During the penetration HMP SON registers the number of the impacts. For every impact the corresponding penetration depth is measured. The depth per impact and the number of impacts per 10cm are stored in the device and are available for other evaluations. By means of the PC software PROSON the series of measurements, stored in the HMP SON, can after measurement be transferred to the PC, stored and evaluated. The determination of measuring protocols and graphs according to DIN EN ISO 22476-2 can take place immediately. A short protocol can even be printed out directly at the site via thermal printer..