The Best IR Thermometer for 2021: Top Reviews & Guideline

The best IR thermometer calculates the temperature based on the amount of thermal radiation emitted by the measured object. They come in a variety of styles and sizes to meet a range of needs.

IR Infrared Thermometers are used by HVACR technicians, electricians, plumbers, building inspectors, manufacturing technicians, food processing inspectors, and homeowners. Common styles are gun-style IR thermometers, food-grade IR thermometers, and visual IR thermometers. Some models include temperature probe options for contact readings.

Best IR Thermometer Applications

Detecting hot spots in mechanical equipment, electrical circuit boxes, or outlets

Monitoring materials during heating and cooling processes

Research and development

Manufacturing quality control situations

Heat Loss Energy Audits

Measuring and logging food temperatures during cooking, serving, cooling, storage, transport, and reheating

Types of Infrared Thermometers

This video demonstrates the Extech 42511 Dual Laser Infrared Thermometer. It is just one of IR gun-style thermometers available. It features adjustable emissivity, audible alarm alerts, and more.

Food Grade IR Thermometers: Food Grade IR thermometers meet GMPs and HACCP requirements set by the FDA. They are used to ensure food safety, quality, and consistency by measuring and logging food temperatures during cooking, serving, cooling, storage, transport, and reheating.

Visual IR Thermometer: Visual IR Thermometers combine the convenience of a spot thermometer with the visual advantage of a thermal imager, creating a brand new tool category. They feature a troubleshooting camera with an infrared heat map that instantly identifies the exact location of the problem.

This video demonstrates the Fluke VT02 Visual IR Thermometer. It works by taking a visual image and applying a thermal heat map.

Choosing an Best IR Thermometer

Field of View (FOV) / Distance-to-Spot ratio (D:S). The field of view is essential to obtain an accurate temperature reading.  The target being measured should completely fill the field of view of the instrument.

A measurement error can occur if the background temperature is different from the object’s temperature.  This is why the distance to spot ratio is important when selecting an IR thermometer.

The distance-to-spot ratio (D:S) is the ratio of the distance to the object and the diameter of the temperature measurement area. The larger the ratio number is the better the instrument’s resolution, and the smaller the spot size that can be measured.

For instance, an IR thermometer with a 50:1 ratio will accurately measure the temperatures of smaller objects than an IR thermometer with a 10:1 ratio. If the D:S ratio is 10:1, the measurement of an object 10 inches (25.4 cm) away will average the temperature over a 1 inch (25 mm) diameter area.

A ratio of 50:1 will measure a 1 inch (25mm) diameter area that is 50 inches (127 cm) away. When selecting an IR thermometer consider the distance from the target to be measured and select a model with an appropriate distance-to-spot ratio.

Temperature Range

When selecting an IR thermometer, a wide temperature range is important. Since these thermometers are used in applications with very high and very low temperatures, the thermometer must be able to accurately measure these temperatures. This is especially important in food and beverage applications as well as applications that measure frozen materials.

Adjustable Emissivity: Emissivity is the ratio of energy radiated (invisible heat) by a material to the energy radiated by a black body at the same temperature. It is the only type of heat that can be used to measure the surface temperature of an object. Reflected and transmitted heat cannot be used.

However, IR thermometers recognize reflected, transmitted, and emitted heat, so the device must be adjusted to read-only emitted heat in order to provide a surface temperature.

A black body will have an emissivity of 1 and objects will have a value between 0 and 1. The emissivity of common objects is generally available in the IR thermometer instruction manual or on the internet.

Better IR thermometers have adjustable emissivity settings. Others have a pre-set emissivity of 0.95. For better results with these 0.95 fixed models use emissivity tape, available from equipment, on the surface to be measured.

To learn more about emissivity tape, see the section “What is Non-Reflective Tape for IR Thermometers (Emissivity Tape)?” below.

Data Capture:  When selecting an IR thermometer, look at the data logging features. Many store dozens of reads and feature connectivity options that allow for easy recording and analysis. This makes the user’s job easier and more efficient.

Additional Features of Best IR Thermometer to Consider

Fast Response Time

A dual laser targeting system helps approximate the target spot size

Large backlit LCD

Automatic temperature “hold” when the trigger is released

Display and backlight turn off after 15 seconds of inactivity

Auto-power off after 60 seconds of inactivity °F and °C selectable


Thermocouple port

Min/Max. modes

High and Low-temperature alarm

Differential and Average Temperature functions

Low battery indication

Includes Certificate of Traceable Calibration

ROHS, CE, and WEEE approved

Meets GMPs and HACCP requirements set by the FDA.

HACCP check lights for instant recognition of safe/unsafe temperatures

Countdown timer to monitor cooking, cooling, and HACCP exposure times

Velcro pipe probe for superheat, sub-cooling, or other contact and ambient measurements

Easily trend and analyze data with the included software

See your data right away without leaving the site, using the USB and your laptop for “Hands-free” data logging

Built-in fold-out probe for measuring internal food temperatures

Quick hot and cold spot finders –  available in visual, infrared, and blended views

Almost invisible penetration hole due to special food probe  

Buying Guide

Simply Point and Press

These amazing thermometers measure the temperature of an object without ever touching it. The temperature is instantly shown on a digital scale to a fraction of a degree in either Celsius or Fahrenheit.

IR Thermometers determine temperature by measuring the black body radiation given off by substances above temperature. Black body radiation is a function of both the temperature and the emissivity of an object.

The instrument is set for an emissivity of 0.95 which is common for objects other than metals or shiny surfaces. To measure the temperature of metal requires aiming at a piece of black tape placed on the object. Because temperature is decided quickly, without direct contact, these thermometers were wont to pre-screen travelers to prevent the spread of the SARS Virus!

Fun to Use!

Easily measure the temperature of:

Solids – very difficult with a daily laboratory thermometer!

Containers of liquids

Food & coffee in restaurants

The surface temperature of living animals

Sealed terrariums

Record temperature without changing it – No need for a heat capacity of thermometer calculation.


Best IR Thermometers are extremely safe! They avoid the hazardous glass, mercury, or alcohol found in regular laboratory thermometers.

  Model #IR-100
  Range-22 to + 110oC
  Response Time1 second
  Emissivity0.95 fixed
  Battery Life40 hours continuous use
  BatteryCR2032 (included)
  Dimensions71 x 47 x 17 mm
  Mass32 grams including battery

Frequently Asked Questions (FAQs) About Best IR Thermometer

Q. What is the best IR thermometer?

Industrial infrared thermometers:

Answer: BTMeter BT-1500. Best infrared thermometer for high temperatures. Time to reading: 0.25 sec | Accurate Range: -50˚C to 1500˚C (-56˚F to 2,738˚F) | Accuracy margin: +/- 2% | Distance spot ratio: 30:1

Etekcity Lasergrip 774. Simple, cheap but effective pistol-grip ABS IR thermometer.

Q. Can you take your temperature with an IR thermometer?

Answer: It is not advisable to use a general-purpose infrared thermometer to live human forehead temperature. That’s because objects tend to emit infrared more efficiently. To measure human temperature, you ought to only use infrared thermometers that are FDA-approved.

Q. How does IR thermometer work?

Answer: IR light works like visible light—it is often focused, reflected, or absorbed. A handheld best IR thermometer typically uses a lens to focus light from one object onto a detector, called a thermopile. The thermopile absorbs the IR radiation and turns it into heat. The more IR energy, the warmer the thermopile gets.

Q. Can IR thermometers read through glass?

Answer: Infrared thermometers: don’t “see-through” glass, liquids, or other transparent surfaces – albeit light (like a laser) passes through them (i.e. if you point an IR gun at a window, you’ll be measuring the temperature of the windowpane, not the outside temp).

Final Thoughts on Best IR Thermometer

Our rugged infrared thermometers measure temperature for a variety of industries – from power utility to petrochemical. One handheld device can display temperatures for mechanical equipment, heating and ventilation systems, or electrical systems. We stock easy-to-use models with high accuracy in compact sizes.

These instruments use laser light technology to deliver safe, non-contact readings of the warmth given off by an object. You can order high-temperature best IR thermometers that provide the minimum, maximum, or average temperature.

Whether you need a standard thermometer for HVAC or an instrument for production applications, our outstanding products from Fluke will keep you on target.

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