For the Medusa DMT the firmware embedded in the electronic board implements the procedure for inflating and deflating the DMT membrane. The hydraulic pressurization of the motorized syringe actuates a volume controlled expansion of the membrane, which enables to impose a programmable timing for achieving the readings. Therefore the Medusa DMT is capable to perform dilatometer tests with the recommended timing suggested in the international standards. At the same time, the highly accurate and repeatable time-for-reading facility provided by the instrument prompts for its potential use for performing dilatometer tests adopting variable pressurization rates in intermediate soils.
The motorized syringe, controlled by the electronic board, is also able to maintain the membrane in equilibrium with negligible displacements of the membrane. This capability enables to obtain continuous measurements of the total horizontal pressure of the soil against the membrane. The Medusa DMT may then be used to obtain continuous measurements of the total horizontal pressure during penetration (equivalent A-reading at T = 0 seconds instead of T = 15 seconds), thus providing useful indications for the assessment of the in-situ stress state and the at-rest lateral earth pressure coefficient (K0).