IR Thermometer uses

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Thought a brake was hanging up. Got out, and dig the laser aimed IR thermometer out of my tool box. Go around and check the temps of the brakes, to find the one running hot.
Other use -- read a thermostat on top of the motor. Find what temp the thermostat maintains.
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Christopher A. Young
You can\'t shout down a troll.
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Stormin Mormon wrote:

ayup, they are very nice when you have a car with an uncalibrated temperature gauge. Turns out 3/4 scale on a '55 Studebaker converted to 12V with the gauges running off a 6V "Runtz" voltage dropper (probably not a configuration the factory anticipated <G>) is about 180 degrees - a little warm for the stock 160 degree thermostat, but not so bad for a '63 Avanti engine with a factory 170 degree 'stat, actually running a 180 stat because you can't get a 170 anymore.
Had I not had the IR thermometer, I might have ASSumed that I had an overheating problem when in fact it was a gauge calibration issue.
nate
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On Thu, 18 Jan 2007 17:46:27 -0500, "Stormin Mormon"

I don't have a thermal camera, but I did a 'scan' of some walls and ceilings, and found I had cold spots. I found my IR thermometer very useful.
tom @ www.MedJobSite.com
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Stormin Mormon wrote:

Yep, they're so useful I keep one in the shop and one in the kitchen.
Pete C.
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On Thu, 18 Jan 2007 17:46:27 -0500, "Stormin Mormon"

Check for leaks around the refrigerator door.
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On Thu, 18 Jan 2007 17:46:27 -0500, "Stormin Mormon"

Does it work for finding cold leaks into the house, or heat leaks out of the house? I mean, can you point it at the edges of the door or window or pipe and get a temp reading off of air that is blowing in or out, or do only solid things radiate IR?
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Point it up at the zenith of a clear, dark sky on a warm night. Brrr!
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"Stormin Mormon" cayoung61-&spamblock*-@hotmail.com> wrote:

Gases don't radiate, generally, but you might sense lower-temp wood trim. Or feel around the door with your hands on a cold day, with a large window exhaust fan running. You can find which rooms have the largest air leaks and measure airsealing progress with a $70 Kestrel 1000 wind velocity meter in another partially open window. When you open a door to a leaky room, the air velocity will decrease. As you airseal, it will increase.

Inexpensive IR thermometers ignore water vapor (so people can use them in boiler rooms full of steam), so this might also work on a warm summer day.
Nick
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Don't misunderstand. You're reading the near-absolute-zero temperature of outer space, through a thin veil of warmer air. The integrated temperature is still below zero even on a warm night. The clear night sky is a cold window.
"Ignore water vapor" is fantasy. Blackbody radiation is the same whether it's a gas, liquid, or solid radiator.
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Try it.

I understand that.

What's an "integrated temperature"? :-)

Clear skies are, but water vapor and clouds absorb IR. So do windows...

Very wrong :-)
Nick
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What the radiation thermometer reads, looking at the background of outer space, overlaid with a transparent but blackbody-radiating layer of atmosphere. This type of thermometer is performing a digital numerical integration as part of its analysis of the blackbody spectrum of the target.

No, your understanding is naive. Ceramics emit radiation like anything else. Nothing absorbs IR from the darkness of outer space, because there's no IR to absorb. A room temperature skylight window is emitting IR, not absorbing it, on a clear night.
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Actually, it's doing *both*, isn't it? I think Nick's point was that window glass isn't nearly as transparent to IR as it is to visible light. Emissions from an IR source inside the building will be mostly absorbed by the skylight, instead of passing through, no? Meanwhile, the skylight will radiate IR as well.
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I think so, for wavelengths longer than 3 microns.

Sure, but we were talking about sky vs skylights, no? A cheap IR thermometer, eg Raytek's $99 version, will ignore water vapor absorption and read a lower sky temp than an expensive one, eg a $1000 Exeltech, which will read a lower sky temp on a cloudy or humid day.
Nick
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Doug Miller writes:

Yes and no. Yes, it absorbs some incident radiation instead of directly transmitting it (depending on wavelength). But it re-radiates much of what it absorbs, which is an indirect transmission.
There is a mythical version of "glass blocks IR" that some people think makes cars hot on a sunny day. In fact it is the *transmission* of shorter IR sunlight (many 1000s deg K blackbody) via the glass into the car interior, where it is absorbed on the interior surfaces, and re-radiated at longer IR spectra (several 100s deg K blackbody) that is blocked by the glass.
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A pane of glass transmits about 90% of the terrestrial solar spectrum (which has very little power at wavelengths longer than 2.5 microns) and blocks almost all of the IR spectrum longer than 3 microns. Wien's displacement law says an 80 F (282K) black body has a spectral peak at 2897.8/282 = 10 microns... 966K (1279 F) has a 3 micron peak.

Windows transmit a lot more beam sun power than the IR they reradiate, since houses scatter and absorb incoming sun over a large interior surface and do not contain IR beam suns of their own.

Glass blocking IR makes cars hot in the sense that without glass, they would be cooler. Polycarbonate also blocks IR. Polyethylene doesn't. My sunspace with 256 ft^2 of poly film glazing seldom reaches 100 F on sunny winter days.
Nick
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Which absorbs IR...

Incorrect.
Nick
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No, like all matter, the atmosphere both emits and absorbs radiation. At night it emits more than it absorbs (thus cooling itself while keeping us warm down here, happily), so it is a net emitter, not an absorber. When you point your Raytek at the clear night sky, you are measuring that emission. If the atmosphere (net) absorbed IR, the sky would feel cryogenic like outer space, instead of just somewhat cooler than the surface, on a warm, clear night.
There is this mythology of the atmosphere (glass, etc.) being nothing but a sink for radiation. Just enough physics to get it wrong. Typical of global warming advocates.
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Richard J Kinch wrote:

Now that everyone has said how cool IR thermometers are (& they're one of the few tools I don't have)
any suggestions on mfr / models?
cheers Bob
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BobK207 writes:

My Raytek MiniTemp is dead on:
http://www.grainger.com/Grainger/wwg/itemDetailsRender.shtml?ItemId11697546
I haven't tried the Chinese clones that are 1/4 the price:
http://search.harborfreight.com/cpisearch/web/search.do?keyword=thermometer
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Richard J Kinch writes:

I should specify the "greenhouse effect" in this regard, not global warming in general.
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