This paper reports the development and application of a new practical photovoltaic (PV) cells based device to measure the solar radiation flux produced by non-imaging Compound Parabolic Concentrators (CPCs) on cylindrical absorbers. The flexible experimental device comprises 12 discrete miniature PV panels that measure solar radiation on the surface of a cylindrical absorber. The device has been used to evaluate the performance of an asymmetric CPC system and results validated with a computer-based Ray Tracing Model. The study attained significant agreement between outdoor results of the experimental device and results of the ray tracing simulation with a difference of <9% in optical efficiencies. The non-imaging reflector illuminates a targeted section of the absorber of a horizontal east-west thermal diode Integrated Collector Storage Solar Water Heater. During outdoor testing, the experiments indicated a local concentration ratio reaching 1.4 suns on the targeted section of the absorber vessel surface for incidence angles - 30 degrees <= theta(i) <= 30 degrees, confirming technical suitability of the asymmetric CPC for deployment in locations at equatorial latitudes.