Correct way to use Temp Sensors?

[lopri]

I recently acquired a rheostat with temp sensors and want to try it out. As I look, the temp sensor seems nothing more than a couple of copper wires wrapped in a thin plastic coating. My question is, is it safe to attach this thing where I want to use? Namely, around the hot NB or the bottom of CPU heatsink, etc. I am wondering if this plastic coat can handle, say, ~100C without melting down.

Edit: I took a couple pictures. My biggest concern is the plastic melting down and touching electrical traces on PCB, Mosfets, or the side of IHS, etc.. and causing a short.

Here is the temp sensor.

http://img502.imageshack.us/img502/3020/dsc01706vj0.jpg

And here is a hypothetical application scenario. Let's assume the GPU is capable of reaching 90C+.

http://img409.imageshack.us/img409/3519/dsc01708qh3.jpg

 

[aigomorla]

Originally posted by: lopri
I recently acquired a rheostat with temp sensors and want to try it out. As I look, the temp sensor seems nothing more than a couple of copper wires wrapped in a thin plastic coating. My question is, is it safe to attach this thing where I want to use? Namely, around the hot NB or the bottom of CPU heatsink, etc. I am wondering if this plastic coat can handle, say, ~100C without melting down.

well first off lopri i dont think it will ever get that hot.

You cant place it inbetween the IHS or your contact will be off. IF you have it on the side of the ihs, theres no way in hell that could get 100C. You'd undergo themal shutdown b4 that happened.

And if you mean a sink, if your sink gets that hot, lopri, your doing something terribly wrong.

 

[lopri]

How about the back of GPU core on the back side of video card or right next to the (shudder) 780i SPP? There is room to stick the thing in next to the core (same applies to the CPU IHS as well)

Edit: Like this

http://img338.imageshack.us/im...1/thermalsensorpy6.jpg

 

[Fullmetal Chocobo]

I have been considering a project, and this thread has finalized my plans I think. I have a ThermalTake Hardcano 13 (worst product ever BTW--don't ever buy one) that I have no problems trashing and a P3 ~450MHz that is not being tasked right now. I'm thinking about drilling into the heatsink to place there temp sensor in there. Maybe then seal it with J-B Weld.

No clue if it will work, but it might be worth playing with.

 

[Bluefront]

You can place those sensors anywhere without fear of melting.......however. Don't place them between the heatsink and the CPU. They'll be crushed and the heatsink will not make contact properly.

The best place for them is as close to the heat source as possible. Here's one way I use that works very well. If you have a CPU heatsink with tight fins, get an aluminum or copper shim about the depth of the heatsink......say 3"x1". Make a little notch in the shim so it won't fall through the fins. Leave a 1/2" or so of the shim sticking out. Attach the sensor to the part of the shim that's sticking out. This works great for me....and it can be removed in a flash.

 

[DerwenArtos12]

The best way to get the most accurate reading would be to remove your IHS and use a non-conductive thermal paste and sandwich it between the CPU packaging(green area) and the heatsink as physically close to the core as possible. Short of that, you're much better off using internal sensors. If you want to use it for chipset temperatures same bsic concept, just please, don't try and remove the IHS from any of intels chipsets, PLEASE. The closer you can get it to the actual heat source the more accurate it will be. In your drawing it apears as though you were going to put it next to the chip, you don't want that, it's innacurate, you want it on top of the chip, next to the core with something like ceramiq helping conduct to it.

 

[Billb2]

Originally posted by: lopri
How about the back of GPU core on the back side of video card or right next to the (shudder) 780i SPP? There is room to stick the thing in next to the core (same applies to the CPU IHS as well)

Edit: Like this

http://img338.imageshack.us/im...1/thermalsensorpy6.jpg

On the side ....or else this!

http://img329.imageshack.us/my.php?image=image14yk2.jpg

 

[lopri]

Oh man.. you guys are getting way dramatic!

I just want to try out this new toy! I just didn't want things to melt down or cause fire. Currently the likely spots I'll put the sensors are (there are total 4 of them):

1) VRMs/MOSFETs around the CPU socket
2) Next to the X48 chipset IHS (as described in the pic above)
3) Back of the video card (right behind the GPU core)
4) And somewhere around the case (this I'd think fairly safe)

As you can see there are quite a few spots that can get hot and my main concern is safety.

 

[Billb2]

Well a good thing to do is to monitor case intake and exhaust. That kind of gives you an "overall" picture of temps.
Generally what happens with temp sensors is that you monitor something for a while, then when you see everything is OK (or you fix it and then it's OK) you move the sensor(s) somewhere else and start playing again.

 

[Modelworks]

If its a couple wires I assume they are using a thermistor at the end.
Not the best way to measure temps, but its the cheapest.

You should not have problems placing them on heatsinks, etc.

A better alternative, although more expensive, is a thermocouple.

I'm working on finalizing my fan, voltage, temp, current, control box and went with thermocouples over thermistors.

 

[lopri]

So you gusy think my plan shouldn't be a prob with a thermal sensor (copper wires wrapped in thin plasticis)? Check my previous post in this thread please.

 

[Modelworks]

Originally posted by: lopri
So you gusy think my plan shouldn't be a prob with a thermal sensor (copper wires wrapped in thin plasticis)? Check my previous post in this thread please.

Its not going to be an issue with what you describe.
Even if you somehow shorted the wires together it would not harm anything.
Thermistors use resistance measurements to calculate termp.
The worst that would happen is a wrong temp reading.

 

[lopri]

Thanks for the assurance, Modelworks.

However, I'd like to triple-check! Here is the temp sensor.

http://img502.imageshack.us/img502/3020/dsc01706vj0.jpg

And here is a hypothetical application scenario. Let's assume the GPU is capable of reaching 90C+.

http://img409.imageshack.us/img409/3519/dsc01708qh3.jpg



What's the melting point of this thin-ish plastic (cellophane)?

 

[lopri]

Anyone?

 

[DerwenArtos12]

Thats definately a basic thermistor. Placing it on the back of the PCB behind the GPU isn't going to give you a temperature very relative to anything though. I know I've run similar thermistors to about 80-85C with zero issues or any visible damage to the shielding.

 

[Zepper]

That's not just any plastic that the thermistor or thermocouple is housed in, it is Kapton probably with acrylic adhesive which should be good at least up to 300 deg. F. - the same Kapton with silicone adhesive is good up to 400 deg. F. IDK what the Kapton plastic itself can take, but probably more than 400 deg. F.

.bh.