Electronic system for the measurement of elasticity moduli and internal friction of thin metallic ribbons

A system for the measurement of moduli of elasticity and internal friction (or alternatively of sound velocity and mechanical quality factor) of thin metallic ribbons is proposed. The system was designed for the 'vibrating reed method', but it can also be applied in the torsion pendulum method. The solutions of the main parts of the electronic system, including the vibration pick-up and two units for automatic measurements of the damping decrement, have been described in detail. The sensitive vibration pick-up and the other two units are very cheap and easily made. The transducer described converts mechanical vibrations with amplitudes from 0.1 to 2000 mu m and frequencies below 5 kHz into an electric signal. This conversion is approximately linear for small amplitudes of vibration and the sensitivity depends on the distance between the two detecting electrodes. The measuring system does not require any expensive instruments, but it can be easily automated using computer control.