I don't think that's as likely as a thermocouple... but i really can't be sure. it doesn't click when operating, i know that (from the small amount of time i spent using it before it failed)
i won't get into it in this thread but the way the sensor portion is interfaced is analog (op-amp circuits, etc) so i doubt it is a "digital" type of magnetic temperature sensor as you mention.
also, the entire heating/sensor element is a separate unit from the rest of the iron. it is a narrow ceramic-coated tube with 4 wires coming out of it that is located inside the metal shaft of the iron. and finally, the iron is fully temperature-controlled.
**broken link removed**
so theoretically, if i hook the thermocouple up to an oscilloscope and dunk it alternately in very hot and very cold water, i should see a few dozen millivolts on the scope?
the station did come with an extra heating/sensor element, i was just hoping to confirm that the current one isn't busted (bunch of stuff blew on the main board, i just hope this wasn't one of the victims)