The objective of this study was to investigate the characteristics of a solid-state detector commonly available at hospitals for parallel use as a real-time personal radiation monitor following radiation emergency situations. A solid-state detector probe with an inherent filtration (R100, RTI Electronics AB, Mölndal, Sweden) was chosen for evaluation. The energy dependence and the linearity in signal response with kerma in air were examined, and the detector was exposed to both X-ray beams using a conventional X-ray unit with effective photon energies ranging between 28.5 and 48.9 keV and to gamma rays 1.17 and 1.33 MeV from 60Co. The R100 exhibited ∼1.7 times over-response at the lowest X-ray energy relative to the 60Co source. The detector demonstrated a linear response (R2 = 1) when irradiated with 60Co to air kerma values in the range of 20–200 mGy. The conclusion is that high-energy photons such as those from 60Co can be detected by the R100 with an energy response within a factor of <2 over the energy range examined and that the detector can provide real-time dose measurements following nuclear or radiological events.