Abstract: Apparatus and method of characterizing a material. A sample of a material to be characterized is placed into a thermomechanical analyzer (TMA) instrument, the material sample being a cylindrically- or rectangularly-shaped pellet having parallel top and bottom faces. The TMA has a measurement probe with a single buffer rod intermediate an ultrasound transducer and the top face of the material sample. Ultrasound waves are transmitted through the buffer rod and the top face of the material sample. Signals from the ultrasound waves passing through the material sample are received using a receiving sensor below the bottom face of the material sample. The TMA instrument is then used to control the temperature and forces applied to the material sample and to measure changing length of the material sample. Finally, the ultrasonic attenuation and velocity properties of the material are calculated as a function of the material sample length measurement and received ultrasound signals.