The detailed evaluation of a PCB-based microfluidic sensor directly integrated on a polymeric microchannel is presented in this work. The sensor consists mainly of polymeric materials, therefore the operational characteristics are enhanced due to the high level of thermal isolation. The maximum measurement range was 0-400μl/min which occurs in hot-wire operation, while under the calorimetric operating principle a minimum detectable flow rate of 250nl/min and a maximum sensitivity of 2.110-3 (μl/min) -1 were recorded. The custom definition of the measurement range is feasible by adjusting the geometry of the microchannel crossection.