A Novel Optical Fibre Methane Sensor

This paper describes a novel fibre optic methane sensor which has several advantages over previously published fibre optic techniques. It is based on a scanning Fabry Perot etalon filter and is self-referencing, requiring only a single optical sensing path and photodetector. A laboratory version of the sensor, employing a white light source, has been constructed and tested, and was found to be capable of detecting 0.25% by volume methane in air, with a response time of approximately 1.5 seconds.