Solder PT100 cartridge leads?

  • I have a Duet3 6HC which has PT100 sensors in both the hot end and the heated bed. The one in the hot end works flawlessly, but I have ongoing battles with and distrust in the one in the bed which periodically devlops an offset (random, but up to 20ish degrees) or goes open circuit (so report 2000C). Both are genuine E3D parts (bought from E3D direct).

    I mostly blame the connection to the wiring, which I've terminated in a genuine molex microfit housing and contacts (sourced from Farnell). Partly it's self inflicted because my printer design puts this plug and socket in an awkward and fiddly place. However, I'm becoming very tempted to cut the plug and socket off and just solder the PT100 leads to the end of the cable that goes back to the 6HC.

    Have I overlooked any really good reason not to do this?

    Obviously it means more aggro if I need to swap sensor or rewire the printer, I'm thinking something along the lines of the wires emerging from the PT100 cartridge can't be soldered or something like that?

  • administrators

    Yes you can solder PT100 wires, just like I did on my Delta. See

  • Thanks. Done and immediately getting more believable / consistent values.

    For anyone else stumbling upon this - mine had a single fine strand of (copper?) wire in the leads, so stripping the fabric insulation is tricky. With retrospect, the insulation is stretchy, so it might be best to stretch the insulation, cut across flush, then push the insulation back to expose some conductor.

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