Abstract: A method and device for determining the tension, or tensile stress in a metal strip between two bearing points, e.g., between two roll stands, between a roll stand and a coiler, in a breakdown stand, or in front of, or behind a deflection roll. The excursion of the metal strip is measured, and the natural frequency of the metal strip is determined on the basis of the excursion of the metal strip.

Abstract: A method for producing submicron polytetrafluoroethylene (“PTFE”) powder in a free-flowing, readily dispersible form. The irradiated PTFE starting material is placed in a desired solvent and undergoes grinding until the PTFE particles reach submicron size. The submicron particles are subsequently recovered from the solvent and dried to form a powder that may have particles less than 1.00 ?m in size. The dry PTFE powder may then be readily dispersed to submicron size into a desired application system. The submicron PTFE powder of this method is free-flowing, readily dispersible in various application systems, tends not to “dust” or self-agglomerate. Improved aqueous and organic dispersions of submicron PTFE particles may also be formed that display increased stability and require much less agitation than other processes of forming such dispersions. Such improved PTFE dispersions may be formed with or without the addition of surfactants, wetting agents, rheology modifiers, pH-adjusting agents, and the like.