Jeff Liebermann wrote in message
...
On Thu, 23 Feb 2012 02:44:16 -0000, "Arfa Daily"
wrote:

I'll give your soda
straw idea a try next time.

What worked the best was a sheet of black construction paper.
http://www.staples.com/Construction-Paper-9-x-12-Black/product_402652
The idea is the same as in a telescope. You don't want anything that
reflects light or heat. My first attempt was a brass tube and brass
washer to fit over the lens. Even painted flat black, the IR
thermometer would read the temperature of the brass tube, and not the
heat source. I substituted ordinary paper, which proved to be IR
transparent. I also stupidly left the brass washer, which again
caused local heating. Eventually, the gears operating the brain
engaged, and I realized that I needed something that was opaque to IR
and had minimal thermal mass. Black construction paper was the best I
could find. I wanted it corrugated to minimize reflections, but that
proved to be difficult to build.

Several variations were built. The one that worked best was a conical
like construction, that covered the entire lens on the IR thermometer
end, and narrowed to almost a point on the other. However, attachment
of this arrangement to the IR thermometer proved fragile, so I tried a
soda straw shape, and washer cut from a shipping box. For light
proofing, I buried the mess under a layer of black electrical tape.

I suggest you try the cone first as it's easiest to build.

I just ordered a B&D TLD100 heat leak detector, which seems to have
more resolution over its narrow -30C to 150C range, than the wide
temperature range common IR thermometer. $50.
http://www.blackanddecker.com/power-tools/TLD100.aspx

Drivel: In the past, I've ranted on building several IR flying spot
scanners using bar code readers and various pyrometers. I never
really finished. I demonstrated that it worked, but was very slow to
respond. I'm tempted to resurrect that project and build a real far
IR imager.

http://groups.google.com/group/sci.e...se_thread/thre
ad/92c3879a53a8f9f1

Some ideas:

http://spill.tanagram.com/2010/11/24...em-for-under-2
00/
Moving the camera for scanning sucks.


--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558


I used some matt black rubber tubing .about 5mm diameter as a shroud but as
I say the resolution , down to SMD dimensions , seemed to be no different
with or without the tube