To determine the peak pressure induced versus the incident intensity of a neodymium (Nd) glass pulsed laser, with a duration of 25 ns in glass confined geometry, two methods have been comparatively used. Free surface velocity measurements have been performed using an electromagnetic gauge. The results are compared with pressure measurements realized at the back of irradiated aluminum targets with the use of polyvinylidene fluoride (PVDF) gauges. Both diagnostics provide consistent results. The measurements of peak pressure as a function of laser irradiance are used to determine the calibration curve (current density versus loading pressure) for new VF2/VF3 copolymer shock gauges used in this lasermatter interaction configuration. These experimental set-up deliver time resolved measurements that are interpreted by the shock-propagation phenomena.