DIY Submersible Temperature Probe

[diannotti]

I keep seeing the mention of "hobby shop", what exactly is that? The only "hobby shops " around me are usually for radio control devices. I do remember hobby shops in the 70's. Where and when do you guys live that you have hobby shops? I really cant think of anywhere else I can get metal tubing other than the hardware store. Is there someone online you know of that would sell different diameter tubing?

 

[diannotti]

Shouldn't have to shrink-wrap the tube, as the probe itself is buried in the tubing, and the epoxy is sealing both ends -

I was asking if you would shrink wrap the wire lead to the probe.

 

[Hang Glider]

ah...
I didn't... the insulation is waterproof - but the probe is deep enough into the sleeve that the epoxy effectively seals against the insulation, and acts as a bit of a strain relief between the probe and the wire.

 

[cobolstinks]

i just bought a few LM35 sensors and a netduinio. I'm gonna need to build probes at some point and was wondering what your thoughts on using just 1/2" OD copper tubing and soldering a cap on the end of it. Do you think this will work? Don't know where to get the SS tubing otherwise.

 

[Hang Glider]

I think 1/2" od copper might provide too much air space between the sensor and what it's measuring. Air can be an insulator...

yellow pages "hobby" in your area, and look for a display like this...(possibly an Ace hwde-type store as well)

 

[cobolstinks]

Ok cool thanks for the pic. Super excited to get this setup. couple of questions, I see you list 22 gauge wire, but I have a bunch of cat 5 laying around ~500' is that heavy enough? what do you use to termunate the lines ot did you feed them directly to your audriuno?

 

[Nicoolai]

Sorry for necro'ing this post, but I am in doubt about how this is made.

Is the temp sensor incased in the epoxy inside the tube? Or is it "free floating" in the tube, with only epoxy sealing the ends?

 

[Hang Glider]

Mine is free-floating, although the fit is plenty snug. I cut to size and plugged the end of my tube with epoxy, let it dry, slid the sensor inside, and dabbed epoxy over the wires and tube on the other end. Voila, sealed temp sensor.

 

[Nicoolai]

Mine is free-floating, although the fit is plenty snug. I cut to size and plugged the end of my tube with epoxy, let it dry, slid the sensor inside, and dabbed epoxy over the wires and tube on the other end. Voila, sealed temp sensor.

Excellent, thank you!

 

[Jared311]

What are folks getting for a response time with the stainless steel / epoxy combination?

 

[Brumateur]

Epoxy is not food safe. I'd rase use pure silicon sealant.

 

[Hang Glider]

My epoxy goes no where near the beer - I don't drop the probe into the beer - only into the water bath to control temps. Others TAPE the probe to the side of the fermenter.

IF you are dropping your probe into your beer, then YES, you must use food safe ingredients. (even the wire insulation??)