ISO 7991:1987 Preview
Glass -- Determination of coefficient of mean linear thermal expansion
This standard was last reviewed and confirmed in 2010. Therefore this version remains current.
The method deals with the measurement of the change of length of a glass fibre under specified conditions. The apparatus including the used dilatometers and the possibilities of corretion, the formulae for the final length and the expansion coefficient are specified. In the annex, devices for self-adjusting alignment of specimen and push-rod axis are described and illustrated.