An extensometer including: a first arm assembly and a second arm assembly, each arm assembly including first and second reciprocating contact arms (16, 18); the first and second arm assemblies (12, 13) each including: a camming element, each camming element including first and second inclined camming slots (42, 44), which are inclined with respect to each other, a first lever arm with a first proximal end engaged within the first inclined camming slot and a first distal end engaged with the first contacting arm, and a first pivot point between the first proximal end and the first distal end; a second lever arm with a second proximal end engaged within the second inclined camming slot and a second distal end engaged with the second contacting arm, and a second pivot point between the second proximal end and the second distal end; a support member upon which the first and second pivot points (38, 30) are pivotably mounted; wherein when the camming element is in a first position, the first and second contact arms (16, 18) are urged toward each other and wherein when the camming element is in a second position, the first and second contact arms (16, 18) are urged away from each other; and a drive mechanism configured to urge the camming element from the first position to the second position, the drive mechanism being separated from the camming element; said extensometer further comprising a vertical track structure upon which the first and second arm assemblies (12, 13) are configured to travel. a first arm assembly and a second arm assembly, each arm assembly including first and second reciprocating contact arms (16, 18); the first and second arm assemblies (12, 13) each including: a camming element, each camming element including first and second inclined camming slots (42, 44), which are inclined with respect to each other, a first lever arm with a first proximal end engaged within the first inclined camming slot and a first distal end engaged with the first contacting arm, and a first pivot point between the first proximal end and the first distal end; a second lever arm with a second proximal end engaged within the second inclined camming slot and a second distal end engaged with the second contacting arm, and a second pivot point between the second proximal end and the second distal end; a support member upon which the first and second pivot points (38, 30) are pivotably mounted; wherein when the camming element is in a first position, the first and second contact arms (16, 18) are urged toward each other and wherein when the camming element is in a second position, the first and second contact arms (16, 18) are urged away from each other; and a drive mechanism configured to urge the camming element from the first position to the second position, the drive mechanism being separated from the camming element; said extensometer further comprising a vertical track structure upon which the first and second arm assemblies (12, 13) are configured to travel. a camming element, each camming element including first and second inclined camming slots (42, 44), which are inclined with respect to each other, a first lever arm with a first proximal end engaged within the first inclined camming slot and a first distal end engaged with the first contacting arm, and a first pivot point between the first proximal end and the first distal end; a second lever arm with a second proximal end engaged within the second inclined camming slot and a second distal end engaged with the second contacting arm, and a second pivot point between the second proximal end and the second distal end; a support member upon which the first and second pivot points (38, 30) are pivotably mounted; wherein when the camming element is in a first position, the first and second contact arms (16, 18) are urged toward each other and wherein when the camming element is in a second position, the first and second contact arms (16, 18) are urged away from each other; and a drive mechanism configured to urge the camming element from the first position to the second position, the drive mechanism being separated from the camming element; said extensometer further comprising a vertical track structure upon which the first and second arm assemblies (12, 13) are configured to travel.