You keep posting this link, so why don;t you *read* it?
Water has a thermal IR emissivity of 0.98, about as black as anything gets.
John
You keep posting this link, so why don;t you *read* it?
Water has a thermal IR emissivity of 0.98, about as black as anything gets.
John
Nothing like a little actual data to cut through the fog...
or a little confirmation from them that depends on this stuff for their income...
[...]Or an oft-referenced expert source.
Thanks again, John. Dave (OP)
-- DaveC me@bogusdomain.net This is an invalid return address Please reply in the news group
Can you really be that dumb?
If the instrument has a one inch focus, your reflection is hardly going to affect what it reads from the face of a "shiny piece of copper". It will read the copper, and be off be the emissivity factor.
Focus is extremely important in the energy gathered by an IR instrument. EXTREMELY. Do you think the 1000' focus device looking at the space shuttle launch pad would get enough energy to give a calibrated reading if it were focused for 20 feet, despite being 1000' away from the target being measured?
Use some common sense, man.
You're an idiot, and there are NO 1.0 emissivity sources.
I think you need to re-learn what is in the realm of possibility. Try the PDF I posted a link to for starters.
It isn't the gradient across it, it is what it inhibits THROUGH it. It does have good surface quality for high emissivity, however.I merely stated that there would be losses.
Yes.It was me, and a MATTE finish (flat black paint) WILL yield a BETTER surface quality with reference to IR readings than a shiny surface will.
List all the 1.0 emissivity sources you know of.
The expert source would certainly NOT be john, and the link was from ME, asshole.
Well read it then. Water is 0.98.
John
Use a melting ice cube for zero C, and boiling distilled water (in a clean container) for 100 C.
What part of "close to" do you not understand?
robert
[...]
Are you illiterate? Why don't you look up water in the data YOU provide and see for yourself how shiny it is? Hint 0.98 isn't shiny. 0.98 is about as black as it gets.
robert
In the chart the link to which YOU keep posting here, nothing has a higher emissivity than water.
Which makes water an extremely good choice for a reading on the IR instrument.
robert
I agree that illiteracy combined with extreme stupidity is a tough burden to carry.
robert
It shows ice/water having a very high emissivity.
-- Tony Williams.
No, it wouldn't because it is four times more expensive, and it's electrical conductivity and its thermal conductivity are not the same, asswipe.
Alumininum is he right medium conduction wise, AND it is the right medium cost wise. The coating on eother would yield the same result so any point you thought you were making is moot.
You need to get off you "f*ck with dark matter" high horse, and get back to reality, boy.
The KeithTard, and the Grisetard can't f*ck with me, so what makes you think you can, dipshit?
absolutely the wrong choice though. It is unstable, and gives off vapors, throwing off surface conditions, which is what an imager MUST focus on to get reliable calibration data.
Why do you even bother reading his posts? He is wrong far more often than right and never admits an error.
Actually, the international standard is a bunch ice covered in water a stirred well. The standard clearly says that this must be done in your own coffee cup and the stirring must be done with a plastic coffee stirrer. You have to stir it up while standing in the company kitchen and then measure as soon as you are done stirring. You can't stop to answer the "What the heck are you doing?" question from the cute accountant.
Did you miss the word "almost"? 3rd line, 2nd word in my paragraph above.
With an imager, it takes a few seconds to test a surface to get a pretty good idea of its emissivity. The whiteboard marker, and the water, and the ice cube, all passed my tests for "so black that it doesn't matter", or, equivalently, "almost 1.0"
I read it; you didn't.
John
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