An infrared thermometer might look simple. All you have to do is aim it at an object and pull the trigger to get the object’s temperature, right? Actually, it’s a little more complicated. To get the most accurate temperature readings—and use your thermometer safely—you’ll want to control the situation as much as possible. Follow these tips:
Equipment
How to Use an Infrared Thermometer
Want the most accurate results from your infrared thermometer? Here are some tips.
By Published May 9, 2022.
Sign up for the Well-Equipped Cook newsletter
Shop smarter with our ATK Reviews team's expert guides and recommendations.
America's Test Kitchen will not sell, rent, or disclose your email address to third parties unless otherwise notified. Your email address is required to identify you for free access to content on the site. You will also receive free newsletters and notification of America's Test Kitchen specials.
- Make sure the thermometer is at room temperature. If the thermometer is too hot or too cold, it won’t be as accurate.
- Temp from above. Whenever possible, position your infrared thermometer at a 90-degree angle, directly above your cookware, in order to take its temperature. The more oblique the thermometer’s viewing angle, the greater the likelihood that it will be measuring surfaces besides the one you want to temp and the more inaccurate your reading will be.
- Temp a flat surface. Infrared thermometers sample temperatures from a small area around their laser(s), so they do best when temping continuous surfaces. You will likely get a flawed reading if you try to temp a grill grate—the thermometer will take into account the grill surface under and around the skinny grates in addition to the grates themselves. If you want to know how hot your grill is, stick a skillet on the grates and heat the skillet with the grill. When you think you might be ready to grill, add a little oil and temp the oil in the skillet (oil has an emissivity value of 0.95).
- Adjust the emissivity value on your thermometer to match your cookware’s material. Every material has a different emissivity value (the amount of energy radiated by any object, measured on a scale from 0 to 1). Adjusting this value on your thermometer helps ensure more accurate results. You can find different emissivity charts online. Note that the values stated are always approximate; your specific cookware may have slightly different values.
- Add a thin layer of oil to your skillet, griddle, or flattop. If you’re making pancakes, searing a steak, or doing anything else that involves fat, temp the oil. Oil has a known emissivity of 0.95, so it’s easier for your infrared thermometer to temp correctly.
- Never point the laser at a person’s face. The laser guide can damage their vision.
- Keep it clean. Dirt, grease, and dust can interfere with the thermometer’s reading. (For similar reasons, the thermometer will also be less accurate in humid or smoky conditions.) Wipe the viewfinder with a clean cloth or cotton swab, applying a little rubbing alcohol to the cloth/swab if necessary. Never get any part of the thermometer wet! You can damage it.
- Get to know your thermometer—and your cookware. It may not always be possible to follow these best practices—you can’t put oil on an outdoor pizza oven stone or temp the stone at a 90-degree angle. For this reason, it’s not always practical to expect your thermometer to provide you with the exact temperature of your cookware. (This is also why we don’t prescribe specific target cookware temperatures for searing steaks, making pancakes, or grilling chicken—you may never get the specific values we recommend.) But if you use your thermometer regularly, you’ll learn how to interpret even values you know to be inaccurate. For example, maybe you’ll learn that your pizza oven makes perfect pies when your infrared thermometer is set to an emissivity value of 0.89 and reads between 690 and 725 degrees, even though you know the oven is actually hotter than that. If you accept a certain margin of error, you can still get a lot of useful data from this tool—data that helps you be a more consistent, successful cook.
