Gadgetory

they won today we are doing a demonstration of science experiments showing improper use of thermal cameras and how to correctly use them at least at a very top level because this is a common problem these things are so common i buy these for a couple hundred bucks for phones that they're kind of proliferating everywhere and they're normally used inappropriately in ways that actually provide temperatures that are completely useless so we're gonna show why and how that happens specifically using a case in tempered glass as an example before we get into that this content is brought to you by catalyst mints catalyst energy mints are a zero sugar zero calorie alternative to energy drinks they're packed with vitamins and provide a boost without the traditional negatives of those energy drinks learn more at the link in the description below and use coach gamers Nexus for 5% off so this is something that we discussed briefly in our EVGA vrm thermals video where we were demonstrating how does a thermal camera respond to a backplate versus a thermocouple or a direct probe but it's better demonstrated on something like this I've lately seen a few people pointing thermal cameras at cases that are closed with glass on them or acrylic or something like that and it's not a good way to get your measurement so why is that well first to kind of note very briefly how thermal cameras work the very top level is that with a lower temperature you're going to have a longer or protracted wavelength it's obviously this sees wavelengths that we can't really necessarily see there is visible spectrum thermal vision so to speak if you heat up an iron and you pull it out of a furnace and you look at it it's probably going to be red or orange or some hot color and you can tell by looking at that as a human but we can't always see the heat that something produces the components in this case I can't see with my eyes how hot they are but they produce a they radiate the heat and that's thermal radiation which we can measure with a camera like this even though this is a cheap one it's a thermal imaging device it looks at infrared for it's for what it's producing when you're seeing the red colors and the blue colors on your screen for the temperature values but how does it do that like I said the lower temperature is going to be a longer wavelength and these devices can be customized but they often show blue for a lower temperature or green and then the higher temperatures are a much more intense wavelength there the peaks are closer together and when the peaks are closer together you end up it basically means there's a hotter temperature so whatever your point into that is going to be harder to touch and the relationship between the radiation intensity and temperature is the stefan-boltzmann law which we won't get into today that's way out of scope but you can see the basics on the screen and the camera sees temperature from a few different sources so this camera here the infrared camera is this is a Seikh thermal one I bought myself it sees the temperature readout that we get the sort of human readable temperature has three different items there's emission so what how much heat is being emitted there's transmission or sort of what's going on beneath the surface if he's being transmitted almost in a subterranean fashion we can call it below the surface and then the third item is what is reflected and that's the point of this glass which we can demonstrate really easily so this is an example of an improper use case for pointing your thermal camera and we've got other tools for this I have for example thermocouple readers which that has two k-type thermocouple is coming out of it you can figure it three k types you calibrate them we use boiling water and hot water I've calibrated them a while ago so I know the the range of the two thermocouples and it's generally about 2.2 Celsius which I know thanks to Bobby Kim stole from Corsair and then there's another type of device like this which is basically a laser pointer and it reads the laser and the temperature of the surface you're pointing at but this is all kinds of flawed too we're not really going to get into that today what we're getting into is this so let me do a demonstration so right now we're looking at the case in front of me and what it's showing is with the side panel on we have prime95 with L F of T's running on the system and fur mark running so this is a very tortured machine it's an S 340 elite pretty bad cooling performance as we've shown but the temperatures here it's saying well if you point out the CPU cooler area which by the way you'll notice this very bad resolution which you'll see it improves when I remove the glass CPU cooler areas clearly there it's somewhere around 35 degrees according to this but there's a big flaw and that's that there's reflection in the glass so if we I see your legs where's my hand so he can actually you can see and you're the camera man's legs reflected right here and I think part of my body is reflected here that's not good that means you can actually see my hand moving around there in the background too it's it's not quite as easy to see but there it is over there on the far right side you can see the hand reflected that's useless that's not the temperature of the inside of the case that's the temperature of what's being reflected so this is part of knowing the emissivity of the object that's under test if you don't understand the emissivity what the sort of the emission index is what the number is it's 0 to 1.0 is the scale and this ideally you have let's say a painted black piece of steel that would be what you call an ideal blackbody for in the world of physics for measuring temperature this is not that so if we remove this panel c40 see see my hand holding it up let's remove that panel and see how things change now we can see the computer much different let me put this glass down so now we can actually see the components you can individually make out the CPU cooler that's the msi cooler you can see the GPU the back plate and the vrm area is about 70 C from this distance which is how they flow on these things and then we can see the individual motherboard components you kind of see the RAM this is obviously a far different temperature now I I would not recommend ever taking measurements of components with this because that's not looking at diode temperatures we don't know what the core temperature is by looking at the temperature of the CPU cooler we don't know what the GPU core or the vrm temperatures are by looking at the temperature of the heat pipes which are up here or the shroud or of the back plate and these if you have a shinier back plate even worse if you have a shiny like copper nickel alloy or something for your for whatever material you're measuring the thermals of your reflectivity your emissive index is probably something like 0.03 or 0.06 something like that for something shiny like electroplated copper or copper nickel alloy or something like that totally useless measurement because all we're seeing is the reflection of other things basically if I took a thermocouple and stuck this to the different parts on the system primarily the reflective ones we would get a much different temperature and this will take a moment to heat up so the larger number up here is around 50 Celsius that's the temperature of the particular heat pipe in the specific spot that I'm touching this thermocouple the lower-left temperature is now the ambient temperature of the room about 23 Celsius but we're looking at somewhere under 50 C for this thing 45 something like that let's look back at our thermal camera see what it thinks it is the resolution here is not great but I can still get an idea where is our where's our heat pipe that would be right about there I can't even get an exact measurement but it is well above 40 this is looking like let's see let me use my hand here to pinpoint there's my hand so there is the heat pipe move my hand and that's in the red white area so it's somewhere in the 70s high 67 DC area it's not white-hot that's up here closer to the PCB but the point is it's several degrees higher than what we were seeing with with the thermocouple neither is necessarily a perfect way to measure that he wouldn't really need to measure a heat pipe but that's an example of how the emissivity index is interfering with our measurements you can calibrate these devices maybe not the phone ones but a good fluke meter or something if you calibrate in a way that would better account for the emissivity and an easy way to do that would be to paint one of these heat pipes just black and then you take a measurement of it black and you can use that versus the other to get an idea of how do we calibrate this device to read an appropriate temperature but again not an ideal use case what these are useful for if you look at a system like this it gives you an idea of where are my hot spots in the case even you have to take in all these things to account like the emissivity but you can still use it as a good tool to figure out where am I getting a little too hot can I move my fans around it's just not a perfect way to measure for diodes you want to use software like the CPU core temps and the GPU core temps for MOSFETs you can really only get the case temperature easily anyway and you would want to use a thermocouple for that and then anything else that requires a different type of probe than what we have on the table so I think that gives an idea of how to use these and how not to use them fluke has a really good article it's a PDF on base that some research they did explaining emissivity and how to use their devices and they have a really good article put on the screen now where they do a similar test but a bit more advanced they bake a block of stainless steel so they put it in an oven for three hours of the high temperature and they paint half of it black and they leave half of it stainless steel and take a measurement with one of their meters uncalibrated for the emissivity and they report a difference of more than a hundred degrees Fahrenheit between the two halves so this is a piece of steel that's been put in an oven it's one uniform piece it's the same core temperature if you were to bore a hole into it and stick a thermometer and they're almost like you would do with a steak or something like that it would be the same temperature on either side within reason but they painted one half black and left one reflective and the difference was something like 100 degrees Fahrenheit so that further demonstrates this issue we're using a thermal camera incorrectly with the glass on totally useless results of course we don't get anything close to the temperatures this is actually experiencing have no resolution and we're seeing more reflection of me and whomever else is in the room then the in turn of the case but when you pull the glass off it's still not perfect so it can't be reported as hard fact what different temperatures are without first accounting for emissivity is the thing you're pointing at really shiny if you've got a CPU cooler that's something like the old Zalman ones that were just really really shiny copper or nickel plated copper those metrics without calibrating for them are useless you'd be better off with a thermocouple that you've also calibrated or something else like just using salt or to measure core temps like people would normally do because this is kind of not really a normal way to measure your temperatures how effective a case is but I think that's enough for now so that's the PSA if any if you have thermal imaging devices hopefully you know a bit more about them now as always it links in the description below for more information subscribe for more content patreon link in the post oral video if you would like to help us out directly and support more of these you can go to patreon.com/scishow more zexis thanks for watching I'll see you all next time you