A study concerning the use of a 1 cm2 p-i-n (alpha) -Si:H structure coupled to a 1 cm3 CsI(Tl) scintillator is presented and discussed as a survey meter in the range from 20 to 125 keV x ray peak energy. A particular mesa etch, coupled with standard photolithography, lowers dark current in the pA region, allowing the use of the detector in the photovoltaic mode. In this work, we describe the details of detector fabrication, the various steps of detector simulation in order to look for detector performance improvements, and the different stages of detector testing in the reported energy range. For each energy, the linearity of the detector response as a function of the dose rate has been accurately measured and compared with standard ionization chambers of different volumes. Finally, the effective energy reconstruction and the instrument calibration is presented and discussed. Wearing-on applications, similar to film badges, are envisaged and possible solutions are introduced and discussed.