Measurement of sound intensity
Book details
- Title
- Measurement of sound intensity
- Publication year listed
- 1923
- Format
- Public domain eBook
- Reading access
- Free online reader; no registration required
- Source record
- View on Archive.org
About this book
Measurement of sound intensity
Year: 1923
A sound-detecting device, such as a magnetophone or electrostatic transmitter, and two coils whose mutual inductance can be varied by known amounts constitute a measuring instrument. The sound detector and one coil are connected to an indicating instrument, consisting of a vacuum-tube amplifier, a rectifier, and galvanometer. The e.m.f. generated in the detecting instrument is compared by substitution with the e.m.f. generated in coil when the other carries a known current. Since the sound intensity is proportional to the square of the e.m.f. generated in the detector., a means of making sound intensity measurements is presented. The necessity for the calibration of an amplifier is obviated. The instrument has a sensitivity range of about a million fold, the lower limit being near the threshold val