In a tensile test, a sample of known dimensions (including thickness) is held between two clamps.
As the sample is stretched, the force exerted by the instrument and the length (and sometimes cross-sectional area) of the sample are measured. This data can be used to construct a stress-strain curve and to calculate several mechanical properties of the polymer.
David Whisnant (Wofford College). Partial support for this work was provided by the National Science Foundation's Division of Undergraduate Education through grants DUE #9950809 and DUE #9950296. Additional support was provided by the Camille and Henry Dreyfus Foundation.