SMPTE RP 143-2004

This practice specifies a type U audio frequency test film to be used for adjusting the mechanical and electrical parameters of 35-mm motion-picture magnetic audio reproducers intended for striped release prints perforated CS, operating at 24 frames (96 perforations) per second (approximately 90 ft [27 m] per minute [18 in or 457 mm per second]) for proper playback.
The International Organization for Standardization recognizes two reference levels for test films: Type U with a reference level of 185 nWb/m and type E with a reference level of 320 nWb/m, in order to account for differing meter types in common use in the United States and Europe.