Infrared thermometer gun

[philips]

So I am thinking about buying one those thermometer guns with a laser pointer for measuring card temps, and probably annoying my cat.
Something like :

Any advice on what to search for, what to avoid...or a good brand maybe?

[Aggrophobia]

don't use it for metallic surfaces

phps you search better for a contact thermometer http://www.onlinecomponents.com/fluke-cnx-t3000.html?p=44434473

[Photon939]

I bought this one: http://dx.com/p/1-2-lcd-non-contact-digital-infrared-thermometer-with-laser-sight-50-c-380-c-35754

It's cheap and the readings seem pretty accurate. I can point it on the back of the PCB on my GPUs and it will report a temperature within a degree or two of what the card's internal temp sensor reads.

Has a good temperature range for other stuff as well. Backlit screen and laser pointer, I recommend it

If you've never bought from DX before beware that their stuff can take a while to ship sometimes

[philips]

don't use it for metallic surfaces

OK...why is that?

It's cheap and the readings seem pretty accurate. I can point it on the back of the PCB on my GPUs and it will report a temperature within a degree or two of what the card's internal temp sensor reads.

Yup, that's my intention. thinking about checking VRM temps (no software for that in Linux).

[Aggrophobia]

http://www.thermoworks.com/blog/2012/03/infrared-thermometry/

i hope this will help

[philips]

http://www.thermoworks.com/blog/2012/03/infrared-thermometry/
i hope this will help

It did
 
Well illustrated here:

If you were to point an infrared thermometer with fixed emissivity at the side of a stainless steel pot filled with boiling water, for example, you might get a reading closer to 100°F (38°C) than 212°F (100°C). That’s because the shiny metal is better at reflecting the ambient radiation of the room than it is at emitting its own infrared radiation.

So this is one thing I will look for:

Other infrared thermometers come with adjustable emissivity settings, so you can more accurately prepare your thermometer for the type of surface being measured, particularly when measuring non-organic surfaces.

Great, thanks guys.

[BBQKorv]

Yeah, just get a proper one and your good to go. I can recommend Testo 830 series with an additional surface probe for extreme accuracy if needed.

Avoid all the really cheap ones, they don't have a feature to adjust the emissivity settings (thats like measuring distance by counting steps while running...).

[philips]

Yeah, just get a proper one and your good to go. I can recommend Testo 830 series with an additional surface probe for extreme accuracy if needed.

Avoid all the really cheap ones, they don't have a feature to adjust the emissivity settings (thats like measuring distance by counting steps while running...).

Noted, thanks.

[ReCat]

don't use it for metallic surfaces

OK...why is that?

Ok. I'll explain for you in the best possible way I can. :3 Starting off assuming there's no prior knowledge of physics, just to be clear.

All matter emits radiation when it has thermal energy (heat) in it.

For example. The sun, being super freaking hot, emits all sorts of radiation, and by radiation, I mean electromagnetic radiation. This is what light, radio waves, microwaves, xrays and such are made out of.

But anyways, within what the sun emits, it also emits electromagnetic radiation that is within a range that we call the "visible spectrum", which is basically the types of electromagnetic radiation that what we call "light", ie, what our eyes can see.

The sun shines because of this principle. This is the same principle that makes an iron rod glow red when it is extremely hot.

So, due to this principle, we (our bodies), animals and electronics ALSO glow. Because they are warm. Except they don't glow in the visible spectrum. They glow in a different kind of light, a type that we can't see with our eyes. This light is called infrared light. It's like red light, except it's more red than red light, in a sense.  So much that it's not visible to our eyes anymore.

Your infrared temperature meter works by exploiting this principle. It measures how much infrared light it is picking up from wherever it's pointed at, and does math within it's internal electronics, and gives you a temperature.

But anyways. Now that you understand this concept, you can understand why not to point it at metallic surfaces.

In the same way that cellphones don't work well in elevators, due to the metal walls, or in the same way that you can see absolutely nothing through a sheet of tin foil, no matter how thin it is, the infrared temperature gun will not be able to get a correct temperature reading if you point it at metal, because the metal will be reflecting infrared light from somewhere else. Such as your hand.

I know this was an overkill explanation, but perhaps you or someone else will enjoy not only knowing why, but understanding why. :3

[philips]

.....................................................

...but...but...you still haven't explained why the dinosaurs died  

[ReCat]

Meteor fell and killed everyone

[philips]

Meteor fell and killed everyone

Shit! 

[ReCat]

I was hoping you'd appreciate my long and detailed explanation of why it won't work on metal, a bit more though. XD

[philips]

I was hoping you'd appreciate my long and detailed explanation of why it won't work on metal, a bit more though. XD

I do appreciate the effort, really, no joke about it.

I only asked (why is that?) though because the sentence "don't use it for metallic surfaces" sounded (for me at least) a bit ominous, as in "whatever you do, don't do that", as opposed to something like "it doesn't work on (reflective) metallic surfaces", which is pretty much self explanatory.

Respect.

[ReCat]

Oh! Derp. Great, I answered when it wasn't even necessary. Ah well. x3

[philips]

But it was a great answer anyway, you should consider a career in teaching

[ReCat]

But it was a great answer anyway, you should consider a career in teaching

Thanks I suppose, But as ironic as it may seem, I'm in fact nowhere near smart enough to teach.

[kevinm]

I use one all the time on my cards (sapphires) and mobos.
The hottest spots on the cards are 3/4 ways to the back on the lateral centreline. This happens to be on a spot of dense metallic contacts. I dont think the EMR emmitted by my hand at say 37 deg C is gonna interfere with the reading of say 76 deg C from the card, especially at about 3 feet distance.
I have used them extensively in industry to detect hot or cold spots on the innerside of metallic surfaces (pressure vessels, heat exchangers, furnaces, tanks etc) to detect spots of internal errosion or where refractory & insulation linings may have deteriorated.

mine is "UNI-T" and is decent enough for home use, cost about 40 bucks.
No need to go for top brands like "Fluke"

If you do not manage all your rigs from one desktop, these are a very handy tool to have.

cheers,
kev

[Bicknellski]

But it was a great answer anyway, you should consider a career in teaching

Thanks I suppose, But as ironic as it may seem, I'm in fact nowhere near smart enough to teach.

As a teacher I can tell you... point blank it isn't a measure of intelligence that makes a great teacher. It is having the commitment to find any avenue possible to disseminate information only insofar that the students takes control of the learning and is motivated to move forward. The best teachers know that it is not about their knowledge but how to exemplify, illustrate and allow the student the freedom of choice to learn more.

Oh and this is the one I bought for BKKCoins and the Klondike project. Should be picking it up soon!



http://www.aliexpress.com/snapshot/231230115.html

US $24.95 / piece

[toni_iommi]

Consider painting a small target area flat black. Shoot temps on the same flat black spot every time and you are good to go even on metal.  Just a thought.

You will have consistency to see deltaT. Man.