標準號：BS 7034-3-1988
中文標準名稱：玻璃粘度和測定粘度固定點.第3部分:采用纖維拉伸粘度計對粘度的測定方法
英文標準名稱：Viscosity and viscometric fixed points of glass - Method for the determination of viscosity by fibre elongation viscometer
標準類型：Q30
發布日期：1989/1/31 12:00:00
實施日期：1989/1/31 12:00:00
中國標準分類號：Q30
國際標準分類號：81.040.10
適用范圍：This part of ISO 7884 specifies a method of determining the dynamic viscosity of glass by measuring the elongation of a glass fibre under a defined uniaxial stress. In addition, the viscosity-temperature relationship and the dependence of the viscosity on the thermal history can be determined.NOTE —Using this method, all parts of the tested material are subject to the same mechanical stress when the shape of the fibre is correct, the glass is homogeneous and isotropic, and the influence of gravity on the fibre itself can be neglected. The deformation is a pure elongation instead of a simple shear. Without major uncertainty, the determi-nation of the shear viscosity by an elongation experiment is possible only when the material behaves like a Newtonian fluid.The knowledge of equilibrium viscosities in the low-tempera-ture range is useful for fitting suitable viscosity-temperatureformulae over the whole range of glass viscosities and for a more detailed survey on thermal history influences than can be derived from fixed-point methods alone.note:* 1 dPa·s=1 dN·s/m