A Contactless CCD Dilatometer for Foil Materials

A contactless, compact, low-cost dilatometer based on a laser-pulse thermalconductivity apparatus has been developed to measure the linear thermal expansion of foil materials. The two sample-edge images are projected onto the array of a charge-coupled device (CCD). Changes in sample length are determined from measurements of the corresponding displacements of the sample-edge images focused on the CCD. The dilalometer performance was tested by comparing results of measurements of the thermal expansion for pure copper with published data. The linear thermal expansion of an L-16-type foil of 20-1mm thickness, which is a candidate material for thermocontrol layers (in engineering), was measured with the apparatus.