Sonometer Three Wire Pattern. A hollow wooden sounding box with scales divided in mm between fixed bridges over which three wires are stretched.To one wire, spring balance reading to 100 x5 is fitted and the tension exerted and measured can be finely adjusted by wing-nut. Another wire passes over pulley and can be loaded as desired. third wire is provided for comparison, its tension may be adjusted by means of wrest-pinThe distance between the fixed bridges is 72 cm. Complete with three movable bridges, wrest-pin key and set of steel wires, length 1.5 of 22, 24, and 26 SWG.The pack of replacement wires, sold separately, has steel and brass wires, each in 22, 24, and 26 SWG.Dimensions (L W H): 129 13 11 cm
