Dip Thermometer Solution for a furnace...???

Hey,
What would be the Ideal solution for a Dip Thermometer (by Dip I would
meant a probe that would be in constant contact with what ever I wanna
measure the temperature of in a furnace) as a permanent installation so
I can get REAL TIME temperature.

Anothe solution I could think of was to drill a hold in the furnace
wall and get the probe to be close to the furnace insides. I know there
would be a certain offset... but what the hell :)

If theres anyother solution let me know. Cause something tells me the
DIP would mean that Id be losing the probe even after a sheeth in about
a few months.

Just wondering what else can I do???

Thanks in advance,

Regards
Taji

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