A thermocouple welder is a heat-resistant tool used to weld thermocouple junctions. Thermocouples act as temperature sensors and are directly welded to the metal piece to sense temperature changes. There are various types of thermocouple welders such as the ones which use the Micro TIG technology to create uniform bead junctions. Thermocouple welding helps create a strong thermocouple junction. Therm-X is a well-known manufacturer of thermocouple welders, and we offer various models of the same. The Therm-x Model 300 welder is a tungsten-inert-gas (TIG) type of welder.