Hi. Now it's a very common thing in the electronics design industry to measure the thermal performance of a product. especially when you've got like a reasonably large system like uh, something like this that's got fans in it and you got to manage the thermal performance. I've talked about this a lot on the blog and well how do you measure it well? There's many different ways to measure it but one of the big mistakes you can make.

One of the traps for young players is to measure things with the lid off like this and you've seen me do in videos cuz I'm just getting like ballpark temperature measurements. but as you should know the with something like this that's got a fan in it with the lid off, you're not going to get the true temperature measurement of the devices in there. they're actually going to be hotter than the what they should be. Why? cuz you haven't got the proper thermal management and the air flow going over the devices over the heat sinks and things like that.

So really, if you want to properly characterize and measure the temperature of a device or the thermal performance of your product, you need to do it with the lid on and everything in place. and and they could have uh air ducting guides inside for example. You've seen those uh various times in product tear downs and things like that so that's all well and good. But how do you measure the thermal performance with the lid on? and of course one of the best tools these days and they becoming lower and lowering cost are one of these uh Flur thermal imaging cameras.

This is the E8 very nice 320x200 resolution. brilliant and these are great for getting uh, thermal, uh, measurements of your products like this, overall thermal map and also individually uh measuring the thermal performance without having to get your usual uh, multimeter and your thermocouple and trying to attach it and stuff like this. these can work really well. although ultimately uh, thermocouple attachment is probably going to uh end up being the most accurate.

These are great if you got the lid off but then your temperature measurements inside aren't going to be accurate. So how do you solve it? Well, you can't just whack the lid on cuz this is no good anymore and then you would uh often you would have to uh attach uh, thermocouples through the vent holes and then actually connect them to the devices you want to do. Then put the lid on and you got to have multiple thermal couples and all sorts of things. It's a really nasty piece of work.

so how can you measure the thermal performance, especially using one of these thermal imaging cameras with the lid on and with all your air flows in place? Well, there's a neat little trick you can use to do it. I'm going to show you cling wrap Beauty So taking a product like this as an example, uh, when you got the lid off like this, yeah, the Fan's Going full ball sucking out trying to suck out the air. But where's the air coming from? Well, just around the inlet to the fan there. It's not coming from anywhere else, so it doesn't get to flow from the vent holes here and here.

That's what the system is designed for. Air flows into this hole, into this hole, over all of the electronics, and then over these heat sinks here and then out the back like that. That's how they've designed the thermal Management in this product. but with the lid off, all of that's red.

It's just being sucked there. There's no air flowing over either the electronics or more, crucially, these heat sinks at the back here. And heat sinks are designed to work with air flowing over them. They're really, uh, you know, if you just put them in still air.

They're not very efficient at all. They're vastly more efficient with that air flowing over. So we take our thermal imaging camera here. We can actually see parts of our product that are lit up there.

We can see individual chips and reays down in there that are lit up. You can see the coils on the re layer analogize. You can see our five heat sink devices up here. You can see our Transformer over in the corner and that's all fantastic.

But well, these aren't a true temperature measurement. You can see up in the Uh top left corner of the screen there that, uh, that device in there. you know, 70, 80 odd degrees, 85 something like that. but that's not what it will be with the lid on.

it'll be lower than that. So to solve that problem, yes, we can actually use some cling rack. We can just put it over the top of the product where the lid is going to be or whatever covering it is on your particular product you want to, uh, test. And of course being that on it works like a lid and it allows the air to flow exactly how it was designed in the system.

But as I'll demonstrate now, it's pretty transparent, although not 100% but pretty well transparent to that infrared heat energy. So you'll be able to use your thermal camera to see right through this with all your air flow in place. Let's check it out. All right, let's try this out and see if it works.

I've got my flu E8 mounted on a an extension arm here. it doesn't have annoyingly doesn't have a tripod mount on it. I Know you can physically hack them to actually add that, but uh. Anyway, here we go.

It's nice and set up. it's stable. It's actually uh, measuring that heat sink in there. See? Uh, so the top left, uh, temperature up here? That's what.

The cursor right in the middle? 73.4 So that heat sink down in there is about 73 and2 degre or thereabout. So I'm going to get my cling wrap. now. Here we go.

and I'm going to put it over it. Let's see if it changes, it will change. Of course there is some loss by doing this, but you'll notice that the heat map will stay exactly the same. It does not distort the map so you can should be able to see it coming across.

So it's 74 74 and it's dropped to 79 and2. So there you go. 70. So it's dropped by 4.

that's instantly. Now if you leave it there, it might actually come back up to temperature if you'll leave it there long enough enough. So it's yeah, it's got some loss. So your absolute uh temperature is going to be out a bit, but you'll see that that heat map is still there.

That image is not distorted at all. so there it is. Look at that. Fantastic.

So four or 5 drop you can compensate for that. But the whole idea is that you can still see the thermal image of it and the flow. And if you're lucky, you'll be able to see the air flow as well through your product. Fantastic! Now if we take a look at the overall product here, we've got a temperature range as you can see in the Uh right corner here of you know, 83 down to about 27.6 at its lowest part here.

Now what I'm going to do is I'm going to try and leave the Flo camera in position here and cover it with cling wrap and actually see if we can see a difference. But what I'm going to do instead of having the fan uh, blowing out, I'm going to have the fan blow flowing back in and then see if we can see maybe if we're lucky, some air flow coming out the holes out the side here, some air flowing into it cuz otherwise most of the hot Parts as you can see are up the back of the unit there. so this isn't a particularly great example from that aspect. So I'm just going to flip the fan around so that it blows back out.

so I can simply just take that out and ta now it's blowing into the product and coming out the vent holes on the side. And yeah, we should. Maybe if we're lucky, see a heat map. Oh there's my hand and here we go.

I've had the Uh cover in quote marks on for a little bit and you can. maybe you can see a difference. down in here you can see that the heat has more spread and is Flowing across. Here you'd have to read individual uh temperature points to actually see it.

but the um, you can see that the thermal spread across these parts here has also changed and gone higher. but once again, you would have to get uh in there and actually measure those individual uh points and you'll notice that the maximum temperature to minimum temperature has also dropped as well. Now I've been sneaky and I've covered up this uh, left hand vent over here. So I've only got the air flow out the right hand vent so you can actually probably see maybe some of the heat spreading across.

not not out this side, but it's spreading in this direction. Like this, it's probably hard to see not the best example, but hopefully you can get the idea. and if you got one of these thermal cameras, you can play around with something like this. So if we move the camera over towards the side of the Chazzy over here, you can see that this air flow is Flowing out over this what would ordinarily be a cool area of the board over here and it's flowing all towards this exit.

Uh, point over here this vent hole on the side cuz we're forcing air in at the back here and it's flowing over here and going there. But once again, you'd have to get in there and measure individual temperature points. but you can see how the concept actually can work. Got this tectronics TDS 3054 oscilloscope you've seen in a previous video and yes, I've wrapped it all up.

Check it out! Woohoo! So as you know in previous video, uh, this thing actually stops working if you don't have the fan on. It overheats in like a couple of minutes and the software detects that and actually shuts the thing down. So what I've done is I've wrapped it in plastic. it's dead wrapped in plastic all right.

and uh, I've basically sealed up all of this side so the fan sucks in here like this. over the main uh Asic down the bottom which actually gets hot. the main ADC chipset and all that sort of stuff. so it gets really hot.

that's the thing that's uh, shutting down so the air goes in here. it's got nowhere to go but out this other side. Ordinarily on this thing, the vent holes over here somewhere. but I've just got it coming out the end cuz I just want the air to go in and flow through and go over.

All right here we go. Let's power it up and see what we get. I'm capturing this video cuz you can actually uh, stream out of this via the USB So here we go. Look.

You can actually see the uh, there we go look. You can see the main Asic right up there heating up. You can see the four uh, front end chips, the four front end hybrids. They're all heating up the uh, probably the analog to digital converter in there.

or is the one at the back the ad DC I can't remember. um, this one here. that would be the Transformer core powering up. uh and yeah, some of the front end uh components there on the power supply.

so that's the entire power supply board in there. This is the DC Todc uh converter powering the main board so there's some voltage Regulators they're just uh, freestanding to 220s there and uh, there we go. Hopefully can we actually see I Think we can see some I Think we can see some of this air flow happening here cuz this is all cold stuff down here. but it's it.

What should be cold? But it's not because that air flow is happening and flowing out this side of the board. over here. there you go. So it looks like we are getting to see a bit of air flow and maybe if you use your imagination you see some heat spreading out that way.

oh maybe not, maybe not. but yeah, I Can definitely see a heat pattern flowing out that way. so that's that is really quite neat. We can leave that uh running for a bit of course and uh, it shouldn't shut down like the um like it does without the case because this is effectively you've got a case on it.

And that airflow I Mean this. That's the thing this cling wrap is not. You know, it's not that great. Okay, it's going to have loss in it and everything else, but it allows you to see the uh thermal profile through there without Distortion really.

And it gets most crucially, it does get that air flow happening which is what you want to test your real product, so that's working really quite well. I'm rather, uh, rather pleased with that. There you go. Yeah, all that stuff over there should be.

Yeah, yeah, you can see it all heating up around here and all flowing out. That is neat and you can see the fan. Of course you can see the motor in the center of the fan there. Okay, what I'll do now is I will, uh, change the image mode because you can see all of the creases.

You can see the cling wrap and everything else. You know, it really screws things up. Uh, because this camera is so good that it has uh, this MSX technology which overlays a True Image in that true visual image over the top so that you can see more detail. and I Love it.

It is absolutely brilliant, but if we switch to there it is thermal MSX and you can see the uh, you can see the physical cling wrap on there, the Reflection from my studio lights, and the creases and all sorts of stuff. But if we put it in traditional thermal mode Bingo there it is and that looks much better. I Like it and hopefully yeah, it's It's hard to tell, but you can sort of see the Heat spreading out towards this corner of the thing where it's all escaping right out here. So that is brilliant.

I Mean that is basically So you get the benefits of having that case on there and getting your true airf flow. But look, it's like this thermal imaging camera is seen right through the case of the instrument. It's fantastic. I Love it.

So there you go I Hope you found that A useful little tip there of how to see through your product with a thermal imaging camera. It works remarkably well actually. And yes, this thing is still going. It hasn't rebooted so it's working just like the real thing with the case on.

Fantastic! Hope you enjoyed it. Catch you next time.