Re: gEDA-user: sparkfun 4 layer boards

[John Griessen <john@xxxxxxxxxxxxxx>]

Eric Brombaugh wrote:
> Dave McGuire wrote:

>>    I'd be shocked and amazed if they could detect thermal IR.
> 
> Agree - there's a big difference between the short-wave IR that's used 
> by common IR remote controls (which is easily seen on most any webcam) 
> and the long-wave IR used in thermal imaging.

Ohh...  we can control the situation to get near enough IR.  We're looking for shorts
anyway, not normal operating temps of + 1 degree...   Seeing just the really hot spots
-- meaning  120 deg F is plenty good, and the amount of near IR in that temperature surface is
enough to see with a CCD I bet.  Thermally emitted IR is a continuous curve or frequencies for a given temperature.
Low temps just emit less near IR, but always some.

So, I still bet CCD cameras could be very useful even without long IR sensitivity for
a short detector, including shorted outputs and shorted traces.

One way to test shorted traces without just burning through them would be to power with a current source
to generate heat, then look with hacked CCD camera.

One source of IR clear/ visibly opaque material is old corning Ceran glass stove tops.  They are very dark to visible light.

There is a kind of plastic sheet -visible/+nearIR filter also, but it's not a garden variety so likely expensive.

John Griessen

-- 
Ecosensory   Austin TX


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