An extensometer for measuring strain in a materials test specimen includes a frame (126) and a pair of arms (112, 114) each having one end (116, 118) for contacting a portion of the specimen and a remote end (144, 146). A noncontact sensor (128) assembly e.g of the capacitative type is mounted on the arms to measure change in distance between the contact ends. The arms are pivotally supported between the ends by the frame at the centre of gravity of the arms and attached components of the sensor, to permit the arms to be freely pivotal. The extensometer is used to measure expansion of a ceramic sample (120) in a materials testing machine and heated to 1500 DEG C. <IMAGE>
