A Compact Solid-State UV Flame Sensing System Based on Wide-Gap II–VI Thin Film Materials

A compact solid-state UV flame sensing system is developed and tested. We have addressed two approaches for obtaining additional six orders of long-wavelength rejection power on top of that of the built-in UV sensor based on a wide-bandgap II-VI Schottky-barrier structure. An op-amp-based amplification circuit with an average gain of 16 600 is used for signal amplification. It is demonstrated that the developed sensing system could detect a standard butane-air flame with excellent solar-blind characteristics, potentially capable for monitoring industrial boilers. Several feasible approaches were discussed for further improvement in the performance of the developed sensing system targeting its general usage in fire-safety applications.