3 Types Of Thermometers And How To Use Them


Currently, there are various types of thermometers available on the market. Before choosing one or the other, it is important to know how they are used and how they differ. Let’s also remember that this element is used to take body temperature.

When a fever is suspected, the use of this device allows determining the degree of body temperature. If it is above 36.3 or 37.3, it is an indication that something is not quite right in health. Let’s see then which are the most used.

Types of thermometers and how to use them

Ideally, temperature measurement techniques should be safe, easy to perform, non-invasive, inexpensive, and reliable. Thus, when choosing how to quantify body temperature, we will find several types of thermometers.

Mercury thermometer

It is the quintessential body temperature measurement method, given its reliability and precision. It is made of glass and contains mercury inside, which reacts by expanding when it comes into contact with body heat. They present a graduated scale for quantification, and it can be difficult to read.

It requires touching the skin or mucosa (inside the mouth, for example) for 2 to 3 minutes; it can also be used in the armpit or rectum (anal). Of these three, the rectal is the most accurate, and it is the one that can be most uncomfortable and dangerous when handling.

Among the disadvantages it has we can name the following:

  • The long time you need to contact the skin.
  • Insecurity (because it is a glass instrument).
  • The fact of containing mercury inside, a chemical element (heavy metal) dangerous to health given its toxicity.

Since 2005, the World Health Organization (WHO) began to recommend using alternative thermometers for the reasons mentioned. By now, they should no longer be in use; They have even banned its sale in many countries.

How to use

  • Check the temperature of the thermometer before using it. To do this, it is observed if the liquid is close to the lowest temperature.
  • Then place the metallic tip under the armpit and hold the arm still.
  • Wait 3 minutes, remove it from the armpit, and check the temperature. The temperature value will be the one observed at the place where the liquid ends.

Non-contact infrared thermometry

This thermometer measures the infrared flux (heat flux) of surfaces, skin or mucosa without touching them. It is placed at a short distance from them. Some are designed to be used inside the ear canal (through a probe), and others in areas such as the forehead or wrist.

In a fraction of a second, take a “snapshot” of the heat these surfaces emanate. The method can be attractive to doctors and caregivers, especially children, due to the ease and speed of measurement. Accuracy is quite reliable.

It is a simple, fast, and reliable method that is more relevant in terms of technical simplicity and the absence of invasiveness, especially in pediatrics.

How to use

  • Turn on the thermometer and bring it close to the forehead, in the area above the eyebrows (one to three centimeters away).
  • Read the temperature value that comes out immediately and remove the element.

T digital thermometer with contact

They have an electronic sensor that requires touching the body. They present the temperature recorded digitally. There are those used at the axillary, oral or rectal level, and others at the tympanic level (within the ear canal). It is placed until you hear the sound of the alarm.

Its use is simple and fast (takes a few seconds), as well as reading. Temperature measurement is quite reliable. They are also very cheap.

How to use

  • Turn on the thermometer, place its tip under the armpit and wait a few seconds until you hear the alarm.
  • Remove and verify the temperature value on the screen.

What thermometers are currently recommended?

Body temperature measurement is an important tool for reaching a diagnosis and monitoring febrile illnesses.

The mercury thermometer has been used since its invention in 1724, to date. Given its dangerousness and the development of alternative forms of measurement, the medical community began to recommend other forms of temperature quantification.

Read More: 10 Possible Causes Of Body Pain

Thus, they are being replaced by other types of thermometers, such as digital and infrared, with and without contact.

Debbie Lentz

Debbie Lentz

Accomplished Global Supply Chain executive with significant experience in the consumer products and retail industries with large brand name firms in the public and private sectors. Strategic and operational, drives change and creates efficiencies through integration of end to end process improvement focused on enhancing the customer experience and fostering company growth. Collaborative leader with high integrity who builds talented, results-oriented teams.

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