[en] The High Pressure Gas Scintillation Proportional Counter (HPGSPC) is one of the Narrow Field Instruments of the Italian-Dutch X-ray astronomy satellite SAX. Sensitive in the hard X-ray band (4-120 keV), with a very good energy resolution, the HPGSPC is well suited for studying in detail the cyclotron features present in the hard X-ray spectrum of some celestial sources. The scientific calibration of the flight model of the HPGSPC took place at the LABEN premises (Vimodrone-Milano) during October and November 1994. In this paper they briefly describe the on-ground instrument calibration system and they report some preliminary results that show the performances of both single/double event and position reconstruction /energy correction onboard processing. Preliminary results concerning the energy resolution and energy linearity are reported too

[en] In the following paper we describe an event position reconstruction and energy correction technique that is being implemented on the High Pressure Gas Scintillation Proportional Counter (HPGSPC), that will be flown aboard the Italian Satellite for X-ray astronomy, SAX. We discuss how this technique will greatly enhance the spectroscopic performances of the detector and we report some results regarding the full area energy resolution of the scientific model of the HPGSPC. ((orig.))