The standard "DIN ISO 7884-3:1998 Glass viscosity and viscous fixed points - Part 3: Determination of viscosity by fibre elongation Viscometer" specifies a method for determining the viscosity of Glass using the fibre elongation Viscometer. The fibre elongation method evaluates the viscosity properties of Glass melts by measuring their tensile behavior against elongated fibers at high temperatures. This method is suitable for studying the rheological performance of Glass in the molten state, especially processing performance at high temperatures. The standard describes in detail the equipment requirements, specimen preparation, experimental procedures, and Data processing methods to ensure the accuracy and repeatability of test results. This method has important applications in Glass manufacturing and research, especially for optimizing Glass melting process and increasing product mass.