The Calibrated Multi-Frequency Test-Film

F. C. Gilbert

After discussing some of the requirements of a multi-frequency test-film, some of the early efforts to produce test-films and the difficulties involved in so doing are described. The present technic of producing test-films is very involved because of the need of exactness of calibration. Microdensitometric measurements of each frequency are made in order to assure as great constancy of the sound level as possible. The films when finished are reproduced on a special reproducing system which furnishes correction values for each film.

Print ISSN
Published
1935-12
Content type
Original Research
DOI
10.5594/J08730