Push-rod dilatometry measurements at IMGC

A push-rod dilatometer, operating from room temperature up to 1250 K, has been developed at Istituto di Metrologia "G. Colonnetti" (IMGC). The apparatus was designed for solid specimens having cylindrical shape. After mechanical measurement of the length at the reference temperature of 293 K, the specimen is then housed inside a furnace, in order to obtain thermal expansion as a function of temperature, detected by means of a laser interferometer system in conjunction with simultaneous temperature measurement. The apparatus is described and measurements on SRM 738 (stainless steel) are reported, along with a description of possible improvements in the future.