These days, it’s hard not to feel paranoid when you have to be in close contact with other people. When a disease is prevalent and observing proper hygiene is crucial, investing in the best infrared thermometer is ideal.
However, it’s not enough to buy just any brand. With so many options to choose from, you can easily end up getting overwhelmed picking the right one for you.
To help you with that, below is a handy guide to choosing the best infrared thermometer for your needs.
What Are Infrared Thermometers?
An infrared thermometer is considered non-contact temperature devices. They rely on infrared radiation to determine the temperature of a surface without the need for contact.
Their history is quite a short one.
In 1901, the very first radiation thermometer patent was granted. However, it wasn’t until the late 1800s that a commercially available model was released to the public.
Following World War II, a lot of developed nations saw their benefits. They started pouring money into infrared technologies. This continued throughout the Cold War, causing an increase in modern infrared thermometers.
In the early 2000s, people started getting their hands on more accurate and affordable IR thermometers. They had become widely available at that time, offering a different range of applications.
How Accurate are Infrared Thermometers
Honestly, the answer to this question varies.
While there are studies suggesting that IR thermometers are quite accurate, some say otherwise.
One particular study was done in 2012 to determine the clinical accuracy of a noncontact infrared skin thermometer. The study involved kids aged 1 to 48 months, both from an inpatient unit and the emergency room.
All of them were carefully assessed using three different kinds of thermometers: rectal glass mercury thermometer, temporal artery thermometer, and non-contact infrared thermometer.
The infrared thermometer showed 97% sensitivity and specificity. Overall, the study revealed that noncontact infrared thermometers are reliable and accurate.
Another study in 2020 agrees but to a certain degree. It suggests that while IR thermometers are good for quick screening, they shouldn’t be used to represent a person’s actual body temperature.
Now, here’s the thing:
While the FDA says that IR thermometers offer an effective way to check a person’s skin temperature, particularly with the rise of COVID-19 cases, they do have some limitations. They cited two:
1. The close distance required to get a person’s temperature properly
2. How and where the thermometer is used
Like with other types of thermometers, the accuracy of IR thermometers depends on a lot of factors, like the product you are using. The way you’re using the thermometer can affect its accuracy, too.
Are IR Thermometers Safe?
These days, people tend to use more IR thermometers to check temperatures than other types. Because of such need, some people express concern about their safety.
If you’ve been on social media frequently, you’ve probably come across posts about IR thermometers posing dangers on people’s skin. The claim is that repeated use of thermometer guns can impact the sensory signals that are present beneath the skin. They are usually pointed in the areas where the pituitary and pineal glands are located.
But here’s the truth:
Infrared thermometers work by using radiation. However, they don’t necessarily send them inside your body. Because of that, IR thermometers don’t necessarily affect you.
Think of your TV and other gadgets you may have at home.
Like IR thermometers, they also make use of low-impact radiation. The same is true with diagnostic tools like CT scans and X-ray.
Pituitary and Pineal Glands
The claim that IR thermometers can damage these glands has reached the attention of the Malaysian Health Ministry. And to address this, they’ve issued a statement telling the public to not be afraid of IR scanners.
A part of their statement says:
“A non-contact infrared thermometer is not a shooting device emitting radiation. It detects and emits heat emanating from the human body in the form of infrared rays and converts it into electricity.”
You can read the full article here.
Other people also claim that the radiation levels emitted by IR scanners can affect the brain. And like the first claim, there’s no truth to it.
You will only experience issues with thermal scanners that are meant for industrial use. They aren’t recommended to be used on humans.
The frequency of temperature scanning doesn’t pose any threat, too. Most of the time, they are done from a distance and they aren’t repeated several times throughout the day. Getting scans three to four times a week won’t likely cause harm.
Now, can they leave you blind?
Most IR thermometers show a red dot when used. This is the light that they provide to let people know where they are measuring.
Basically, the light isn’t laser. You’re not going to damage your retina by pointing it to the eyes.
However, even though it’s not damaging, you should still refrain from doing it as it’s uncomfortable for the other person.
The Different Types of Infrared Thermometers
In general, there are three main classes of IR thermometers. Each of them is designed for specific purposes.
Spot Infrared Thermometers
These thermometers can measure the temperature of a small area. They usually come with a visible red dot at the center of the area being measured. As mentioned earlier, the light simply serves as a guide. It doesn’t play any role in measurement.
Spot infrared thermometers are quite diverse. Here are some of their common subtypes:
- Infrared thermocouples
- Handheld infrared thermometers
- Fixed-mount infrared transmitters
- Fixed-mount infrared thermometers
- Pocket infrared thermometers
- Two color-ratio thermometry
Infrared scanning systems
These are used to scan a bigger area. Usually, they involve the use of a spot thermometer which is pointed towards a rotating mirror.
You can find them mostly used in manufacturing that involves ‘web’ processes like fabric, large sheets of glass, and paper.
Infrared thermal imaging cameras
These are used to measure the temperature of several spots over a big area to create a two-dimensional image called a thermogram. Compared with the other types, this type is more software-intensive. They are typically used in process quality monitoring, perimeter, and enclosed space monitoring.
How Do They Work?
Infrared thermometers work based on ‘black body radiation’.
This theoretical concept refers to the spectrum of light that’s emitted by any heated object.
Anything that has a temperature of above absolute zero possesses molecules inside of it that move around. And as they move, they emit infrared radiation.
Once they get hotter, they start to emit more infrared. Some may even begin to emit visible light.
Infrared thermometers come with a lens that focus infrared light from a surface onto a thermopile. This detector has the ability to absorb infrared radiation and turn it into heat.
If there’s more infrared energy, the thermopile gets hotter. This heat is eventually turned into electricity which is sent to a detector. Hotter objects have more electricity.
Why Do You Need an IR Thermometer?
Remote temperature measurement
Fever is one of the most common symptoms for those who get sick. This makes taking temperature important.
However, because some diseases can be contagious, taking temperature at a distance is ideal. This is one of the reasons why IR thermometers are experiencing a huge demand these days.
Human temperature isn’t the only thing they can measure. Depending on the device, you can also check the metal surfaces that can cause injuries if someone touches them.
Additionally, IR thermometers can detect temperature of moving objects. This is why they are also commonly used in airports.
Stores detected temperature
The best IR thermometers can keep records of detected temperature in a given time. They can also be erased whenever the need arises.
This is helpful when you want to make a temperature comparison.
Easy to use
Most brands offer thermometers that are shaped like a gun. This makes it easy for people to use them. Plus, they are compact and can be carried anywhere.
Apart from that, IR thermometers are also give quick temperature readings. You don’t have to wait a long time just to check for one’s temperature. They can show you the reading in a matter of seconds.
Disadvantages of Infrared Thermometers
IR thermometers aren’t cheap
Compared with other types, they are quite more expensive. Their price ranges between $30 to $60.
You can buy cheaper models but they may not be that accurate. They may not last long, too.
Susceptibility to false measurements
This is another issue you have to consider before buying an infrared thermometer. Remember, you need to use them from a distance. Sometimes, the distance can create temperature errors.
The presence of dust or smoke can also make it hard to get an accurate measurement.
If you closely look at these disadvantages, you’ll realize that they are manageable. For example, cleaning your device can help make sure that there’s no dust that can interfere with temperature readings.
Other uses of IR thermometers
Infrared thermometers aren’t limited to measuring human temperatures. They also have lots of professional applications.
IR thermometers are great for checking food quality and safety. They can help monitor cross-contamination as well as checking the temperature at critical points whenever you need to reheat, cool, or serve foods.
You can use IR thermometers to diagnose overheating. They are also quite useful in checking and identifying poor-performing A/C systems.
These thermometers are helpful in monitoring manufacturing processes and high-temperature substances. They can also be used to check for insulation problems. IR thermometers are great in performing energy audits, too.
How to Use An Infrared Thermometer
As mentioned earlier, the proper use of infrared thermometers helps ensure accuracy. To help you get an accurate reading, here’s a list of tips you can use the next time you want to measure someone’s temperature properly:
Pick the right infrared thermometer
To make sure you get an accurate reading, it’s a good idea to invest in a high-quality infrared thermometer. Make sure that it’s FDA-certified and designed for medical use.
Well, medical infrared thermometers can cover a limited range of temperatures. Usually, it’s around 10°C. This is typically suitable for reading body temperature at a range of about 32..43°C.
Consider IR thermometers made for domestic use and industrial applications. Since they have an accuracy tolerance of about ± 2°C, they can’t keep body temperature readings with really high accuracy. This is due to its bigger temperature range.
Apart from that, you also need to pick one that has a good response time. Remember, the quicker the reading, the better. It’s recommended that you get one with a response time of less than 1.5 seconds.
Read the manual
Products have different specifications and functionalities. Reading the manual carefully allows you to be more familiar with them.
Being familiar with your IR thermometer’s specifications is good if you want your device to be more efficient and precise. It prevents confusion, too.
Check your device
Before using it, make sure that there’s no dust, dirt, smoke, moisture, or frost. Keeping your device clean and dry is one way to get an accurate temperature reading.
Note: IR thermometers are easily affected by dirt and moisture.
If you notice that your device isn’t clean, there’s a section discussing how to clean IR thermometers below.
Turn on your device
Most thermometer guns can be turned on by pressing the trigger you can find on their handles. Some can be powered by pressing the designated power button.
With that, check the design of your product. If you can’t find a way to power it on, check the manual.
Adjust the settings
Most medical infrared thermometers come with multifunctional settings to meet different needs. Before using your device, make sure to adjust them.
For example, identify the unit you need the temperature readings to be. You can usually just switch between ℃ and ℉ by pressing the “Set” button. You can see the temperature unit on the screen readout.
Some medical IR thermometers can also be used for detecting surface temperatures like food, water, and room. If your device comes with this feature, adjust the mode first.
Pick the best body part for detecting temperature
The most common body part used for temperature taking is the forehead. It’s highly accessible and not that invasive. You can just point your device on one’s forehead and you’ll instantly get a reading.
However, when it comes to accuracy, the forehead may not be the most ideal part.
You see, your forehead is exposed to external factors. The temperature outside can affect the temperature of your forehead. If it’s hot outside, you’ll likely get a higher reading than your actual body temperature.
If you want to get a more accurate reading, screen the wrist or the armpit. Compared with the forehead, these parts aren’t too exposed to the temperature outside.
Whether you choose to scan the forehead or the wrist, make sure that the part is clean and dry. Your target part shouldn’t be covered with clothes, too. If you’re scanning the forehead, remove any hair covering it.
Be mindful of the distance
You’ll be able to determine the best distance-to-spot ratio of your device by checking the manual.
In general, the closer you are to the target, the more accurate the reading you’ll get. So, before scanning, it’s a good idea to check if your device is at the right distance from the body part you want to scan.
Note: The ideal distance for using an IR thermometer is 6 inches.
Aim the thermometer and scan
Within seconds, the temperature reading will be displayed on the screen. If the temperature is normal, you’ll hear a soft beep with most models.
However, if the reading is abnormal, you’ll likely hear an urgent beep. In case your device features a memory recall function, you can save the data so you can make comparisons later.
Save the data
Not all infrared thermometers come with this feature. However, if yours do, don’t forget to check if it automatically saves data. If not, find out if you have the option to manually save it.
Keeping a record is important when you need to compare your temperature readings. You may also find it useful when you need to report the data to your healthcare provider.
To get the best possible results, keep in mind to do the following:
- Keep your thermometer’s lens clean. Check for scratches, too.
- Determine the distance-to-spot ratio of your device. This will get you a more accurate measurement.
- Be careful with objects with low emissivity
- Remove dust and grease as they can affect the accuracy of your IR thermometer
How to Calibrate An IR Thermometer
Infrared thermometers usually operates within a specific accuracy range. If you are using professional ones, a deviation of ±1°C is normal. For the cheaper thermometers, it’s ±2°C deviation.
If you notice that your IR thermometer shows a bigger deviation from those ranges, you’ll need to have your device calibrated.
There are a couple of ways to calibrate your device. There are simple DIY methods you can try. If you don’t feel confident doing them, you can always submit your thermometer to professionals to get it checked.
The DIY Method
For this solution, you’ll need to measure the deviation of your device from the correct temperature. You can use an accurate contact thermometer for comparison.
Get a bowl and fill it with crushed ice. Then, add ice-cold water to make sure everything is mixed well. Continue stirring it until you come up with an ice bath with a uniform temperature reading.
Next, dip your thermometer into the ice bath and take its temperature reading. Get your IR thermometer and take another reading.
To get a proper reading, push down the ice gently. Make sure that there are no floating pieces of ice on the surface when you scan the water.
Check the readings on both thermometers. If they don’t match, calibrate your IR thermometer accordingly. Most units have a button you can use to access their calibration settings.
With a calibrator
In case you are using a professional infrared thermometer, the ice bath method may not be that precise. For this, you’ll need a calibrator.
You have two options here: a flat-plate IR calibrator and black body calibrator.
Set your preferred temperature and wait for your calibrator to work. Then, measure your target with your device.
If your IR thermometer is working well, you should be able to get the same reading as the temperature you’ve set. If there’s a huge difference, you can make the necessary adjustments.
Ask for help
Another option is to send your device for professional calibration. Take note that having your device professionally calibrated may cost money.
How to Clean Your IR Thermometer
Even though your thermometer doesn’t require direct contact, you need to keep it clean. It doesn’t just help ensure your device’s accuracy but it helps prevent the spread of diseases, too.
To clean your IR thermometer, all you need is a piece of cotton swab or soft cloth. With medical alcohol or water, carefully wipe the lens first. After that, you can clean the rest of the body of the thermometer.
Take note that you shouldn’t use chemicals or soap in cleaning your device. Also, don’t submerge any of its parts in water.
To keep your thermometer working well, try to keep it in a place with a temperature between 4°C to 65°C. Make sure that it’s not exposed directly to extreme temperatures.
The Most Common Mistakes When Using Infrared Thermometers
Skipping the instructions
Reading an entire booklet may feel tedious but it’s necessary. Reading your thermometer’s complete manual helps you be more familiar with your device. You may even find additional tips and features there.
Not cleaning the lens first
Keep in mind that the lens of your thermometer is sensitive. Dirt and grease can easily clog them up, leaving you with incorrect temperature readings.
Not waiting for the thermometer to adjust to the temperature of the environment
If you stored your thermometer in a cold room, wait for about 30 minutes before using it to scan temperatures. The differences in ambient temperature can prevent you from getting an accurate result.
You don’t necessarily have to do anything complicated while waiting. You can just let the thermometer rest on a table before using it.
Things to Consider When Buying An Infrared Thermometer
Infrared thermometers aren’t that cheap. This is one good reason to be extra careful when looking for the best IR thermometer.
When looking at products, consider checking the following factors:
This refers to the ratio of the energy being radiated from a certain surface to that of radiated from an emitter. In general, the range is between 0.0 to 1.0.
Perfect emitters are those that have an emissive value of 1.0. This means that they are capable of radiating 100% energy.
With IR thermometers, you need to check their emissivity since it’ll give you an idea of how much infrared energy they can give out at a certain time. Those that have an emissivity value closer to 1.00 can be used to read more materials than those with low emissivity values.
If you will be measuring the temperature of reflective surfaces, consider investing in a thermometer with adjustable emissivity.
This is an important factor to consider when looking for the best infrared thermometer. It can affect the work you can do with your thermometer.
As much as possible, pick one with a wide temperature range. This will allow you to record different processes with various temperatures.
On the other hand, if you only need to work on a specific process, you can choose one with a narrow temperature range since their resolutions are higher.
Of course, if you will be investing money in the best infrared thermometer, you need it to be accurate.
However, as discussed earlier, their accuracy depends on their distance-to-spot ratio/. If you need to measure the temperature of something with great distance, you need to choose a unit that comes with bigger ratios.
This is something you shouldn’t miss when you want to measure the temperature of moving objects. You’ll also find it useful to buy a thermometer with a good response time if you need to check the temperature of objects that heat up quickly.
The presence of a good backlit screen makes it easier for you to read thermometers even if the lighting isn’t good.
You want an IR thermometer that’s durable, particularly if you need industrial models.
Most Fresnel lens thermometers are quite durable because they’re made with polymer. The material helps keep them safe.
Mica lens, on the other hand, requires a more durable shell. You’ll need to have a good carrying case, too. It’ll keep them from cracking.
IR thermometers are fragile so you need to find one that comes with a warranty. This guarantees that the device is free from both workmanship and material defects.
The 10 Best Infrared Thermometers
If you do a quick search online, you’ll probably feel overwhelmed with all the infrared thermometers available on the market these days. The demand is high, particularly with the pandemic affecting everyone’s life.
To make sure you only end up what’s best for you, here are the best infrared thermometers you can find on the market today.
#1 Withings Thermo – Smart Temporal Thermometer
Withings Thermo is one of the best IR thermometers around. Its 16 infrared sensors allow users to get highly accurate results.
And the best part?
It can take over 4,000 measurements.
This best infrared thermometer is quick and easy to use. It even comes with a color-coded fever indicator to let you know if someone’s temperature is above normal. And since it’s thermal, it offers non-invasive measurement.
Withings Thermo is multi-user friendly. In fact, it allows up to 8 users to keep track of their temperatures. They can even share it with health professionals.
The clinical accuracy of this thermometer is ±0.2°C which is actually good for an infrared thermometer. When it comes to battery life, it can operate for up to two years and you’ll just need to use two standard AAA batteries for it.
Another nice thing about this product is that it features automatic synchronization. Your data gets transferred to its dedicated app which is available to both Android and iOS users.
One of this thermometer’s best features is its fast reading time. In fact, in just 0.5 seconds, you’ll be able to know your temperature.
With its pistol-like design, you can use it not just on yourself but on a group of people, too. This makes it an ideal thermometer for keeping track of the temperatures of your colleagues or students.
The device has a measuring range of 5 to 15 centimeters. This distance greatly reduces the risk of actually touching someone else’s forehead and transmitting infections.
Another thing you’ll love about this thermometer is its easy-to-read LCD screen display. You won’t have a hard time reading the numbers. Plus, the button controls are big, too.
The device comes with two AA batteries and a carrying pouch.
This is a good thermometer for all ages. By removing its cap, you can use it as an ear thermometer or forehead thermometer. This feature also lets you measure the temperature of other objects and liquids without the need to touch them.
The device comes with a colored fever LED display. Its backlit screen will turn red if your temperature is elevated. It’ll also start beeping
It’ll shut down after 10 seconds of activity. This is a nice feature if you want to save its power. The thermometer works on two AAA batteries.
If you are looking for a really good industrial thermometer, you can’t go wrong with Fluke 62 Max. Capable of measuring temperatures from 30 to +5000 degrees C, you’ll find it useful in monitoring mechanical, HVAC, electrical, and automotive systems.
The thermometer features dual lasers to help you achieve superior targeting. It also comes with alarms to alert you of high and low readings. Its distance to spot ratio is 12:1.
It comes with a large backlit LCD screen, making it easier to read data even when you’re in dark areas. Plus, it also has a rugged built. Its designed to withstand even when dropped at a height of 3 meters. Certified IP54, the thermometer also has protection against splashing liquid and dust.
Fluke 62 Max is small and light. You can just clip it to your belt and it won’t get in your way.
This is an excellent thermometer to invest in if you intend to use it for culinary applications. With a dual function unit, you can use it to check the internal temperature of meat as well as surface temperatures.
It’s fitted with three LED lights. They help let you know if your food is hot, cold, or has a medium temperature.
For example, you can scan the temperature of surfaces before putting your pizza on a stone or if you need to sear your meat.
The thermometer has a temperature range of -67 to 482°F. As for the margin of error, it’s quite small.
When it comes to cons, the first on the list is its lack of a backlit display screen. If you’re working in the kitchen, you’ll need to make sure that there’s enough light for you to read the data. Plus, it takes a bit longer to show temperature readings.
SURPEERInfrared Thermometer is a reliable option for those who are looking for a versatile non contact infrared thermometer. It can read temperatures with ±1℃ accuracy and a reading time of 0.5 seconds.
The device comes with a laser which helps with precise aiming. With it, you can accurately measure the temperature of the surface you’re targeting.
Its distance to spot ratio is marked at 12:1. This means that you can use it to target surfaces at a longer distance.
The infrared thermometer also comes with a large screen display to make reading data easy. It comes with a backlight which you can turn on or off depending on the lighting in the room.
There’s also a buzzer alarm that’ll beep when the value reaches the minimum and maximum temperatures you’ve set.
Like most of the thermometers on this list, the device comes with an auto-off feature. It’ll shut down after 6 seconds of inactivity to increase battery life and save power.
This infrared thermometer features three ultrasensitive sensors to let you get a fast add precise temperature reading. It’s programmed to collect over 150 data points for every second. Whether you are inside your home or outdoors, you’re guaranteed to get maximum accuracy.
And if you’ll be using it on your baby, you’ll love the option to turn off any sound. This is a nice feature to have when you don’t want to disturb your baby’s sleep at night.
Using this infrared thermometer isn’t confusing. In fact, you can adjust most of its setting options by pressing a single button.
For example, you can change between its two measurement modes by pressing the forehead/object button. You can also switch between units by pressing the Celsius/Fahrenheit button.
This particular infrared thermometer is a bit different from the other ones on this list. Instead of having a gun-like design, this one’s wall-mounted.
To use it, all you need to do is stand in front of it with your forehead about two to four inches away. This helps you get the best reading.
If you see a green light, it means that your temperature is within normal range. A red light followed by an alarm means that the temperature is high.
The lights aren’t the only indicators this infrared thermometer has. You can actually see the data on its LCD screen.
And if you worry about losing your data, don’t worry. You have the option to connect it to its dedicated app where you can log and track your temperatures throughout the day. You can download it via the Google Play store or the App store.
This device is great to use in both public and private settings. It’s recommended to be used in businesses, bars, bus stations, offices, and even hospitals. Since it’s a non contact thermometer, it minimizes the risk of spreading diseases.
When it comes to installation, the unit doesn’t require advanced DIY skills. Inf act, the instructions to install it are easy to understand. All you’ll need are nails, brackets, and hooks.
The thermometer is powered by a rechargeable battery. Alternatively, you can also use its USB charging cord.
iHealth Forehead Infrared Thermometer has one of the most elegant designs on this list. It actually looks sleek and pretty for a thermometer.
Now, this device is more than just its look. It delivers quick and accurate results and those are just some of the things that sent it to this list.
The thermometer can measure temperatures in just one second. Its recommended distance is 1.18 inches to ensure not just accurate reading but safety, too.
Its LCD screen comes with large digits so you can easily read the numbers and indicators. It’s also color-coded, similar to most of the thermometers on the list.
The device can collect 100 data points per second. It also has built-in smart chips to ensure reliable results each time you use it.
If you are looking for a cheap but accurate option, this industrial infrared thermometer is a good option. It gets the job done without burning holes in your wallet.
It’s easy to use. You just have to point and shoot. With its backlit LCD screen, you’ll find reading the data quite easy. It also automatically stores data.
The thermometer comes with a low battery indicator. All you need to do is check its power status before starting with any project so you won’t have to worry about stopping midway just to charge it.
Like what was mentioned earlier, cheap infrared thermometers aren’t 100% reliable when it comes to accuracy. Although this one measures temperatures perfectly fine, you shouldn’t expect incredible accuracy. Its number is at ±2℃. Its distance to spot ratio, on the other hand, is 12:1.
When it comes to temperature range, this one can read between -50°C to 550°C. You have the option to switch between °C and °F.