Re: Electrical Tape IS IR PROOF!

["Rolland Elliott" <rolland_elliott@xxxxxxxxxxx>]

<<<Actually many brands of electrical tape [are] transparent to infrared. I 
built an infrared meter once and used a piece of black electrical tape as 
the visible light blocking filter.
This is because of using dyes instead of carbon black to make the tape
black..... One way to check would be with an IR sensitive
ccd camera and see how dark the tape looks with light behind it.>>>

I have two kinds of black electrical tape at home
1) Generic Black Elec. Tape that says UL Listed on the inside of the core.
2) Scotch Super 33+ Vinyl Electrical Tape

I put both kinds of tape infront of a homemade IR JVC camcorder.  The 
generic Black electrical tape leaked a very little amount of IR light, but 
two layers of the tape effectively blocked out all IR light

One layer of Scotch Super 33+ tape blocked out all the IR light.

The camcorder was pointed at a 200 Watt bulb during this test.

I should note that this camcorder can easily see through a 87A, 87B, 87C and 
87 visually opaque gels. Lastly, while I'm not an electrician, I do buy 
electrical tape often, and these two types of tape are quite common in many 
hardware stores I visit. They are probably the most common type of 
electrical tape used.

As one can see your own proposed testing method proves that your above 
statement is incorrect. Maybe you should use some 87C gel over that 
lightmeter. I don't think it's doing what it's supposed to.

Other people on this list have claimed that black garbage bags leak IR 
light.  This is NOT TRUE! Some bags do and others don't, it depends on the 
manufacturer. I've yet to come across a bag that looks like it's made out of 
clear plastic when looking at it through an IR camcorder.
-Rolland
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