EEVblog Electronics Community Forum
Products => Thermal Imaging => Topic started by: Ultrapurple on March 03, 2021, 08:59:22 am
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Either my thermal camera has discovered a whole new set of temperatures *way* below Absolute Zero :scared: or the correction algorithm has (temporarily) crashed.
(https://www.eevblog.com/forum/thermal-imaging/ok-how-dis-possible/?action=dlattach;attach=1185264;image)
Discuss! Extra points will be awarded for humour and/or definitively re-writing established laws of physics.
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Interestingly, -514.3°C + 273.15°C + 273.15°C = +32.0°C .
It really looks like a temperature scale conversion bug. Celsius and Kelvin scales only differ by the zero point, 0°C = 273.15 K.
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Smart thinking, Nominal Animal!
I do know that there was something resembling an inverted high-end bit in the algorithm (or NUC data or data or comms or...), which is why there is a fairly large, fixed-pattern swathe of 'bad data'.
That particular camera has a chequered history (though I've had it from new). With the right driver software it produces perfectly good pictures; it's only a specific set of (repeatable) circumstances when the picture gets munged like the example above.
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Cosmic rays, CIA spy radio towers.
It's not something in your control.
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Does your lady tell you, that you have very cold hands?
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Cosmic rays, CIA spy radio towers.
You mean like Operation Easy Chair (https://www.cryptomuseum.com/covert/cases/nl/ra1958.htm)?
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Not specifically, but a long time ago you posted something where a radio tower or cell phone one interfered with the imaging.
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Well remembered! If I recall correctly, I was using an early Therm-App to watch a loading coil at the base of a ham radio transmitting antenna running about a hundred watts. The Therm-App was on the end of a very long USB active extension cable and whenever the transmitter was keyed above a certain power, the Therm-App stopped. At lower powers, there was interference on the thermal image.
The electric field strengths close (50cm) to a transmitting antenna of any kind can be high (and essentially depend mainly on the transmitter power). The UK telecoms regulator is presently rolling out a requirement to evaluate field strengths and concomitant safety zones for all transmitters of 10W or more, irrespective of frequency or purpose. (I say 'all'; I'm not sure if non-fixed transmitters are included). Even radio hams, who have traditionally been exempt from just about everything, are included (https://www.ofcom.org.uk/manage-your-licence/emf), much to their consternation. The national society for radio amateurs has published guidance (https://rsgb.org/main/technical/emc/emf-exposure/).
But I digress! The upshot of looking at the loading coil with the thermal camera was to determine that it was quite lossy - getting warm - and so it was replaced with a lower-loss design.