TUNING FORK 1. Application The tuning- fork model440Hz is a basic sonic instrument which performs sound occurrence and interference. It can be used to measure the sonic speed and check the traveling sound as well as carry out various other sonic experiments. 2. Performance and Specification This instrument is composed of a single tuning--fork made of high zinc-aluminum, a round handle, a resonant box and a rubber beater. It is coated with chromium, the 4 faces are even and straight and the edge angles are regular. The total length is 173mm. The tuning fork prong size is 7*9.6mm. Its frequency is 440cycle, with the tolerance ±0.4 indicated by the stamp. 3. Usage Plug the fork into the socket on the resonant box, then beat the forkprong with the beater of other elastic matter, the sound wave with the frequency 400cycle/second can be produced. Neither beat the fork with hard matter, nor beat it at the desk. If so, a great deal of subwave would be produced. After usage, it smeared with the rust-proof oil all over and stored in a dry place in order to avoidrust.