extensometer
Ex`ten*som"e*ter, n. Etym: [Extension + -meter.] Defn: An instrument for measuring the extension of a body, especially for measuring the elongation of bars of iron, steel, or other material, when subjected to a tensile force.
Ex`ten*som"e*ter, n. Etym: [Extension + -meter.] Defn: An instrument for measuring the extension of a body, especially for measuring the elongation of bars of iron, steel, or other material, when subjected to a tensile force.