Sound logger sensor NUL-212

This sensor has two modes of operation. In slow mode it can be used to measure sound-pressure level in decibels. In fast mode it can display waveforms of different sound sources such as tuning forks and wind-chimes so that period and frequency can be determined. With two sound sensors, the velocity of propagation of sound in various media could be determined by timing a pulse travelling between them. The sound sensor is located in a plastic box accessible to the atmosphere via a hole in its side.