Thermal Imaging Cameras

How Thermal Imaging Cameras Operate

A thermal imaging camera may look like a normal video camcorder, but it operates somewhat differently.

About thermal imaging cameras

Rather than using a CMOS or CCD detector which records different levels of a range of visible light colours, a thermal imaging camera uses a microbolometer array to accurately measure levels of infrared radiation across a scene.

Glass is opaque to most wavelengths of infrared light, so in place of conventional glass lenses, exotic materials such as germanium must be used.

Different cameras use different parts of the infrared spectrum and are useful for different applications, such as high-temperature industrial gas environments. Some require complex on-board cooling systems.

Algorithms in the camera incorporate a number of factors controlled by the operator – such as the surface emissivity of the object in view, and the humidity of the ambient air – to interpret the temperature of the object in question. As humans can’t see infrared, the camera logic turns temperature variations across the sensor into false-colour images where a range of colours represents a range of temperatures.

Thermographic cameras are not point-and-shoot. So many factors affect the output – including the nature of the subject, the ambient surroundings, the range of temperatures detected and even the choice of colour palette – that they are only useful in the hands of specialist, highly trained and experienced thermographers.

Why use thermal imaging?

Thermal cameras are an invaluable tool in undertaking temperature measurement activities for building, electrical, mechanical, aerial and even equine applications. By identifying minute temperature differences, trained thermographers can utilise both qualitative and quantitative surveying techniques to identify areas of heat loss in buildings, overloaded connections in distribution boards and defective diodes within photovoltaic installations.

Looking for training?

The iRed Academy is the UK’s leading provider of accredited thermal imaging training courses.

To learn more, please visit

Need advice?

iRed is not bound to a particular manufacturer: our philosophy is to use the most appropriate tool for the job. Consequently we use, and can advise on, a wide range of different cameras and technologies depending on the application in question.

Got a question in mind? Get in touch.


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Thermal Imaging Surveys

Commercial thermal imaging surveys in accordance with the criteria set out in BRE 176 and BS EN ISO 13187.

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