Potentiometric sensors are broadening their application scope because they are affordable and scalable devices capable of being used in-field and online. In that frame, the use of proton-conducting solid-state electrolytes in these sensors architecture offers the possibility to operate at high temperatures, with high physical and chemical stabilities. A potential application for this kind of sensor is tritium monitoring in future fusion reactors. The first steps toward the development of this analytical tool will be devices capable of measuring hydrogen in high temperature applications In the present work, a potentiometric sensor based on BaCe0.6Zr0.3Y0.1O3-alpha (BCZY) solid-state proton-conductor was tested for hydrogen monitoring at 325 degrees C, 350 degrees C and 375 degrees C. BCZY was synthesized by the solid-state method and characterized using XRD. The sensor's linear range, accuracy and limit of detection were evaluated at the selected temperatures (325 degrees C, 350 degrees C and 375 degrees C). Moreover, sensors presented a very short response and recovery times (<100 s).