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.
Lumbar spine problems can cause pain in the lower extremities that feels like an electric shock. Nerves provide a pathway for information to go to and from your brain and body. In many common spine conditions, the nerves that travel to your brain are pinched or compressed. This pressure on the nerve can cause abnormal sensations, commonly experienced as electric shock pains. When the nerve that runs from your spinal cord to you leg is pinched, you may experience an electric shock pain traveling down your legs.