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Thermocouple in the brew path

Postby popeye on Sun Mar 02, 2008 3:53 am

I'm thinking about adding a T to the piping just prior to my grouphead so that i can work an unshielded thermocouple into the dispersion block. Anyone have any ideas about this? i don't think sealing off the bare wires will be that difficult, i'm more worried about the effect of the metals on my system (my body). Will the metals leach off the thermocouple over time? Anybody currently running this setup?
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Postby HB on Sun Mar 02, 2008 10:02 pm

Why not use Eric's E61 thermocouple adapter? Or, if you want to fit your own, get a Low Cost Hollow Tube Thermocouple Probe from Omega and an adapter from Swagelok. Greg shows how he installed one by tapping the grouphead in Installing a PID into an ASTRA Gourmet.

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Postby erics on Mon Mar 03, 2008 12:04 am

Spencer -

Taking your words exactly as you have written - I would have to say that is NOT POSSIBLE. See image below, courtesy of Verna Design, Inc.

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Drilling the grouphead from the underside using either the dispersion screw as a "jig" or a custom "jig" (preferred) which duplicates the dispersion screw threads and then reversing the grouphead to drill and tap for an appropriate fitting is no trivial machining chore either.
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Postby popeye on Mon Mar 03, 2008 1:24 am

sorry, I guess i'm throwing everyone off because i list the zaffiro. I'm now working with a bezzera bz-40. It's a commercial form-factor and the solenoid to grouphead piping is about 6" and really easy to access. I'm just asking about the health dangers of an unshielded thermocouple (I believe you have a stainless steel shield on your adapter, eric?)
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Postby erics on Mon Mar 03, 2008 8:37 am

I'm just asking about the health dangers of an unshielded thermocouple (I believe you have a stainless steel shield on your adapter, eric?)

See this: ideas-on-protecting-thermocouple-welded-tip-t6318.html

I also assume you have downloaded the illustrated parts list for the BZ40 from here: http://www.bezzera.it/home_ing.html

Because the Bezzera grouphead design is somewhat similar to the Elektra, you might benefit from doing a search on "Elektra Thermocouple". Also, I would purchase a spare 6" feed line to the group just to have it handy or maybe even build a new line from scratch incorporating a Swagelok tee designed for a small shielded thermocouple. Swagelok tee's that are designed for thermocouples (bored-through) are almost a stock item.

You might also consider purchasing a spare grouphead (Bezzera calls it a coupling ring) and having a shop machine it to accept a standard Swagelok or Omegalok thermocouple adaptor. That would be the BEST way to go to give you the info you want.
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Postby popeye on Mon Mar 03, 2008 10:07 pm

thanks for the ideas eric,

I'm gonna check into purchasing a spare grouphead, so i can drill it out and mount a permanant solution. I've already got a thermocouple wedged in between the grouphead and the support bar that reaches out from the boiler, but it's not in the brew path and not as responsive as i'd like.
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