Thermal Imaging and Its Applications

Don’t you know what a thermal camera is or what it’s good for? Here’s what you need to know:

For god’s sake! I can’t believe how many people don’t know what a thermal camera is good for! And believe me I’ve seen a few already. So I had to explain it here.

A thermal camera is like a normal camera, but instead of visible light, the sensor just picks up the infrared generated by a warm surface. Any material radiated infrared, with a strength proportional to how warm it is. So if some area has lots of detail but all of it is at the same temperature, then it looks blank to the thermal camera. On the other hand what looks completely flat to human eye, could have many details due to thermal difference on the surface, like water leakage or hot water pipes and such.

You cannot see behind a wall, through clothing or glass. Because infrared is a low frequency light and has a hard time passing through objects in general. The light you are looking for is X-Ray if you like to see through things. So the thermal infrared is what radiated from the surface, but yet it shows very valuable information.

Different material have different infrared emissivity that usually should be accounted for for more accurate temperature measurement. Also material reflectivity effects the temperature reading. The more reflective a material is, the less accurate the thermal reading becomes. Because rather than radiating its own temperature, it reflects the heat from surrounding objects.

Sensor pixels are each a infrared thermal sensor. The lens in front of the camera is a special glass filter that can pass infrared.

Also when you use such cameras, you hear a constant clicking every few seconds and thermal image freezes for a fraction of the second. That is a shutter used in all these cameras during the period that the camera re-calibrates its sensor. It needs to re-calibrate the sensor as the temperature sensing starts to drift while the camera temperature or conditions constantly change.

I listed a number of applications for it in my video which are:

  • Detecting broken and heating components in a circuit
  • Understanding the thermal performance of a circuit or a product in general
  • Detecting over loaded circuit and wiring at home
  • Finding spots of water leakage inside the walls which are at different temperature than dry wall
  • Finding locations where energy is lost around a house, or where the cold air is getting inside
  • Seeing in the complete dark, of course environment’s thermal signatures only
  • Finding wildlife at night
  • Finding cold spots which are likely ghosts 🙂
  • Any many more

A Quick Review of SEEK Compact Thermal Camera

My SEEK Compact Thermal camera has been pretty useful and I have been using it many times at work to detect broken components on PCBAs. It may sound a bit expensive for its size. But I assume thermal imaging is a special technology and is not as widely used as regular cameras, which adds to the cost. Yet SEEK is one of the cheapest thermal cameras out there.

I compared SEEK Compact and FLIR One and although the FLIR leaves an impression of better image due to its image overlay technology, the thermal image is not different from SEEK, and SEEK has way more functionality built in its software and they are planning to release an even more elaborate app for the phones.

Of course with anything cheap, comes some negative points compared to high-end cameras. There are really two things that come to mind:

  • Image resolution is not great, and yet thermal resolution is higher than its peer, FLIR One.
  • Thermal accuracy is low, around 0.5 degrees Celsius, which results in lower image quality compared to high-end cameras

At the end of the day the most important differentiating factor in the price of these cameras is the sensor resolution. But never the less, I like my SEEK and it has been pretty useful for me for professional work, and also pretty fun in dark nights in a jungle or beside a lake.

I needed to get a thermal camera for my work and videos and I contacted SEEK Thermal. So I like to thank them for providing the camera to me and one of my patrons for free. Make sure to use the promotion code if you want to get this camera.