AASHTO R 32-11 (2015)

This standard practice covers the annual calibration of the load cell and the deflection sensors and monthly relative calibration of the deflection sensors of a falling weight deflectometer (FWD) or a heavy weight deflectometer (HWD). It is used to establish calibration factors for correcting FWD and HWD measurements. For this practice, the term "FWD" also refers to an HWD unless otherwise noted.This procedure is not applicable to the calibration of lightweight deflectometers or of cyclic loading and other types of pavement deflection testing equipment.