inline temp probe

[justDIY]

I'm looking for a inline temperature probe to monitor the temp of water going to my RO+DI unit.

the few i've found online all appear to be industrial in nature, or otherwise very expensive

so I'm thinking along these lines...

1) go to discount store and get a $10 digital thermometer

2) also pickup a 1/4" x ? x 1/4" tee - hopefully like a 3/8th center tap or something larger than 1/4", so I don't have to trim the probe of it's plastic shell.

3) taking the probe, coat it with some jb-weld, and cram it into the T, and finish off with some more jb-weld

after the epoxy has cured for 24 hours, hook it up and test it out

sound good?

I've been trying to think of a better way to seal the probe in, but nothing is coming to mind ... the water pressure is considerable, but jb weld works well on metal, so I'm hoping it will hold in there.

 

[fishfreek]

Just one way to find out.

 

[BillyZ]

yea that sounds like a decent plan to me. I actually just picked up one of those digital thermometers for $10 at our local conglomomart bulk retail store. Nothing like buying enough kool-aid mix for 12 gallons of kool-aid in a single can!

 

[Centurion]

radio shack sells a dual temperature monitor. it has a temp probe inside the unit itself and another on a cord, designed to be run out a window or what not. if you were to silicone the probe into a Y fitting, i think it would work out. and because i lub paint (dont harrass me cuz i spend 30 seconds on a drawing =p):

 

[justDIY]

inline temp probe completed

total build time: 8 min

total build cost: $15

my plan for the tee worked better than expected. I didn't have to use expoxy or anything. the probe itself worked out to be just a hair bigger than the ID on some 1/4" tubing, so I heated the tubing up with boiling water, crammed the probe into it, and then installed the tubing into a 1/4x1/4x1/4 normal compression style tee.

anyway, heres some pics, click this first one to visit the project gallery:

 

[loganj]

That looks great! I might put one together here.

 

[BillyZ]

That looks sweet!

The simplest solutions are the best.

 

[sellis]

Looks great. One suggestion.
The brass fitting will lose heat to the air quite fast and give a lower reading with low flow rate. It would be more accurate if you put some insulating material around it (some thin foam or cloth would do).

 

[Guest]

I have a question. If an RO+DI is supposed to be hooked up on the cold side plumbing, why would you have to monitor the temperature of the water going in an RO+DI when it wouldn't be hot anyway?

 

[fishfreek]

Our RO membranes work most effectivly at warmer temperatures. I belive the sweet spot might be something like 70*F. For those in warmer climents its not uncommon for their ground water to be in the 40's. That cold of water can cause a large drop off in the GPD production of the RO unit. My carefully mixing cold and hot water to acheve a water temperature close to 70F the full effecency of the RO unit can be acheved.

This is what I have heard. I have no practicle experence to base this on.

 

[BillyZ]

I live in Buffalo, NY... our cold tap water in the winter can get well into the 30's. I tried using just cold water and the output of the unit was probably 1/10th the normal amount. I have to use a hot/cold mix to bring the temp up on the input line.

 

[dansemacabre]

Couldn't you use that as a large display of tank temperature? No more tiny thermometer. Visible across the room. You would just have to epoxy it into a T fitting on some PVC somewhere in the flow of the tank. Probably the return. I know it wouldn't work like a heater controller, but I want to get some WonPro Titanium Heaters. If I go w/ Pro Heat I, I'll have reliable heaters, and I can get the temp probe from Radioshack. Does it have an alarm (even if it's just a beep) if it goes above/below a certain temp? What do you all think, and what exactly was this called at Radioshack? And how much was it, I think I missed that part. Thanks!

[edit] Oh, and yeah, I live in MI, and it's been dropping below 0, with average high in the teens. What's a safe and effective way to combine hot/cold water to go into the RO/DI unit? It barely trickles, and I'm assuming it's because the water is darn chilly. Thanks. [/edit]

 

[BillyZ]

What's a safe and effective way to combine hot/cold water to go into the RO/DI unit?

I actually use a faucet connector for mine and have it attached to the basement sink. I just turn on the hot and cold to get the right mix and let it go.

 

[dansemacabre]

Well, there's no sink in the basement. Right now, it's using a self-piercing saddle that has it connected to the cold water line. I dunno if there's much I can do.