A low DC voltage is produced by the thermocouple when the two junctions are at different temperatures. This voltage is referred to as the thermoelectric voltage. This thermoelectric voltage is produced by the temperature gradient along the thermocouple wires.
Re: What's causes the electric shock type pain in a tooth Hi DM69. I'm not a dentist but I'm pretty sure its the erosion of your tooth exposing the pulp, I had the exact same feeling in my tooth before I had it extracted a month ago, so I feel your pain.
Hi Deb, Not being a medical professional, I can't say for sure what is causing your electric shock sensation. But I can tell you from personal experience that before my RA was treated, I had a similar electric shock feeling which traveled from my forearm through my fingers on the palm side.