For highest measurement accuracy, DIL 802 provides a truly differential measurement. Measuring only the difference between the sample and the reference specimen with the same, single LVDT-sensor, the True Differential design negates the influence of measurement system expansion on the sample measurement. This measurement design is of particular benefit for dynamic temperature programs such as those employed in Rate-Controlled-Sintering (RCS) and for measurements of samples with small thermal expansion. The DIL 802 is designed for measurements under vacuum or inert gas while the DIL 802L is designed for measurements under air.