Measuring surface temperature of MBP, emissivity question

Discussion in 'MacBook Pro' started by swingerofbirch, Aug 4, 2012.

  1. swingerofbirch macrumors 68030

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    #1
    I have a 13-inch MBP from 2010, and I have wanted for some time out of curiosity to measure the surface temperature of it. I've sent it in for two repairs to Apple, and each time while they have fixed other problems it's had, I've asked them to look at the heat issue, but they never comment on it.

    I can tell from using iStat Pro that the internal temperature of the CPU gets as high as 218 F, which I guess is in the normal operating range, although it's awfully strange to think that the processor is hotter than boiling temperature.

    Apple ran through a "safety script" (have you seen sparks, smelled smoke, etc) with me and even after I told them I had burned my leg on it before (which I actually had), they didn't seem to care.

    I know that both the computer and power adapter are abnormally hot. Apple asked me if I felt I was in danger and I said no, but it's not the type of thing you would let a child use, because you would burn yourself if you held it for more than half a minute or so.

    I actually keep the computer on a block of granite, which I have found is the best way to absorb the heat, but when I take it off, the granite is even hot to the touch.

    Anyhow, I'm in a stalemate with Apple, and I would like to test the heat myself. I've read about IR thermometers but it mentions that they need to be calibrated to the surface you're using (something about emissivity). Does anyone know about this type of technology and what you would calibrate it to for the surface of a MacBook Pro? Are there other, better ways of measuring the temperature than IR thermometers?

    Thanks very much!
     
  2. T5BRICK macrumors 604

    T5BRICK

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    #2
    I really don't think you need your measurement to be THAT accurate.

    Also, keep in mind Apple doesn't sell their MacBooks as "laptops" due to the heat issue.
     
  3. swingerofbirch thread starter macrumors 68030

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    #3
    I don't think it has to be that accurate, either, but it seems surprisingly complicated to take the temperature of a surface. And from what I've read, the reflectivity of the material can make a big difference when using an IR thermometer. I'd be happy if I could get something +/- 5 F, but I just don't know very much about this sort of thing. I would guess this is the domain of some form of science, maybe physics?

    I know about the laptop vs notebook issue as well, but mine is running like a furnace even on a desk.
     
  4. T5BRICK macrumors 604

    T5BRICK

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    #4
    The finish of the aluminum is very dull, I don't think it has a lot of reflectivity if that is the issue. We use IR thermometers where I work to measure PCBs after they are run through an oven. I know we calibrate them yearly, but we don't have to calibrate them between uses for different types of material.
     
  5. swingerofbirch thread starter macrumors 68030

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    #5
    Good to know, thanks!
     
  6. mateo124 macrumors regular

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    #6
    I don't think its normal to get that hot. If the power supply gets that hot it could very well start to melt. I would try to contact Apple support again and see about a replacement. My MBP 13" reaches at max 70 degrees celcius even under a heavy load. You could always lie to them and say it turns off or starts freezing when it gets hot
     
  7. zwodubber macrumors 6502a

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    #7
    Anywhere from .09 to .30 depending on the condition of the aluminum. It will change if there are areas of heavier wear which will create a more reflective surface.

    My 13" MBP under a decent load (pic shows the heat vent) which was a major source of debate a while back. Temps ar in fahrenheit btw.

    If you need any more pics let me know :)

    [​IMG]

    ----------

    Every type of surface requires a change in emissivity settings. Yearly calibration and proper use of the camera are 2 different things :eek:

    For example, etched copper has an emissivity of .09 while cuprous oxide copper is about .83
     
  8. zwodubber macrumors 6502a

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    #8
    Here's a shot using incorrect emissivity, span and level settings. You could make it appear the mac is about to spontaneously combust (note the lower temperatures as well :))

    [​IMG]
     
  9. swingerofbirch thread starter macrumors 68030

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    #9
    WOW!

    How did you do that? And how can I? Hehe.

    I don't think I'll be able to afford whatever it is you are using, but if you buy an IR thermometer that has variable emissivity will the thermometer be able to detect the proper emissivity or do you need to program it with the right one? Like you said between .09 and .30, and how do you know between those numbers which it is?

    Also, you said there was debate about this recently, do you mean debate you had with Apple, and if so how did it go? Did they consider your temps acceptable?

    Thanks very much!

    BTW, these are the types of products I was looking at buying:

    http://www.amazon.com/s/ref=sr_nr_s...ywords=temperature+gun&ie=UTF8&qid=1344140597
     
  10. T5BRICK macrumors 604

    T5BRICK

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    #10
    I'm not sure we're talking about using the same tool here. I don't use an IR camera like you used to make that image(although I wish we had one, it would make troubleshooting boards with hidden shorts much easier). I'm talking about your basic hand held non-contact IR thermometer, or I guess they're called Pyrometers.

    If these need to be calibrated for emissivity, I'll make sure to point it out to the manufacturing engineers on Monday. :p
     
  11. swingerofbirch thread starter macrumors 68030

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    #11
    When I was reading reviews for these on Amazon, I read that some of the models seemed to have adjustable emissivity and some didn't, and I guess it's a feature of the higher end models. I really don't even know what emissivity is. All I know on this subject is from Amazon reviews, which is why I said at the beginning of this thread: taking a temperature seems surprisingly complicated.

    Here's an example of one that has variable emissivity:
    http://www.amazon.com/KINTREX-IRT04...33&sr=1-3&keywords=temperature+gun+emissivity

    @zwodubber, if you're able to provide some more info on this, pretend I'm stupid, it'll save us both a lot of time!
     
  12. zwodubber macrumors 6502a

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    #12
    My apologies, I did not know you were using a non contact IR thermometer, I thought you meant a thermal imager. In your case get a basic model unit(but I suggest Fluke or another reputable brand minus all the bells and whistles) and you will be fine.

    T5Brick, the non contacts do not need emissivity calibration, again I thought you had thermal imager, my bad.

    Imagers require a certain amount of skill and training to become fluent in emissivity, RTC and producing quality images in critical applications which is why I jumped on you guys lol.

    Anyway I use a Fluke non contact and a Fluke IR camera. PM me with any additional questions and maybe I can help you get this resolved.


    [​IMG]
     
  13. Puevlo macrumors 6502a

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    #13
    This whole thing sounds a little nuts to me. Their technicians know what they're doing. If they say it's not over heating then it's likely not over heating. They're not trying to scam you.
     
  14. swingerofbirch thread starter macrumors 68030

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    #14
    Well, the last time I sent it in for repair they quoted me $800 to fix the computer because they claimed water damage. They even sent me a picture of a corroded logic board. I called up and told them it was impossible. They didn't believe me. I persisted. The next day someone called me and told me there had been a mix up and they sent me the information for a different customer's computer and that my logic board was in fact not damaged. Not even an apology offered.

    The repair took 3 days longer than they quoted me, and they kept stopping the repair due to really flaky reasons, like a third party hard drive. They finally said they would make an exception even though I shouldn't have put in a third party hard drive (I pointed out that they include instructions on their web-site on how to install a third party hard drive). They still told me they were being very generous in overlooking that even though the hard drive wasn't the issue.

    Anyhow, they ultimately did repair it, but I don't think they tested it for heat under load. I'm not sure if they test for heat at all when you send it in. I'm not sure if they were trying to scam me or not (although I'm sure they would have happily taken $800 from me), but they were definitely not concerned with helping me.

    I have to say Apple's support has in the past been much better than it was on these two most recent repairs.
     
  15. zwodubber macrumors 6502a

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    #15
    The debate was on the forum about overheating. As far as knowing emissivity levels it comes with training and hands on use to get a feel for each surface (I also have a handy cheat sheet just in case). My non contact thermometer does not have emissivity settings, only the ir camera. For what you are doing I would just go with a basic thermometer and skip any with emissivity features to save any headaches :)
     

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