PT100 constant calibration

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aeviaanah

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I have to constantly calibrate PT100 every brew day. Typically seeing around -12 offset throughout the brewery. I use cheap chinese PT100, wired with approx 60'-80' wire shielded 3 wire tied back to ground at panel side only. Would higher quality PT100's yield better results? I do have a m12 connector at the panel. Perhaps this is a failure point? Cant figure out why they would lose calibration so often
 

Deadalus

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I was having trouble with mine and determined that my connectors weren't a great design and the females were getting loose. It was mainly on my MT which gets disconnected more than my HLT. Since I already had that style of connection, I clipped the female off and soldered a new one on. I just did it though and only have run one brew through. The connection is much tighter and I think that has solved the problem. The original solder connection was fine when I examined it but the sleeves on the inside of the female connection seem to have expanded ever so slightly. I would recalibrate every brew and finally I noticed that the values were changing when I jiggled the connection. It didn't seem loose at all but the new one is noticeably tighter (slow creep over time).

I went with trying the female first as the plug was cheaper than a new sensor.

I'll see if I can show you what I was working with as when I went looking to replace them, I did see there were different styles of plugs. This was also my first build and I think I picked a low end connection.
 

Deadalus

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This was the connector


Like in this type of setup. I have the same wire, maybe even the same panel connector I'd have to double check. It was a bit of a PITA to strip.

 
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