Thermocouple Waterproofind

[fromar]

#3536

Hi All,

I bought a thermocouple from Amazon here: http://www.amazon.com/gp/product/B003V8BF2U/ref=oh_o01_s00_i00_details

I did not realize, but the tip of the thermocouple is not waterproof. Lucky for me, dipping it in water just causes the thermocouple to cease working. It didn’t get fried.

What are you guys doing to solve this? I have a couple of ideas:

• A bead of hot-glue at the end
• Vacuum seal the end
• A zippy bag

All of these methods have the problem of insulating the sensor – which means slower response time on the osPID measurements.

[Brett]

#3752

How about tool dip? although that’s pretty close to hot glue.

for water temperature, insulating the thermocouple a little probably won’t have too much of an effect. you’re introducing a 2-5 second lag in a process that moves on the order of minutes

[fromar]

#3753

I tried saran wrap with a rubber band, but it leaked after a while.

In the end, I wrapped the thermocouple in a condom, and even when things got hot, nothing leaked. 😀

[Brett]

#3754

I wrapped the thermocouple in a condom

that is, without a doubt, the funniest thing I’ve heard all week. love the idea though. a balloon would probably work as well. nice thin layer, water pressure presses it up to the element… nice work!

[ezflyr]

#3755

Hi all,

An interesting question would be why immersion in water causes the thermocouple to stop working? Obviously, the Maxim part doesn’t provide an “isolated” input, but that shouldn’t matter in this situation. It seems that a current flow path would have to exist for the thermocouple to stop working? I’m trying to imagine another explanation to this issue? What happens if the water is isolated rather than the probe?

John

PS it seems that my kit has been delivered, but I won’t get to play with it until I return from skiing in California next weekend.

[FJK]

#3756

Tcs do generate a miliamp current that a meter would pick up and convert into a temp measurement. Do a search on Immersion Thermocouples, a lot of different kinds out there… 🙂

http://www.omega.com/ppt/pptsc.asp?ref=HSTC
http://www.te-direct.com/products/immersion-temperature-sensors/thermocouples/

Just some TC info…

http://www.omega.com/temperature/Z/pdf/z204-206.pdf

http://www.omega.com/thermocouples.html

http://www.omega.com/techref/colorcodes.html

http://www.omega.com/temperature/Z/pdf/z052.pdf

[AustralianRobotics]

#3757

I am using this for my sous vide cooker:

http://www.ebay.com.au/itm/High-Temperature-Thermocouple-K-type-Probe-Sensors-/250824170032

[AustralianRobotics]

#3758

Here’s a real liquid probe:

http://www.phidgets.com/products.php?product_id=3108

Also available on eBay from a few Hong Kong sellers for less.

[Author]

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