How Do Infrared Thermometers Actually Work in Practice?

According to CDC, COVID-19 spreads when an infected individual breath out virus-containing droplets. Other individuals may inhale these droplets, or they may fall anywhere on their bodies. Imagine if you are in the healthcare industry, and you have to measure the body temperature of your patients; what should you do?

Luckily, infrared thermometers can determine your patient’s temperature at a distance. That means you wouldn’t have to risk getting infected, but how does it work? Continue reading to learn more about these thermometers in the medical industry.

What Are Infrared Thermometers?

Infrared thermometers (laser thermometers) allow you to measure the temperature of an item or person from a distance. Like visible light, infrared light may be directed, reflected, or absorbed. Infrared thermometers use a lens to concentrate infrared light from one item onto a thermopile detector.

The thermopile absorbs and converts infrared radiation to heat. The thermopile becomes hotter as the infrared energy increases. This thermal energy turns into electricity, where it’s sent to a detector to help determine the temperature.

What to Consider When Purchasing an Infrared Thermometer?

When buying a thermometer to add to your arsenal of tools, you want to look for quality and accuracy, like the smarttemp. If you are still not convinced, here are the following reasons for getting the best infrared thermometer:


Accuracy depends on the distance-to-spot ratio (D/S ratio). This ratio shows the greatest distance at which a thermometer can determine the surface area of a particular object. A large ratio means the temperature can be measured from a greater distance.

For instance, you need to record the surface temperature of a 4-inch region. You decided to use an infrared thermometer with an 8:1 D/S ratio. This means the greatest distance to record the temperature is 32 inches (8:1 x 4).


Emissivity indicates the amount of infrared radiation that a thermometer may emit. IR thermometers with an emissivity value of 1.00 can read a wider range of materials than those with a lower emissivity value.

You want a thermometer with an adjustable emissivity level to fine-tune the quantity of infrared energy emitted. This also helps to account for energy reflected by the substance being measured.

Response Time

The reading speed is the time required for the thermometer to provide an accurate reading after starting the reading process. This factor is critical for determining the temperature of a moving item or when the object is rapidly heating up.

Obtaining The Range

Each infrared device on the market contains a particular temperature range. It will be inaccurate to monitor temperatures that fall outside of that range. Therefore, you should consider the object’s anticipated temperature range before selecting a thermometer.

Measure Body Temperature: Where Can You Learn More?

If you work directly with patients, then checking for a healthy temperature is part of the job description. Infrared thermometers can help you perform these functions at a distance without touching the patient. Therefore, keeping you safe from potential infections.

It’s important to ensure that you get the best infrared thermometer. However, there are so many options available; how do you know which one is the best? You can explore our blog posts to learn more about these thermometers in practice.