Abstract: A plugging device, including a first part, and a second part connected to the first part. The first part or the second part includes a plurality of braiding filaments and a gathering member; portions of the braiding filaments that are close to one ends of the braiding filaments cooperate to form a disc face. The plugging device further includes a film member. The film member at least covers part of an outer surface of the disc face; the gathering member includes an inner sleeve and an outer sleeve, both of which are hollow and sleeved; and one end of each braiding filament and at least part of a gathering region of the film member are all fixed to the gathering member.

Abstract: Electrochemical sensors are provided having improved sensitivity, stability and dirability. In accordance with preferred embodiments, such sensors comprise protective sheath means having at least one opening. Within the sheath and sealed thereto at the opening is a sensing body comprising metal oxide and an oxide from group IIA or IIB of the periodic table. Reference electrode means are also provided. Methods for monitoring the concentration of a species in a melt are also provided.