An interferometric fiber optic sensor embedded in a spark plug for in-cylinder pressure measurement in engines

The feasibility of measuring in-cylinder engine pressure with a novel spark plug embedded fiber optic sensor is demonstrated. This result, combined with the proven ability of FFPI (fiber Fabry-Perot interferometer) sensors to operate reliably at high temperatures in engines, suggests that fiber optic sensors merit consideration for use with engine control systems for reducing emissions and improving fuel economy in automobiles of the future.