electrical heating wire elements mounted to said housing within said chamber, said heating wire elements being subject to damage in a reduction atmosphere, and exposed to a central portion of said chamber, said {HEAD ~ electrical heating elements} having an energized and {TAIL ~ a deenergized state}, said chamber being heated when said electrical heating elements are energized 
electrical heating wire elements mounted to said housing within said chamber , said heating wire elements being subject to damage in a reduction atmosphere , and exposed to a central portion of said chamber , said { HEAD ~ electrical heating elements } having an energized and { TAIL ~ a deenergized state } , said chamber being heated when said electrical heating elements are energized
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH