Measure the temperature of your roast meat, electrical equipment, automotive, or other surfaces from a distance with an infrared thermometer. It provides a fast and easy way of measuring the temperature without touching the item you are measuring. And, with the auto shut off feature, you can use the device with minimal supervision. The following discussion elaborates on the uses of this device. We’ll cover how infrared thermometers work, different types of IR thermometers, their pros and cons, and usage tips. We’ll review TOP 5 Best Infrared Thermometers to make choosing one less of a hassle.

Infrared thermometers are used in different industries and work environments to determine the temperature of objects from a distance. The distance can range from an inch to miles. These thermometers are used in areas where other kinds of thermometers can't be used, e.g., electrical circuits, mechanical equipment, building systems, moving objects, and objects in a vacuum for time-sensitive readings.

What You Will Learn from This Guide:

How it Works

These devices measure infrared radiation to determine the temperature of an object.

Infrared radiation is one type that occurs within the electromagnetic spectrum; other types include visible light, x-rays, and microwaves.

It is based on the concept of blackbody radiation, which means that any object whose temperature is above zero has molecules moving around. Higher temperatures cause the particles to move faster thus, emitting infrared radiation. Increased temperature leads to a higher emission of the infrared radiation, which then begins to emit visible light. It explains the change in the color of metals when they are extremely hot.

Other theories state that infrared thermometers measure the gradient in radiation between objects. For example, if there is a difference in temperature between an object and the surrounding environment, it is estimated and used as the temperature. As such, if the object has the same temperature as the environment, the net radiation is zero.IR thermometers measure this gradient to determine the temperature of the object and display the results.

The IR light can be absorbed, focused, or reflected. Handheld thermometers use a lens to focus the light from the object to the detector (thermopile). The sensor absorbs radiation and converts it to heat then to electricity. The electricity is then sent to the detector using it to determine the temperature of the object. More electricity is produced as the object becomes hotter.

Uses of IR Thermometers

Professional Applications


  • Perform energy audits to identify infiltration and leaks
  • Identify insulation problems
  • Manufacturing
  • Monitor manufacturing process
  • Monitor high-temperature substances like metals and plastics


  • Testing the thermostat to diagnose overheating
  • Identify poor performance of A/C systems


  • Measure the body temperature for fever (measures the temperature through the ear)


  • Avoid cross-contamination
  • Check the quality of food and safety
  • Monitor temperature at critical control points when goods are reheated, cooked, cooled, and served

General Applications:

  • Check door and window frames for leakages
  • Determine the temperature of freezers and refrigerators
  • Identify insulation problems in a home

How to Use an Infrared Thermometer

It's pretty easy; you only need to fix the batteries in their compartment and activate the desired temperature unit (Celsius or Fahrenheit).

Turn on the device by pressing the power button and aim the gun to the surface you want to measure the temperature.

Be sure to stand close to the object or within the DS ratio indicated by the manufacturer for accurate readings.

Pull the trigger to observe the reading on the digital display on the thermometer.

Types of Infrared Thermometers

The construction of infrared thermometers comprises an optical system to collect energy, an emissivity adjustment that matches the calibration of the thermometer to characteristics of the object and a detector (thermopile).

Modern infrared thermometers mimic the same concept, but numerous advances in technology have introduced sophisticated devices to widen the scope of their applications. As such, detectors are designed to match specific applications to improve performance.

Here are the different types of infrared thermometers.

  • Spot infrared thermometers: these kinds display the temperature on a particular spot on a surface.
  • Infrared scanning systems: the devices scan larger areas and are used in manufacturing processes that involve conveyors, e.g., when continuous piles of objects move along a large sheet of metal from an oven.
  • Infrared thermal imaging cameras: these kinds use cameras to measure the temperature at different points over a larger area to create two-dimensional images called thermograms. The technology applied to the devices is more hardware and software intensive compared to regular infrared thermometers.

What to Look for When Buying Infrared Thermometers

  • Emissivity

It refers to the efficiency with which an object absorbs or emits infrared energy. The values range from 0.0 to 1.0.

Objects that have an emissive value of 1.0 are called perfect emitters as they radiate 100% energy.

An efficient infrared thermometer should factor in this feature based on the type of object in question because various surfaces emit radiation differently.

  • Speed and Accuracy

Effective IR thermometers deliver temperatures fast and accurately.

Advanced versions factor is adjustable emissivity for more accurate readings. Experts allow a +1% margin of error when using professional IR thermometers and +2% for less expensive devices.

  • The Temperature Range

The primary factor here is whether the thermometer is used for professional or home-based applications.

For regular use, e.g., around the house, a temperature range of -58 to 1022 degrees Fahrenheit is ideal. However, in advanced applications like in manufacturing processes, the temperature range should be more than 1487 degrees Fahrenheit.

  • DS Ratio

The distance to spot ratio affects the accuracy of the readings from the thermometer. The rate is determined by the size of the area being measured in relation to the distance.

For example, if an object has a D/S ratio of 10:1 and it is 5 inches in size, the maximum distance the thermometer can accurately measure the temperature is within 50 inches.

Distances larger than that range will be inaccurate as the IR thermometer will include the temperature of the surrounding objects and surfaces. Most IR thermometers in the market have a DS ratio of 12:1.

  • Warranty

A warranty is a good indication of a high-quality IR thermometer. The period can range from 90 days to 10 years based on the manufacturer.

Top 5 Infrared Thermometers

ANKOVO Thermometer

ANKOVO Infrared Thermometer: photoThis medical IR thermometer is ideal for all ages. It has a dual mode thus, can function as a forehead and ear thermometer for kids older than three months.

The thermometer delivers temperature readings in just eight seconds, and users can view a maximum of 20 previous readings if monitoring the temperature of a child.

The LCD flicker alarm makes this device even more efficient as it alerts the user using seven short, rapid rings when the temperature exceeds 37.5 degrees Celsius. Compared to other thermometers that use mercury, the Ankovo is entirely safe as the glass does not break.

Pros: Cons:
  • It is budget-friendly
  • User-friendly
  • Has a fever alarm that beeps to alert you to read the results
  • It takes eight seconds to display the reading
  • Requires contact with the mouth, ear, or armpit
  • Requires sterilization using isopropyl or alcohol

Equinox Digital Non-Contact Infrared Forehead Thermometer

Equinox Non-Contact Thermometer: photoThis three-in-one thermometer is designed to measure the body temperature, that of a room, and surfaces. If you are taking the temperature of a child, you don't need to disturb him as you can accurately do it within a distance of 3-5 cm from his forehead. It is fitted with a 3-color changing LCD screen to help the user determine if the subject is normal, has a high temperature, or is just medium.

Equinox thermometer uses infrared technology to deliver instant results, and the built-in alarm system alerts you if a fever is detected. It also has a backlight that turns red and makes a sound if the child has a high fever. Additionally, it displays up to 32 previous readings, so you can monitor the progress of your little one.

Users can also change the settings from Celsius to Fahrenheit (and vice versa) with a simple click of the button. Medical experts say that the Equinox Digital Non-Contact Infrared Forehead Thermometer is the most accurate for taking temperature readings of a child. It measures the body temperature within a range of 32-42.9 degrees Celsius and 0-60 degrees for surface temperature.

Pros: Cons:
  • Does not need contact
  • Measures the temperature of other surfaces
  • Sometimes it delivers inconsistent readings

Etekcity Lasergrip 1080 Non-Contact Digital Laser Infrared Thermometer Temperature Gun

Etekcity Infrared Thermometer: photoThe Lasergrip 1080 is designed for indoor and outdoor use. It measures temperature within a range of -58 degree Fahrenheit and 1022 degrees Fahrenheit, which is pretty impressive for household use. The Lasergrip 1080 is fitted with an LCD screen that has a backlight and users can switch between degrees Celsius and Fahrenheit just by a simple click of a button.

Its response time is almost instant, i.e., 15 seconds within a Distance to Spot ratio of 12:1. For more accurate results, the distance between the object and the thermometer should be 36 cm/ 14.17 inches.

The Etekcity Lasergrip 1080 Non-Contact Digital Laser Infrared Thermometer Temperature Gun is designed for various applications such as home repairs, measuring the surface temperatures of objects beyond the freezing and boiling point, barbequing, cooking, and when performing auto maintenance.

A nine-volt battery powers it and the low-battery indicator should alert the user when it needs to be replaced. Note that the lasergrip 1080 does not measure the internal temperature of the object thus, it can't be used to obtain the temperature of animals and humans.

Pros: Cons:
  • Offers a wide temperature range
  • Has an auto shut-off feature helps preserve the life of the battery
  • Affordable
  • Has a two-year warranty
  • Its emissivity is fixed at 0.95
  • Its plastic construction is delicate

Infrared Thermometer, SURPEER IR5D Laser Thermometer

Infrared Thermometer SURPEER: photo

This IR thermometer combines the most recent temperature sensor technology with the advanced Frensel lens to deliver accurate readings with only +/- 1.5% margin of error in just 0.5 seconds.

Its wide temperature range allows application on auto maintenance, cooking, home repair, and barbecuing, among other household tasks. T

he Super IR5D has a built-in laser that delivers instant results displayed in the form of Max/Min/Average/Diff values on the LCD screen.

The buzzer alarm beeps immediately it attains the high/low temperature set by the user. The thermometer is powered by a 15mAh battery that lasts 6-12 months. And, with its eight-second auto-off feature, the battery is likely to last longer.

The package comes with a free meat thermometer that has a food-grade stainless steel construction. It measures the inner temperature of food within a range of -50-300 degree Celsius.

Pros: Cons:
  • Very accurate
  • Allows measurement of objects at a long distance
  • Low-priced
  • Comes with a free a meat thermometer
  • Loses accuracy when used within longer distances

Dual Temperature Infrared/Thermocouple Thermometer

Infrared/Thermocouple Thermometer: photo

The thermometer is designed for culinary applications and has a dual function unit that allows users to determine the internal temperature of meat and obtain surface temperatures using the built-in infrared feature.

As such, users can view the temperature of the surfaces before searing the meat or putting the pizza on a stone.

It has a temperature range of -67-482 degrees Fahrenheit. The margin of error is pretty small, i.e., +/-2 for 14 degrees Fahrenheit and +/-1% for 149 degrees Fahrenheit.

This thermometer is fitted with three LED lights that signal when the food is cold, hot, or has a medium temperature.

Pros: Cons:
  • Measures surface and the internal temperature of food
  • Has auto-off feature
  • Its step-down ending creates small punctures
  • Its construction is splashproof
  • Is not user-friendly
  • Does not have a backlit display screen
  • Takes long to display temperature

Comparative Chart of Infrared Thermometers


DS Ratio

Temperature Range




ANKOVO Infrared Thermometer min: photo

Nil (contact thermometer)

Up to 37.5



Equinox Non-Contact Thermometer min: photo

3-5 cm

  1. 90 C (body temperature)
  2. 0-600 C (Surface temperature)

Medical, Surfaces, Ambient room temperature


Etekcity Infrared Thermometer min: photo


-50-5500 C

Household use


Infrared Thermometer SURPEER min: photo


-50-5500 C

Household use (cooking and auto applications)

Taylor Precision Products

Infrared/Thermocouple Thermometer min: photo


-67-4820 F

Culinary use


How safe is an Infrared Thermometer?
The device only measures infrared radiation and does not release it. However, thermometers that have built-in lasers may be harmful when used on delicate areas like the eyes. As such, experts advise using non-laser models for medical applications for safety. 

How Do I reset an Infrared Thermometer?
When you have installed the battery, initiate the trigger system to turn the device on or off. Most wireless thermometers have an automatic shut-off feature that turns the unit off after some time (usually 7-15 seconds).

How Do I Calibrate an Infrared Thermometer?
The thermometers can be calibrated using an infrared comparator cup. Experts advise calibrating one temperature more for enhanced accuracy. If you can't access an infrared comparator cup, you can use an ice bath as it has a temperature of 0.0 degrees Celsius.

How Accurate is an Infrared Thermometer?
Accuracy depends on the model and the brand of the IR thermometer, as well as its application. Most manufacturers provide a range within which the accuracy lies, but they can only be met if the item has a known emissivity of 0.95. That's why it is essential to buy a thermometer that allows emissivity adjustment for accuracy.

How Do I use Infrared Thermometer on a Baby?
You can measure the temperature of a baby by:

  • Placing the thermometer on the rectal opening (it is the most accurate as thermometer displays the slightest change in the kid's temperature)
  • Measuring the temperature from the eardrum; use tympanic thermometers and hold it in the right position for accurate reading. Standard digital thermometers do not apply in this case
  • Placing the device in the armpit; this method is ideal for kids older than three months
  • Placing it on the forehead

Can infrared thermometer measure air temperature?
No, because air does not emit radiation energy and its emissivity is too low to be detected. However, users can determine its temperature by pointing the thermometer at an item that has the same temperature as the air.

Pros and Cons of Infrared Thermometers


  • Allows measurement of temperatures of hot surfaces from a distance
  • Are versatile as they can measure the temperature of moving parts, foods, and in manufacturing applications
  • Can detect room temperature, soil temperature, that of pipes and windows
  • The device can be mounted a short distance from the hot object for operation for extended periods
  • Users can determine the temperature of an object if its emissivity is known
  • Can be used to diagnose problems in electrical and mechanical appliances by measuring the temperature on heating points


  • Does not measure the temperature of liquids and gases
  • Accuracy can be affected by dust and high humidity
  • IR thermometers only measure the surface temperature and not the internal temperature
  • Users may obtain inaccurate readings caused by reflection of radiation from hot objects
  • Rapid changes in temperature can affect IR thermometers

Tips & Life Hacks

To get the most accurate readings from the infrared thermometer ensure that:

  • The item covers the whole field of view of the thermometer
  • Avoid pointing the device at shining surfaces. You can add an electrical insulating tape on the metal surface for more accurate results
  • Adopt a perpendicular position with the target surface or item when using the device


Infrared radiation technology in thermometers has certainly made it easy to obtain temperatures of items we could never imagine in the past. Thermometers are now not only limited to medical purposes, but users can determine the hotspot of an oven using the Dual Temperature Infrared/Thermocouple Thermometer or that of auto parts with the Etekcity Lasergrip 1080 Non-Contact Digital Laser Infrared Thermometer Temperature Gun. You just need to purchase a suitable thermometer for the right application.