Abstract: An apparatus and methods for evaluating the radial compressive strength of ceramic honeycomb samples. The apparatus includes a housing defining a testing compartment. A pressure subsystem is configured to introduce a pressurizing fluid into the testing compartment. A flexible member is in fluid communication with the pressure subsystem. The flexible member defines a testing area within the testing compartment configured to receive the ceramic honeycomb sample. The flexible member expands inwardly and subjects the honeycomb sample to a compressive force by engaging against the outer surface of the honeycomb sample when pressurized by the pressurizing fluid. An end cap covers an end face of the ceramic honeycomb sample when the ceramic honeycomb sample is positioned in the testing compartment. An acoustic sensor disposed on the end cap is configured to translate acoustic waveforms propagating through the acoustic sensor to a signal representative of the acoustic waveforms.