Multipoint thermocouple assembly

Abstract

A multipoint thermocouple assembly for monitoring temperatures at various locations, for example, at different depths in a process vessel, includes a plurality of thermocouples, a protective tube well having a hollow interior, elongate guides in the protective well for guiding respective thermocouples along the interior of the protective well, and wedges in the guides at respective axial locations along the protective well for urging the measuring junctions of respective thermocouples into thermal transfer contact with the wall of the well. In one form of the invention, the guides may comprise plural channels on the exterior surface of an elongated support member, formed as by attaching fins or dividers to such exterior surface, or by providing a plurality of splines on such exterior surface. In another form of the invention, a plurality of elongated thin walled guide tubes are brazed or welded to the exterior surface of a plurality of longitudinally spaced support rings. The guide tubes have openings in the outer walls thereof at the respective points of thermocouple measuring junction locations, and wedges in the tubes at such points for urging the measuring junctions out through the openings at such points. The well when inserted in a process vessel protects the thermocouple measuring junctions while positioning them simultaneously to sense temperature at different respective locations or depths in the vessel. The invention also relates to methods for making a multipoint thermocouple assembly and for replacing a thermocouple therein.