Nanometrology and high-precision temperature measurements under the temperature conditions varying in time temperature conditions

摘要

Significant progress in high-precision temperature measurements of material artifacts has been achieved as a result of a development of a new approach which takes explicitly into account the effect of a heat waves propagation in a sample. The approach requires a complete change of a routine procedure in temperature measurements. In order to detect the time delay in a heat wave propagation, it is necessary to have two detectors which synchronously measure the temperatures and temperature rates in two different points of a sample. When these four parameters are recorded for a number of slow heating and cooling procedures, the measurement results can be corrected on the velocity error, which is associated with the time delay in the wave propagation between the two measurement points on a sample. As an intermediate result in the new method, we obtain the value of the thermal field variation (temperature gradient) between the two points of the artifact. We also use a special type of synchronous detection, with a complete averaging within a half-cycle of a modulation procedure, in order to measure precisely a self-heating effect of a resistance thermometer, which is attached to the artifact surface. This results in a reduction of the uncertainty of measurements to a few μK level.