Oh wow a simple toaster was enough to do that? I've taken a photo of a toaster and nothing happened.
Have a look at the
Flickr page and the description, plus the associated video.
I also points at a friend's engine turbo which was on the 200 degrees and didn't get any burn on the sensor. Also points at a gas stove which was over 250degrees, with no sign of damage.
Is there a temperature at which we should avoid pointing the thermapp at? I have the regular thermapp and thermapp TH.
The Therm-App technical data doesn't give any particular clues other than it's supposed to be
calibrated from 5-90°C; given that the sensor is supposed to be sun-safe then we can infer that the upper limit is several thousand kelvin (viewed from a suitable distance), but it's not guaranteed to give an accurate temperature reading.
The issue with the toaster was that it was very close; the sheer radiant heat was enough to physically heat the sensor, probably the ROIC as well, and it takes time for that heat to dissipate. It would be quicker if the sensor was mounted on a thermally stabilised platform like a Peltier system, but the power consumption would then be way over what would be acceptable for a phone. Pointing the camera at the toaster from further away and/or for a shorter time would have made an enormous difference. The amount of energy received is subject to the inverse square law, so doubling the distance quarters the heat load, but the sensed temperature would (should) remain the same. Hence my earlier comment about viewing the sun from a suitable distance.
Also why does your pictures show all of the app buttons and not just the thermal? Also your app looks very different to mine.
The images were posted on Flickr in 2014. The Therm-App UI has been through several revisions since then.