Sonometer, 3-Wire Pattern
Appealing and elegant, the Sonometer is a classical device developed in order to study vibrating strings. With this apparatus it is possible to investigate the dependence of the pitch on the length, tension and thickness of a vibrating string.
Laws and principles investigated:
• Vibration frequency of a stretched string as a function of the length, tension and density of the string
• Frequency versus length
• Frequency versus tension
• Frequency versus mass per unit of length
Students can readily verify the dependence of the pitch on the length of the string, by inserting a bridge under the string at certain lengths. Two strings of different diameter can be put under tension with tuning machines: masses or a dynamometer can be attached to the other string. Strings may be sounded by bowing or plucking.