Thermal Imaging Part 1: Tech & Science

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IRT Surveys LiteratureOur customers are often astounded at the seemingly simple technology used by our qualified IRT surveys thermographors to produce high quality, clear thermal, or infrared, images, which, when analysed, allows them to make informed decisions on the condition of their built asset portfolio.

This short blog post gives you brief information about the equipment and science behind infrared technology.

Thermal imaging technology

JL Baird & infrared camera
JL Baird demonstrating his infrared camera

Infrared images have been around since John Logie Baird demonstrated his camera at Box Hill in Surrey in 1929. Nearly 100 years on the physics are the same – but the cameras are infinitely better.

John’s camera was huge, needed liquid nitrogen to keep it cool and wasn’t exactly the last word in ergonomic style and practicality. Nevertheless it paved the way for where we are today.

Things went digital in the 1990’s and camera prices have fallen year after year as economies of scale are brought to bear on this emerging technology.


IRT Surveys entered the market back in 2002 when cameras were digital, uncooled, radiometric (every pixel has a recorded temp) . The price point was then around £40,000.

Now, as then, FLIR and FLUKE dominate the market with a plethora of smaller players catching up and innovating for their own USPs.

Equipment is now much smaller, portable, better performing and of course cheaper.

Thermal imaging science

If you think of the thermal cameras as normal cameras but seeing in a different wavelength, then you are spot on. They don’t beam anything out, they are merely seeing a different bit of the electromagnetic spectrum. Infrared energy is all around you and is emitting from every object you can think of.

As temperature increases, energy levels increase as molecules get all excited and start rushing about. Conversely as temperature lowers, molecules slow down. When they reach absolute zero (-273 degrees C) they stop.

IRT cameras can see energy from excited, animated molecules. The detector within the camera is sensitive to radiated energy in a certain wavelength in exactly the same way your digital camera is sensitive to visible light. Infrared is at the invisible (to the naked eye) end of the visible spectrum.

When you presnon destructive survey with infrared camera at a homes the button on a thermal camera, an area of thermometers record the temperature they see in front of them. Today’s cameras typically have around 76,800 thermometers within them.

You get what is called a thermal picture displaying an array of colours, all having a meaning in terms of energy absorption and loss. An invaluable tool to have access to when wanting to ascertain property stock condition and performance.


To understand what the thermal image tells you, please click on the link to read Thermal Imaging Part 2: Understanding colours.

To find out more about how infrared energy can help you prioritise your investments, please contact us by clicking the button below.

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