Abstract: A millivoltage generator is provided in which a rod formed of a first metal extends in spaced relationship within a tubular sheath of a second metal, the rod being welded to the sheath at one end to form a conductive junction and held in place in the sheath by an epoxy seal proximate the other end of the rod which prevents moisture from collecting inside the sheath. The space between the sheath and the rod is filled with an insulating material. Preferably, a wire connector is fixed to the end of the rod which extends through and beyond the epoxy seal. It is also preferred that a bushing be welded to the outside of the sheath proximate the epoxy seal and that the bushing be externally threaded to facilitate mounting of the millivoltage generator. A second metal rod welded to the bushing extends from the bushing parallel to the first metal rod and beyond the epoxy seal. Another wire connector is fixed to the second metal rod to facilitate electrical connection of the millivoltage generator.