- Ways to read hidden lettering? - 1 Update
- Do Polyswitches ever go bad? - 1 Update
| N_Cook <diverse@tcp.co.uk>: May 25 03:19PM +0100 On 25/05/2015 13:16, Rich Webb wrote: > quite useable for PCB inspection. FLIR doesn't supply them, so it's > ebay for the lenses and 3D printing for the holders. Works, though. > https://www.dropbox.com/s/cca4mu28b11ilpt/FLIR.jpg?dl=0 The trouble with thermal imaging cameras is I'm not sure they would work for this purpose. I've not found an image of something that is natively at the same temperature to its surroundings , hidden under something visibly opaque. I'm assuming some sort of search heat source would be required to highlight hidden black from white, but I've not found a pic of someone doing that . My coupled use of non contact pyro thermometer and external heat sourse seemed to just show differences in the thermal capacity of the underlying structure. to differentiate , it would probably require a very specific wavelength of IR, specific for picking up paint v plaster difference. |
| ggherold@gmail.com: May 25 06:42AM -0700 > http://www.te.com/usa-en/products/circuit-protection/overcurrent-devices/polyswitch-resettable-devices.html > We ended up not using them, but now I am curious if they show up in > damaged equipment. The trip current tends to decrease slightly with each fault. And if left in the tripped (heated) state for extended time, (like hours.) then again the trip current tends to decrease. Which is exactly how you'd like a fault detector to fail. George H. |
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