Not sure where temperature sensors go

[Bob Kruse]

Hi folks,

I'm installing a Sunbeam brand front panel card reader in a friend's
computer, It's a card reader, a fan controller, has ports for USB,
firewire, audio and has an LCD screen that shows temperature and fan
speed. It's a gizmo that caught his eye and he wanted it so now I'm
the guy he's asked to install it.

I'm trying to figure out what to do with the two temperature sensors.
I'm assuming they are both just to measure the temperature inside the
case because I'm not sure how they would be placed to give an accurate
CPU temperature reading. Maybe in the heatsink fins or is that not a
reasonable place to put a sensor? If I did that, what would a normal
temperature be in the heatsink fins? And where would you place the
other sensor where it would most accurately gauge the ambient
temperature inside the case?

The sensors just look like small wires at the end of a flat cable.
They're thin, but not paper thin.

Any ideas on where to place these would be appreciated.

Thanks,
Bob Kruse

 

[Mike T.]

Hi folks,

I'm installing a Sunbeam brand front panel card reader in a friend's
computer, It's a card reader, a fan controller, has ports for USB,
firewire, audio and has an LCD screen that shows temperature and fan
speed. It's a gizmo that caught his eye and he wanted it so now I'm
the guy he's asked to install it.

I'm trying to figure out what to do with the two temperature sensors.
I'm assuming they are both just to measure the temperature inside the
case because I'm not sure how they would be placed to give an accurate
CPU temperature reading. Maybe in the heatsink fins or is that not a
reasonable place to put a sensor? If I did that, what would a normal
temperature be in the heatsink fins? And where would you place the
other sensor where it would most accurately gauge the ambient
temperature inside the case?

The sensors just look like small wires at the end of a flat cable.
They're thin, but not paper thin.

Heat rises. I'd put one as near the base of the CPU heatsink as possible.
I'd put the other one in the top of the case, a couple of inches away from
the power supply. -Dave

 

[Clint]

The case I just got had two sensors and a front-panel display for them,
labeled "CPU" and "HD". I taped the CPU lead to the underside of the HS, as
close as I could to the disk where the CPU and HS contact (without
interfering with the CPU/HS connection). The MB has a CPU temperature
utility, and the two agree "close enough" for me. I think the front-panel
temperature doesn't change as fast as the CPU temperature, but what the
heck.

The other one I put on a hard drive, between the two drives. I figure
that's the "worst case" temperature for the drives. As far as a case
temperature, I'd probably put it in the exhaust flow somewhere. Either
around the grill of the PSU, or another case exhaust fan.

Clint

 

[Don Taylor]

The case I just got had two sensors and a front-panel display for them,
labeled "CPU" and "HD". I taped the CPU lead to the underside of the HS, as
close as I could to the disk where the CPU and HS contact (without
interfering with the CPU/HS connection). The MB has a CPU temperature
utility, and the two agree "close enough" for me. I think the front-panel
temperature doesn't change as fast as the CPU temperature, but what the
heck.

The other one I put on a hard drive, between the two drives. I figure
that's the "worst case" temperature for the drives.

I tend to think "good thermal contact" first.

So I'd probably try to bond that to the thickest part of the aluminum
case of the top drive. I'm expecting that would give a better idea
of what the actual internal temperature of the drive would be. But
contact with the metal of your computer case acts as a large part of
the heat sink to drain heat away from drives. (This explains why
people who mount their drives on rubber standoffs, to cut down noise,
see a substantial increase in drive temperature) But the thickest
part of the aluminum case of the drive is probably as good as you can
get.

As far as a case
temperature, I'd probably put it in the exhaust flow somewhere. Either
around the grill of the PSU, or another case exhaust fan.

That would give "ambient" but this could easily be 10-20 C cooler
than being in contact with the aluminum heat sink of the part
producing the heat.

As temps go up and fan whine drives me even further up, I'm really
thinking about slicing up some sheets of Celotex (tm) to make a
baffle around the outside of the case to deaden sound, and then
adding a couple of extra (as quiet as I can get) fans to suck hot
air out of the thermal and sound insulating barrier of Celotex.