BS 7034-8:1988:1989 Edition
$86.31
Viscosity and viscometric fixed points of glass – Method for the determination of (dilatometric) transformation temperature
| Published By | Publication Date | Number of Pages |
| BSI | 1989 | 12 |
This part of ISO 7884 specifies a method of determining the (dilatometric) transformation temperature tg of a glass by means of the thermal expansion method. This temperature characterizes a certain glass transition range from the elastic brittle (low temperature) state to the viscous (high temperature) state of glass. The transformation temperature has been found useful for specifying cooling programmes and estimating the upper temperature limit of applicability of the respective glassware.
NOTE The more direct viscometric method of annealing point and strain point determination (see ISO 7884-7) serves similar purposes. The determination of the transformation temperature tg might be convenient if a suitable device for determining the coefficient of thermal expansion is available in the laboratory.
Thermal expansion method.
