How to mount thermocouple

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ontum
Posts: 87
Joined: 12 years ago

#1: Post by ontum »

Hello,

I would like to add a PID on my La Cimbali M30 machine and I cannot figure out how to add the thermocouple. I've read several topics about people adding PIDs to the La Cimbali Junior, but I cant find where and how they are adding the thermocouple.

I have plugged ports on my boiler, but I'm not sure how to connect the thermocouple. I believe the ports are British Pipe thread and I am not sure if I can buy a thermocouple to thread in, or if I can drill and tap a plug to customize one.

Does anyone have experience with this? How are others adding a thermocouple to their HX boiler?

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Craig

HoldTheOnions
Posts: 764
Joined: 9 years ago

#2: Post by HoldTheOnions »

You can get a washer type thermocouple and use existing bolt somewhere on the boiler to secure it. http://www.thermomart.com/thermocouple- ... ure-sensor or http://www.thermomart.com/thermocouple- ... ture-gauge I never used one, but it seems like it should work fine.

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ontum (original poster)
Posts: 87
Joined: 12 years ago

#3: Post by ontum (original poster) replying to HoldTheOnions »


That is an interesting idea. Has anyone tried this and had success? Would the temperature reading be accurate enough? Or would the temperature output be delayed?

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Craig

User avatar
Bluecold
Posts: 1774
Joined: 16 years ago

#4: Post by Bluecold »

If you attach your thermocouple to your boiler you'll have a lot of lag I think.
You can use a compression fitting.
http://en.wikipedia.org/wiki/Compression_fitting <--
There are multiple vendors if you search, and I have no experience with any of them so I'll have to let you figure that out yourself.
Pressure ratings seem to be sufficient for espresso machine use. I've seen quoted values of '200 psi working pressure'. http://mdmetric.com/prod/legris/section_g.pdf
LMWDP #232
"Though I Fly Through the Valley of Death I Shall Fear No Evil For I am at 80,000 Feet and Climbing."

HoldTheOnions
Posts: 764
Joined: 9 years ago

#5: Post by HoldTheOnions »

Issue is this machine will have pressure stat, so you could also insert a temp probe straight into the water, but then you will have to drill a hole and make sure it is sealed. Personally, I would avoid that unless you know you have the skills to do a proper job of it. You could also try something like this guy https://www.coffeegeek.com/forums/espre ... ods/309316

A pressure stat has a dead band, so I really don't see how a surface mounted sensor could be any worse. In my mind the lag will be smaller than the deadband, but I have no factual basis for such a claim just my brain to hypothesize ;-), so Bluecold could be right. Regardless, I would try a surface mounted sensor first anyway, just because it is so cheap and easy to do, and then take the next step if aren't happy with it e.g. pressure is all over the place. Unless other people can speak to whether it will work poorly from the git go.