[en] The responses of a variety of different types of surface contamination monitoring probes to both small area and distributed sources of the β-emitting nuclides, ⁹⁰Sr/⁹⁰Y, ²⁰⁴Tl, ¹⁴⁷Pm, ¹⁴C and ⁶³Ni, have been measured. The responses to the low-energy X-ray emitting electron-capture nuclide, ⁵⁵Fe, have also been measured. A figure of merit for the comparison of different types of probe has been derived and applied to the measured responses. The responses of a beryllium-window sodium iodide scintillation probe to ⁵⁵Fe with integral and differential bias is described in detail; calculated responses to the electron-capture nuclides, ¹⁰⁹Cd and ¹²⁵I, are also included in this report. (author)