In the emerging field of energy geotechnics, many applications involve changes of temperature above and below ambient. This has led to the development of laboratory apparatus to enable the study of soil behaviour under various temperature ranges and under well-controlled conditions. To understand the effect of temperature on soil behaviour it is necessary to separate the thermal behaviour of the apparatus itself and of the instrumentation used to measure loads and displacements from the soil behaviour, i.e., a careful calibration of the equipment is required. The thermal calibration of an oedometer with temperature control in the range 5◦C to 70◦C is discussed here in detail. As the innovative design of the new oedometer enables isotropic heating of the soil specimen and thermal
isolation of the instrumentation, the calibration focuses on the thermally-induced deformations of the apparatus and the differential radial thermally-induced deformation of the
soil and of the stainless-steel confining ring. Although the developed methodology has limitations when used to predict the results of 1D tests, as do previously proposed
methodologies, it represents improvements on previous schemes, as it allows for Poisson’s ratio effects to be taken into account. An example of how the proposed calibration can be used in practice and how the confining ring corrections compares with previous schemes is presented.