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.
Electric shock like feeling in the chest can be momentary discomfort in the chest, which causes sudden, sharp pain. Such sharp pains in chest are often rapid and last for few seconds to minutes or sometimes more. Electric feeling in chest is a feeling of discomfort or a feeling of uneasiness with sudden shooting type of sensation in the chest.