True, now a decent unit with a good resolution is around $7 - 8 thousand which includes a 1 week class, because as GregDi so aptly pointed out, if you can't read it, the image is worthless.The prices have also dropped dramatically for these units.
i have some old digital cameras laying around. I would love to try this. Got Link?There is at least one website that tells you how to remove the IR filter from almost any cheap digital camera and so the camera goes back to being sensitive to IR rather than the visible spectrum.
It'll show hot spots but not the temps of them.
To do the temps you have to aim the camera at objects with known temperatures and see what it looks like it.
There is also the object emissivity to consider.
With experience it might work as well as some of the units mentioned.
Who gets to pay for that learning process on a homegrown DIY jury-rig? :whistlingWith experience it might work as well as some of the units mentioned.