diode reader
 

i just set up a reader and cant get the remote reading to work properly. its reading -198 F anyone know what might be the problem (im useing a max 6658)

Check if:
1-the chip is powered
2-the probes are not too long
3-none of the conections cross each other.

chances are you have a fault in the circuit somewhere... The fact that it is reading so low...

most theromcouples are rated for a certain temp range (the most common is copper constantan, -180C to 400C) and -198 sounds like the low end of your particular probe.

Here is how a thermocouple (diode) works: Two dissimilar metals are fuzed together. Since they are different metals there is a voltage drop (contact potential) accross the interface. This voltage drop increases with increasing temperature.

so your temp probe is just a calibrated voltmeter. which also means if the metal in your thermocouple is touching a charged surface you will get erronious readings.

sorry if that was too disjointed...

Tokamac

ur problem is that u put the wires in the wrong place, desolder them and switch them. I had that problem. Leave the ground wire (if u have one) in the same place, it doesnt really matter much. But make sure u switch the other two.

just tried switcking them... still the same reading
im reading off the XP internal
the local is reading correct
just haveing trouble with the remote reading

ok i just resoldered the wires.... now my temps are...
case 77 F
cpu 68 F
water 71 F
room 73 F
sound right ???

What are you using to cool the CPU?. Bong?,TEC?. cause it being below ambient is stange otherwise. it being cooler than the water cooling it definatly! ;) ...

Case: 25 C
CPU: 20 C
Water: 22 C
Room: 23 C

Either you just turned on the comp, or you are running that CPU at basically idle. Which CPU is it?

xp1700
fan/ hc
custom block
those reading were off i resoldered everything, and used another ic (still max 6658) ant the temps are better now
case 75 F
cpu 86 F
water 77 F
room 72 F

Do you have a pic, or a description on how you wired that chip?

the cpu temp does not go up (goes down a couple degrees)
when i shut my pump/fan off..
the under chip temp goes up tho...

I wish MY temp reader told me my CPU was -198 degs ... I'd have a frickin' party and call the Vatican (Saint Airspirit ... patron saint of ugly hose-filled computers ... naw).