Date: Fri, 21 May 2004 13:46:16 -0500

Author: Stan Dodds

Subject: Re: IR Camera

Post:

True, but silicon sensors only register relatively short wave IR,
typically 0.7 - 1.0 micrometers. You will see LED emitters this way, or
objects that reflect IR. Black bodies near room temperature have strong
emission at much longer wavelengths, about 8-15 micrometers. These can
be detected with 'thermographic' cameras which use bolometers (low heat
capacity thermometers) rather than junction devices. Traditionally
these required cooling but I think some now work at room temperature.
They are probably still expensive, as in several thousand dollars. Nice
if you can afford it, but pricey for a one-off demo.

Stan

On Friday, May 21, 2004, at 12:05 PM, Chuck Britton wrote:

> Virtually ANY video camera will be sensetive to the IR.
> Aim the camera at a TV 'clicker' in action.
>
> A filter to block the visible, but pass the IR would work.
>
> SOME camera have an IR BLOCKING filter so you can't 'see thru' some
> bathing suits and other this polymer clothing.
>
>
>
> At 10:15 AM -0400 5/21/04, Gerald Zani wrote:
>> Tappers,
>>
>> I want to find an IR camera with a video output which when pointed at
>> the students in a darkened classroom will show them that their bodies
>> are black body emitters which emit in the IR.
>
> --
> I never teach my pupils; I only attempt to provide the conditions in
> which they can learn.
> - Albert Einstein
>
From cablem@wfu.edu Fri May 21 14:40:09 2004

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