Field evaluation of a multi-point fibre optic sensor array for methane detection (“OMEGA”)

摘要

A multi-point fibre optic sensor array for methane detection (“OMEGA”) has been developed and tested under semiquantitativefield conditions. The new system employed wavelength modulation spectroscopy using a DFB laser sourcescanned across the Q6 methane line at 1.665•m. A branched fibre network connected the single source to up to 64 sensorheads. Controlled releases of natural gas were provided for test purposes within an array of four optical sensors and fourpellistor reference sensors. An automated system delivered standard gases to each sensor, to enable routine calibrationchecks to be carried out. Agreement between the conventional and optical systems was excellent in the range 0-100% LEL(lower explosion limit). The optical system offers a simple, intrinsically safe design with a low cost of ownership per sensorhead.