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A mechanical resonance apparatus has been developed which allows automatic recording of internal friction Q-1and dynamic Young’s modulus E as a function of temperature. The attainable accuracies ΔQ-1/Q-1 and ΔE/E are approximately equal to 3.5×10-2 and 1×10-5, respectively. The vibrating sample is kept at resonance, during heating and cooling, by continuously readjusting the frequency of the driving signal supplied by a computer‐controlled frequency synthesizer. The frequency regulation is obtained by keeping either the amplitude of the response signal at its maximum level or the phase difference between the excitation and vibration signals at a fixed, selected value. In comparison with previous automatic control systems designed for similar applications, the one described here is more versatile, being able to measure internal friction from the width of the resonance curve as well as from the logarithmic decrement of freely decaying vibrations, and being able to regulate the vibration frequency by either the amplitude or the phase control method. The two automatically interchangeable measuring procedures allow recording over wide ranges of the dissipation coefficient (10-5≤Q-1≤10-2),while the two frequency regulation methods permit, according to the requirements, either higher data acquisition rates (phase control approach) or better accuracies (amplitude control approach). Tests carried out on a CuZnAl alloy show good performance of the apparatus during temperature‐induced martensitic transitions, which are associated with large relative changes of frequency and energy dissipation. © 1996 American Institute of Physics.