The Resonance Tube lets you investigate the propagation of sound waves in a tube. The waves in the tube are produced by a built in speaker. Drive the speaker with a function generator to create stable wave patterns at specified frequencies. You can observe standing wave patterns in a closed tube or open tube, and locate nodes and antinodes while varying the length of the tube. Connect an oscilloscope to the microphone to examine the waveforms in detail. The 90 cm long, clear plastic tube is simple and rugged.