For demonstrating formation of stationary longitudinal waves in air or gases and for determining the wavelength and velocity of sound in metal rods, air and other gases.
Consists of a glass tube about 1000mm long and 30mm in diameter, which is closed at one end with a cork. The tube rests on wedge supports securely fastened by coil springs and mounted on a base. A 90cm long aluminum rod having a terminal disk of diameter slightly less than that of the glass tube acting as a piston in the glass tube. The aluminum rod is rigidly clamped in the middle, on a metal post. Lycopodium powder (not supplied) can be used to show nodal points.