Simple Question About Water Temp
 

How do you measure the water temperature. Do you just insert a temperature probe from say a compunurse or digidoc?

Thanks!

Pretty much. Just stick it inline somewhere and seal it well.

Do I seal the temp probe with plastic or can it be directly submerged?

See my hightech resivore, that little black wire is my thermoprobe. I just dropped it in.
http://www.dorrellco.com/watersetup/res.jpg

you should probably seal it off so only the top is in contact with the water.....

Top of what? Seal it off why? The temps are measuers at the tip of the probe so..????:confused:

i would seal all BUT the very top off so no water can get trough to the wires inside and cause a short.

It dosn't work quit like that. My probe is powered by a AA battery. You can run DC power under water without causing a short. That's why car headlights will work under water ect... My probe has no seal around the wires at all. And I don't think the probe is positive in and negative out. It is the same polarity through out the probe so it cannot short out in any event.

im the carefull type and would therefore seal it off just to be extra sure :)

the sensors work off of resistance (pretty sure). you can't have a short, but the water might alter readings if it connects both leads.

When I first hooked up my probe I tested it's accuracy with one of those medical probes you stick on your mouth. The temps where the same so I can't see the water being an issue. I have run it for over 6 months that way with no problems that I know of.

even if it does go inaccurate, it will still give you relative temperatures.

you can use Y's, like what Joe does in the crucible, have just the tip going into the main water flow, goop up the other side of the Y

Yeah I seen that deal and like it. Once I get modify Antec SX830 case with my water cooler in it I am going to do something like that. Thats down the road a bit though.

yes, it is a cool idea. It will drop your flow a little bit though because of the Y, the water will need to turn a bit.

what about just using a t bit then :)

that'd work fine obviously. Or you could just use a 5/8" Y with your 1/2" setup, so you won't have any flow restrictions

I just bought a comair rotron "Major DC" 172mm fan... This fan has a temp probe with a metal end. See this for some pics and this for details. I was reading above and see that DC can play with water, so can I just stick this metal temp probe into the water and not worry about it causing a short b/c this fan is DC driven?? Im obviously not an electrician... any help?

kem-

DC doesn't play with water. The water will be an added parallel resistance which can cause your temp readings to be inaccurate. You should always used a sealed probe underwater. As for the probe on a major Dc, I'm familiar with the device and that probe will be pretty much useless for water temps as it needs to get far too hot before the fan gets significantly faster. I just cut the sensor off on mine (leaving the wires unconnected seems to give max speed).

I don't agree with that. My probe is not sealed and is bare and sunk right into the water. The temps are identical to the medical (sealed) thermal probe I used to test it. I don't think it makes a noticable difference at all.

remember that the voltage across a diode is very little, the diode is designed to measure a resistance, when the resistance changes then it records a differant temperature.

Water is very very barely conductive, and in the space between the two pins of the diode will be way too much to affect the temp readings at all

Diodes don't measure resistance brad, that's thermistors. Thermistor sensors can have problems with water submersion, diodes and thermocouples work on voltage differential with temperature so are less likely to have issues.

Well, I hate to snip off a perfectly good temp probe...:dome: But I dont have a need for my rad fan to run off the amb temp... Can I replace the existing probe with one from something like my DD5? Something more water friendly? It seems silly to waste a perfectly good native thermistor.... :D Anyone have any clever ideas on what to do with it before I condemn it to my nippy cutters?

You can seal it with silicone or some water proof stuff. Shouldn't hurt the temps much.

/me eyes jaydee116 cautiously


But that would be..... simple... that cant possibly be a good idea!


/me ponders




:drool:

:D