This dual purpose apparatus provides a compact facility for the measurement of the velocity of sound in air and also for the analysis of standing waves. It requires an audio signal generator and a dual beam oscilloscope (not included). A phase measurement between the speaker and microphone signals is made on an oscilloscope. The distance required to traverse through a 360° phase shift is noted. Knowing the frequency and distance, the speed of sound is computed. With the reflector in place a standing wave can be generated. Nodes and antinodes can easily be seen from the amplitude variations on the CRO.
Features
Primary Function: Used to find the speed of sound in air at room temperature by using the principle of resonance.
Measurement Method: Requires identifying two resonance positions using a tuning fork and an adjustable air column length, and then calculating the velocity using the formula.
Main Components: A long, transparent, graduated tube (e.g., plastic or acrylic, often around 1 to 1.2 meters long). A movable water reservoir (vessel) to easily adjust the water level and thus the length of the air column. A support stand and clamps to hold the tube and a tuning fork in place. A rubber pipe for connecting the reservoir to the tube. Often comes as part of a set that includes several tuning forks of known frequencies and a rubber hammer (mallet). Other necessary materials typically include a thermometer and a plumb line, though these may be separate.