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

The Sonometer consists of a wooden box with scales divided in mm between fixed bridges over which wires are stretched. The distance between the fixed bridges is 720mm. To one wire, a Newton Meter reading 100N can be fitted and the tension is exerted and measured.

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 and masses or a dynamometer can be attached to the other string. Strings may be sounded by bowing or plucking.

• Dimensions: (L)1290mm x (W)130mm x (H)110mm

A replacement set of strings are available to order separately: B8H25821