1.1 This test method describes measurement procedures for determining physical properties of polymer matrix thermoset prepreg such as resin content, fiber volume, fiber areal weight, and thickness per ply. It provides a systematic process for measuring these physical properties using a combination of mechanical and ultrasonic methods.

1.2 The procedures are applicable to quality/process control, manufacturing acceptance and incoming inspection of prepreg composite materials.

1.3 The test method consists of a procedure for obtaining reproducible configurations for measurement of ultrasonic properties and associated geometrical properties of thermoset prepreg specimens and three calculation procedures which utilize these data to determine thickness per ply, resin content and fiber areal weight, attached as Annex A1, A2, and A3 respectively.

1.4 This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.