:max_bytes(150000):strip_icc()/sea-product-infrared-thermometers-ashlee-redger-24-9dec9585225541458213e80942b0cdc7.jpeg)
Straight to the Point
Our top infrared thermometer was the ThermoWorks Hi-Temp Industrial IR With Circle Laser. It had supreme accuracy, adjustable emissivity, and a target-shaped laser that made aiming easy. It also had a large distance-to-spot ratio, which allowed for more specific readings from greater distances. We also liked the Wintact Infrared Thermometer. It was the most affordable model we tested and had fewer functions than our high-end favorites, but was still reliable.
We’re big fans of thermometers. They turn cooking from speculation into science—as long as you have the right one for the job. We love wireless versions for grilling and wouldn’t dream of roasting without a probe thermometer. We always have an instant-read pen in arm’s reach for quick temp checks. But our thermometer arsenal doesn’t stop there. When we want to sear, griddle, or make pizzas with precision, we turn to an infrared thermometer.
Infrared thermometers measure the temperature of surfaces. Unlike other types of thermometers, though, infrareds can be hard to easily validate in terms of accuracy, especially at home. With an instant-read thermometer, for example, you should be able to cut into a steak and see pink inside if the thermometer measures its internal temperature as 130°F. But unless you’re an Ooni expert, most home cooks won’t be able to tell if an 800°F surface temperature reading from their infrared thermometer is accurate, or a hundred degrees off. So how do you know which thermometer you can trust? That’s where we come in.
To find our infrared thermometers, we tested 10 notable models priced from $13 to $169. Along the way, we learned about the specific vocabulary that accompanies infrared usage. (Like, what is emissivity, anyway?) We also discovered the limitations of using this style of thermometer in a real-world environment, plus some tips for success. After over 300 readings, we found three infrared thermometers that were easy to use and dependable.
The Winners, at a Glance
:max_bytes(150000):strip_icc()/thermoworks-hi-temp-industrial-ir-wcircle-laser-ir-ind-9be0c44a783445c5901c74a8dfa74e6e.jpg)
Thermoworks
As the name describes, this model projected a bullseye-shaped laser that offered a more accurate view of the entire target area than the single red dot of its competitors. Its screen was easy to read at a glance, and it had fully adjustable emissivity for taking the temperature of a wide range of materials. It could also be paired with wired probes (available separately) and display both readings simultaneously.
:max_bytes(150000):strip_icc()/industrial-ir-gun-ir-gun-s-193914a32a1b4a318e5cc85cacb4ca39.jpg)
Thermoworks
The Industrial IR Gun was a pared-down, mid-priced version of the Hi-Temp thermometer. It still had many of the same features (including high and low-temperature alarms, modes for displaying maximum, minimum, and average readings, and adjustable emissivity), but had a single laser instead of a bullseye-shaped one.
:max_bytes(150000):strip_icc()/wintact-infrared-thermometer-40a391f47afa42848135cb4544c2eb2c.jpg)
Amazon
We were shocked (albeit pleasantly so) by the accuracy of this model, especially considering it was under $15. In our controlled accuracy test, its readings averaged less than 1°F away from the calibrator’s temperature. It was also the only model that allowed the user to fine-tune the measurements by 5°C (9°F) in either direction for calibration, although we didn’t have to with its out-of-the-box precision.
The Tests
Serious Eats / Ashlee Redger
- Accuracy Test: We used a portable infrared calibrator to verify each thermometer’s readings in a controlled environment. We set the blackbody target to 122°F, 250°F, 375°F, 500°F, and 700°F (allowing the temperature to stabilize for 30 minutes after every change) and took an average of five readings from each model at every step. Throughout the test, we also evaluated how easy it was to aim the thermometers accurately, examined if the displays were clear and readable, and noted how visible the lasers were.
- Usability Test: To emulate real-world usage, we took the temperature of a pizza stone in a 500°F oven. We took an average of five readings for each thermometer (in case of glaring inaccuracies). Still, we primarily used this test to assess the thermometers’ ease of use, including how comfortable they felt in our hand and how quick it was to pinpoint the lasers inside a hot oven.
What We Learned
Distance-to-Spot Ratios Were Important to Know
Serious Eats / Ashlee Redger
As a rule, an infrared thermometer doesn’t just measure the small dot that their laser illuminates. In fact, the laser itself is only an approximate guide for the invisible measurement area, which actually changes in size depending on how close the thermometer is to its target. This correlation is known as the distance-to-spot ratio (sometimes called optical resolution) and varied in the models we tested. The most common ratio we saw was 12:1, which meant the target area would be about an inch in diameter when the thermometer was held 12 inches away.
Serious Eats / Ashlee Redger
Thermometers with larger distance-to-spot ratios could be held further back from their targets while still measuring a minute area. Our favorite ThermoWorks Hi-Temp Industrial IR With Circle Laser had a 30:1 ratio, so it could measure the same size spot as a 12:1 thermometer from over double the distance. This helped keep the thermometer cooler in the usability test (if the lens absorbed too much heat from the sweltering oven, it could have led to skewed readings). The Klein Tools IR1 Infrared Thermometer, on the other hand, had a 10:1 ratio. When held about three feet away from the hot pizza stone, it scanned a diameter of more than three-and-a-half inches. This wasn’t a deal breaker, but we were more cautious about pointing the laser in the center of the stone rather than getting close to the edges, which could have accidentally factored in the temperature of the oven floor.
Single-Dot Lasers Didn’t Show the Whole Measurement Target
Serious Eats / Ashlee Redger
Thermometers that had a single laser point (like the budget Wintact Infrared Thermometer) meant we only had a rough estimate of what area we were measuring, assuming the dot was at the center of that span (which didn’t seem to always be the case). That’s why we loved the outlined target that the ThermoWorks Hi-Temp IR offered with its circular laser beam since it did most of this visualization work for us.
Serious Eats / Ashlee Redger
We also liked the Klein Tools Dual Laser Infrared Thermometer. Instead of a bullseye-shaped light, it projected two red dots to represent the outer edges of the measurement spot diameter.
Emissivity Could Skew Measurements
Serious Eats / Ashlee Redger
All objects above −459.7°F (absolute zero) emit thermal energy—AKA infrared radiation—which is what infrared thermometers pick up. Emissivity is the efficiency at which thermal energy is radiated and is generally expressed on a scale from zero to one. Shiny surfaces tend to have lower emissivity because they reflect a higher quantity of energy than they emit, while dull and carbon-containing materials radiate more of their own heat.
A majority of the infrared models we tested had emissivity settings that could be fully adjusted from 0.1 to 1. Those that didn’t, including the Etekcity Infrared Thermometer and the Cuisinart Infrared Surface Thermometer, had a fixed value of 0.95 (which lines up with most organic substances, food, and water). We spoke to Kyle Halvorson, the Consumer Marketing Manager at ThermoWorks, to find out the importance of having variable emissivity. He explained that having a thermometer set to the wrong value could sometimes result in readings off by a hundred degrees or more. As an example, he told a story of measuring a stainless steel grill lid on a warm spring day and seeing it temp at -56°F when other parts of the grill were temping in the mid-80s. To get more accurate readings, he would have had to set the thermometer to stainless steel’s emissivity rating around 0.59.
“It’s not all that extreme,” Halvorson says. He clarified that, often, temperatures would vary by 10 or 15 degrees rather than a hundred or more, which would still be within a workable range when, say, measuring a cast iron skillet for searing temperatures or working with a pizza oven. It could also be difficult to find exact emissivity values of various materials to start with (we couldn’t find one for the cordierite pizza stone we used in the usability test, for example). Plus, emissivity can vary even among cookware of the same material, depending on wear and carbon buildup. Even so, we ultimately found it helpful when models (like the ThermoWorks Industrial IR Gun) had adjustable emissivities to correct dramatic inaccuracies.
Infrared’s Accuracy Was Relative
Serious Eats / Ashlee Redger
During our accuracy test, we measured the temperature of a precise calibrator target with a known emissivity of 0.95. We shot straight on and from a close distance. It told us how exact the thermometers were under near-perfect conditions, which weren’t really possible to accomplish in the real world. All infrared thermometers (including every one of the models we tested) are fallible to ambient temperature changes, particles in the air, lasers that are skewed from the center of the measurement area, and the aforementioned measurement distances and emissivity discrepancies. In some cases, a surface probe could be used to verify an infrared reading, but those are often costly and tend to have relatively low-temperature thresholds. For those reasons, we found it best to consider infrared thermometers’ readings as relative rather than exact during everyday use. Thermometers that had modes for maximum, minimum, and average temperatures across each trigger session also helped us better understand the general measurements across a surface. Although they come with a built-in level of variability, we still think infrared thermometers can offer vital insights for being a more informed cook.
A Few Tips for Infrared Thermometer Success
Serious Eats / Ashlee Redger
Although it’s difficult to guarantee correctness with infrared thermometers, we did learn a few tricks that can yield better reliability. First of all, remember that infrared thermometers can only read surface temperatures, not internal temperatures. They can’t be used to know if a steak or piece of chicken is done on the inside, only what its external heat is. They also can’t “see” through glass, water, or air that’s filled with smoke, steam, or dust (even if the lasers shine through). When possible, aim the thermometer perpendicularly to its target. If it is pointed at an angle, the measurement area becomes elongated and oblong (picture shining a flashlight straight down versus from the side).
Lists of emissivity values can be found around the internet, but if you can’t determine an exact value for your specific cookware (or can’t adjust the emissivity with your thermometer), you can put a thin layer of oil (which has an emissivity around 0.95) on top and aim the thermometer at that. Masking tape can also be used at ambient temperatures. Infrared thermometers aren’t great for temping inside grills because they will measure beyond the thin metal grates and also read the flame or coals beneath, so let a cast iron skillet preheat for 10 minutes or so on top and measure its surface instead. When temping liquid (like oil for frying or sugar for making candy), stir it beforehand to even out the temperature before measuring.
The Criteria: What to Look for in an Infrared Thermometer
Serious Eats / Ashlee Redger
Our favorite infrared thermometers were accurate under controlled conditions and had easy-to-read displays. Models that had larger distance-to-spot ratios could measure more precise points from further away, and those that displayed circular lasers or double points offered a better representation of the actual zone being measured than single-dot lasers. Adjustable emissivity and modes that displayed maximum, minimum, and average readings were a big plus. An upper measurement threshold of 750°F or so would be okay for most indoor cooking, but we liked thermometers that could measure up to 900°F or more, especially for use alongside outdoor pizza ovens (which, depending on the style of pizza, we often recommend preheating to at least 800°F).
The Best Infrared Thermometers
Thermoworks
What we liked: ThermoWorks is a titan of all things temperature, and its products have been winning us over for years. This model stood out from the rest in part because of its bullseye laser shape that helped us gauge the measurement area much more easily than we could with a single laser point (although, depending on distance, it can still be a slightly skewed representation). Of all the infrared thermometers we tested, it also had the highest temperature threshold (up to 1400°F!) and largest distance-to-spot ratio (30:1 versus the more common 12:1). In the accuracy test, it consistently averaged less than 1°F away from the goal temperature, making it one of the most accurate models of the lineup. For serious thermometer aficionados, this model had the capability to display readings from type K thermocouples, which included options for measuring internal, air, and surface contact temperatures (although these were available separately, and we did not evaluate their performance).
What we didn’t like: This thermometer is a true professional tool. As such, it was the most feature-heavy of the models we tested as well as the most expensive. It may be overkill for most home uses, and, given its price, we think a majority of cooks would be just as happy with our other, budget-friendlier favorites. For those who want the best of the best, though, this ThermosWorks model is it.
Price at time of publish: $169.
Key Specs
- Average difference from accuracy test goals: 0.9°F
- Measurement range: -76 to 1400°F (-60 to 760°C)
- Accuracy: ±4°F plus 0.09°F per degree below 32°F (±2°C plus 0.05°C per degree below 0°C); ±4°F (±2°C) or 2% (whichever is greater) for measurements 32°F and above. From 59 to 95°F (15 to 35°C), the accuracy increases to ±1.8°F (±1°C).
- Resolution: When measuring below 1000°F, the temperature displays to the tenth of the degree (0.1°F/0.1°C). When measuring over 1000°F, it displays in whole degrees (1°F/1°C).
- Adjustable emissivity: 0.1 to 1 in 0.01 increments (0.95 by default)
- Distance-to-spot ratio (optical resolution): 30:1
- Response time: 1 second
- Handle length: 4.5 inches
- Care instructions: Store the thermometer at room temperature. If needed, clean the sensor lens with a soft cloth or cotton swab with water or rubbing alcohol (allow to dry completely before using).
- Primary features: Circular laser targeting; Celsius or Fahrenheit toggle; optional backlight and laser; modes to display the maximum, minimum, difference between maximum and minimum, and average readings from each session as well as a trigger-less continuous measure option; high and low-temperature alarms; low battery indicator; can be paired with ThermoWork type K probes to take surface contact, internal, or air temperatures (accessories must be purchased separately)
Serious Eats / Ashlee Redger
Thermoworks
What we liked: This model had both impressive dependability and simple-to-operate accessibility. It was quick to scroll through the thermometer’s complete set of modes and we particularly liked being able to view the combined average of the temperatures from each session alongside the current reading. It also offered full control over the emissivity settings and could measure temperatures just over 1000°F.
What we didn’t like: It only had a single laser, which made it harder to know exactly how large its measurement zone was, but we were still able to get spot-on readings in both the accuracy and usability tests with a few extra seconds of scanning the surfaces.
Price at time of publish: $77.
Key Specs
- Average difference from accuracy test goals: 1.1°F
- Temperature measurement range: -76 to 1022°F (-60 to 550°C)
- Accuracy: ±4°F plus 0.09°F per degree below 32°F (±2°C plus 0.05°C per degree below 0°C); ±4°F (±2°C) or 2% (whichever is greater) for measurements 32°F and above. From 55 to 95°F (15 to 35°C), the accuracy increases to ±2.7°F (±1.5°C).
- Resolution: When measuring between -9.9°F and 199.9°F, the temperature displays to the tenth of the degree (0.1°F/0.1°C). Outside of that range, it displays in whole degrees (1°F/1°C).
- Adjustable emissivity: 0.1 to 1 in 0.01 increments (0.95 by default)
- Distance-to-spot ratio (optical resolution): 12:1
- Response time: 1 second
- Handle Length: 4 inches
- Care instructions: Store the thermometer at room temperature. If needed, clean the sensor lens with a soft cloth or cotton swab with water or rubbing alcohol (allow to dry completely before using).
- Primary features: Single laser targeting; Celsius or Fahrenheit toggle; optional backlight and laser; modes to display the maximum, minimum, difference between maximum and minimum, and average readings from each session as well as a trigger-less continuous measure option; high and low-temperature alarms; low battery indicator
Serious Eats / Ashlee Redger
Amazon
What we liked: The Wintact Infrared Thermometer averaged a mere 0.6°F difference from the calibrator’s temperature in the accuracy test. It also just happened to be the most affordable model of the lineup. This was the only model to offer a “self-calibration” mode, where the user could adjust the temperature by ±5°C (9°F) based on its accuracy at 0°C (32°F). This would allow the user to point the thermometer at an ice bath and then adjust the temperature accordingly should they notice the readings becoming skewed over time, although we didn’t need to use it.
What we didn’t like: Like the ThermoWorks Industrial IR Gun, this model only has a single laser pointer. It also beeped after each trigger session, which got annoying when we were temping multiple spots in quick succession. It does not have fully adjustable emissivity—rather, it only had an option to toggle between 0.8 and 0.95. The maximum and minimum modes must be scrolled through while your finger is still on the trigger; otherwise, it won’t display accurate readings from the previous session (and they do not display simultaneously with the current reading). We also found during the accuracy test that the laser was skewed slightly higher than where the thermometer was actually measuring, but we think this would be less noticeable in real-world applications.
Price at time of publish: $13.
Key Specs
- Average difference from accuracy test goals: 0.6°F
- Temperature measurement range: -58 to 986°F (-50 to 530°C)
- Accuracy: ±5°F (±3°C) for measurements 32°F or less; ±2.7°F (±1.5°C) or 1.5% (whichever is greater) for measurements 32°F and above
- Resolution: Temperatures display to a tenth of a degree (0.1°F/0.1°C).
- Adjustable emissivity: 0.8 option (0.95 by default)
- Distance-to-spot ratio (optical resolution): 12:1
- Response time: Less than 0.5 second
- Handle length: 3.5 inches
- Care instructions: Blow off loose particles on the sensor using clean compressed air. Gently brush any remaining debris away with a cotton swab dampened with water. The exterior can be cleaned with a damp sponge or cloth and mild soap.
- Primary features: Single laser targeting; Celsius or Fahrenheit toggle; optional backlight and laser; modes to display the maximum and minimum temperature readings; a calibration mode to adjust temperature readings by 5°C (in 0.1°C or 0.2°F increments); low battery indicator
Serious Eats / Ashlee Redger
The Competition
- Klein Tools Dual Laser Infrared Thermometer: We loved that this model had two laser dots to denote the span of the measurement area, but its user interface was slow and hard to navigate at times. It also had a maximum of 744°F, which was on the low side (especially for pizza ovens).
- ThermoPro Digital Infrared Thermometer: This affordable thermometer had adjustable emissivity and could read up to 1022°F, but it had one annoying flaw. While its live readings were quite precise, the infrared would continue to measure temperatures after we let up on the trigger, which caused skewed readings (sometimes off by hundreds of degrees) unless we kept it frozen in place for several seconds after each session. We found this most inconvenient when we were measuring from an open oven and when we didn’t have a clear view of the display to see live readings.
- Etekcity Infrared Thermometer: Although it was budget-friendly, the Etekcity thermometer averaged about 10°F off the target temperature in our accuracy test and maxed out at 716°F.
- Sovarcate Infrared Thermometer: The Sovarcate wasn’t as precise as other models in our controlled accuracy test and had a dark display with light text that was hard to read unless viewed straight-on. Like the Wintact, it also beeped after every reading.
- Kizen Infrared Thermometer Gun: The Kizen was a copycat design of the Sovarcate but with different coloration (and louder beeps).
- Klein Tools IR1 Infrared Thermometer: This model had the smallest measurement range (-4 to 752°F) and the lowest distance-to-spot ratio (10:1) of the lineup. It also required the user to unscrew the battery compartment in order toggle between temperature units and did not allow any other display modes.
- Cuisinart Infrared Surface Thermometer: During both tests, we noticed this model’s readings varied by dozens of degrees depending on the distance and angle it was measuring from, which made it hard to trust.
FAQs
How do you use an infrared thermometer?
To use an infrared thermometer, point it at whatever you would like to measure and press the trigger to activate it. The thermometer will project a laser to indicate to the user where it is reading, although the actual measurement zone is usually larger and can be slightly skewed from where the laser is displayed. It is a good practice to move the thermometer around the item you are analyzing to get an idea of the general temperature range across the whole plane instead of taking the temperature of a single point. Infrared thermometers only measure the first surface in front of it, and can’t “see” through glass or water (even if the laser shines past it).
Are infrared thermometers accurate?
Under perfect conditions, infrared thermometers can be quite precise and measure within a degree or less of the actual temperature. During real-world usage, though, they can be affected by several factors—including distance, angle, emissivity, and if there is smoke, steam, or dust in the air. Infrared thermometers can still provide valuable context for cooking, even if their measurements should be treated as relative rather than exact.
How does an infrared thermometer work?
All objects that are above absolute zero (−459.7°F) generate infrared radiation. The higher something is in temperature, the more energy (AKA infrared light) it emits. We can’t see this radiation, but we can feel it in the form of heat. An infrared thermometer can detect and focus the infrared light using a lens and then convert it into electrical energy via a thermopile. The resulting voltage is translated into a temperature reading that is displayed in Fahrenheit or Celsius. The coolest part? Most infrared thermometers can do all of this in under a second.
How do you calibrate an infrared thermometer?
The only way to be sure of your infrared thermometer’s accuracy is to test it against a known reference thermometer using a calibrator, but they can be inaccessibly pricey (and frankly, unnecessary) for most cooks. We suggest testing your thermometer against an ice bath, which will reliably measure at 32°F if made with plenty of ice. Most infrared thermometers can’t actually be adjusted up or down for calibration at home, but you can make a note of any inconsistencies for future reference.
Why We’re the Experts
- For this review, we evaluated 10 popular infrared thermometers and ranked them based on accuracy and real-world usage.
- We also spoke to an expert from ThermoWorks to understand emissivity, technical specifications (like optical resolution), and proper temping techniques.
- Ashlee Redger is a freelance food writer who has been reviewing equipment for Serious Eats since 2022. She has interned at America’s Test Kitchen, innovated consumer products and restaurant menus for national brands, and developed hundreds of recipes for home cooks.
Ashlee Redger
Source link
:max_bytes(150000):strip_icc()/20230306-TahdigPersianRiceNaderMehravari14-6c57568b6bd045b480a3d541c9464d72.JPG)
:max_bytes(150000):strip_icc()/20230905SEA-HowtocutCarrots-AmandaSuarez-09-46e51251c2414647905db3561eab773c.jpg)
