Low frequency tuning fork.
PIRA: Unknown
A large tuning fork has an adjustable frequency realized by moving weights along the prongs. If the weights are at the tips, the rate of oscillation is slow and all phases of the motion can be detected. As the weights are moved down the prongs, the frequency increases becoming audible at around 20 hertz.
Equipment | Storage |
---|---|
Tuning fork with moving weights | 021-9D |
rubber mallet or striker |