Infrared Thermometer Accuracy | How To Choose A Quality Thermometer

Throughout the past year, you’ve likely seen more infrared thermometers than ever before. As a convenient, no-contact measuring tool, they have been incredibly useful and widespread in the aftermath of the COVID-19 pandemic. But when it comes to infrared thermometer accuracy, you’ve probably wondered: how accurate are these things, anyway?

In this article, we’ll first talk about how infrared thermometers work. Then, we’ll discuss their accuracy and whether you can rely on them for truthful measurements.

How Infrared Thermometers Work

Infrared thermometers work by measuring the amount of infrared light energy emitted from the target object. If you can feel the heat coming from an object, whether it’s a cup of coffee, a machine, a cat, a dog, or a human being, it’s emitting infrared energy.

This infrared light travels through the atmosphere and lands on the lens of the thermometer. The lens then focuses this energy onto a sensor, which – through some electronic processing – allows the thermometer to display a temperature.

It can be confusing, though, because many of these thermometers have a laser pointer. The pointer, though, is just to help you aim at what you’re measuring; the laser doesn’t measure anything.

Infrared Thermometers for COVID-19

The pandemic has caused people to become more interested in measuring body temperature as a measure of safety. However, it’s important to note that not all infrared thermometers are suited for use on the human body. While there are many new entrants to the market, there isn’t much information on whether these tools are well-made, reliable, and accurate. However, knowing some crucial facts about infrared thermometers is important when choosing the right one for your needs.

Ensuring Infrared Thermometer Accuracy

    The accuracy of an infrared thermometer boils down to several factors:

  • Emissivity
  • Without getting too technical, this is a measure of how much energy is coming off of an object. For example, it’s difficult to measure the temperature of a metal object because it has low emissivity. Human skin has an emissivity between 0.94 and 0.98. A quality thermometer should allow you to set this value manually.

  • Geometry
  • Since infrared is an optical measurement, it’s important to know that the measurement changes with the distance from the object. A quality thermometer has optics that specify the size of the measuring area, which increases the further you are from the object. Low-quality thermometers might have such poor lenses that you practically have to press it against someone’s forehead for a reliable measurement.

  • Wavelength
  • Quality thermometers specify the wavelength of infrared light that they can detect. Generally, a wavelength of 8 – 14 µm allows for reliable measurements at room temperature. Examine your thermometer to ensure it can detect in this range.


We hope this article helps you choose a quality infrared thermometer that you can rely on.

Iluminar specializes in the manufacture of superior, professional-quality LED lighting solutions for license plate capture systems, as well as video surveillance. To top it off, we offer unmatched customer service for all of our clients.

Our invisible and visible series of products all come in various form factors, with many angle choices, wavelengths, range, and power ratings available to choose from. All of our illuminators come with covert and semi-covert options capable of running off AC or DC power. Best of all, we offer weatherproof systems with exceptional build quality to survive even the most brutal deployment application.

Our product experts will personally guide you towards choosing the right product for your application. Don’t hesitate to get in touch with us at (281) 438-3500 today!

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