Full Guide & Tips: How to Use An Infrared Thermometer

Carrie Tsai - Neway
8 min readApr 30, 2020

Source: Full Guide & Tips: How to Use An Infrared Thermometer

More recently, with the outbreak of the 2019-nCoV epidemic, non-contact infrared thermometer guns have been broadly used as the most prevailing tool for scanning people in crowded places in hope of finding those who have elevated temperatures, the earliest symptoms of virus infection. Actually, since the previous battles to prevent the diffusion of Ebola and SARS, the infrared thermometers have already been deployed worldwide for public screening purposes of detecting the first virus-infected symptoms in people.

By taking the advantages of supporting non-invasive, non-contaminated, immediate and accurate temperature measurement, the infrared thermometers are applied for medical use and have gradually stood head above the conventional probe-style ones. That being said, they are useful instruments for detecting the body temperature.

Although they have been broadly used, a large number of the public still know nothing about how to use them. If you also have any confusion, keep reading to find the step-by-step instructions of how to properly use an infrared thermometer for body temperature measurement. Also, there are helpful tips for you to better use your infrared thermometer.

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What Is An Infrared Thermometer and How Does It Work

Make Sure You’ve Got the Right Infrared Thermometer

Prior to using an infrared thermometer for measuring the body temperature, all you need to do is make sure you have the right one at hand. In order to detect the body temperature with the intent to get quick and accurate reading, you should use a high-quality (ideally FDA-certified) infrared thermometer specially for medical use.

This is because medical infrared thermometers cover a limited temperature range of around 10°C/20°F (Suitable for detecting the body temperature whose range is about 32..43°C/90..110°F), which achieves higher accuracy (accuracy tolerance of ± 0.3°C/0.6°F).

Besides, when selecting your infrared thermometer, you need to pay close attention to the response time. Always choose an infrared thermometer gun with quicker response time (better to be fewer than 1.5 seconds). This is because fast response time helps your gun to get the body temperature more immediately, leading to more accurate reading.

Tip: An infrared thermometer designed for industrial applications and domestic use isn’t appropriate for detecting the human body temperature. This is because it has an accuracy tolerance of nearly ± 2°C/3.5°F due to its much bigger temperature range, which cannot keep the body temperature reading with high accuracy.

Now after making sure you’ve got the right infrared thermometer gun, just follow the instructions below to utilize the gun for accurately detecting the body temperature step by step.

Ensure You’ve Read the Instruction Manual Carefully

Before using your body temperature measuring infrared thermometer, you need to read the instruction manual carefully to make sure you know all the specifications and functionality well. Being familiar with the specifications is very helpful for you to use your infrared thermometer more efficiently for checking more precise temperature reading.

Make Sure Your Infrared Thermometer Is Clean and Dry

Before entering into the temperature detecting process, make sure the infrared thermometer is free of dirt, dust, frost, moisture, and smoke. Keeping the thermometer clean and dry is in favor of getting accurate temperature reading since infrared thermometers are easily affected by moisture and dirt.

If you find that the infrared thermometer comes under dirt, moisture, and smoke, you’re in need of cleaning it.

Here’s how to clean your infrared thermometer:

You can clean the infrared thermometer by using a lithe cloth or cotton swab with water. Also, you can utilize medical alcohol to clean. When cleaning, just meticulously wipe the lens first and then the main body of the thermometer. Then you need to wait for the thermometer to dry completely before using it.

Tip: It’s advisable that you regularly clean the infrared thermometer. You can clean it around every six months.

Warning: Never utilize soap or chemicals to clean.

Turn on the Infrared Thermometer

The vast majority of infrared thermometer guns are able to be turned on by depressing the trigger on its handle. But some support being powered on by pressing the power button on the front side which is usually named as “Scan”.

That being said, how to turn on your infrared thermometer really rests with its particular design. Therefore, the most efficient approach to switch your thermometer on is to check the user manual and then follow the guide.

Adjust Multifunctional Settings

Nowadays, the majority of infrared thermometers for medical use are powered with multifunctional settings to meet the variety of user needs and preferences such as temperature unit switch, multifunctional modes, and memory recall. Therefore, after turning on the infrared thermometer gun, you can adjust the settings to achieve optimal measuring effect according to your needs.

* C/F Temperature Unit Switch

Firstly, check if your infrared thermometer gun supports the switching temperature unit. (Almost all types support). Usually, if an infrared thermometer supports the temperature unit switch, there will be a button called ℃/℉ on it. So if you find the ℃/℉ button on your thermometer, just press it to change the temperature unit displaying on the screen readout.

Another case is that the temperature unit switch can be adjusted by pressing the “SET” button or the power button. If so, by pressing the button, you’re able to select the unit you prefer.

* Multifunctional Modes Switch

In addition to the body temperature measurement, the majority of infrared thermometer guns for medical use are also able to be applied to detect the surface temperature of objects like water, food as well as surroundings like rooms. Thus, you need to check if your infrared thermometer supports multifunctional modes.

Usually, if there is a button showing “MODE,” “Body/Surface” or “Body/Object,” your infrared thermometer is able to support modes switch. If so, you need to choose the Body mode for detecting the human body temperature.

Choose the Optimal Body Part for Detecting

What is the optimal body part to detect, the forehead, the wrist, or the armpit? In order to acquire more precise temperature reading, you need to use the infrared thermometer gun to scan the body part which is less affected by the outside environment.

Screening the forehead is the common method for detecting body temperature since it’s convenient and easy-to-operate. However, scanning the forehead may make the temperature reading less accurate. This is because the forehead which is exposed to the outside world is easily affected by the temperature of the outside, making its temperature much lower or higher than the actual body temperature.

Compared with forehead scanning, screening the armpit or the wrist can make the temperature measuring more accurate since they are covered by the clothes and thus less affected by the temperature of the outside world. Nevertheless, it’s really unrealistic to measure the armpit temperature at public places since lifting the clothes is unsuitable. Therefore, scanning the wrist temperature is really the ideal approach to measure body temperature.

Whether to scan the wrist or the forehead or the armpit, you need to make sure the surfaces are kept dry and clean. Before testing the temperature of the wrist or the armpit, make sure these parts of the targeted person aren’t covered by clothes on the surface. When scanning the forehead, make sure the hair of the targeted person doesn’t cover it.

Keep the Infrared Thermometer Close to the Target

While reading the manual, you must notify the distance-to-spot ratio of your thermometer. Distance-to-spot ratio is the surface area being able to be detected compared to the distance taken from the target. As a rule of thumb, the closer you are to the target, the smaller the measurable surface area is, thus the more accurate the measurement.

Therefore, prior to the detection, for accurate temperature reading, you are in need of keeping the distance between the infrared thermometer and the body part of the targeted person close (ideally 5–8cm).

Pull the Trigger to Check the Temperature on the Screen

Now aim the infrared thermometer gun at the optimal body part of the targeted person which you want to measure and then pull the trigger to view the accurate temperature reading on the digital display within seconds.

After checking, if your infrared thermometer is powered with the functionality of backlight and alarm, you’re able to view green backlight and hear a soft beep if the temperature is normal. If the targeted person has a fever, the gun will display red backlight and ring an urgent beep. If your infrared thermometer supports memory recall function, you’re able to check the previously-measured data by pressing the “Memory” key or the “SET” button.

Important Note: During the recent coronavirus epidemic period, when measuring the body temperature by using an infrared thermometer gun, everyone should wear a face mask, gloves, and goggles.


With a number of powerful features, infrared thermometers for medical use is an effective tool for detecting the human body temperature immediately, accurately with no contact with the targeted person. Currently in the battle to the new coronavirus epidemic, they have been broadly used to scan a large number of people in public areas to achieve quick, non-contaminated as well as precise temperature measurement.

Now everything about how to use an infrared thermometer for detecting the body temperature is in focus. In short, it’s of great necessity to make sure all necessary preparations have been made before using the thermometer. When using it, it’s advisable to adjust all the settings to the optimal state, point to the optimal body part, and keep it close to the target.

About Author

Carrie Tsai is part of team Neway and is always actively to share her ideas of Neway. She enthusiastically dives each day into the depths of the mobile interconnection industry waiting for new cool stuff to be shared with you and her team.



Carrie Tsai - Neway

Carrie Tsai is part of team Neway and is always active to share her ideas of Neway. She enthusiastically dives each day into the depths of the mobile industry.