Sonalert swung on the end of a string.

Measurement of speed of sound with mic, speaker & oscilloscope. Pressing the switch on the capacitor box discharges the capacitor through the speaker,-producing an audible click. The discharge also triggers a single sweep of the oscilloscope, and the capacitor discharge is displayed on channel 1. At some later time t the click reaches the mic and is displayed on channel 2. The mic can be placed at different distances from the speaker, and the corresponding click waveforms can all be shown, using the storage function of the scope. The speed of sound is the distance between 2 mic positions divided by the difference between corresponding mic click-waveform times.Note: If you want measurements for more than one distance, you must push the single-sequence button in the 'acquire' section to reset the scope. Note: See set-up sheet in file cabinet in 72 Le Conte Hall