The DCP was improved and patented by the US Army Corps of Engineers. Our new models have an 8 kg (17.6 lb) hammer and/or a 4.6 kg (10.1 lb) hammer to better evaluate weak soils. The DCP is primarily used to determine in place soil shear strength in road construction. It has a CBR range from less than 0.5 to 100% and bearing value range from 430 to 10,800 psf. The User’s Manual provides tables with relationships between penetration per blow, CBR value and psf.