ASTM E2583
This test method covers the determination of deflections of paved and unpaved surfaces with a Light Weight Deflectometer (LWD). This device is also referred to as a Portable Falling-Weight Deflectometer (PFWD). The LWD is lightweight, portable, and generally used for testing unbound pavement layers. The deflections measured using an LWD can be used to determine the stiffness of bound and unbound pavement surfaces using appropriate back or forward calculation analysis techniques.