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.
5. Why is it difficult to identify which tooth which is causing the pain? The trigeminal nerve is the great nerve of the face and jaws. All the teeth are linked by branches of the same nerve. A pain may be felt in the upper jaw, when the cause is a tooth in the lower jaw. This is called a 'referred pain'. It occurs when decay within a tooth is the source of the pain. When pain is caused by decay that has spread to the area around a tooth, it is quite simple to locate it.