Abstract:
An apparatus is described for precise measurement of
creep properties in specimens with gauge lengths down to 1.2
cm. An extensometer has been developed which is supported
independently of the specimen and exerts a load on the specimen
of less than 5 grams. It can thus be used with small non-rigid
specimens. The extensometer will detect strains down to
2 x 10-6. The stability is excellent. An adaptation of the
system which allows simultaneous measurement of tensile strain
and lateral strain during creep is also described. The apparatus
was designed for the measurement of anisotropy of creep
properties in oriented thermoplastics and reference to such
measurements is given. It is however entirely suitable for
general application to small specimens.
