dud thermocouples

[bisland9]

when i built my wfo, i placed 2 inner and outer thermocouples in each of the hearth, dome, and the walls. much to my dismay when i finally fired up my newly operational wfo, only 2 wires, both, in the dome, gave me an actual temperature readings. the others gave me the same temperature prior to firing. about 79-84 f. the installation seemed straight forward, twist the wires, put in drilled hole, fill with refractory cement, connect to connector with magnetic wire being the negative. any ideas of what went wrong? thanks,
bernie

[MK1]

Re: dud thermocouples

I had this problem with my dome probe. It read OK at first but then went to -43. Check your wires where they attach inside the connector plug. If they are at all touching or lack a decent insulated separation they'll give some strange readings. I re-did my connector with some additional heat shrink tubing and better separation and now it works fine.
I find it really handy to know the saturation temps and not just the surface readings.

Mark

[bisland9]

Re: dud thermocouples

thanks for your input mike. i will check and reinstall my connectors using shrink wrap.