Resonant Ultrasound Spectroscopy (RUS) is a technique for the determination of the full elastic modulus tensor of low-acoustic-loss solids. There is a characteristics of this technique that is of particular importance when the modulus temperature dependence is needed. Because all moduli are determined in a single measurement, errors introduced when each modulus is measured separately are eliminated, and only a single temperature run is required. We describe here, and show a typical measurement of, a system that is capable of RUS measurements from room temperature to about 1000°C in a controlled atmosphere. The system uses buffer rods and a low-acoustically coupled heat sink so that PZT transducers can be used, remain well below their curie temperature, and can yield resonances with Q exceeding 20 000. The system has a unique temperature controller. Its firmware “knows” how much power to deliver for a particular temperature because it is designed to work with a specific furnace. Thus if the feedback control thermocouple fails, the power delivered is that which brings the system to ambient temperature, eliminating any chance of thermal runaway.
Migliori et al. (2025) studied this question.