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.
One of these symptoms is the experience of shock. For some people it's like they suddenly got electrocuted. For others it's like the nerves on part of their body are activated for strange reasons. It's possible that these symptoms are caused specifically by your anxiety.