Infrared thermometers

Infrared thermometers measure surface temperature by detecting infrared radiation emitted by an object. They provide quick, non-contact readings, making them ideal for high-heat or hard-to-reach areas.

Infrared Thermometer Need-to-Knows 

IR thermometers only measure surfaces

They shouldn’t be used for core food temperatures, and they cannot measure through glass or transparent packaging.

Take care with shiny surfaces

They reflect infrared energy, which can cause inaccurate readings. To get an accurate measurement, you can apply black tape or paint, wait a few minutes, then take the reading. For cooking surfaces, use a thin layer of oil. 

IR thermometers aren’t as accurate as surface probes

You should only use one if the surface is too hot to get close to, or too difficult to reach, such as hotplates or pipes.

You need to care for your IR thermometer

To get accurate readings, you must clean, store, and calibrate your instrument correctly. 

You need to understand emissivity

Each object emits at a different level, which affects your infrared thermometer reading. Some IR thermometers have adjustable emissivity for full flexibility over what you measure, while others are fixed to cover a range of standard measurements.

Popular Infrared Thermometers

Thermapen IR

Two-in-one infrared and probe thermometer for portable surface and internal measurements. Adjustable emissivity. Made in the UK with a 2-year guarantee and free traceable calibration certificate. 

RayTemp 28

Robust infrared thermometer with a wide temperature range, ideal for industrial use. Dual laser alignment and a 30:1 optical ratio — perfect for small or hard-to-reach targets. Adjustable ratio. Type K thermocouple socket included for internal/air measurements.

RayTemp 38

Ideal for measuring small surface areas at extended distances with accuracy (50:1 optical ratio). Adjustable emissivity. Type K thermocouple socket included for internal/air measurements.

Infrared Resources

How Infrared Thermometers Work

How to Clean & Store an Infrared Thermometer

Is Your Infrared Thermometer Accurate? How to Check

• Cooking surfaces — Grills, hotplates, pans and pizza stones.
• HVAC & building maintenance — Pipes, equipment and walls.
• Industrial & electricals — Machinery, motors, and electrical panels.
• Medical screening — Medically approved IR thermometers can be used for quick fever checks.
• Automotive diagnostics — Engine parts, brakes, and cooling systems.

Yes, high-quality infrared thermometers provide precise readings when used correctly. Ensure you’re measuring the right surface at the correct distance and adjusting for emissivity if needed.

For applications where precise accuracy is critical, you can use a surface probe.

Infrared thermometers are not suitable for measuring internal temperatures (like food or liquids) and may give inaccurate readings on reflective or shiny surfaces unless the emissivity setting is adjusted. They also cannot measure through transparent surfaces, such as plastic packaging or glass. For these types of surfaces, we recommend a surface probe.

Emissivity measures how well a material emits infrared energy, and the setting on your thermometer should match the material you're measuring. Most IR thermometers have a default emissivity of 0.95, since most materials are close to this value, but many allow adjustments for greater accuracy across different surfaces.

View our Emmisivity table for a guide to settings.

Yes, but only medical-grade infrared thermometers should be used for this purpose. Standard IR thermometers may not provide accurate body temperature readings.

1. Check the emissivity
   Some models let you adjust emissivity (how a surface emits heat). For most food and everyday materials, the default setting works fine, but it’s worth tweaking for specialist uses.
2. Aim at the surface, not the air
   Infrared thermometers measure surface temperature only. Point it at what you actually want to measure (like a pan, grill, or wall), not the air around it.
3. Get the right distance
   Each thermometer has a “distance-to-spot” ratio (often shown as D:S). The further away you are, the larger the area it measures. For best accuracy, move closer so you’re only measuring the target area, not the surroundings.
4. Pull the trigger or press the button
   Hold steady, aim the laser (if it has one), and take the reading.
5. Watch out for shiny surfaces
   Reflective materials like polished metal can give misleading readings. If needed, place a bit of matte tape on the surface and measure that instead.
   

This depends on the distance-to-spot (D:S) ratio of your thermometer. An 8:1 ratio means that from 8 metres away, the measurement spot is 1 metre wide, while a 50:1 ratio means the spot is just 1 metre wide even from 50 metres away. Always check your product guidelines for the best results.

The ETI Pizza IR is the best thermometer for pizza ovens. It features a laser pointer for easy targeting, reads up to 550 °C, and is accurate to ±2 °C.