摘要 |
An extensometer is used for measuring axial and diametral strains in a material test specimen. The extensometer comprises an assembly of extensometer sections positioned on diametrally opposite sides of the specimen with specimen engaging points spaced axially along the specimen. The extensometer assembly is arranged so that the two extensometer sections will average the axial strain measured by the two extensometer sections. Also, if desired, the two extensometer sections may provide an indication of the average change in diameter of the specimen at the location of the upper contact points and at the location of the lower contact points of the extensometer sections on opposite sides of the specimen. The support system between the extensometer sections provides for the necessary degrees of freedom to provide measuring only in the axis desired, and sufficient restraint in other axes to insure that accurate measurements are obtained.
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