Performing energy measurement per ASTM D4633 involves both laboratory calibration and field verification. Here is the typical workflow.
The hammer is raised to the specified drop height (e.g., 30 inches or 76 cm for SPT) and released. The drop is performed using the standard release mechanism (e.g., rope and cathead for SPT, free fall for DCP). astm d4633
Once the probe is paused at the target depth, a seismic source is activated at the surface. The most common source is a horizontal shear wave source, often a beam struck with a sledgehammer. The beam is anchored to the ground (often by the weight of the CPT truck) and struck horizontally to generate a polarized shear wave. This wave travels down through the soil layers. Performing energy measurement per ASTM D4633 involves both