Alcance
Describes a method of measuring and calibrating the photoelectric output factor of single-channel photographic-type audio-level test films in all gauges by means of a calibrating sound reproducer. The specifications apply to both vaiable-area and variable-density sound records with a silver audio track. Calibrated audio-level test films are used for the precise measurement of the output level of photographic sound reproducers and the photoelectric output factor of different sound records. In addition, the performance of a calibrating audio reproducer is described.