SPT Energy Measurements and Hammer Calibration
SPT (Standard Penetration Test) energy measurements, using the PDA and instrumented SPT rods to measure and calibrate the energy efficiency of SPT hammers used for geotechnical investigations. This calibration is required for ASTM D6066 standard when SPT is used for liquefaction evaluation. It is also routinely required by the California Department of Water Resources, the California Department of Safety of Dams, and the US Army Corps of Engineers.
Below is a picture of an SPT hammer being readied to be calibrated.