you to know if they have reached the necessary temperature to eliminate any toxins that they could have if they are not cooked correctly.

Environmental thermometer

An environmental thermometer can calculate the temperature of an environment either open or closed depending on the specifications of the thermometer, this is done through an internal sensor or an external probe as the case may be.

The environmental thermometer can measure the temperature using the air in its environment, to exemplify this, if the thermometer is placed at the temperature of a baby’s room it will tell you what it is taking into account the air present; on the other hand, in a refrigerator it can also be used to ensure that it maintains the ideal temperature.

Environmental thermometers can show you the temperature of a closed or even airtight place, it is ideal to keep the temperature of your home controlled to avoid getting sick; You can also calculate that the temperature in pantries and refrigerators does not exceed or decrease the temperature that keeps the food in perfect condition.

For its part, environmental thermometers open spaces are constructed to possess greater resistance to environmental factors such as rain, the extreme heat , the blizzards and even snow. Generally, thermometers for open places are made of mercury since it offers better precision in addition to being simple and with a fairly long useful life. However, mercury is now being replaced with alcohols that are less harmful.

Fever thermometer

Thermometers are too important in medicine, they are the only reliable way to calculate a person’s temperature and, in turn, to diagnose their fever and determine if it is linked to any disease beyond a common fever.

Thermometers offer a way to calculate the degrees of a fever in order to decide what treatment is recommended, and can even be used regardless of the age of the patient. In general, thermometers are used by the axillary or oral route , since they are the most practical in the same homes although in a hospital they may even have infrared thermometers available that allow to calculate the temperatures from a distance.

Thermometers are ideal for those with a family that has children, that way every time the little ones get sick they will have a way to diagnose at least one of the symptoms and be able to treat them at home when they are such common diseases or decide whether to take it to a hospital where they receive more specific treatment.

Gallium thermometer

The gallium thermometer has become the most widely used today, this is because it is the ideal substitute for the mercury thermometer with the advantages that it is much less harmful than this and also it is not necessary to use batteries as in the electronic thermometers.

Mercury thermometers can sometimes not offer full accuracy and that is where the gallium thermometer comes in, which offers the same effectiveness as any traditional mercury thermometer.

Gallium thermometers are the most reliable when it comes to measuring temperatures; Although, many consider a disadvantage that it takes 4 minutes for the thermometer to give you the result of the measurement and that like the mercury thermometer it is made of glass and that makes it a fragile object that must be handled with watch out.

To understand how this thermometer works, you must understand what gallium is: this is an element of the periodic table of the metallic type, it is white and has the ability to change color when exposed to certain temperatures, being more grayish as the temperature is higher (liquid) and more silver as the temperature is lower (solid).

Baby digital thermometer

Digital thermometers are the most recommended by experts, this is because they are considered to have the most up-to-date technology in addition to being considered to be very effective. An advantage of these thermometers is that all their temperature readings are fast and in addition to that they are sold in many sizes, shapes and for different types of measurement.

Mainly the thermometers available for babies are oral, rectal or axillary since it is where the temperature of an infant can most easily be measured. There are also digital ear thermometers and pacifier thermometers , but both are considered inaccurate and therefore not very reliable.

In babies of 6 months or even less, it is better to have the temperature calculated rectally, it is recommended that if the child’s temperature is 38 ° C or higher, it is taken with a professional to a hospital. From 6 months of age, axillary temperature measurements are also recommended.

Some digital thermometers include disposable plastic covers or covers , these can be used in certain measurements and also wash the thermometer after it is finished.

Best baby thermometer

When it comes to measuring children’s temperatures, there are many viable options, all with a different degree of reliability. It should be said that a type of thermometer that is always recommended is the traditional mercury thermometer since it is considered the most effective even if it is not available in the current market due to the toxicity of mercury gases.

The mercury thermometer will continue to be considered the best option since it is the only one that offers a temperature reading close to the core temperature of the body, which is the most important for doctors since it is the one that is taken into consideration to diagnose fever.

Then the digital thermometer is recommended , it offers ease, speed and efficiency when measuring the temperature of a child although some people disagree with their readings and do not consider them entirely reliable.

In third place of the recommendations are the ear thermometers , their functionality is based on the measurement of the infrared energy emitted by the eardrum and is totally related to the temperature of the body. The diagnosis is carried out in a few seconds, although, in children it is somewhat difficult to obtain the precise temperature since they do not usually stay still and their narrow ears do not allow the thermometer to reach the necessary distance.

Finally there are two options that should be mentioned, the gallium thermometer which is just as effective as the mercury thermometer and many recommend it because of it; On the other hand, the infrared thermometer offers a lot of reliability and precision, only with the disadvantage of being much more expensive than the other options.

Digital thermometer price

Digital thermometers are the most recommended option on the current market, this is due to the fact that doctors consider them innovative and the best technological evolution of the classic mercury thermometers that were used until a few years ago.

When it comes to acquiring these thermometers there are different options and at the same time different prices, some models that we must highlight are:

  • Braun PRT2000. This thermometer is capable of taking your temperature depending on your age and build; its value is € 16 .
  • Omron eco temp basic. This thermometer is highly recommended, however, the signal it emits to indicate that the temperature measurement has finished usually sounds earlier than it should, so if you buy one of these you must take that into account; the price of the Omron is € 5.87 .
  • Misiki. The Misiki is highly recommended for babies and young children, it has the ability to work 24 hours and a smart monitor; its price is € 25.99 .
  • Braun ThermoScan. This is used to measure temperature through the ears and has an age-determining sensor to correctly calculate temperatures; its price is € 59.99.
  • Medisana. The Medisana thermometer is excellent for both children, adults and babies; It has an alarm that alerts when it detects fever and it can come for rectal, axillary or oral route, in addition to this it is also water proof. The price of the medisana thermometer is € 3.41 .

Each of the aforementioned thermometers have excellent quality and experts recommend them due to their effectiveness in determining temperatures and diagnosing a possible fever.

Oven thermometer

This is one of the types of kitchen thermometer and is intended to be used only with baked foods, so it can cover quite high temperatures while still being able to offer excellent effectiveness as well as recommended quality.

Oven thermometers focus on measuring the air temperature of the oven where it is integrated, its shape is spiral and they are made of metal, its temperature range is from 37 ° C to 315 ° C. This thermometer can be conveniently left in the oven while it is being used, so that you can ensure that the temperature is just right without any problem. They are used in traditional ovens or current electric ovens .

Oven thermometers are ideal when cooking dishes such as meat, poultry, and other foods that require specific cooking. The main function of this thermometer is to verify that the food can reach the temperature that eliminates all the bacteria and toxins that could cause some disease of animal or vegetable origin, because of that, these thermometers become a very important tool when it comes to Cook in the oven.

Wifi thermometer

Thermometers with wireless technology, that is, Wi-Fi or Bluetooth connection to your phone , are usually environmental thermometers that allow you to know the temperature of your home no matter where you are. Almost all of these thermometers have the ability to measure humidity as well as the same temperature in your home.

Most wifi thermometers have applications that allow you to connect with it even without being at home; The benefit of this is that you have the possibility to record and save each data on the temperature in your house, in this way you can get a more graphic idea of ​​when the temperature is higher and when it is lower.

If, in addition to having your thermometer connected to your phone, you have other appliances such as heating or air conditioning , you can use the thermometer to make sure you condition the temperature until it is ideal, especially if you are far from home.

Bimetallic thermometer

They can be called bimetallic sheet thermometers or simply bimetallic thermometer, it is used to measure temperatures through the use of two metal sheets of different metals rigidly joined demonstrating the temperature with the coefficient of expansion. High temperatures will cause the thermometer to expand and bend in an arc.

They are mainly used to measure the temperature of liquids and are quite versatile in terms of the applications that can be given to them.

There are also spiral bimetallic thermometers (as in the case of kitchen thermometers), in that case, when the temperature is high, instead of bending the thermometer will end up unwinding. The way in which the bimetallic thermometer works is through its plates, one always has a better size than the other and it is the one that causes the reactions where it curves or becomes straight.

The thermometer is connected to a system that has needles, which point to the number of the temperature that the thermometer measures.

Digital environmental thermometer

These thermometers are responsible for measuring temperatures in closed or open environments, that is, they can be useful indoors or outdoors depending on the needs that are had.

Digital room thermometers can be in charge of presenting you the values ​​in discrete numbers (they can be configured in Fahrenheit or Celsius) which are presented on an LCD screen that allows them to be easier to read and at the same time has the ability to store the data. of each temperature that you record so that they can be used later if needed.

Most digital environmental thermometers have only two methods to measure temperatures, which can be a probe which is present in the cable of the device or on the other hand a thermistor which is housed inside the cover of the same device.

As for the precision, it can vary between each model and therefore the applications that each of the characteristics offered by the different models of digital thermometers for environments should be studied.

Pool thermometer

Pool thermometers are a technology that has advanced over the years to ensure that pool temperatures can be controlled, either when it is winter and the water is much colder than usual or if, on the contrary, it is too hot for your liking. The pool thermometer is a viable option to keep your pool temperature in check.

Pool thermometers simply need direct contact with the water to determine its temperature; There are two essential types of pool thermometers, the analog ones that work like a regular thermometer and on the other hand the digital ones that work with energy and have somewhat more advanced functions.

Some thermometers are placed on the surface of the pool while others are placed at the bottom just a few centimeters from the ground, the latter is controlled through a wireless device to receive temperature readings.

Infrared baby thermometer

Infrared thermometers are usually used primarily on the forehead and ears to calculate the temperature of infants ; This reads infrared energy and gives you a result depending on it, in the ears it is calculated through the eardrum and in the forehead the energy emitted by that area of ​​the body is captured.

Both types of thermometers offer safety to the child; In the case of ear thermometers, the probe used has a width that does not allow it to reach the eardrum and accidentally damage it; on the other hand, for forehead temperature measurements they are done remotely and it also provides good results.

In terms of reliability, sometimes they do not give the exact temperature when used in the ears, this may be due to the presence of wax that according to the manufacturers of many of these thermometers affects the exact measurement of temperature. The most advisable thing in matters of calculating the temperature is to do it 5 cm from the forehead , in this way the result is almost exact (it can only vary by 2 tenths of a degree) and it can be determined when the child has a fever or not.

Electronic thermometer

Electronic thermometers offer a viable and risk-free option, they provide an accurate measurement of your body temperature efficiently and quickly. Since there is no mercury inside these thermometers, intoxication due to a rupture is not possible, due to this electric thermometers are a perfect option for either home or professional use .

These thermometers have a screen in which the temperatures it measures can be read, in addition to this it has the ability to save the record of the last temperatures and gives a warning in cases where it reaches much higher temperatures; Also, they are considered accurate and not slow at all.

Digital thermometers also offer a measurement range from 32 ° C to 44 ° C , in this way they can measure temperatures both in common fever and in cases of hypothermia.

Bearing in mind the wide range of thermometers available today, which ones are better for the little ones and the prices of the most innovative model on the market (digital thermometers), you can already figure out and have the knowledge of which of them you will need in each case, because it can always be a different one that will really give you good results for what you are looking for.

Dr. Loony Davis5
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Born and raised in Brussels in an English family, I have always lived in a multicultural environment. After several work experiences in marketing and communication, I came to Smart Water Magazine, which I describe as the most exciting challenge of my career.
I am a person with great restlessness and curiosity to learn, discover what I do not know, as well as reinvent myself daily, someone who is curious about life and wants to know. I enjoy sharing knowledge.
This is my personal project but I also collaborate in other blogs, it is the case, the most important web on water currently exists in the US, if you are interested you can read my articles here.

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